Coffee ranks as the second most consumed beverage globally, and its popularity is associated with the growing accumulation of spent coffee grounds (SCG), a by-product that, if not managed properly, constitutes a serious ecological problem. Analyses of SCG have repeatedly shown that they are a source of substances with antioxidant and antimicrobial properties. In this study, we assessed SCG as a substrate for the production of edible/biodegradable films. The κ-carrageenan was utilized as a base polymer and the emulsified SCG oil as a filler. The oil pressed from a blend of Robusta and Arabica coffee had the best quality and the highest antioxidant properties; therefore, it was used for film production. The film-forming solution was prepared by dissolving κ-carrageenan in distilled water at 50 °C, adding the emulsified SCG oil, and homogenizing. This solution was cast onto Petri dishes and dried at room temperature. Chemical characterization showed that SCG increased the level of polyphenols in the films and the antioxidant properties, according to the CUPRAC assay (CC1 23.90 ± 1.23 µmol/g). SCG performed as a good plasticizer for κ-carrageenan and enhanced the elongation at the break of the films, compared with the control samples. The solubility of all SCG films reached 100%, indicating their biodegradability and edibility. Our results support the application of SCG as an active and easily accessible compound for the food packaging industry.

Department of Plant Origin Food Sciences Faculty of Veterinary Hygiene and Ecology University of Veterinary Sciences Brno Palackeho tr 1946 1 612 42 Brno Czech Republic

Zobrazit více v PubMed

Statista.Com. [(accessed on 3 August 2023)]. Available online: https://www.statista.com/statistics/282732/global-production-of-plastics-since-1950/

World Economic Forum, Ellen MacArthur Foundation, and McKinsey and Company (2016). The New Plastics Economy-Rethinking the Future of Plastics. [(accessed on 3 August 2023)]. Available online: https://www.weforum.org/press/2016/01/more-plastic-than-fish-in-the-ocean-by-2050-report-offers-blueprint-for-change/

OECD.Org. [(accessed on 3 August 2023)]. Available online: https://www.oecd.org/environment/plastic-pollution-is-growing-relentlessly-as-waste-management-and-recycling-fall-short.htm.

Santos É.M.D., Macedo L.M.D., Tundisi L.L., Ataide J.A., Camargo G.A., Alves R.C., Oliveira M.B.P.P., Mazzola P.G. Coffee By-Products in Topical Formulations: A Review. Trends Food Sci. Technol. 2021;111:280–291. doi: 10.1016/j.tifs.2021.02.064. DOI

Skorupa A., Worwąg M., Kowalczyk M. Coffee Industry and Ways of Using By-Products as Bioadsorbents for Removal of Pollutants. Water. 2022;15:112. doi: 10.3390/w15010112. DOI

Oliveira G., Passos C.P., Ferreira P., Coimbra M.A., Gonçalves I. Coffee By-Products and Their Suitability for Developing Active Food Packaging Materials. Foods. 2021;10:683. doi: 10.3390/foods10030683. PubMed DOI PMC

Klingel T., Kremer J.I., Gottstein V., Rajcic De Rezende T., Schwarz S., Lachenmeier D.W. A Review of Coffee By-Products Including Leaf, Flower, Cherry, Husk, Silver Skin, and Spent Grounds as Novel Foods within the European Union. Foods. 2020;9:665. doi: 10.3390/foods9050665. PubMed DOI PMC

Statista.Com. [(accessed on 4 August 2023)]. Available online: https://www.statista.com/statistics/292595/global-coffee-consumption/

Lee K.-T., Shih Y.-T., Rajendran S., Park Y.-K., Chen W.-H. Spent Coffee Ground Torrefaction for Waste Remediation and Valorization. Environ. Pollut. 2023;324:121330. doi: 10.1016/j.envpol.2023.121330. PubMed DOI

