Advancement in the utilization of agri-food waste for the production of melanin-based bacterial cellulose

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Ημερομηνία έκδοσης

2025-03-10

Συγγραφείς

Tolia, Eirini
Τόλια, Ειρήνη

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Εκδότης

Άδεια Creative Commons

Attribution-NonCommercial-NoDerivatives 4.0 International
Εκτός εάν σημειώνεται διαφορετικά, η άδεια αυτού του αντικειμένου περιγράφεται ως Attribution-NonCommercial-NoDerivatives 4.0 International

Περίληψη

Melanin derived from microorganisms, plants and mammals possess exceptional characteristics, including radioprotective and antioxidant activity, as well as the ability to chelate heavy metals and absorb organic molecules. Research has demonstrated a direct and proportional correlation between the antioxidant activity of food packaging films and the augmentation of melanin nanoparticles. Cellulose is the primary natural polymer, possessing a diverse array of uses owing to its biocompatibility and exceptional ability to create films. BC possesses the capability to serve as a polymer matrix and can undergo ex-situ and in-situ alterations to tailor the functional qualities of the material for its intended application in food packaging. In this study, utilization of cheese whey for BC production from bacterial strain Komagataeibacter rhaeticus UNIWA AAK2 was studied. Moreover, the production of melanin through citrus waste valorization using the black yeast strain Exophiala phaeomuriformis EXF- 6108 was also examined. The characterization of BC based films reinforced with microbial melanin showed that carbon sources as well as melanin enrichment had a significant impact on the films’ characteristics. In the case of BC, color analysis showed that the L* differed significantly depending on the film composition, with DCW films presenting the highest L* values (84.07 ± 0.73) and glucose-melanin (Glu-Mel) films the lowest (37.37 ± 1.77). The WVP ranged from 1.86 gmm/m²hkPa for the DCW-melanin films to 3.37 gmm/(m2dkPa) for the Glucose films, indicating the effect of carbon source and melanin. The solubility was higher in Glu-Mel films (55.06 %) and lower in DCW films (13.46 %). The mechanical properties showed low tensile strength (TS) and elongation break (E%), with maximum values reaching 12.75 MPa and 3.29% respectfully. Melanin’s addition showed slight enhancement of the film’s mechanical properties. BC enrichment with melanin indicated UV-blocking properties, and most particular in the UVC and UVB spectrum (200 - 320 nm). The findings showed that the analyzed films enriched with microbial melanin could potentially act as a viable alternative to current synthetic films, as well as those improved with natural or synthetic melanin for packaging applications. Cost-effective melanin and BC production on a large scale, is a major technical challenge. The strategy of utilizing low cost and abundant agro-industrial waste and by-product streams to produce both microbial melanin and BC is in line with the concepts of sustainable development and circular economy.

Περιγραφή

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Παραπομπή

Συμπληρωματικό Υλικό

URI

https://hdl.handle.net/11610/33896
 https://doi.org/10.26215/heal.uoa.12309

Συλλογές

Master of Research, Global Innovation and Sustainability in the Food Industry and Nutrition