Determination of Methanol, Aldehydes, and Ethanol Concentrations in Local Alcoholic Beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) from the Coastal Regions of Tanzania

Determination of Methanol, Aldehydes, and Ethanol Concentrations in Local Alcoholic Beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) from the Coastal Regions of Tanzania | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Determination of Methanol, Aldehydes, and Ethanol Concentrations in Local Alcoholic Beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) from the Coastal Regions of Tanzania Pius Albert Makene, Msafiri Samuel Samuel, Leonia N Henry This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6568348/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Traditional alcoholic beverages produced by local distilleries in Tanzania may contain hazardous levels of methanol and aldehydes, posing significant health risks to consumers. This study quantified methanol, aldehydes, and ethanol concentrations in seven locally produced beverages ( Gongo , Mnazi , Ulanzi , Mbege , Komoni , Pingu , and Wanzuki ) from coastal Tanzania using Gas Chromatography-Flame Ionization Detector (GC-FID) for methanol/ethanol analysis and High-Performance Liquid Chromatography (HPLC) for aldehyde detection. Validated methods confirmed reliable detection limits (LOD), quantification limits (LOQ), and recoveries. Results revealed methanol concentrations ranging from 95 to 2115 (mg/L), with Gongo consistently exceeding the Tanzania Bureau of Standards (TBS) safety limit (≤ 1000 mg/L or 0.1%) by 56–112%. Statistical analysis (ANOVA, p < 0.001) confirmed Gongo ’s methanol levels were significantly higher than other beverages. While aldehydes were undetectable, the elevated methanol levels, particularly in Gongo , highlight acute risks of toxicity, including blindness and neurological damage. These findings underscore the urgent need for stricter quality control, regulatory enforcement, and public awareness campaigns to mitigate health hazards associated with traditional alcoholic beverages. Methanol Ethanol Aldehydes Local Alcoholic Beverages GC-FID HPLC Tanzania Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction An alcoholic beverage is any drink, other than water, that has an alcohol content of more than 1.2% alcohol by volume. It can be categorized into two major types, which include undistilled which including bear, wine, hard cider, mead and saké. (Companion, 2022 ). Also, there are distilled (liquor and spirits) alcoholic beverages including: Gin, brandy, whiskey, rum, tequila, vodka, absinthe and ever-clear(Yerby, 2022 ). Alcoholic beverages in various forms are commonly consumed all over the world from ancient times to date. Alcoholic beverages are produced locally (homemade) or in factories (small or large) for home consumption or trading purposes from the available resources across the world. Several raw materials, not limited to millets, maize, fruits, cassava, bananas, palm, bamboo, sugar cane, coconuts and cereal crops, are used for the production of alcoholic beverages. In the production of alcoholic beverages, the basic method for the production process of alcoholic beverages is fermentation and simple distillation.(Tadesse et al., 2017 ). Traditional fermented beverages are Indigenous to a particular area and produced by the local people using age-old techniques and locally available raw materials.(Abegaz et al., 2002 ). The basic method for producing these beverages typically involves fermentation, and in some cases, simple distillation. In literature, traditional African alcoholic beverages such as Gongo , Mnazi , Ulanzi , Mbege , Komoni , Pingu , and Wanzuki have been documented with unique production methods and raw materials. Gongo is typically distilled from fermented mixtures of maize, sorghum, or sugarcane juice, often using a homemade apparatus. Mnazi is a palm wine tapped directly from coconut or date palms and consumed fresh or slightly fermented. Ulanzi is a bamboo wine extracted from bamboo stems and fermented naturally with wild yeasts. Mbege , a traditional Chagga beverage, is made from fermented bananas and finger millet flour through a multi-step process involving cooking and natural fermentation. Komoni is a maize-based fermented drink prepared with the addition of sugar and left to ferment for several days, then distilled. Pingu is traditionally made by fermenting a mixture of maize and sugarcane juice. Wanzuki is produced from millet or sorghum and bananas through spontaneous fermentation. These beverages reflect indigenous knowledge systems, utilizing available local resources and microbial communities for fermentation, resulting in diverse flavours, alcohol content, and cultural significance. Production of alcoholic beverages in industries is characterized by quality control aspects, where all factors related to enhanced quality and safety are taken into account. In that regard, quality-controlled production ending up with beverages with higher methanol and other non-targeted alcohol by-products, such as aldehydes, is not expected. Due to limitations such as know-how, economic and technological affordability, some of the traditional alcoholic beverage manufacturers cannot afford to produce under optimal ideal conditions to remove the methanol content and other potential health-threatening components, such as aldehydes, during production. This malpractice brings about the consumption of unsafe drinks at the expense of being cheaper, locality and prestige feelings towards the consumers. In Tanzania, locally produced beers include: komoni and mbege , while wines include wanzuki , and spirits include the beverage, namely gongo; these are particularly popular for their affordability and accessibility. Tanzania in 2016 was ranked 10th among African countries, where the estimated beverage consumption was 11% from beer, and only 0.2% came from wine. Spirits account for 1.8%, and 87% of consumption is from other types of forms of alcoholic beverages. (WHO, 2014 ). Alcoholic beverages are widely consumed in the world. Alcoholic beverages are produced locally for home consumption or in factories in small or large quantities for trading from the available resources across the world. The raw materials used for the production of alcoholic beverages include fruits, cassava, palm, sugar cane, and cereal crops. The basic method for the production of alcoholic beverages is fermentation and simple distillation. Most traditional alcoholic beverage manufacturers cannot remove the methanol from the beverages during production and hence may end up producing alcoholic drinks with high methanol content and other potentially health-threatening components. Methanol has similar physicochemical properties to those of Ethanol and is present as a by-product after distillation. Toxic chemicals such as lead and methanol may be present at trace levels in the beverages and pose a threat to human health. (Paine & Dayan, 2001 ). Aldehydes have attracted attention since they may cause off-flavour in several foodstuffs, such as milk, butter, vegetables, and oils, considering food product staling and instability.