Postharvest preservation effects of starch-based self-reinforcing nanocomposite coatings on mechanically graded Huangguan pear

Fruit coating preservation technology has garnered increasing attention. However, the current research mainly focuses on optimizing coating formulations while overlooking the influence of coated fruits under external mechanical treatment. This study developed two types of edible starch-based self-reinforcing nanocomposite coatings. The coatings differed in composition based on their reinforcing agents: starch nanocrystals (SNCs) and cross-linked starch nanocrystals (CSNCs). The application performance of the optimal nanostarch addition level of starch-based self-reinforcing coating after automatic mechanical grading of Huangguan pear was also studied. Specifically, the physicochemical properties of graded pears during the 4-week storage after the coating treatment were also explored, including weight loss rate, color, texture and biochemical activity. It was found both the starch-based self-reinforcing nanocomposite coatings could achieve the quality preservation effect on graded pears and the CSNCs-reinforced edible nanocomposite coating performed better in maintaining the appearance, texture and biochemical activity of pears. On day 28 of storage, CSNCs-reinforced coatings reduced weight loss, cell membrane permeability, POD and PPO enzyme activity of pears compared to SNCs-reinforced coatings. The results confirmed the potential of starch-based self-reinforcing nanocomposite coatings to improve the preservation effect of graded pears, thus contributing to the quality preservation of fruits and vegetables after automatic mechanical treatment.