Development and functional characterization of edible bioplastic films from Spirulina and protein isolate extracted from wheat straw (agricultural waste) for sustainable food packaging

Development and functional characterization of edible bioplastic films from Spirulina and protein isolate extracted from wheat straw (agricultural waste) for sustainable food packaging | 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 Article Development and functional characterization of edible bioplastic films from Spirulina and protein isolate extracted from wheat straw (agricultural waste) for sustainable food packaging Shima Omidi, Maryam Haghighi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7977098/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 13 You are reading this latest preprint version Abstract This study develops and characterizes edible bioplastic films formulated from Spirulina platensis and wheat-straw protein isolate (WSPI) obtained from agricultural residues for sustainable food packaging. A Box–Behnken experimental design evaluated the effects of WSPI (3–6% w/w), Spirulina (0.5–2.0 g/L), and glycerol (30–40% w/w) on mechanical, barrier, optical, solubility, biodegradability, and bioactive responses. Films were assessed for tensile strength (TS), elongation at break (EAB), water vapor permeability (WVP), transparency, solubility, biodegradability, antioxidant activity, and antimicrobial inhibition, with complementary FTIR, TGA, XRD, and SEM analyses. TS and EAB ranged from 6.54 to 9.46 MPa and 7.02 to 13.59%, respectively, while WVP varied between 6.80 and 10.24 g·m⁻¹·s⁻¹·Pa⁻¹. Glycerol significantly increased EAB, transparency, solubility, and biodegradability, whereas higher Spirulina concentrations enhanced elasticity, antioxidant, and antimicrobial performance. The optimal formulation containing 6% WSPI, 2 g/L Spirulina, and 30% glycerol achieved a TS of 8.69 MPa, an EAB of 12.42%, a WVP of 7.20 g·m⁻¹·s⁻¹·Pa⁻¹, and 70.8% biodegradation within 7 days. FTIR spectra confirmed intensified hydrogen bonding, TGA revealed delayed thermal decomposition, and SEM micrographs displayed a compact, homogeneous structure. These findings demonstrate that combining WSPI from agricultural waste with Spirulina bioactives can produce functional, biodegradable, and antioxidant edible films, supporting circular and sustainable food-packaging applications. Biological sciences/Biochemistry Biological sciences/Biotechnology Earth and environmental sciences/Environmental sciences Biological sciences/Microbiology Edible bioplastic films Spirulina Wheat straw protein isolate Sustainable food packaging Agricultural waste valorization Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 09 Dec, 2025 Reviews received at journal 08 Dec, 2025 Reviews received at journal 02 Dec, 2025 Reviewers agreed at journal 28 Nov, 2025 Reviewers agreed at journal 21 Nov, 2025 Reviews received at journal 16 Nov, 2025 Reviewers agreed at journal 06 Nov, 2025 Reviewers agreed at journal 06 Nov, 2025 Reviewers invited by journal 04 Nov, 2025 Editor invited by journal 04 Nov, 2025 Editor assigned by journal 02 Nov, 2025 Submission checks completed at journal 02 Nov, 2025 First submitted to journal 29 Oct, 2025 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. 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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-7977098","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":542159823,"identity":"ec7942ab-33ef-407f-a7e2-f9b634bb8a23","order_by":0,"name":"Shima 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packaging","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":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Edible bioplastic films, Spirulina, Wheat straw protein isolate, Sustainable food packaging, Agricultural waste valorization","lastPublishedDoi":"10.21203/rs.3.rs-7977098/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7977098/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study develops and characterizes edible bioplastic films formulated from \u003cem\u003eSpirulina platensis\u003c/em\u003e and wheat-straw protein isolate (WSPI) obtained from agricultural residues for sustainable food packaging. A Box\u0026ndash;Behnken experimental design evaluated the effects of WSPI (3\u0026ndash;6% w/w), Spirulina (0.5\u0026ndash;2.0 g/L), and glycerol (30\u0026ndash;40% w/w) on mechanical, barrier, optical, solubility, biodegradability, and bioactive responses. Films were assessed for tensile strength (TS), elongation at break (EAB), water vapor permeability (WVP), transparency, solubility, biodegradability, antioxidant activity, and antimicrobial inhibition, with complementary FTIR, TGA, XRD, and SEM analyses. TS and EAB ranged from 6.54 to 9.46 MPa and 7.02 to 13.59%, respectively, while WVP varied between 6.80 and 10.24 g\u0026middot;m⁻\u0026sup1;\u0026middot;s⁻\u0026sup1;\u0026middot;Pa⁻\u0026sup1;. Glycerol significantly increased EAB, transparency, solubility, and biodegradability, whereas higher Spirulina concentrations enhanced elasticity, antioxidant, and antimicrobial performance. The optimal formulation containing 6% WSPI, 2 g/L Spirulina, and 30% glycerol achieved a TS of 8.69 MPa, an EAB of 12.42%, a WVP of 7.20 g\u0026middot;m⁻\u0026sup1;\u0026middot;s⁻\u0026sup1;\u0026middot;Pa⁻\u0026sup1;, and 70.8% biodegradation within 7 days. FTIR spectra confirmed intensified hydrogen bonding, TGA revealed delayed thermal decomposition, and SEM micrographs displayed a compact, homogeneous structure. These findings demonstrate that combining WSPI from agricultural waste with Spirulina bioactives can produce functional, biodegradable, and antioxidant edible films, supporting circular and sustainable food-packaging applications.\u003c/p\u003e","manuscriptTitle":"Development and functional characterization of edible bioplastic films from Spirulina and protein isolate extracted from wheat straw (agricultural waste) for sustainable food packaging","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-13 17:58:45","doi":"10.21203/rs.3.rs-7977098/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-09T09:48:38+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-08T11:10:05+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-02T10:59:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"22670423846506671297984955591526862471","date":"2025-11-28T10:54:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"30810650174862683245908162923519991029","date":"2025-11-21T11:04:55+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-16T17:07:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"100032836567626052554550498503488754064","date":"2025-11-06T13:25:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"34596645184296375339164792652251735174","date":"2025-11-06T06:10:28+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-04T11:21:23+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-04T10:37:55+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-03T04:15:44+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-03T04:15:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-10-29T07:40:42+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"cc25a88a-2d02-4daf-b7df-5cab36773b81","owner":[],"postedDate":"November 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":57675814,"name":"Biological sciences/Biochemistry"},{"id":57675815,"name":"Biological sciences/Biotechnology"},{"id":57675816,"name":"Earth and environmental sciences/Environmental sciences"},{"id":57675817,"name":"Biological sciences/Microbiology"}],"tags":[],"updatedAt":"2026-04-03T17:08:14+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-13 17:58:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7977098","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7977098","identity":"rs-7977098","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}