Zhang L., Sun X. Using Cow Dung and Spent Coffee Grounds to Enhance the Two-stage Co-Composting of Green Waste. Bioresour. Technol. 2017;245:152–161. doi: 10.1016/j.biortech.2017.08.147. PubMed DOI

Forcina A., Petrillo A., Travaglioni M., Di Chiara S., De Felice F. A Comparative Life Cycle Assessment of Different Spent Coffee Ground Reuse Strategies and a Sensitivity Analysis for Verifying the Environmental Convenience Based on the Location of Sites. J. Clean. Prod. 2023;385:135727. doi: 10.1016/j.jclepro.2022.135727. DOI

Passos C.P., Rudnitskaya A., Neves J.M.M.G.C., Lopes G.R., Evtuguin D.V., Coimbra M.A. Structural Features of Spent Coffee Grounds Water-Soluble Polysaccharides: Towards Tailor-Made Microwave Assisted Extractions. Carbohydr. Polym. 2019;214:53–61. doi: 10.1016/j.carbpol.2019.02.094. PubMed DOI

Bomfim A.S.C.D., De Oliveira D.M., Walling E., Babin A., Hersant G., Vaneeckhaute C., Dumont M.-J., Rodrigue D. Spent Coffee Grounds Characterization and Reuse in Composting and Soil Amendment. Waste. 2022;1:2–20. doi: 10.3390/waste1010002. DOI

Wang Y., Wang X., Hu G., Al-Romaima A., Liu X., Bai X., Li J., Li Z., Qiu M. Effect of Green Coffee Oil as a Natural Active Emulsifying Agent on the Properties of Corn Starch-Based Films. LWT. 2022;170:114087. doi: 10.1016/j.lwt.2022.114087. DOI

Davis A.P., Rakotonasolo F. Six New Species of Coffee (Coffea) from Northern Madagascar. Kew Bull. 2021;76:497–511. doi: 10.1007/s12225-021-09952-5. DOI

Bosmali I., Lagiotis G., Stavridou E., Haider N., Osathanunkul M., Pasentsis K., Madesis P. Novel Authentication Approach for Coffee Beans and the Brewed Beverage Using a Nuclear-Based Species-Specific Marker Coupled with High Resolution Melting Analysis. LWT. 2021;137:110336. doi: 10.1016/j.lwt.2020.110336. DOI

Wagemaker T.A.L., Carvalho C.R.L., Maia N.B., Baggio S.R., Guerreiro Filho O. Sun Protection Factor, Content and Composition of Lipid Fraction of Green Coffee Beans. Ind. Crops Prod. 2011;33:469–473. doi: 10.1016/j.indcrop.2010.10.026. DOI

Piotr Konieczka P., Aliaño-González M.J., Ferreiro-González M., Barbero G.F., Palma M. Characterization of Arabica and Robusta Coffees by Ion Mobility Sum Spectrum. Sensors. 2020;20:3123. doi: 10.3390/s20113123. PubMed DOI PMC

D’Amelio N., De Angelis E., Navarini L., Schievano E., Mammi S. Green Coffee Oil Analysis by High-Resolution Nuclear Magnetic Resonance Spectroscopy. Talanta. 2013;110:118–127. doi: 10.1016/j.talanta.2013.02.024. PubMed DOI

Lin Y.-T., We Y.-L., Kao Y.-M., Tseng S.-H., Wang D.-Y., Chen S.-Y. Authentication of Coffee Blends by 16-O-Methylcafestol Quantification Using NMR Spectroscopy. Processes. 2023;11:871. doi: 10.3390/pr11030871. DOI

FDA.Gov. [(accessed on 14 August 2023)]; Available online: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=172.620/

Tomadoni B., Cassani L., Ponce A., Moreira M.R., Agüero M.V. Optimization of Ultrasound, Vanillin and Pomegranate Extract Treatment for Shelf-Stable Unpasteurized Strawberry Juice. LWT—Food Sci. Technol. 2016;72:475–484. doi: 10.1016/j.lwt.2016.05.024. DOI

