Application of gelatin film and coating prepared from dried alaska pollock by‐product in quality maintanance of grape berries

In this study, gelatin extracted from dried Alaska pollock by-product (DAPG) was used as an edible film and coating source. Rosewood essential oil (RO) or pine needle extract (PE) was incorporated into the DAPG film and coating to provide antioxidant and antimicrobial activities. The DAPG film containing 1.0% PE had desirable physical properties as well as superior functional activities compared with the DAPG film containing 1.0% RO. The DAPG film and coating containing PE were then applied to Kyoho grape berries. Grape berries treated with the DAPG coating had lower populations of total aerobic bacteria and yeast and molds compared with the control after 20 days of storage and these differences were 3.62 and 1.46 log CFUg(-1), respectively. Furthermore, the grape berries exhibited lesser weight loss and changes in anthocyanin content than the control, suggesting that DAPG coating is effective for the quality maintenance of grape berries during storage. Practical applicationThe quality maintenance of Kyoho grape berries is needed due to postharvest spoilage during storage. Conventional methods such as modified atmosphere packaging and sulfur dioxide treatment may have inefficient effect and sulfite residue problems. Therefore, development of edible film and coating prepared from fish gelatin and the incorporation of essential oil or plant extract as an antioxidant or antimicrobial agent in this study can be a new approach to prevent postharvest loss of Kyoho grape berries during storage.