(Vanderhaegen et al., 2006 ). In sub-Saharan Africa (Mascia et al.)The annual consumption of pure alcohol has been estimated to range from 4.9–7.1 L per capita, although intake is likely to be significantly higher because of the unrecorded consumption of traditionally produced beverages.(WHO, 2014 ). These account for an estimated 30% of pure alcohol consumption. In Tanzania, the per capita consumption of industrially produced alcoholic drinks is equivalent to about 5 L of pure alcohol, and the additional annual per capita amount of unrecorded consumption of locally brewed alcohol has been estimated at 2 L of pure alcohol. (WHO, 2014 ). The presence of methanol and other toxic substances in alcoholic beverages affects the health of the people, resulting in complications and chronic diseases or ill health, such as blindness, dizziness, respiratory diseases, etc. (Lachenmeier et al., 2007 ). The reason for many poisonings is the ingestion of methanol and aldehydes themselves or the ingestion of alcoholic beverages containing high quantities of methanol and aldehydes. Alcoholic beverages are popular in many countries and are often consumed. Due to its effects on human organisms, its popularity is linked to the content of ethanol. The ingestion of drinks containing high levels of methanol and aldehydes can cause serious health difficulties – metabolic problems, blindness, permanent neurological damage or even death. This is a great risk for consumers of alcoholic beverages taken from unknown sources. (Vaskova, 2014 ). In the body, methanol converts to toxic metabolites, including formaldehyde and formic acid, via hepatic alcohol dehydrogenase and aldehyde dehydrogenase, respectively. These metabolites cause toxic presentations such as severe metabolic acidosis, optic neuropathy, cerebral oedema and acute renal failure. (Kadam et al., 2018 ). However, limited data exist for Tanzanian beverages, creating a research gap. This study aims to address this gap by conducting a trend analysis of methanol, ethanol, and aldehydes in selected local beverages, providing insights into their safety and compliance with standards such as TZS 468:2015, WHO, and FDA guidelines. Materials and Methods: Study Area and Sampling Twenty-one samples of seven types of local alcoholic beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) were randomly purchased from various shops in the Dar es Salaam and Pwani regions of Tanzania. The selected alcoholic beverages were in the categories of spirits (Gongo and Pingu), wines (Wanzuki) and beers (Mnazi, Ulanzi, Mbege, Komoni). The collected samples were then given unique serial codes (Gongo-G1, G2, G3), (Mnazi-Z1, Z2, Z3), (Ulanzi-U1, U2, U3), (Mbege-M1, M2, M3), (Komoni-K1, K2, K3), (Pingu-P1, P2, P3), and (Wanzuki-W1, W2, W3). Samples were properly homogenised to ensure reproducibility and accuracy, stored in airtight containers at 10–15°C and analyzed daily over five days. Reagents and Instrumentation Reagents Analytical-grade methanol, ethanol, acetaldehyde, formaldehyde, and DNPH were used to prepare calibration standards. Equipment Gas Chromatograph (Varian CP 3800) with Flame Ionization Detector (GC-FID) a GC model of Agilent US (California, USA) for methanol and ethanol analysis; High-performance Liquid Chromatography (HPLC) SHIMADZU NEXERA 40LC with a UV/Vis detector, HPLC model of Shimadzu Scientific Instruments (Kyoto 604–8511, Japan) for aldehyde analysis. Sample preparation 2.5 ml of each local alcoholic beverage sample was measured into a measuring cylinder and topped up with de-ionized water to the mark. Filtration was done to obtain a clear solution for GC and HPLC analyses. A portion of the prepared sample was then used for the GC and HPLC analysis. Analytical Methods Methanol and Ethanol Analysis Calibration curves for methanol and ethanol were prepared at concentrations of 0.0625%, 0.125%, and 0.25% (v/v), which are presented in Figs. 1 and 2 . Samples were diluted to 1% (v/v) and analyzed using GC-FID under the following conditions: DB-WAX Ultra Inert column, carrier gas (hydrogen) at 6 mL/min, and a column oven temperature range of 40°C to 225°C. Aldehyde Analysis Aldehydes were derivatized with DNPH, extracted with methylene chloride, and analyzed using HPLC. Calibration curves for acetaldehyde and formaldehyde were generated at equivalent concentrations shown in Figs. 3 and 4 . Statistical Analysis Data were analyzed using Python (version 3.8) with the scipy.stats library. A one-way ANOVA was performed to compare methanol and ethanol concentrations across beverage types and time points, followed by Tukey’s HSD post-hoc test for pairwise comparisons (via the statsmodels library). Significance was set at p < 0.001. Assumptions of normality (Shapiro-Wilk test) and homogeneity of variance (Levene’s test) were verified before analysis. Results Methanol and Ethanol Concentrations Methanol concentrations ranged from 95 to 2115 (mg/L) as illustrated in Table 1 . Gongo consistently exhibited methanol levels exceeding safe limits (< 1000 mg/L). Ethanol concentrations varied widely, with Gongo showing the highest levels (17.39–39.89% v/v), while Mbege exhibited the lowest (1.21–2.58% v/v), as illustrated in Table 2 . Table 1 Summary of the mean concentrations in mg/L of methanol in the trend analyzed alcoholic beverages over five days. Pingu Komoni Gongo Mbege Ulanzi Mnazi Wanzuki Days Hours 1 0-hrs 416 402 1562 242 180 n.d n.d 8-hrs 582 392 1689 284 220 n.d n.d 16-hrs 620 510 1714 295 230 n.d n.d 2 0-hrs 745 583 1852 315 270 n.d n.d 8-hrs 812 447 1939 337 220 n.d n.d 16-hrs 725 370 2052 359 180 n.d n.d 3 0-hrs 617 303 2115 390 150 n.d n.d 8-hrs 524 214 1724 415 140 n.d n.d 16-hrs 476 155 1508 445 n.d n.d n.d 4 0-hrs 206 95 1468 342 n.d n.d n.d 8-hrs 146 n.d 1392 307 n.d n.d n.d 16-hrs 97 n.d 1292 n.d n.d n.d n.d 5 0-hrs n.d n.d 1154 n.d n.d n.d n.d 8-hrs n.d n.d 1039 n.d n.d n.d n.d 16-hrs n.d n.d 1052 n.d n.d n.d n.d Table 2 Summary of the mean concentrations in percentage v/v of ethanol in the analyzed alcoholic beverages over five days Pingu Komoni Gongo Mbege Ulanzi Mnazi Wanzuki Days Hours 1 0-hrs 6.49 5.34 34.6 2.21 2.78 3.68 3.51 8-hrs 6.56 5.35 35.5 2.24 2.84 3.79 3.39 16-hrs 6.74 5.37 37.11 2.25 2.95 3.86 3.26 2 0-hrs 6.31 5.81 38.09 2.51 3.09 4.02 3.12 8-hrs 6.01 5.52 39.4 