Behbahani B.A., Shahidi F., Yazdi F.T., Mortazavi S.A., Mohebbi M. Use of Plantago Major Seed Mucilage as a Novel Edible Coating Incorporated with Anethum Graveolens Essential Oil on Shelf Life Extension of Beef in Refrigerated Storage. Int. J. Biol. Macromol. 2017;94:515–526. doi: 10.1016/j.ijbiomac.2016.10.055. PubMed DOI

Thaipong K., Boonprakob U., Crosby K., Cisneros-Zevallos L., Hawkins Byrne D. Comparison of ABTS, DPPH, FRAP, and ORAC Assays for Estimating Antioxidant Activity from Guava Fruit Extracts. J. Food Compos. Anal. 2006;19:669–675. doi: 10.1016/j.jfca.2006.01.003. DOI

Apak R., Güçlü K., Demirata B., Özyürek M., Çelik S., Bektaşoğlu B., Berker K., Özyurt D. Comparative Evaluation of Various Total Antioxidant Capacity Assays Applied to Phenolic Compounds with the CUPRAC Assay. Molecules. 2007;12:1496–1547. doi: 10.3390/12071496. PubMed DOI PMC

Khalifa I., Barakat H., El-Mansy H.A., Soliman S.A. Improving the Shelf-Life Stability of Apple and Strawberry Fruits Applying Chitosan-Incorporated Olive Oil Processing Residues Coating. Food Packag. Shelf Life. 2016;9:10–19. doi: 10.1016/j.fpsl.2016.05.006. DOI

Symoniuk E., Ratusz K., Krygier K. Evaluation of the Oxidative Stability of Cold-Pressed Rapeseed Oil by Rancimat and Pressure Differential Scanning Calorimetry Measurements. Eur. J. Lipid Sci. Technol. 2019;121:1800017. doi: 10.1002/ejlt.201800017. PubMed DOI PMC

Merillon J.M. Bioactive Molecules in Food. Springer Berlin Heidelberg; New York, NY, USA: 2019.

Issaoui M., Delgado A.M. Grading, Labeling and Standardization of Edible Oils. In: Ramadan M.F., editor. Fruit Oils: Chemistry and Functionality. Springer International Publishing; Cham, Switzerland: 2019. pp. 9–52.

Panpraneecharoen S. Optimization of the Oil Extraction, Study the Chemical and Physical Properties of Arabica Spent Coffee Grounds. Sci. Technol. Asia. 2020;25:1219. doi: 10.14456/SCITECHASIA.2020.45. DOI

Bijla L., Aissa R., Bouzid H.A., Sakar E.H., Ibourki M., Gharby S. Spent Coffee Ground Oil as a Potential Alternative for Vegetable Oil Production: Evidence from Oil Content, Lipid Profiling, and Physicochemical Characterization. Biointerface Res. Appl. Chem. 2021;12:6308–6320. doi: 10.33263/BRIAC125.63086320. DOI

Kusnandar F. Prediction of Acid, Peroxide and TBA values of Heat-Treated Palm Oil Using a Partial Least Squares–Ordinary Least Squares Model Based on Fouriertransform Infrared Spectroscopy. J. Oil Palm Res. 2020;33:514–523. doi: 10.21894/jopr.2020.0106. DOI

Prakoso F.A.H., Indiarto R., Utama G.L. Edible Film Casting Techniques and Materials and Their Utilization for Meat-Based Product Packaging. Polymers. 2023;15:2800. doi: 10.3390/polym15132800. PubMed DOI PMC

Douny C., Tihon A., Bayonnet P., Brose F., Degand G., Rozet E., Milet J., Ribonnet L., Lambin L., Larondelle Y., et al. Validation of the Analytical Procedure for the Determination of Malondialdehyde and Three Other Aldehydes in Vegetable Oil Using Liquid Chromatography Coupled to Tandem Mass Spectrometry (LC-MS/MS) and Application to Linseed Oil. Food Anal. Methods. 2015;8:1425–1435. doi: 10.1007/s12161-014-0028-z. DOI

