Active/smart carboxymethyl cellulose‐polyvinyl alcohol composite films containing rose petal extract for fish packaging

Summary In this study, a film was developed for packaging fish that not only enhanced its shelf life but also was visually receptive to its spoilage. Rose petal extract (RPE) having excellent bioactivity was used as the functional component in carboxymethyl cellulose‐poly vinyl alcohol packaging film. Due to its high anthocyanin content, RPE could be used as a pH indicator, as its colour changed from bright red (pH 2) to yellow (pH 10). The developed film was used for packing Indian Mackerel and assessing its quality during chilled storage. Mackerel packed in neat film spoiled in 3 days while that in RPE containing films had shelf life of 12 days. Total bacterial count, pH, total volatile basic nitrogen and thiobarbituric acid reactive substance of fish in control were higher as compared to in RPE films. On spoilage RPE containing films showed visible colour response from red to green.