Polyphenol treatment delays the browning of litchi pericarps and promotes the total antioxidant capacity of litchi fruit

Abstract

Rapid pericarp browning is the leading factor for quality deterioration and marketing decline of litchi fruit. In the present study, litchi fruit was treated with phenolic compounds, proanthocyanidin, p-coumalic acid, chlorogenic acid, apple polyphenol, and tea polyphenol, before being stored at 20°C for 10 d. Phenolic compound treatment delayed pericarp browning and weight loss, reduced respiration rate, and maintained high total acid levels and vitamin C content in litchi fruit. Subsequently, the key antioxidant characteristics were determined to evaluate the effects of phenolic compounds on the antioxidant system during pericarp browning. The phenolic compound-treated fruit exhibited higher levels of antioxidant enzymes, anthocyanins, total phenols, flavonoids, and antioxidant capacity, as well as a lower superoxide radical production rate and polyphenol oxidase and peroxide activities during whole-fruit storage than the control. Of the five treatments, proanthocyanidin application produced the most significant effects; therefore, this may be the best method for inducing antioxidant system-related factors, enhancing antioxidant capacity, and delaying pericarp browning in litchi.