Ma L., Liu G. Simultaneous Analysis of Malondialdehyde, 4-Hydroxy-2-Hexenal, and 4-Hydroxy-2-Nonenal in Vegetable Oil by Reversed-Phase High-Performance Liquid Chromatography. J. Agric. Food Chem. 2017;65:11320–11328. doi: 10.1021/acs.jafc.7b04566. PubMed DOI

Custodio-Mendoza J.A., Valente I.M., Ramos R.M., Lorenzo R.A., Carro A.M., Rodrigues J.A. Analysis of Free Malondialdehyde in Edible Oils Using Gas-Diffusion Microextraction. J. Food Compos. Anal. 2019;82:103254. doi: 10.1016/j.jfca.2019.103254. DOI

Papastergiadis A., Fatouh A., Jacxsens L., Lachat C., Shrestha K., Daelman J., Kolsteren P., Van Langenhove H., De Meulenaer B. Exposure Assessment of Malondialdehyde, 4-Hydroxy-2-(E)-Nonenal and 4-Hydroxy-2-(E)-Hexenal through Specific Foods Available in Belgium. Food Chem. Toxicol. 2014;73:51–58. doi: 10.1016/j.fct.2014.06.030. PubMed DOI

Cong S., Dong W., Zhao J., Hu R., Long Y., Chi X. Characterization of the Lipid Oxidation Process of Robusta Green Coffee Beans and Shelf Life Prediction during Accelerated Storage. Molecules. 2020;25:1157. doi: 10.3390/molecules25051157. PubMed DOI PMC

Viau M., Genot C., Ribourg L., Meynier A. Amounts of the reactive aldehydes, malonaldehyde, 4-hydroxy-2-hexenal, and 4-hydroxy-2-nonenal in fresh and oxidized edible oils do not necessary reflect their peroxide and anisidine values. Eur. J. Lipid Sci. Tech. 2016;118:435–444. doi: 10.1002/ejlt.201500103. DOI

Bouyanfif A., Liyanage S., Hequet E., Moustaid-Moussa N., Abidi N. FTIR Microspectroscopy Reveals Fatty Acid-Induced Biochemical Changes in C. Elegans. Vib. Spectrosc. 2019;102:8–15. doi: 10.1016/j.vibspec.2019.03.002. DOI

Ma L., He Q., Qiu Y., Liu H., Wu J., Liu G., Brennan C., Brennan M.A., Zhu L. Food Matrixes Play a Key Role in the Distribution of Contaminants of Lipid Origin: A Case Study of Malondialdehyde Formation in Vegetable Oils during Deep-Frying. Food Chem. 2021;347:129080. doi: 10.1016/j.foodchem.2021.129080. PubMed DOI

Muangrat R., Pongsirikul I. Recovery of Spent Coffee Grounds Oil Using Supercritical CO2: Extraction Optimisation and Physicochemical Properties of Oil. CyTA—J. Food. 2019;17:334–346. doi: 10.1080/19476337.2019.1580771. DOI

Obruca S., Petrik S., Benesova P., Svoboda Z., Eremka L., Marova I. Utilization of Oil Extracted from Spent Coffee Grounds for Sustainable Production of Polyhydroxyalkanoates. Appl. Microbiol. Biotechnol. 2014;98:5883–5890. doi: 10.1007/s00253-014-5653-3. PubMed DOI

Al-Hamamre Z., Foerster S., Hartmann F., Kröger M., Kaltschmitt M. Oil Extracted from Spent Coffee Grounds as a Renewable Source for Fatty Acid Methyl Ester Manufacturing. Fuel. 2012;96:70–76. doi: 10.1016/j.fuel.2012.01.023. DOI