2.55 3.12 4.11 2.97 16-hrs 5.89 5.01 39.89 2.58 3.18 4.01 2.85 3 0-hrs 5.69 4.12 35.74 1.92 2.06 3.63 2.79 8-hrs 5.52 3.82 28.98 1.86 1.94 3.54 2.65 16-hrs 5.21 3.18 27.01 1.69 1.59 3.47 2.56 4 0-hrs 5.07 2.85 24.19 1.58 1.45 3.31 2.41 8-hrs 4.78 2.8 22.58 1.44 1.35 3.09 2.33 16-hrs 4.69 2.77 22.01 1.31 1.16 2.79 2.26 5 0-hrs 4.43 2.69 19.96 1.26 1.12 2.45 2.19 8-hrs 4.15 2.65 18.06 1.24 1.09 2.29 2.05 16-hrs 3.81 2.62 17.39 1.21 1.05 1.98 1.59 Statistical Findings ANOVA revealed significant differences in methanol concentrations (F = 110.75, p < 0.001). Post-hoc tests showed Gongo contained 1338–1570 mg/L more methanol than other beverages (all p < 0.001), exceeding safety limits. Mnazi and Pingu also differed significantly (p < 0.001). Discussion The findings of this study reveal critical public health risks associated with locally produced alcoholic beverages in Tanzania, particularly Gongo, which consistently exhibited methanol concentrations exceeding the permissible limit of < 1000 mg/L (TZS 468:2015). Statistical analysis (one-way ANOVA, p < 0.001) confirmed that Gongo’s methanol levels were significantly higher than all other beverages (Tukey HSD, *p* < 0.001), with mean differences ranging from 1172 to 1570 mg/L. These results align with global reports linking methanol contamination to severe health outcomes, including blindness, neurological damage, and death (Lachenmeier et al., 2007 ; Kadam et al., 2018 ). The stark deviation in Gongo’s methanol content underscores the dangers of unregulated distillation practices, where inadequate methanol removal during production poses life-threatening risks to consumers. Ethanol concentrations varied widely across beverages (1.98–39.40% v/v), with Gongo again showing the highest levels. While ethanol itself is the primary intoxicant in alcoholic beverages, its extreme concentrations in Gongo may compound health risks when consumed excessively. Notably, the absence of detectable aldehydes in our samples suggests effective fermentation control or low pectin content in raw materials. However, the presence of high methanol levels raises concerns about potential in vivo conversion to formaldehyde (Kadam et al., 2018 ), warranting further investigation into aldehyde formation under real-world consumption conditions. The methanol heatmap (Fig. 7 ) revealed critical safety trends: Gongo consistently exceeded safety limits (1,562–2,115 mg/L; 56–112% above TZS 468:2015 standards), with peak levels suggesting batch variability (Day 3: 2,115 mg/L). While most beverages showed gradual methanol decline (likely from volatilization), Gongo maintained hazardous concentrations (> 1,000 mg/L) through Day 5, contrasting with undetectable levels in Mnazi/Wanzuki. Clear risk gradients emerged - Gongo (high-risk) demands immediate regulation, Pingu/Komoni (400–800 mg/L) require monitoring, and Mnazi/Wanzuki pose minimal risk. These patterns reflect faulty distillation in Gongo (inadequate head removal) and inadequate storage controls. The visual clustering of high-risk batches underscores the urgent need for market-level screening, mirroring contamination patterns in Ethiopian areki (Tadesse et al., 2017 ). Comparative analysis with studies from Ethiopia and Ghana (Tadesse et al., 2017 ; Tulashie et al., 2017 ) reveals a regional pattern of methanol contamination in traditional beverages. However, Tanzania’s challenge is intensified by the widespread availability of unregulated products. For instance, our statistical models (Levene’s test, p < 0.001) confirmed significant heterogeneity in methanol variances across beverages, highlighting the inconsistency in production standards. These findings advocate for the adoption of WHO and FDA guidelines into Tanzania’s regulatory framework to standardize production and mitigate health risks. In conclusion, this study provides unequivocal evidence (p < 0.001) of hazardous methanol levels in Gongo, demanding urgent intervention. By integrating regulatory reforms, producer education, and consumer outreach, Tanzania can safeguard public health while preserving cultural beverage practices. Future research should explore longitudinal contamination patterns and evaluate the efficacy of policy interventions. Abbreviations ANOVA: Analysis of Variance GC-FID: Gas Chromatography-Flame Ionization Detector HPLC: High-Performance Liquid Chromatography TBS: Tanzania Bureau of Standards WHO: World Health Organization Declarations Availability of data and materials The datasets generated and analyzed during this study are available from the corresponding author upon reasonable request. Raw chromatographic data and statistical analysis scripts are also available upon request. Competing interests The authors declare no competing financial or non-financial interests related to this work. Funding This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Authors' contributions Pius Albert Makene : Conceptualization, Methodology, Formal analysis, Writing- original draft Msafiri Samuel : Investigation, Data curation, Validation Leonia N. Henry : Resources, Supervision, Writing -review & editing Acknowledgements We thank the Dar es Salaam Institute of Technology for laboratory support and local beverage producers for providing samples. References Abegaz K, Beyene F, Langsrud T, Narvhus JA (2002) Indigenous processing methods and raw materials of borde, an Ethiopian traditional fermented beverage. J Food Technol Afr 7(2):59–64 Anderson HE, Santos IC, Hildenbrand ZL, Schug KA (2019) A review of the analytical methods used for beer ingredient and finished product analysis and quality control. Anal Chim Acta 1085:1–20 Companion B (2022) Alcoholic beverages, spirits and food. Bus Companion. https://www.businesscompanion.info/en/quick-guides/food-and-drink/alcoholic-beverages-spirits-and-food Kadam D, Salvi S, Chandanwale A (2018) Methanol poisoning. J Assoc Physicians India 66(4):47–50 Lachenmeier DW, Rehm J, Gmel G (2007) Surrogate alcohol: what do we know and where do we go? Alcoholism: Clin Experimental Res 31(10):1613–1624 Mascia I, Fadda C, Karabín M, Dostálek P, Caro D, A (2016) Aging of craft durum wheat beer fermented with sourdough yeasts. LWT-Food Sci Technol 65:487–494 Paine A, Dayan A (2001) Defining a tolerable concentration of methanol in alcoholic drinks. Hum Exp Toxicol 20(11):563–568 Parker D (2012) Beer: Production, sensory characteristics and sensory analysis. Alcoholic beverages. Elsevier, pp 133–158 Tadesse S, Chandravanshi BS, Ele E, Zewge F (2017) Ethanol, methanol, acid content and other quality parameters of Ethiopian traditional fermented, distilled and factory-produced alcoholic beverages. SINET: Ethiop J Sci 40(1):16–35 Tulashie SK, Appiah AP, Torku GD, Darko AY, Wiredu A (2017) Determination