Characterisation of Single-step Charcoal-purified Cosmetic-grade C- Phycocyanin Produced from Native Spirulina platensis in Bangladesh

Characterisation of Single-step Charcoal-purified Cosmetic-grade C- Phycocyanin Produced from Native Spirulina platensis in Bangladesh | 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 Characterisation of Single-step Charcoal-purified Cosmetic-grade C- Phycocyanin Produced from Native Spirulina platensis in Bangladesh Anthony Samit Baidya, Natasha Nafisa Haque, Safaet Alam, Shyama Prosad Moulick, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8820282/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract C-Phycocyanin (C-PC), a water-soluble phycobiliprotein from Spirulina , possesses significant commercial value for food, cosmetic, and pharmaceutical applications due to its natural blue colouration and bioactive properties. However, conventional production methods, involving freeze/spray-drying and complex, multi-step purification processes, impose substantial costs that limit widespread commercialisation, particularly in resource-limited settings. This study presents the first characterisation of C-PC from a local Spirulina (Arthrospira) platensis strain in Bangladesh, systematically evaluating cost-effective drying, extraction, and purification methods. Among employed drying techniques, low-humidity air-drying at 25°C preserved approximately 95.4% of extractable C-PC content (160.87 mg g -1 DW) relative to freeze-drying (168.59 mg g -1 DW). Biomass drying at 25°C was accelerated with humidity reduction (< 25%), and the drying time (24 h) was comparable to other reported methods. Shaking-assisted aqueous extraction of C-PC at a 1:30 solvent-to-biomass ratio for 16 hours at 25°C exceeded 85% C-PC extraction efficiency, with food-grade purity (≥ 0.86). Single-step purification of crude C-PC extracts at 25°C using activated charcoal adsorption (ACA) with 60 g L -1 charcoal for 16 h yielded cosmetic-grade C-PC (≥ 2.19) with more than 70% recovery. UV-Vis, fluorescence, and infrared spectra of the lyophilised C-PC preparations confirmed structural integrity comparable to the analytical reference standard. Purified C-PC exhibited moderate antioxidant activity (IC 50 574.4 - 620.1 µg mL -1 ) in DPPH radical scavenging assay and moderate cytotoxicity (LC 50 78.6 - 122.5 µg mL⁻¹) in brine shrimp lethality bioassays. Additionally, heavy metal content in the fresh Spirulina biomass remained within regulatory limits. The optimised combination of low-humidity air-drying, stirred aqueous extraction, and single-step ACA purification for C-PC production provides a green, cost-effective, scalable approach for commercial applications, addressing economic constraints for developing countries. Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementaryinformation.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 06 Mar, 2026 Reviews received at journal 06 Mar, 2026 Reviews received at journal 26 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviews received at journal 17 Feb, 2026 Reviewers agreed at journal 14 Feb, 2026 Reviewers agreed at journal 12 Feb, 2026 Reviewers invited by journal 12 Feb, 2026 Editor assigned by journal 12 Feb, 2026 Submission checks completed at journal 10 Feb, 2026 First submitted to journal 08 Feb, 2026 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-8820282","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":592829477,"identity":"21834ed6-3aab-41a9-9478-95a2bcb7a631","order_by":0,"name":"Anthony Samit Baidya","email":"","orcid":"","institution":"Bangladesh Council of Scientific and Industrial Research","correspondingAuthor":false,"prefix":"","firstName":"Anthony","middleName":"Samit","lastName":"Baidya","suffix":""},{"id":592829479,"identity":"78b6f034-8540-4ded-9502-2c76b9e6012b","order_by":1,"name":"Natasha Nafisa Haque","email":"","orcid":"","institution":"Bangladesh Council of Scientific and Industrial Research","correspondingAuthor":false,"prefix":"","firstName":"Natasha","middleName":"Nafisa","lastName":"Haque","suffix":""},{"id":592829482,"identity":"0c99020c-8ba2-4a9d-9afb-050d7e3c6edf","order_by":2,"name":"Safaet Alam","email":"","orcid":"","institution":"Bangladesh Council of Scientific and Industrial Research","correspondingAuthor":false,"prefix":"","firstName":"Safaet","middleName":"","lastName":"Alam","suffix":""},{"id":592829485,"identity":"d39dbf2f-5351-4e96-850a-ab3b77519571","order_by":3,"name":"Shyama Prosad Moulick","email":"","orcid":"","institution":"Bangladesh Council of Scientific and Industrial Research","correspondingAuthor":false,"prefix":"","firstName":"Shyama","middleName":"Prosad","lastName":"Moulick","suffix":""},{"id":592829488,"identity":"889d473b-5dcc-45c5-a340-ae2ce52c326d","order_by":4,"name":"Chapol Kumar Roy","email":"","orcid":"","institution":"Bangladesh Council of Scientific and Industrial Research","correspondingAuthor":false,"prefix":"","firstName":"Chapol","middleName":"Kumar","lastName":"Roy","suffix":""},{"id":592829491,"identity":"00f55af8-6861-4bba-ad4b-554441aa30cc","order_by":5,"name":"John Liton Munshi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBACxgYeBoYHBkAWew+QMICIMjOwEdCSYABUynOGSC1ApUAtIKUSOQgxvFqY23uPPUgo+CNnLvn24McfBfcY5N17DJgLyvA4rOdcugHQYcaWs/OSpXkMihkMz5wxYJ5xDo+WGTlmEkAtiRtu55gxMxgkMBjOSEtg5m0jRsvNM2aMP0jTcoPHjIEHqEVeIvkAfi09Z0BajI0NzoD9ksBjwHP4wGF8fjFs7zGT+PBHTs7g+FlgiP1JkJNvb2x8jC/EDBvQBHgMDjAwHMCtgYFBHlME3ZBRMApGwSgY8QAAGHlKsa5T38gAAAAASUVORK5CYII=","orcid":"","institution":"Bangladesh Council of Scientific and Industrial Research","correspondingAuthor":true,"prefix":"","firstName":"John","middleName":"Liton","lastName":"Munshi","suffix":""}],"badges":[],"createdAt":"2026-02-08 08:54:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8820282/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8820282/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102903688,"identity":"f3a51e70-66b0-42a9-8361-ba2eb2465c6c","added_by":"auto","created_at":"2026-02-18 08:42:40","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":678305,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptRvs01.