Lauberts M., Mierina I., Pals M., Latheef M.A.A., Shishkin A. Spent Coffee Grounds Valorization in Biorefinery Context to Obtain Valuable Products Using Different Extraction Approaches and Solvents. Plants. 2022;12:30. doi: 10.3390/plants12010030. PubMed DOI PMC

Liu Y., Kitts D.D. Confirmation That the Maillard Reaction Is the Principle Contributor to the Antioxidant Capacity of Coffee Brews. Food Res. Int. 2011;44:2418–2424. doi: 10.1016/j.foodres.2010.12.037. DOI

Nicoli M.C., Anese M., Manzocco L., Lerici C.R. Antioxidant Properties of Coffee Brews in Relation to the Roasting Degree. LWT—Food Sci. Technol. 1997;30:292–297. doi: 10.1006/fstl.1996.0181. DOI

Liao Y.-C., Kim T., Silva J.L., Hu W.-Y., Chen B.-Y. Effects of Roasting Degrees on Phenolic Compounds and Antioxidant Activity in Coffee Beans from Different Geographic Origins. LWT. 2022;168:113965. doi: 10.1016/j.lwt.2022.113965. DOI

Opitz S.E.W., Goodman B.A., Keller M., Smrke S., Wellinger M., Schenker S., Yeretzian C. Understanding the Effects of Roasting on Antioxidant Components of Coffee Brews by Coupling On-Line ABTS Assay to High Performance Size Exclusion Chromatography: Analysis of Coffee Antioxidants Using ABTS-HPSEC On-Line Assay. Phytochem. Anal. 2017;28:106–114. doi: 10.1002/pca.2661. PubMed DOI PMC

Andrade C., Perestrelo R., Câmara J.S. Bioactive Compounds and Antioxidant Activity from Spent Coffee Grounds as a Powerful Approach for Its Valorization. Molecules. 2022;27:7504. doi: 10.3390/molecules27217504. PubMed DOI PMC

Choi B., Koh E. Spent Coffee as a Rich Source of Antioxidative Compounds. Food Sci. Biotechnol. 2017;26:921–927. doi: 10.1007/s10068-017-0144-9. PubMed DOI PMC

Sharma A., Ray A., Singhal R.S. A Biorefinery Approach towards Valorization of Spent Coffee Ground: Extraction of the Oil by Supercritical Carbon Dioxide and Utilizing the Defatted Spent in Formulating Functional Cookies. Future Foods. 2021;4:100090. doi: 10.1016/j.fufo.2021.100090. DOI

Dordevic D., Kushkevych I., Jancikova S., Zeljkovic S.C., Zdarsky M., Hodulova L. Modeling the Effect of Heat Treatment on Fatty Acid Composition in Home-Made Olive Oil Preparations. Open Life Sci. 2020;15:606–618. doi: 10.1515/biol-2020-0064. PubMed DOI PMC

Dordevic D., Dordevic S., Ćavar-Zeljković S., Kulawik P., Kushkevych I., Tremlová B., Kalová V. Monitoring the Quality of Fortified Cold-Pressed Rapeseed Oil in Different Storage Conditions. Eur. Food Res. Technol. 2022;248:2695–2705. doi: 10.1007/s00217-022-04079-8. DOI

Song J.L., Asare T.S., Kang M.Y., Lee S.C. Changes in Bioactive Compounds and Antioxidant Capacity of Coffee under Different Roasting Conditions. Korean J. Plant Resour. 2018;31:704–713. doi: 10.7732/KJPR.2018.31.6.704. DOI

Alonso-Salces R.M., Serra F., Reniero F., HÉberger K. Botanical and Geographical Characterization of Green Coffee (Coffea Arabica and Coffea Canephora): Chemometric Evaluation of Phenolic and Methylxanthine Contents. J. Agric. Food Chem. 2009;57:4224–4235. doi: 10.1021/jf8037117. PubMed DOI