of methanol and ethanol concentrations in local and foreign alcoholic drinks and food products (Banku, Ga kenkey, Fante kenkey and Hausa koko) in Ghana. Int J Food Contam 4:1–5 Vanderhaegen B, Neven H, Verachtert H, Derdelinckx G (2006) The chemistry of beer aging–a critical review. Food Chem 95(3):357–381 Vaskova H (2014) Spectroscopic determination of methanol content in alcoholic drinks. Int J Biol Biomed Eng 8:27–34 Viejo CG, Fuentes S, Torrico DD, Godbole A, Dunshea FR (2019) Chemical characterization of aromas in beer and their effect on consumers' liking. Food Chem 293:479–485 WHO (2014) Global Status Report on Alcohol and Health 2014 . WHO. Retrieved 09 from https://www.who.int/publications/i/item/global-status-report-on-alcohol-and-health-2014 Yerby N (2022) Types of Alcohol - List of Drinks By Alcohol Content - Alcohol Rehab Guide . https://www.alcoholrehabguide.org/alcohol/types/ Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6568348","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":454369599,"identity":"bc4a568b-55be-4839-a619-c36393d525f3","order_by":0,"name":"Pius Albert Makene","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2klEQVRIie2PsQrCMBCGA4HrcugaqPoMhUCr+DK6dEpWp+JSaJfSZxGErgrFTLp3Lzg4iQVHMamLU9tRMN/w3w33cXeEWCy/CG0TTHfUwSbDFSSwMgoO34YEvU/tI3CQP6potD44WXOrojkSpzztupRFjL4rFKwzvBRLofRhGIZVl+KV6FMBWmGy4AK0wtDvU3gjXkYRVy5ewxTPlUmr0FomA5RFDBtX5sCzs/KpzBlC3y/BuNw34qmmaRrXutnOxk6pug/7FGUCWJtd419KZILe+6YtFovlP3kDc1lBC78AWVwAAAAASUVORK5CYII=","orcid":"","institution":"Dar es Salaam Institute of Technology","correspondingAuthor":true,"prefix":"","firstName":"Pius","middleName":"Albert","lastName":"Makene","suffix":""},{"id":454369600,"identity":"a85d233b-74b9-4774-b229-7a72d6bf9ba2","order_by":1,"name":"Msafiri Samuel Samuel","email":"","orcid":"","institution":"Dar es Salaam Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Msafiri","middleName":"Samuel","lastName":"Samuel","suffix":""},{"id":454369601,"identity":"e7524dc4-a072-4955-bbdc-e72218ccbc03","order_by":2,"name":"Leonia N Henry","email":"","orcid":"","institution":"Dar es Salaam Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Leonia","middleName":"N","lastName":"Henry","suffix":""}],"badges":[],"createdAt":"2025-05-01 00:53:04","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6568348/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6568348/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":82770258,"identity":"aaf2eb88-ed1b-438b-8462-764132b31995","added_by":"auto","created_at":"2025-05-15 06:06:20","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":191621,"visible":true,"origin":"","legend":"\u003cp\u003eMethanol calibration curve\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/a4e1515753db2311eea18485.jpg"},{"id":82769023,"identity":"0e0d522c-49fb-4fe8-9b17-1e4f95506780","added_by":"auto","created_at":"2025-05-15 05:42:19","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":49509,"visible":true,"origin":"","legend":"\u003cp\u003eEthanol calibration curve\u003c/p\u003e","description":"","filename":"Picture2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/b21169514b8404084c2d2e89.jpg"},{"id":82769022,"identity":"d4064284-a0cb-4ef8-b2a0-dea3a4dd0370","added_by":"auto","created_at":"2025-05-15 05:42:19","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":29844,"visible":true,"origin":"","legend":"\u003cp\u003eFormaldehyde calibration curve\u003c/p\u003e","description":"","filename":"Picture3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/01a3787702f274674936031d.jpg"},{"id":82769025,"identity":"3d4acaab-53e8-4f36-a9ad-ed6d7b052eb5","added_by":"auto","created_at":"2025-05-15 05:42:19","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":28104,"visible":true,"origin":"","legend":"\u003cp\u003eAcetaldehyde calibration curve\u003c/p\u003e","description":"","filename":"Picture4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/f7521ebf6746a106368ebeff.jpg"},{"id":82769027,"identity":"90951fa6-5a01-4bdb-a208-077d7c86df4b","added_by":"auto","created_at":"2025-05-15 05:42:20","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":42645,"visible":true,"origin":"","legend":"\u003cp\u003eMean methanol concentrations (mg/L) across beverage types. Values represent daily averages (n=3 samples per beverage). Gongo consistently exceeded permissible levels, while Mnazi and Wanzuki showed negligible contamination\u003c/p\u003e","description":"","filename":"Picture5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/41ce8866d43e22b3ec4173d2.jpg"},{"id":82770261,"identity":"576c1f9c-d957-4fcd-a18a-658d8a6bba84","added_by":"auto","created_at":"2025-05-15 06:06:20","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":40741,"visible":true,"origin":"","legend":"\u003cp\u003eMean ethanol concentrations (% v/v) across beverage types. Values represent daily averages (n=3 samples per beverage). Gongo exhibited the highest alcohol content (peaking at 39.89% v/v), while Mbege consistently showed the lowest concentrations.\u003c/p\u003e","description":"","filename":"Picture6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/69c670a5179f6baeb2f9e9f1.jpg"},{"id":82769036,"identity":"825654b8-23c2-4d52-93e3-65a778da66a2","added_by":"auto","created_at":"2025-05-15 05:42:20","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":56232,"visible":true,"origin":"","legend":"\u003cp\u003eHeatmap of methanol concentrations (mg/L) in Tanzanian beverages over 5 days. Red boxes highlight values exceeding the TZS 468:2015 safety limit (1,000 mg/L). Gongo showed sustained hazardous levels, while Mnazi/Wanzuki had undetectable methanol.\u003c/p\u003e","description":"","filename":"Picture7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/fd2663594567cc423fa4ba6f.jpg"},{"id":83766694,"identity":"ac436410-ebaa-46f6-afe5-92b5e878362c","added_by":"auto","created_at":"2025-06-02 11:16:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1163166,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6568348/v1/65fb73cf-3858-46e5-a282-8dc2a81625ee.