【摘要】 PPO及其相应底物是面条贮存期间 (或挂面干燥过程中 )颜色褐变的主要原因。本试验对我国 16 4份冬小麦品种的籽粒PPO以及 83份主栽品种的面粉PPO进行了筛选 ,研究了基因型、环境及其互作对籽粒及面粉PPO活性的影响 ,同时探讨了PPO活性与其他品质性状的关系。结果表明 ,我国冬小麦品种间PPO活性变异较大 ,籽粒PPO变化范围1 93～ 12 .0 0A475/gmin-1× 10 3 ,面粉PPO变化范围 0 .2 2～ 3.74A475/gmin-1× 10 3 。基因型、环境及其互作对PPO活性的影响都达到极显著水平 ,除软麦面粉外 ,基因型对小麦PPO活性的影响大于环境。面粉PPO活性与面粉白度及 2 4h面团颜色呈显著负相关 ,r值分别为 - 0 .5 0和 - 0 .5 9;容重、千粒重、籽粒硬度、出粉率通过改变面粉中麸皮含量 (主要影响PPO含量 )而影响面团颜色 ,而蛋白质及淀粉特性则通过影响PPO活性的表达导致品种间面团颜色变化的差异。更多还原

【Abstract】 The enzyme polyphenol oxidase(PPO) has been related to undesirable brown discoloration of wheat based end products such as noodles. 164 cultivars from winter wheat region in China were used to screen grain PPO activity, and 83 cultivars were used to determine flour PPO activity and other quality characteristics. Two sets of wheat samples were used to investigate the effects of genotype, environment and their interaction on grain and flour PPO activity. Significant differences in grain and flour PPO activity were observed in the China winter wheat populations. Grain PPO activity among China winter wheats ranged from 1.93 to 12.00 A 475 /g min -1 ×10 3, and flour PPO activity ranged from 0.22 to 3.74 A 475 /g min -1 ×10 3. The variability in grain and flour PPO activities was influenced by growing location and genotype for the winter wheat samples. The variation in grain and flour PPO activities among growing locations appeared smaller than variation produced by genotypes for the winter wheat samples except for soft wheat flour PPO. Flour PPO activities were related to L * of flour and 24 h fresh noodle sheets, correlation coefficients were -0.50 and -0.59 respectively. Quality parameters, such as grain hardness, milling yield, flour protein, water absorption and falling number significantly Correlated with flour PPO activities. Test weight, TKW, grain hardness and flour yield affected PPO content through changing bran content, while protein and starch affected PPO activities.更多还原