Mannino G., Kunz R., Maffei M.E. Discrimination of Green Coffee (Coffea Arabica and Coffea Canephora) of Different Geographical Origin Based on Antioxidant Activity, High-Throughput Metabolomics, and DNA RFLP Fingerprinting. Antioxidants. 2023;12:1135. doi: 10.3390/antiox12051135. PubMed DOI PMC

Dias R., Benassi M. Discrimination between Arabica and Robusta Coffees Using Hydrosoluble Compounds: Is the Efficiency of the Parameters Dependent on the Roast Degree? Beverages. 2015;1:127–139. doi: 10.3390/beverages1030127. DOI

Rocha De Souza M.C., Marques C.T., Guerra Dore C.M., Ferreira Da Silva F.R., Oliveira Rocha H.A., Leite E.L. Antioxidant Activities of Sulfated Polysaccharides from Brown and Red Seaweeds. J. Appl. Phycol. 2007;19:153–160. doi: 10.1007/s10811-006-9121-z. PubMed DOI PMC

Lombo Vidal O., Tsukui A., Garrett R., Miguez Rocha-Leão M.H., Piler Carvalho C.W., Pereira Freitas S., Moraes De Rezende C., Simões Larraz Ferreira M. Production of Bioactive Films of Carboxymethyl Cellulose Enriched with Green Coffee Oil and Its Residues. Int. J. Biol. Macromol. 2020;146:730–738. doi: 10.1016/j.ijbiomac.2019.10.123. PubMed DOI

Dordevic D., Dordevic S., Abdullah F.A.A., Mader T., Medimorec N., Tremlova B., Kushkevych I. Edible/Biodegradable Packaging with the Addition of Spent Coffee Grounds Oil. Foods. 2023;12:2626. doi: 10.3390/foods12132626. PubMed DOI PMC

Balasubramanian R., Kim S.S., Lee J. Novel Synergistic Transparent K-Carrageenan/Xanthan Gum/Gellan Gum Hydrogel Film: Mechanical, Thermal and Water Barrier Properties. Int. J. Biol. Macromol. 2018;118:561–568. doi: 10.1016/j.ijbiomac.2018.06.110. PubMed DOI

Balaban P., Puška A. Influence of Packaging Process on Mechanical Characteristics of the Flexible Packaging Materials. Adeletters. 2022;1:65–70. doi: 10.46793/adeletters.2022.1.2.5. DOI

Kong I., Degraeve P., Pui L.P. Polysaccharide-Based Edible Films Incorporated with Essential Oil Nanoemulsions: Physico-Chemical, Mechanical Properties and Its Application in Food Preservation—A Review. Foods. 2022;11:555. doi: 10.3390/foods11040555. PubMed DOI PMC

Shah Y.A., Bhatia S., Al-Harrasi A., Afzaal M., Saeed F., Anwer M.K., Khan M.R., Jawad M., Akram N., Faisal Z. Mechanical Properties of Protein-Based Food Packaging Materials. Polymers. 2023;15:1724. doi: 10.3390/polym15071724. PubMed DOI PMC

Holm V.K., Ndoni S., Risbo J. The Stability of Poly(Lactic Acid) Packaging Films as Influenced by Humidity and Temperature. J. Food Sci. 2006;71:E40–E44. doi: 10.1111/j.1365-2621.2006.tb08895.x. DOI

Sandhu K.S., Sharma L., Kaur M., Kaur R. Physical, Structural and Thermal Properties of Composite Edible Films Prepared from Pearl Millet Starch and Carrageenan Gum: Process Optimization Using Response Surface Methodology. Int. J. Biol. Macromol. 2020;143:704–713. doi: 10.1016/j.ijbiomac.2019.09.111. PubMed DOI

Bomfim A., Oliveira D., Voorwald H., Benini K., Dumont M.-J., Rodrigue D. Valorization of Spent Coffee Grounds as Precursors for Biopolymers and Composite Production. Polymers. 2022;14:437. doi: 10.3390/polym14030437. PubMed DOI PMC

