Zhejiang Gongshang University

About: Zhejiang Gongshang University is a education organization based out in Hangzhou, China. It is known for research contribution in the topics: Computer science & Chemistry. The organization has 8258 authors who have published 7670 publications receiving 90296 citations. The organization is also known as: Zhèjiāng Gōngshāng Dàxué.

Enzyme‐catalyzed regioselective synthesis of sucrose‐based esters

Abstract: Sucrose-based esters are nonionic biosurfactants, which can be synthesized from the enzyme-catalyzed esterification/transesterification of sucrose. The multi-hydroxyl groups of sucrose and the immiscibility of sucrose with the acyl donors are the main bottlenecks in obtaining highly regioselective sucrose-based esters. In this mini-review, the effects of reaction conditions such as biocatalysts, design of solvent systems used as reaction media, modification and denaturation of substrates, and coupling with external auxiliary physical fields such as microwave irradiation and ultrasonic waves on the yield of sucrose esters and regioselectivity of products are highlighted. The existing problems in the field of enzymatic synthesis of sucrose esters as well as its future perspectives were pointed out. Copyright © 2011 Society of Chemical Industry

Effect of pyrogallol on the physiology and biochemistry of litchi fruit during storage

Abstract: Litchi (Litchi chinensis Sonn.) fruit are highly perishable and have a very short shelf life, easily turning brown and decaying. This study investigated the efficiency of pyrogallol, a catechin on the physiology and biochemistry in relation to storage life of litchi fruit. Fruit were treated with pyrogallol at 1 mM and then stored at ambient temperature (25°C) or low temperature (4°C). Compared with control, pyrogallol significantly reduced pericarp browning and delayed the rotting of fruit day 4 at 25°C, and on day 30 at 4°C. The chemical treatment reduced respiration rate and the activities of peroxidase (POD) and polyphenol oxidase (PPO), and delayed the loss of membrane permeability. Pyrogallol increased the activity of phenylalanine ammonia-lyase (PAL), delayed the loss of anthocyanin and phenolics, and maintained high 2,2-diphenyl-1-picrlhydrazyl (DPPH) radical scavenging activity and reducing power. High performance liquid chromatograph (HPLC) analysis clearly indicated that treated fruit contained higher concentration of the four phenolic compounds procyanidin B1, (+)-catechin, (−)-epicatechin and (−)-epicatechin-3-gallate. The application of pyrogallol partially reducing pericarp browning and changed quality-related physiological activities and, thus, pyrogallol could have beneficial effects on pericarp browning and fruit decay control, and could be helpful for litchi fruit postharvest storage.