Preserving mandarin quality during ambient storage using edible coatings of pregelatinized corn starch Pickering emulsions and essential oil

Abstract

Fruit stored in poor conditions undergo biochemical degradations that impact fruit physical qualities, such color and firmness, and reduce beneficial nutritional content including vitamins, flavonoids, phenols, and antioxidants. This study investigated the impact of a postharvest treatment of mandarins with edible coatings to prevent biochemical degradations and minimize color changes. The edible coating evaluated in this study is a composite of pregelatinized corn starch (PS), with a cellulose nano fiber (CF) Pickering emulsifier, and is enriched with basil essential oil (EO). The results of varying each parameter were then analyzed by the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method to identify the best-performing edible coating. Using this method, the leading edible coating was identified as PS5EO3 formulized from 5% pregelatinized corn starch, 3% basil essential oil and 0.5% cellulose nanofiber, with a ranking of 0.721 based on quality content, and 0.676 based on percentage change in nutrients after the 12 days of storage at 25 °C. Mandarins coated with PS5EO3 significantly suppressed quality losses, and achieving the lowest losses of citric acid (10.45%), while maintaining color stability in terms of color density (14.97%) and percent polymer color (78.14%).