Development of Vitamin C/polyurethane composite films for efficient preservation of grapes with controllable respiration

Abstract

The abundant sugar and water contents make grapes highly susceptible to rot by pathogenic bacteria, which accounts for millions of dollars in revenue loss each year. Herein, to alleviate this problem, rot-proof bronopol embedded-polyurethane hybrid films (PBV) containing 3 g/100 g of vitamin C were developed by electrospinning. PBV films had the lowest water vapor transmission rate when compared to the other groups, with a value of 2.57 mg·cm−2·h−1 (23 °C, 75%), and achieved over 99.99% inhibition of E. coli, S aureus, and B. subtilis. For the PBV films packaged grapes, the content of organic acids increased by more than 10% and the weight loss rate was lowered by over 50%. More importantly, the production rate of CO2 is 1.64 ppm·g−1·h−1 that can substantially delay grape ripening and spoilage resulting from transpiration. This study offers a facile manufacturing route to develop multifunctional composite films for grape preservation.