The color advantage of Chinese wheat with high whiteness and analysis of factors affecting color formation

Chinese. 以进口的高白度品种澳白麦和山东省现在主要推广的济麦21作对照，研究山东省最新育成的几个高自然白度的小麦品种优麦3号、山农12、山农8355及品系62008的色泽优势，对影响面粉及面制品色泽形成的各种因素进行研究，分析其色泽优势形成的主要影响因素，为面粉及其制品色泽性状的改良和高自然白度优质专用小麦品种的选育提供理论依据。运用智能白度仪和色彩色差计对面粉、面片和馒头的色泽进行评价。中国的高白度品种（系）具有很大的色泽优势，在面制品色泽上，和对照澳白麦相比，L*值差异不显著，但b*值极显著降低，特别是62008和山农12加工成馒头后L*值比澳白麦高，b*值比对照澳白麦低。加入增白剂后，中国的高白度品种（系）色泽变化的幅度比澳白麦小。对面粉色泽形成影响因素的研究结果表明，蛋白质含量高的品种，其色泽优势形成的主要原因是PPO活性和黄色素含量低；蛋白质含量低的品种，淀粉含量高是其形成高亮度的主要原因；PPO活性和黄色素含量越高，面粉及面制品黄度越大。在不用增白剂的情况下，通过选育高白度品种，可以满足人们对面制食品高白度的要求。对蛋白质含量高的材料，不过分追求面粉的白度和亮度，但可通过对低PPO活性和低黄色素含量的选择，培育食品色泽优良的高蛋白小麦新品种。对淀粉含量高的材料，既要重视面粉的白度和亮度，又要重视对低PPO活性和低黄色素含量的选择，培育用于加工中国传统食品的高白度小麦新品种。考虑到面食品的多样化，也可以选择蛋白质含量高、PPO活性低、黄色素含量高的特殊材料，培育加工亮黄色食品的品种，丰富中国的小麦品种类型。

English. Aobaimai imported from Australia and Jimai 21 widely planted in Shandong province were used as contrasts materials in this study. Firstly, the color advantage of Chinese wheat cultivars (line) Youmai 3, Shannong12, Shannong8355 and 62008 with good appearance was studied, then analyzed the main factors influencing the formation of the color in order to offer theoretical evidences for the breeding of high whiteness traits of different wheat genotypes. The intelligent brightnessmeter and color and color difference meter were used to evaluate the color of flour, fresh sheet and steamed bread. The brightness of the four wheat cultivars (line) was lower than Aobaimai, but the yellowness was also lower than Aobaimai, especially the appearance of steamed bread of 62008 and Shannong12 was better than Aobaimai. The change of flour color after added with BPO in the four wheat genotypes were smaller than Aobaimai. So the requirement of high white wheat-based products can be met without BPO by breeding of wheat cultivars. Through analysis of the factors affecting the color formation, it was found that the main factors affecting color formation were low PPO activity and yellow pigment content in high-protein content varieties and low protein content and high starch content in low-protein content varieties. In selection and breeding of wheat color, wheat lines with low PPO activity and yellow pigment content in wheat materials with high protein content should be chosen, thus wheat cultivars with both high quality and good color to make steamed bread and white noodle can be obtained. Wheat lines with low PPO activity and yellow pigment content in wheat materials with low protein content and high starch content also can be chosen. Moreover, wheat lines with low PPO activity and high yellow pigment content in wheat lines with low protein content and high starch content can be chosen to make high brightness and yellowness foods.