Yan J., Yu H., Yang Z., Li L., Qin Y., Chen H. Development of Smart Films of a Chitosan Base and Robusta Coffee Peel Extract for Monitoring the Fermentation Process of Pickles. Foods. 2023;12:2337. doi: 10.3390/foods12122337. PubMed DOI PMC

Tarique J., Sapuan S.M., Khalina A. Effect of Glycerol Plasticizer Loading on the Physical, Mechanical, Thermal, and Barrier Properties of Arrowroot (Maranta Arundinacea) Starch Biopolymers. Sci. Rep. 2021;11:13900. doi: 10.1038/s41598-021-93094-y. PubMed DOI PMC

Farhan A., Hani N.M. Characterization of Edible Packaging Films Based on Semi-Refined Kappa-Carrageenan Plasticized with Glycerol and Sorbitol. Food Hydrocoll. 2017;64:48–58. doi: 10.1016/j.foodhyd.2016.10.034. DOI

Martiny T.R., Pacheco B.S., Pereira C.M.P., Mansilla A., Astorga–España M.S., Dotto G.L., Moraes C.C., Rosa G.S. A Novel Biodegradable Film Based on Κ-carrageenan Activated with Olive Leaves Extract. Food Sci. Nutr. 2020;8:3147–3156. doi: 10.1002/fsn3.1554. PubMed DOI PMC

Apriliyani M.W., Purwadi P., Manab A., Apriliyanti M.W., Ikhwan A.D. Characteristics of Moisture Content, Swelling, Opacity and Transparency with Addition Chitosan as Edible Films/Coating Base on Casein. Adv. J. Food Sci. Technol. 2020;18:9–14. doi: 10.19026/ajfst.18.6041. DOI

Abdillah A.A., Charles A.L. Characterization of a Natural Biodegradable Edible Film Obtained from Arrowroot Starch and Iota-Carrageenan and Application in Food Packaging. Int. J. Biol. Macromol. 2021;191:618–626. doi: 10.1016/j.ijbiomac.2021.09.141. PubMed DOI

Travalini A.P., Lamsal B., Magalhães W.L.E., Demiate I.M. Cassava Starch Films Reinforced with Lignocellulose Nanofibers from Cassava Bagasse. Int. J. Biol. Macromol. 2019;139:1151–1161. doi: 10.1016/j.ijbiomac.2019.08.115. PubMed DOI

Nguyen B.T., Nicolai T., Benyahia L., Chassenieux C. Synergistic Effects of Mixed Salt on the Gelation of κ-Carrageenan. Carbohydr. Polym. 2014;112:10–15. doi: 10.1016/j.carbpol.2014.05.048. PubMed DOI

Thakur R., Pristijono P., Golding J.B., Stathopoulos C.E., Scarlett C.J., Bowyer M., Singh S.P., Vuong Q.V. Amylose-Lipid Complex as a Measure of Variations in Physical, Mechanical and Barrier Attributes of Rice Starch- ι -Carrageenan Biodegradable Edible Film. Food Packag. Shelf Life. 2017;14:108–115. doi: 10.1016/j.fpsl.2017.10.002. DOI

Silva M.A.D., Bierhalz A.C.K., Kieckbusch T.G. Alginate and Pectin Composite Films Crosslinked with Ca2+ Ions: Effect of the Plasticizer Concentration. Carbohydr. Polym. 2009;77:736–742. doi: 10.1016/j.carbpol.2009.02.014. DOI

Wahyuni S., Holilah, Asranudin, Rianse M.I.K., Sadimantara M.S. Effect of κ-Carrageenan Concentration on Physical and Mechanical Properties of Vegetable Leather Based on Kelor Leaves (Moringa Oleifera L.) IOP Conf. Ser. Earth Environ. Sci. 2019;260:012180. doi: 10.1088/1755-1315/260/1/012180. DOI