Breeding Indexes Establishment And Germplasm Determination For Soymilk Flavor Quality In Soybean

It is important to establish the breeding indexes and determinate the germplasm for the soymilkflavor quality in soybean in order to develop some novel soybean cultivars for soymilk. Based on theprevious research on the soymilk processing technology and the flavor sensory evaluation, weestablished a soymilk sensory evaluation method and analyzed the characters of soymilk flavor qualityand other quality traits in70soybean cultivars and lines in this paper. The relationships between thesoymilk flavor quality and other quality traits were also analyzed based on the simple correlation,canonical correlation and stepwise regression analysis in order to screen the breeding index for soymilkin soybean. According to the results of soymilk sensory evaluation, the principal component analysisand cluster analysis were performed in70soybean cultivars in order to screen the cultivars with betterquality of soymilk flavor in soybean, which could support the soybean breeding for soymilk. The mainresults were as follows:1. Establishment of sensory evaluation method for soymilk flavor quality in soybeanA sensory evaluation method for soymilk flavor quality was established, including six of thesensory evaluation indexes with color, aroma, sweetness, thickness, smoothness and coordination of theoverall flavor (COF) in soymilk. Soymilk flavor quality was analyzed in20soybean cultivarsdepending on the method. The results showed that there was significant difference among varieties insoymilk color, coordination of the overall flavor (COF) and thickness, and no significant differenceamong field repeats in soymilk COF, sweetness and thickness, while significant difference among fieldrepeats in soymilk color, aroma and smoothness, which explained that the soymilk flavor wasinfluenced not only by genetic factors, but also by the growing environments. There was the betterevaluation repeatability on soymilk color, sweetness and COF, while soymilk aroma, thickness andsmoothness were greater influenced by assessor and evaluation condition, which explained that asvarious assessors had different responses to personal mood and evaluation condition, and differentsensitivity to the various sensory indexes, in result that the bad repeatability of soymilk aroma,thickness and smoothness was presented in the experiment. Moreover, the small sample concentrationmaybe was another reason for the bad repeatability of soymilk aroma, thickness and smoothness.Therefore, some measures should be taken to improve the repeatability during the sensory evaluation,including enhancing the training of assessor, increasing the number of assessor appropriately,establishing the standard evaluation lab, and adjusting the sample concentration.2. Selection of breeding indexes for soymilk flavor quality in soybeanWe determined the soymilk flavor quality and the main quality traits in70soybean cultivars andlines in order to screen the breeding index for soymilk in soybean. The results showed that there wassignificant positive correlation between COF and other five soymilk evaluation indexes, especially, thesignificant correlation presented in sweetness (r=0.538**) and smoothness (r=0.384**) in soymilk, which explained that soymilk COF can express the merits of soymilk. Therefore, the soymilk COF isthe most important index for evaluation of soymilk in soybean breeding. The results of correlationanalysis and canonical correlation analysis showed that there were many correlations among soymilkflavor quality and quality traits of soybean seeds, especially, soluble solid, oleic acid and linoleic acidwere more important to soymilk flavor quality in soybean quality traits, and influenced COF more.8indexes selected from13quality traits of soybean seeds by stepwise regression analysis, including11S/7S ratio, soluble solid, glycitein, palmitic acid, stearic acid, oleic acid, linoleic acid and linolenicacid. Meanwhile, we established6equations for soymilk flavor quality, which can predicted the soymilkflavor quality by quality traits of soybean seeds.3. Germplasm determination for soymilk flavor quality in soybeanAccording to the results of sensory evaluation,70soybean cultivars and lines were classified into6clusters by principal component analysis and cluster analysis. The soymilk flavor quality from betterto worse was in the list of cluster â…¤, cluster â…¢, cluster â… , cluster â…£, cluster â…¡and cluster â…¥.There were two of lines in cluster â…¤, including Zhongzuo09P-2and Zhongzuo09J-28, which soymilkflavor quality were best; cluster â…¢ contained14of cultivars and lines, which soymilk flavor qualitywere better. We totally obtained16of cultivars and lines with well soymilk flavor quality. Meanwhile,some cultivars with special aroma were determined, which could use for studying the components ofsoymilk aroma.