馒头评分指标的小麦高分子量麦谷蛋白亚基评分系统研究

针对现有高分子量麦谷蛋白亚基(HMW-GS)评分系统的局限性,选用100个春小麦品种,测定了其HMW-GS以及馒头比容得分、外观、色泽、结构、弹韧性、粘牙性、气味、总评分等8项馒头评分指标,并通过数量化理论及统计学鉴评方法,研究了HMW-GS与馒头评分指标的关系,得到了8个多元回归方程,决定系数均在0.95以上,能准确预测8个馒头评分指标,建立了针对不同馒头评分指标的HMW-GS评分系统。总体来看,1亚基、2*亚基、7亚基、5 10亚基和10亚基可普遍提高馒头评分指标,属于优质亚基,其中,5 10亚基可有效改善馒头品质,10亚基有利于改善馒头外观,但使馒头结构变劣,1亚基能有效改善馒头色泽,7亚基可改善馒头粘牙性。N、2 10、2 11、2 12和17 18亚基对馒头评分指标贡献普遍较小,属于劣质亚基。     

Influence of puroindoline alleles on milling performance and qualities of Chinese noodles,steamed bread and pan bread in spring wheats

Two trials with a total of 75 spring bread wheat cultivars and advanced lines, were used to evaluate single kernel characterization system hardness, puroindoline alleles, milling yield, flour ash content, flour colour, and end-use qualities for Chinese noodles, steamed bread and pan bread. The results indicated that all International Maize and Wheat Improvement Center hard wheat lines surveyed were Pina-D1b genotype, whereas Pinb-D1b was the most common allele in the remaining cultivars. Genotypes with Pinb-D1b possess significantly lower flour ash content and higher milling yield than those of genotypes with Pina-D1b. For steamed bread, mean scores for loaf volume, crumb colour, width, structure and total score of Pinb-D1b genotypes were significantly higher than those of genotypes with Pina-D1b and wild type. For Chinese fresh white noodles, means for noodle a*, colour score, viscoelasticity and total score with Pinb-D1b were significantly higher than those of Pina-D1b and wild type. Means of loaf volume, texture and total score for Pinb-D1b genotypes were significantly higher than those of Pina-D1b genotypes. This study further illustrated the superiority of the Pinb-D1b allele on milling and processing qualities for various end products and provides useful information for wheat quality improvement.     

低筋小麦配粉及其对加工品质的影响

为改良湿面筋含量较高、面筋指数和稳定时间较低的这一类型小麦的加工品质,选择这三个指标相差较大的三个小麦品种为材料进行配粉,将湿面筋含量较高、面筋指数和稳定时间较低的小麦品种郑麦618的面粉按照0、20%、40%、60%、80%和100%比例分别与面筋指数和稳定时间较高的小麦品种新麦26或郑麦7698的面粉混合,组成不同类型的配粉,对其湿面筋含量、面筋指数、沉淀指数、面团流变学特性、淀粉RVA糊化特性以及面条和馒头的加工品质进行了比较。结果表明,当两个原粉被测指标数值差异显著时,配粉的湿面筋含量、面团流变学特征参数、峰值粘度、最低粘度和最终粘度均随着原粉数值较大一方添加比例的增加而增加。当两个原粉被测指标数值差异不显著时,配粉被测指标的数值会出现大于或小于原粉的现象,比如面筋指数、延伸性和沉淀指数;但衰减值和糊化温度不符合此规律,衰减值更接近于数值较高的原粉,糊化温度更接近于数值较低的原粉。相关性分析表明,面条总分与峰值粘度、最低粘度、衰减值呈正相关,与面团流变学特性参数呈负相关,相关系数较小;馒头总分与面筋指数、沉淀指数、形成时间、稳定时间、能量、拉伸阻力、延伸性和最大拉伸阻力呈极显著负相关,与淀粉糊化各特征值相关性不显著。上述结果证实,优质面条粉和馒头粉均不需要面筋质量过高,优质面条粉的湿面筋含量为30.3%～32.2%,面筋指数为75.2～81.4,稳定时间为4.5～7.2 min,最高粘度为2 330～2 468 cP,最低粘度为1 504～1 607 cP;优质馒头粉的湿面筋含量为30.2%～32.0%,面筋指数为70.8～81.4,稳定时间为3.5～9.1 min。面条和馒头评分结果表明,湿面筋含量较高（30%以上）,面筋指数低的这一类型的小麦可以通过搭配面筋指数较高的小麦来改良其加工 品质。