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Determination of Methanol, Aldehydes, and Ethanol Concentrations in Local Alcoholic Beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) from the Coastal Regions of Tanzania","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAn alcoholic beverage is any drink, other than water, that has an alcohol content of more than 1.2% alcohol by volume. It can be categorized into two major types, which include undistilled which including bear, wine, hard cider, mead and sak\u0026eacute;. (Companion, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Also, there are distilled (liquor and spirits) alcoholic beverages including: Gin, brandy, whiskey, rum, tequila, vodka, absinthe and ever-clear(Yerby, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Alcoholic beverages in various forms are commonly consumed all over the world from ancient times to date. Alcoholic beverages are produced locally (homemade) or in factories (small or large) for home consumption or trading purposes from the available resources across the world. Several raw materials, not limited to millets, maize, fruits, cassava, bananas, palm, bamboo, sugar cane, coconuts and cereal crops, are used for the production of alcoholic beverages. In the production of alcoholic beverages, the basic method for the production process of alcoholic beverages is fermentation and simple distillation.(Tadesse et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTraditional fermented beverages are Indigenous to a particular area and produced by the local people using age-old techniques and locally available raw materials.(Abegaz et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2002\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe basic method for producing these beverages typically involves fermentation, and in some cases, simple distillation. In literature, traditional African alcoholic beverages such as \u003cem\u003eGongo\u003c/em\u003e, \u003cem\u003eMnazi\u003c/em\u003e, \u003cem\u003eUlanzi\u003c/em\u003e, \u003cem\u003eMbege\u003c/em\u003e, \u003cem\u003eKomoni\u003c/em\u003e, \u003cem\u003ePingu\u003c/em\u003e, and \u003cem\u003eWanzuki\u003c/em\u003e have been documented with unique production methods and raw materials. \u003cem\u003eGongo\u003c/em\u003e is typically distilled from fermented mixtures of maize, sorghum, or sugarcane juice, often using a homemade apparatus. \u003cem\u003eMnazi\u003c/em\u003e is a palm wine tapped directly from coconut or date palms and consumed fresh or slightly fermented. \u003cem\u003eUlanzi\u003c/em\u003e is a bamboo wine extracted from bamboo stems and fermented naturally with wild yeasts. \u003cem\u003eMbege\u003c/em\u003e, a traditional Chagga beverage, is made from fermented bananas and finger millet flour through a multi-step process involving cooking and natural fermentation. \u003cem\u003eKomoni\u003c/em\u003e is a maize-based fermented drink prepared with the addition of sugar and left to ferment for several days, then distilled. \u003cem\u003ePingu\u003c/em\u003e is traditionally made by fermenting a mixture of maize and sugarcane juice. \u003cem\u003eWanzuki\u003c/em\u003e is produced from millet or sorghum and bananas through spontaneous fermentation. These beverages reflect indigenous knowledge systems, utilizing available local resources and microbial communities for fermentation, resulting in diverse flavours, alcohol content, and cultural significance.\u003c/p\u003e \u003cp\u003eProduction of alcoholic beverages in industries is characterized by quality control aspects, where all factors related to enhanced quality and safety are taken into account. In that regard, quality-controlled production ending up with beverages with higher methanol and other non-targeted alcohol by-products, such as aldehydes, is not expected. Due to limitations such as know-how, economic and technological affordability, some of the traditional alcoholic beverage manufacturers cannot afford to produce under optimal ideal conditions to remove the methanol content and other potential health-threatening components, such as aldehydes, during production. This malpractice brings about the consumption of unsafe drinks at the expense of being cheaper, locality and prestige feelings towards the consumers. In Tanzania, locally produced beers include: \u003cem\u003ekomoni\u003c/em\u003e and \u003cem\u003embege\u003c/em\u003e, while wines include \u003cem\u003ewanzuki\u003c/em\u003e, and spirits include the beverage, namely \u003cem\u003egongo;\u003c/em\u003e these are particularly popular for their affordability and accessibility. Tanzania in 2016 was ranked 10th among African countries, where the estimated beverage consumption was 11% from beer, and only 0.2% came from wine. Spirits account for 1.8%, and 87% of consumption is from other types of forms of alcoholic beverages. (WHO, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAlcoholic beverages are widely consumed in the world. Alcoholic beverages are produced locally for home consumption or in factories in small or large quantities for trading from the available resources across the world. The raw materials used for the production of alcoholic beverages include fruits, cassava, palm, sugar cane, and cereal crops. The basic method for the production of alcoholic beverages is fermentation and simple distillation. Most traditional alcoholic beverage manufacturers cannot remove the methanol from the beverages during production and hence may end up producing alcoholic drinks with high methanol content and other potentially health-threatening components. Methanol has similar physicochemical properties to those of Ethanol and is present as a by-product after distillation. Toxic chemicals such as lead and methanol may be present at trace levels in the beverages and pose a threat to human health. (Paine \u0026amp; Dayan, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAldehydes have attracted attention since they may cause off-flavour in several foodstuffs, such as milk, butter, vegetables, and oils, considering food product staling and instability.(Vanderhaegen et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2006\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn sub-Saharan Africa (Mascia et al.)The annual consumption of pure alcohol has been estimated to range from 4.9\u0026ndash;7.1 L per capita, although intake is likely to be significantly higher because of the unrecorded consumption of traditionally produced beverages.(WHO, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). These account for an estimated 30% of pure alcohol consumption. In Tanzania, the per capita consumption of industrially produced alcoholic drinks is equivalent to about 5 L of pure alcohol, and the additional annual per capita amount of unrecorded consumption of locally brewed alcohol has been estimated at 2 L of pure alcohol. (WHO, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe presence of methanol and other toxic substances in alcoholic beverages affects the health of the people, resulting in complications and chronic diseases or ill health, such as blindness, dizziness, respiratory diseases, etc. (Lachenmeier et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe reason for many poisonings is the ingestion of methanol and aldehydes themselves or the ingestion of alcoholic beverages containing high quantities of methanol and aldehydes. Alcoholic beverages are popular in many countries and are often consumed. Due to its effects on human organisms, its popularity is linked to the content of ethanol.