Researchers at the São Carlos Chemistry Institute of the University of São Paulo (IQSC-USP) have developed an edible biofilm from agricultural and fishing industry waste. This biofilm can extend the shelf life of strawberries (Fragaria x ananassa Duch) by reducing weight loss and delaying fungal contamination. In refrigerated storage tests, strawberries with the biofilm showed 11% less weight loss and took 6 to 8 days to become contaminated by fungi, compared to 4 days for uncoated fruits.
The study, supported by FAPESP and conducted with Embrapa Instrumentação and the Federal University of São Carlos (UFSCar), was published in Food Chemistry. Mirella Romanelli Vicente Bertolo, a postdoctoral fellow and first author of the study, stated, "By applying the coating, it was possible to double the shelf life of strawberries kept under refrigeration and delay the dehydration of the fruit, while at the same time preserving the flavor, texture, and volatile compounds that give the fruit its characteristic aroma."
The research utilized natural deep eutectic solvents (NADES) to extract antioxidants from pomegranate peel, which were then incorporated into the biofilm made from gelatin and chitosan. Chitosan was sourced from squid shells to avoid allergenicity issues associated with shrimp-derived chitosan.
Strawberries, chosen for their high perishability, were coated with the biofilm through immersion. The film acted as a barrier to microorganisms, moisture loss, and gas exchange, thus extending shelf life while preserving sensory attributes. The researchers have filed a patent and plan to license the technology.
Economic analysis suggests a potential cost of R$0.15 per fruit for the coating.
Source: Abrafrutas