板栗采后“#30707;灰化”#21457;生机理研究

项目名称： 板栗采后“#30707;灰化”#21457;生机理研究

项目编号： No.30871760

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 顾采琴

作者单位： 广州大学

项目金额： 34万元

中文摘要： 板栗采后常温贮藏过程易发生 "石灰化" 现象，导致食用价值丧失。本项目以广东河源板栗为试材，研究了：1)板栗在风干脱水、沙藏过程中 "石灰化"发生率、水分含量、脱水保护物质以及活性氧代谢等指标的变化及相互关系；2）不同"石灰化" 程度板栗中淀粉含量及特性等指标的变化；2) 抗氧化剂处理和不同相对湿度环境贮藏对板栗"石灰化"的调控作用。结果表明：1）板栗失水是导致"石灰化"发生的根本诱因，发现缺乏棉籽糖、水苏糖是板栗对脱水敏感的根本原因；2）失水导致淀粉水解酶活性升高、淀粉含量、硬度和粘性降低；并且失水导致热稳定蛋白分解及活性氧代谢失调，致使细胞膜结构不稳定及发生过氧化，进而导致细胞膜渗透性增加，最终导致细胞死亡。两方面因素构成板栗"石灰化"发生的直接和间接的原因。3）细胞壁分解导致多糖组分改变，胞间连丝消失、胞间距离拉大，是"石灰化"板栗细胞的特征。4）2% 茶多酚处理和在相对湿度90%下贮藏能在一定程度上控制板栗"石灰化"发生。本项目通过研究板栗失水导致的一系列生理生化的变化，初步探明"石灰化"发生及调控机理，为进一步揭示板栗 "石灰化"发生提供了科学依据。

中文关键词： 板栗；"石灰化"；发生机理；调控

英文摘要： The calcification phenomenon of fresh chestnut seeds after harvest happens often during storage at room temperature, which results in great loss of the edible value. Unfortunately, the mechanism of calcification of chestnuts is unclear. This project carried out a series of researches using 'Youli' (Castanea mollissima Blume) from Heyuan city in Guangdong province. The these reserches included that 1) the changes in the calcification rate, moisture content, dehydration protection substances, reactive oxygen metabolism and other biochemical and physiological indexes were investigated in postharvest chestnut seeds during storage at room temperature under natural air-dried and sand accumulation conditions; 2) the changes in the starch contents, starch characters and other phytochemical indexes of chestnut seeds were analysed at different calcification degree; and 3) the control of chestnut calcification was evaluated when the chestnuts were treated with antioxidant or stored under various humidity conditions. The study exhibited that: 1) the loss of moisture content of chestnuts was the essential reason for the calcification occurrence while lack of stachyose and raffinose in chestnut was important reason why chestnuts was sensitive to loss of moisture; 2) the loss of moisture resulted in the increase of (α βamylase activity, and the decreases in starch contents, firmness and adhesiveness leading to calcification, while the moisture loss resulted in the degradation of heat-stable protein (dehydration protection substance) and disorder of reactive oxygen metabolism, causing unstability and peroxidation of membrane structure, then the increase of membrane permeability, reduction of cellular viability, and finally the cellular die; 3) cellular wall degradation of chestnut seeds induced the structural changes in polysaccharides while the disappearing of silk was the character of cell in calcificated chestnut; and 4) the occurrence of chestnuts calcification could be controlled to some extents when chestnuts were treated with 2% tea polyphenol or stored under the 90% relative humidity condition. In this study, the mechanism and control of calcification of chestnut seeds were eluicidated preliminarily based on a series physiological and biochemical changes caused by loss of moisture, which can provide scientific basis for further understanding of the mechanism and control of calcification of chestnut seeds.

英文关键词： chestnut; calcification; occurrence mechanism; control