\u003c/p\u003e \u003cp\u003eThe ingestion of drinks containing high levels of methanol and aldehydes can cause serious health difficulties \u0026ndash; metabolic problems, blindness, permanent neurological damage or even death. This is a great risk for consumers of alcoholic beverages taken from unknown sources. (Vaskova, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the body, methanol converts to toxic metabolites, including formaldehyde and formic acid, via hepatic alcohol dehydrogenase and aldehyde dehydrogenase, respectively. These metabolites cause toxic presentations such as severe metabolic acidosis, optic neuropathy, cerebral oedema and acute renal failure. (Kadam et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2018\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, limited data exist for Tanzanian beverages, creating a research gap. This study aims to address this gap by conducting a trend analysis of methanol, ethanol, and aldehydes in selected local beverages, providing insights into their safety and compliance with standards such as TZS 468:2015, WHO, and FDA guidelines.\u003c/p\u003e"},{"header":"Materials and Methods:","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Area and Sampling\u003c/h2\u003e \u003cp\u003eTwenty-one samples of seven types of local alcoholic beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) were randomly purchased from various shops in the Dar es Salaam and Pwani regions of Tanzania. The selected alcoholic beverages were in the categories of spirits (Gongo and Pingu), wines (Wanzuki) and beers (Mnazi, Ulanzi, Mbege, Komoni). The collected samples were then given unique serial codes (Gongo-G1, G2, G3), (Mnazi-Z1, Z2, Z3), (Ulanzi-U1, U2, U3), (Mbege-M1, M2, M3), (Komoni-K1, K2, K3), (Pingu-P1, P2, P3), and (Wanzuki-W1, W2, W3). Samples were properly homogenised to ensure reproducibility and accuracy, stored in airtight containers at 10\u0026ndash;15\u0026deg;C and analyzed daily over five days.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eReagents and Instrumentation\u003c/h3\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eReagents\u003c/h2\u003e \u003cp\u003eAnalytical-grade methanol, ethanol, acetaldehyde, formaldehyde, and DNPH were used to prepare calibration standards.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eEquipment\u003c/h3\u003e\n\u003cp\u003eGas Chromatograph (Varian CP 3800) with Flame Ionization Detector (GC-FID) a GC model of Agilent US (California, USA) for methanol and ethanol analysis; High-performance Liquid Chromatography (HPLC) SHIMADZU NEXERA 40LC with a UV/Vis detector, HPLC model of Shimadzu Scientific Instruments (Kyoto 604\u0026ndash;8511, Japan) for aldehyde analysis.\u003c/p\u003e\n\u003ch3\u003eSample preparation\u003c/h3\u003e\n\u003cp\u003e2.5 ml of each local alcoholic beverage sample was measured into a measuring cylinder and topped up with de-ionized water to the mark. Filtration was done to obtain a clear solution for GC and HPLC analyses. A portion of the prepared sample was then used for the GC and HPLC analysis.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eAnalytical Methods\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003eMethanol and Ethanol Analysis\u003c/h2\u003e \u003cp\u003eCalibration curves for methanol and ethanol were prepared at concentrations of 0.0625%, 0.125%, and 0.25% (v/v), which are presented in Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Samples were diluted to 1% (v/v) and analyzed using GC-FID under the following conditions: DB-WAX Ultra Inert column, carrier gas (hydrogen) at 6 mL/min, and a column oven temperature range of 40\u0026deg;C to 225\u0026deg;C.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003eAldehyde Analysis\u003c/h3\u003e\n\u003cp\u003eAldehydes were derivatized with DNPH, extracted with methylene chloride, and analyzed using HPLC. Calibration curves for acetaldehyde and formaldehyde were generated at equivalent concentrations shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eData were analyzed using Python (version 3.8) with the scipy.stats library. A one-way ANOVA was performed to compare methanol and ethanol concentrations across beverage types and time points, followed by Tukey\u0026rsquo;s HSD post-hoc test for pairwise comparisons (via the statsmodels library). Significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.001. Assumptions of normality (Shapiro-Wilk test) and homogeneity of variance (Levene\u0026rsquo;s test) were verified before analysis.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eMethanol and Ethanol Concentrations\u003c/h2\u003e \u003cp\u003eMethanol concentrations ranged from 95 to 2115 (mg/L) as illustrated in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Gongo consistently exhibited methanol levels exceeding safe limits (\u0026lt;\u0026thinsp;1000 mg/L). Ethanol concentrations varied widely, with Gongo showing the highest levels (17.39\u0026ndash;39.89% v/v), while Mbege exhibited the lowest (1.21\u0026ndash;2.58% v/v), as illustrated in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSummary of the mean concentrations in mg/L of methanol in the trend analyzed alcoholic beverages over five days.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePingu\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eKomoni\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGongo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMbege\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eUlanzi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMnazi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eWanzuki\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHours\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" 