Effect of composite coating of konjac glucomannan with green tea polyphenols on antioxidant activity and shelf-life of post-harvest passion fruit

In this study, the effect of konjac glucomannan (KGM) and green tea polyphenols (GTP) on the preservation quality of passion fruit was explored by using different GTP (0.1%, 0.2%, and 0.3%) in combination with 0.5% KGM. Quality indexes, physicochemical parameters, and antioxidant enzyme activities of passion fruit were measured every three days during storage. Overall, the results revealed that the 0.2% GTP/0.5% KGM composite coating prevailed as the best preservation group, effectively delaying the increase of shrinkage index, weight loss rate, and respiratory intensity. Moreover, the GTP/KGM composite coating could inhibit the increase of polyphenol oxidase and peroxidase activities while retarding the aging and browning of passion fruit. In conclusion, these results suggested that the treatment of natural composite materials (GTP/KGM) has positive effects on extending post-harvest life and improving the quality of passion fruit.