EDIBLE NANO-COATINGS: A SUSTAINABLE STRATEGY FOR ENHANCING THE SHELF-LIFE AND QUALITY OF FRESH PRODUCE (STRAWBERRIES)

Abstract

Postharvest spoilage of strawberries are lost due to huge amount especially in the countries with weak refrigeration system. Nano-coatings that can be ingested are a sustainable and biodegradable way of improving antimicrobial protection and barrier properties to prolong the shelf life of food. Most of the studies however are limited and are only applicable to a single polymer system, short storage periods or individual quality parameters. In this study, six edible coatings were developed by incorporating either chitosan nanoparticles (CSNPs), nanocrystalline cellulose (NCC), pullulan (PUL), zinc oxide nanoparticles (ZnO NPs), essential oils (EOs), or alginate (ALG) into strawberry edible coating.In this study, six edible coatings were formulated containing either chitosan nanoparticles (CSNPs), nanocrystalline cellulose (NCC), pullulan (PUL), zinc oxide nanoparticles (ZnO NPs), essential oils (EOs), or alginate (ALG) and applied to strawberries in refrigerated storage for 28 days. The effect of each coating was assessed in terms of weight loss, firmness, titratable acidity, microbial count and sensory quality at appropriate time intervals. The findings indicated that coated samples inhibited microbial growth signficantly better than uncoated controls (p < 0.05) with CSNP and ZnO coatings having the most profound effect on microbial growth and least weight loss. Coatings based on pullulan and NCC were able to maintain a longer firmness and appearance of fruits, whereas coatings based on essential oils continued to receive good scores in sensory tests. It is worth noting that coated strawberries stayed acceptable in taste and texture over 21 days, whereas the control lasted just 10 days. These results prove that multi-component nano coatings are capable of maintaining postharvest quality of strawberries in refrigerated storage. The findings suggest their suitability as low-tech, scalable solutions toward enhance produce stability in resource-limited environments. Further studies are recommended to evaluate performance of different fruits and storage conditions.