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\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e812\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e447\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1939\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e337\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e220\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e725\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e370\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2052\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e359\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e180\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e617\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e303\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2115\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e390\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e524\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e214\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1724\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e415\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e140\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e476\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e155\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1508\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e445\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e206\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1468\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e342\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e146\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1392\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e307\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1292\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1154\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1052\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003en.d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSummary of the mean concentrations in percentage v/v of ethanol in the analyzed alcoholic beverages over five days\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePingu\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKomoni\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGongo\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eMbege\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eUlanzi\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eMnazi\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eWanzuki\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHours\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e34.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e2.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e35.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e2.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.39\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e37.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e2.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e38.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e3.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e4.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e39.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e3.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e4.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e39.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e3.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e4.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e35.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e2.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.79\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e28.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e27.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.41\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e22.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e22.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e2.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e19.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e2.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e18.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e2.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16-hrs\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.59\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Findings\u003c/h2\u003e \u003cp\u003eANOVA revealed significant differences in methanol concentrations (F\u0026thinsp;=\u0026thinsp;110.75, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Post-hoc tests showed Gongo contained 1338\u0026ndash;1570 mg/L more methanol than other beverages (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), exceeding safety limits. Mnazi and Pingu also differed significantly (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe findings of this study reveal critical public health risks associated with locally produced alcoholic beverages in Tanzania, particularly Gongo, which consistently exhibited methanol concentrations exceeding the permissible limit of \u003cb\u003e\u0026lt;\u003c/b\u003e\u0026thinsp;1000 mg/L (TZS 468:2015). Statistical analysis (one-way ANOVA, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) confirmed that Gongo\u0026rsquo;s methanol levels were significantly higher than all other beverages (Tukey HSD, *p* \u0026lt; 0.001), with mean differences ranging from 1172 to 1570 mg/L. These results align with global reports linking methanol contamination to severe health outcomes, including blindness, neurological damage, and death (Lachenmeier et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Kadam et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The stark deviation in Gongo\u0026rsquo;s methanol content underscores the dangers of unregulated distillation practices, where inadequate methanol removal during production poses life-threatening risks to consumers.\u003c/p\u003e \u003cp\u003eEthanol concentrations varied widely across beverages (1.98\u0026ndash;39.40% v/v), with Gongo again showing the highest levels. While ethanol itself is the primary intoxicant in alcoholic beverages, its extreme concentrations in Gongo may compound health risks when consumed excessively. Notably, the absence of detectable aldehydes in our samples suggests effective fermentation control or low pectin content in raw materials. However, the presence of high methanol levels raises concerns about potential in vivo conversion to formaldehyde (Kadam et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), warranting further investigation into aldehyde formation under real-world consumption conditions.