Studies on the affecting factors of the storage stability of shredded vegetables.

对果蔬酶促褐变的预防进行了研究。多种蔬菜中均含有多酚氧化酶抑制剂，以萝卜提取物的抑制作用最高。以萝卜提取物为原料，经蛋白质热变性、乙酸乙酯分离、sephadex G-25凝胶过滤纯化该抑制剂。采用疏水色谱、薄层色谱和高效液相色谱对抑制剂组分进行进一步分离。纯化后的抑制剂（JRI）在270 nm处出现吸收峰，对FeCl_3呈阳性，对ninhydrin呈阴性。用SephadexG-25葡萄糖洗脱JRI。这些结果表明JRI是一种低分子量的多酚类化合物。JRI对多酚氧化酶具有竞争性抑制作用。JRI还能抑制生菜和牛蒡表面的酶促褐变现象。上述结果表明，JRI对保持生菜、卷心菜等蔬菜丝的贮藏稳定性有一定的作用。

Prevention of enzymatic browning in fruits and vegetables was investigated. Polyphenol oxidase inhibitors was founud in various vegetables, and the inhibiting effect of Japanese raddish extract was highest. The inhibitor was purified from the Japanese raddish extract by heat-denaturation of protein, fractionation of ethyl acetate, and sephadex G-25 gel filtration. The inhibitor fraction was further fractionated using hydrophobic chromatography TLC and HPLC.The purified inhibitor (JRI) showed absorption peak at 270 nm, and was positive for FeCl_3 but negative for ninhydrin. JRI was eluted after glucose on SephadexG-25. These results indicate that JRI is a low molecular weight polyphenolic compound.JRI inhibited polyphenol oxidase competitively. JRI also inhibited enzymatic browning finding at cutsurface of lettuce and edible burdock.These results indicate that JRI is useful for keeping the storage stability of shredded vegetables, such as sheredded lettuce and cabbage.