The Prolonging Effect Of Natural Plant Extracts On The Storage Period Of Postharvest Litchi

This work was conducted to determine the preservation effects of essential oil to prolong the postharvest storage and freshness period of 'Feizixiao' litchi fruit. Essential oil was extracted from Lysimachi foenum-graecum Hance, Ginkgo biloba extract was obtained from the leaves, and anthocyanin was obtained from eggplant peel. Aspects of quality such as appearance, nutritional value, and enzyme activity were studied in postharvest litchi fruits. The results showed that the weight loss, decay rate, and malondialdehyde (MDA) content of litchi gradually increased in the four treatments and controls, while chroma L* and Vc, soluble solids, and titratable acid contents decreased with the extension of the storage time, while the activities of polyphenol oxidase (PPO) and peroxidase (POD) increased at first and then decreased slowly. Compared with room temperature preservation, the treatments with 0.5% essential oil extract, 0.5% ginkgo biloba extract, 0.5% anthocyanin extract, and 0.05% potassium sorbate reduced PPO and POD activity, membrane lipid peroxidation, decay, and weight loss, while providing better color protection and higher Vc, soluble solids, and titratable acid contents. The extracts delayed fruit browning, protected the nutrients and flavour quality of litchi pulp to a certain extent, and extended shelf life of postharvest litchi. Above all, the effect of 0.5% essential oil extract on the postharvest preservation of litchi was significantly better than other treatments. In addition, that of 0.5% ginkgo biloba extract was similar to that of 0.05% potassium sorbate but better than that of 0.5% anthocyanin extract. These results indicated that essential oil from Lysimachi foenum-graecum Hance prevented the decline of postharvest litchi quality, delayed browning and aging, and had the potential to be further developed as a natural fruit and vegetable preservative.