\u003c/p\u003e \u003cp\u003eThe methanol heatmap (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e) revealed critical safety trends: Gongo consistently exceeded safety limits (1,562\u0026ndash;2,115 mg/L; 56\u0026ndash;112% above TZS 468:2015 standards), with peak levels suggesting batch variability (Day 3: 2,115 mg/L). While most beverages showed gradual methanol decline (likely from volatilization), Gongo maintained hazardous concentrations (\u0026gt;\u0026thinsp;1,000 mg/L) through Day 5, contrasting with undetectable levels in Mnazi/Wanzuki. Clear risk gradients emerged - Gongo (high-risk) demands immediate regulation, Pingu/Komoni (400\u0026ndash;800 mg/L) require monitoring, and Mnazi/Wanzuki pose minimal risk. These patterns reflect faulty distillation in Gongo (inadequate head removal) and inadequate storage controls. The visual clustering of high-risk batches underscores the urgent need for market-level screening, mirroring contamination patterns in Ethiopian areki (Tadesse et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eComparative analysis with studies from Ethiopia and Ghana (Tadesse et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Tulashie et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) reveals a regional pattern of methanol contamination in traditional beverages. However, Tanzania\u0026rsquo;s challenge is intensified by the widespread availability of unregulated products. For instance, our statistical models (Levene\u0026rsquo;s test, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) confirmed significant heterogeneity in methanol variances across beverages, highlighting the inconsistency in production standards. These findings advocate for the adoption of WHO and FDA guidelines into Tanzania\u0026rsquo;s regulatory framework to standardize production and mitigate health risks.\u003c/p\u003e \u003cp\u003eIn conclusion, this study provides unequivocal evidence (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) of hazardous methanol levels in Gongo, demanding urgent intervention. By integrating regulatory reforms, producer education, and consumer outreach, Tanzania can safeguard public health while preserving cultural beverage practices. Future research should explore longitudinal contamination patterns and evaluate the efficacy of policy interventions.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eANOVA: Analysis of Variance \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGC-FID: Gas Chromatography-Flame Ionization Detector \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHPLC: High-Performance Liquid Chromatography \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTBS: Tanzania Bureau of Standards \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWHO: World Health Organization \u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during this study are available from the corresponding author upon reasonable request. Raw chromatographic data and statistical analysis scripts are also available upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;The authors declare no competing financial or non-financial interests related to this work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003e\u003cstrong\u003ePius Albert Makene\u003c/strong\u003e: Conceptualization, Methodology, Formal analysis, Writing- original draft\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMsafiri Samuel\u003c/strong\u003e: Investigation, Data curation, Validation\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eLeonia N. Henry\u003c/strong\u003e: Resources, Supervision, Writing -review \u0026amp; editing\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;We thank the Dar es Salaam Institute of Technology for laboratory support and local beverage producers for providing samples.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbegaz K, Beyene F, Langsrud T, Narvhus JA (2002) Indigenous processing methods and raw materials of borde, an Ethiopian traditional fermented beverage. J Food Technol Afr 7(2):59\u0026ndash;64\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnderson HE, Santos IC, Hildenbrand ZL, Schug KA (2019) A review of the analytical methods used for beer ingredient and finished product analysis and quality control. 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Retrieved 09 from \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/publications/i/item/global-status-report-on-alcohol-and-health-2014\u003c/span\u003e\u003cspan address=\"https://www.who.int/publications/i/item/global-status-report-on-alcohol-and-health-2014\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYerby N (2022) \u003cem\u003eTypes of Alcohol - List of Drinks By Alcohol Content - Alcohol Rehab Guide\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.alcoholrehabguide.org/alcohol/types/\u003c/span\u003e\u003cspan address=\"https://www.alcoholrehabguide.org/alcohol/types/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Methanol, Ethanol, Aldehydes, Local Alcoholic Beverages, GC-FID, HPLC, Tanzania","lastPublishedDoi":"10.21203/rs.3.rs-6568348/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6568348/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTraditional alcoholic beverages produced by local distilleries in Tanzania may contain hazardous levels of methanol and aldehydes, posing significant health risks to consumers. This study quantified methanol, aldehydes, and ethanol concentrations in seven locally produced beverages (\u003cem\u003eGongo\u003c/em\u003e, \u003cem\u003eMnazi\u003c/em\u003e, \u003cem\u003eUlanzi\u003c/em\u003e, \u003cem\u003eMbege\u003c/em\u003e, \u003cem\u003eKomoni\u003c/em\u003e, \u003cem\u003ePingu\u003c/em\u003e, and \u003cem\u003eWanzuki\u003c/em\u003e) from coastal Tanzania using Gas Chromatography-Flame Ionization Detector (GC-FID) for methanol/ethanol analysis and High-Performance Liquid Chromatography (HPLC) for aldehyde detection. Validated methods confirmed reliable detection limits (LOD), quantification limits (LOQ), and recoveries. Results revealed methanol concentrations ranging from 95 to 2115 (mg/L), with \u003cem\u003eGongo\u003c/em\u003e consistently exceeding the Tanzania Bureau of Standards (TBS) safety limit (\u0026le;\u0026thinsp;1000 mg/L or 0.1%) by 56\u0026ndash;112%. Statistical analysis (ANOVA, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) confirmed \u003cem\u003eGongo\u003c/em\u003e\u0026rsquo;s methanol levels were significantly higher than other beverages. While aldehydes were undetectable, the elevated methanol levels, particularly in \u003cem\u003eGongo\u003c/em\u003e, highlight acute risks of toxicity, including blindness and neurological damage. These findings underscore the urgent need for stricter quality control, regulatory enforcement, and public awareness campaigns to mitigate health hazards associated with traditional alcoholic beverages.\u003c/p\u003e","manuscriptTitle":"Determination of Methanol, Aldehydes, and Ethanol Concentrations in Local Alcoholic Beverages (Gongo, Mnazi, Ulanzi, Mbege, Komoni, Pingu, and Wanzuki) from the Coastal Regions of Tanzania","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-15 05:42:15","doi":"10.21203/rs.3.rs-6568348/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"77c56829-63a8-4579-bf79-f91baebfa7c9","owner":[],"postedDate":"May 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-06-02T11:08:43+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-15 05:42:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6568348","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6568348","identity":"rs-6568348","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}