苹果梨和鸭梨酶促褐变机理的研究

Study on the Enzyme Browning Mechanism of Pingguo Pear and Duck Pear

以苹果梨（Ｐｙｒuｓ uｓｓｕrｉｅｎｓiｓ Ｖａr． Ｏｖｏｉｄｅａ）和鸭梨（Ｐｙｒｕｓ ｂｒｅｔｅｃｈｎｅｉｄｅｒｉ Ｒｅｈｄ）为研究对象．在一定的贮藏期内．通过定期测定梨中ｐH值、可溶性固形物、褐变度、总酚和多酚氧化酶活性及其与不同底物的结合能力，分析梨的酶褐变机制，苹果梨和鸭梨在贮藏期间；ｐH值和可溶性固形物的含量总体呈下降趋势；多酚类物质的含量和多酚氧化酶的活性呈上升趋势，与贮藏期间的褐变度的升高是一致的多酚氧化酶与底物结合能力的强弱依次为：没食子酸＞儿茶酚＞绿原酸＞咖啡酸；抗坏血酸和还原糖含量对水果的褐变无显著影响。

The enzyme browning mechanism of pingguo pear (Pyrus ussuriensis Var. Ovoidea) and Duch pear (pyrus bretechneideri Rehd) was studied by determining the PH Value. soluble solid. degree of browning .total phenolics and polyphenol oxidase activity. During storage both PH value and soluble solids were in a general trend of decreasing However the phenolic content and activity of polyphenol oxidase were on the contrary;.It was consistent with the increasing degree of browning The combining capabibity of phenolics and polyphenol oxidase with other materials is in the following order pyrogallic acid>catechol>chlorgenic acid>caffeic acid.Vitamin C and reducing sugar had little effect on browning