Andressa Amado Martin

Biodegradable coatings can improve fruit storage, but physical and chemical interactions might impair performance. This work coated strawberries with a blend based on cassava starch (native, oxidized, or acetylated), gelatin, sorbitol, and two antimicrobial agents (calcium propionate and potassium permanganate) to evaluate potential downsides of exposure to an acidic environment. The coatings varied in thickness (0.124-0.160 nm), opacity (1.37-4.61), solubility (29-55%), and color. Mass loss analysis indicated limited efficiency (the 10% threshold was reached within 48 h) in strawberries due to potential hydrolysis reaction. Soluble solids, titratable acidity, harvest index, and vitamin C concentration confirmed that hydrolysis under acidic conditions strongly impaired acetylated starch coating performance, performing worse than the control group. Further studies are needed to evaluate coating behavior in non-acidic fruits and under different pH conditions.

In this study, cassava starch-based films were produced to protect strawberries. Nine films from natural and modified starches (oxidized and acetylated) mixed to gelatin and plasticizers (sorbitol, glycerol and mannitol) were prepared for strawberry protection after harvesting. The films were homogeneous, transparent and flexible, and the ones that presented the best results were prepared with sorbitol because they presented mass loss indices ranging from 28.17 to 32.96%, after 8-day storage. These values were lower in the control group (without film) that had 53.44% loss. The results indicate a 5-day increase of strawberry shelf life. Regarding color, a difference was verified only in the L* index (brightness) when the coated fruits had lighter color than the control ones. These results show the great potential of film utilization in food preservation, aggregating value to the agricultural activity and helping to reduce nonbiodegradable films in the environment. This study aimed to produce films from modified cassava starches (acetylated and oxidized) and native starch, gelatin and plasticizers (sorbitol, glycerol and mannitol) to coat strawberries, cultivar Dover, as well as to verify the efficiency of these films as a barrier against fruit mass loss in order to improve shelf life. The biodegradable films formed with sorbitol presented smaller mass losses in strawberries after harvest. Mass loss was significantly equal among the three starches. These results show the great potential of film utilization in food preservation, aggregating value to the agricultural activity and helping to reduce nonbiodegradable films in the environment.