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8820282/v1_covered_e64fd8b2-f0e6-4d09-a5a8-b63053440a75.pdf"},{"id":102903612,"identity":"1625c97a-a8c5-4268-ae62-5271799950d4","added_by":"auto","created_at":"2026-02-18 08:42:16","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2532686,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementaryinformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-8820282/v1/e543c1f0cb245606e262c84e.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Characterisation of Single-step Charcoal-purified Cosmetic-grade C- Phycocyanin Produced from Native Spirulina platensis in Bangladesh","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"","identity":"journal-of-applied-phycology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"10811","submissionUrl":"https://submission.nature.com/new-submission/10811/3","title":"Journal of Applied Phycology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8820282/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8820282/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eC-Phycocyanin (C-PC), a water-soluble phycobiliprotein from \u003cem\u003eSpirulina\u003c/em\u003e, possesses significant commercial value for food, cosmetic, and pharmaceutical applications due to its natural blue colouration and bioactive properties. However, conventional production methods, involving freeze/spray-drying and complex, multi-step purification processes, impose substantial costs that limit widespread commercialisation, particularly in resource-limited settings. This study presents the first characterisation of C-PC from a local \u003cem\u003eSpirulina (Arthrospira) platensis\u003c/em\u003e strain in Bangladesh, systematically evaluating cost-effective drying, extraction, and purification methods. Among employed drying techniques, low-humidity air-drying at 25°C preserved approximately 95.4% of extractable C-PC content (160.87 mg g\u003csup\u003e-1\u003c/sup\u003e DW) relative to freeze-drying (168.59 mg g\u003csup\u003e-1\u003c/sup\u003e DW). Biomass drying at 25°C was accelerated with humidity reduction (\u0026lt; 25%), and the drying time (24 h) was comparable to other reported methods. Shaking-assisted aqueous extraction of C-PC at a 1:30 solvent-to-biomass ratio for 16 hours at 25°C exceeded 85% C-PC extraction efficiency, with food-grade purity (≥ 0.86). Single-step purification of crude C-PC extracts at 25°C using activated charcoal adsorption (ACA) with 60 g L\u003csup\u003e-1\u003c/sup\u003e charcoal for 16 h yielded cosmetic-grade C-PC (≥ 2.19) with more than 70% recovery. UV-Vis, fluorescence, and infrared spectra of the lyophilised C-PC preparations confirmed structural integrity comparable to the analytical reference standard. Purified C-PC exhibited moderate antioxidant activity (IC\u003csub\u003e50\u003c/sub\u003e 574.4 - 620.1 µg mL\u003csup\u003e-1\u003c/sup\u003e) in DPPH radical scavenging assay and moderate cytotoxicity (LC\u003csub\u003e50\u003c/sub\u003e 78.6 - 122.5 µg mL⁻¹) in brine shrimp lethality bioassays. Additionally, heavy metal content in the fresh \u003cem\u003eSpirulina\u003c/em\u003e biomass remained within regulatory limits. The optimised combination of low-humidity air-drying, stirred aqueous extraction, and single-step ACA purification for C-PC production provides a green, cost-effective, scalable approach for commercial applications, addressing economic constraints for developing countries.\u003c/p\u003e","manuscriptTitle":"Characterisation of Single-step Charcoal-purified Cosmetic-grade C- Phycocyanin Produced from Native Spirulina platensis in Bangladesh","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-18 08:39:39","doi":"10.21203/rs.3.rs-8820282/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-06T16:23:04+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-06T15:40:55+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-27T01:22:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"272155279337620157419562269779902073757","date":"2026-02-20T13:48:40+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-18T03:35:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"321755795313612569976122504411684377245","date":"2026-02-14T15:28:54+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"259030843878891121349759159901375063254","date":"2026-02-12T20:59:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-12T14:00:45+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-12T11:51:41+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-10T07:25:36+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Applied Phycology","date":"2026-02-08T08:39:20+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"","identity":"journal-of-applied-phycology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"10811","submissionUrl":"https://submission.nature.com/new-submission/10811/3","title":"Journal of Applied Phycology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"7087e3a9-243d-40c6-ab43-dbacee6ac816","owner":[],"postedDate":"February 18th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-03-26T02:53:05+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-18 08:39:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8820282","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8820282","identity":"rs-8820282","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}