Nutritional and consumer acceptance evaluation of soymilk from specialty and conventional soybean cultivars

Abstract

The soymilk is a ready-to-eat, nutritious and naturally cholesterol-free product. Several soybean specialty cultivars were developed in Brazil in order to increase the human consumption of soybean products. The aim of this work was to evaluate the nutritional composition and consumer acceptance of soymilk from three soybean cultivars with special features such as high-protein and isoflavone contents, mild flavor and lipoxygenase-free compared to three conventional ones. The soymilk was obtained after blanching with a bicarbonate solution, grinding, centrifugation and pasteurization. The physicochemical and nutritional evaluation data were analyzed using Analysis of Variance (ANOVA) and Tukey’s test to check differences among means, and the consumer data through cluster analysis and internal preference mapping. The lipoxygenases were inactivated after thermal processing. There were significant differences among soybean cultivars and soymilks related to the protein, isoflavones, oil, and sugar contents and soymilk yield (p < 0.05). The BRS 133 and BRS 284 cultivars and soymilks presented the highest total isoflavone content (p < 0.05). Regarding the overall consumer acceptance, there were significant differences among cultivars (p < 0.05) with means ranging from 5.9 to 6.7 and the lower score was obtained by BRS 267. However, the cluster analysis identified three consumer segments according to preference similarity. The cultivars BRS 284 and BRS 267 reached the highest mean among the consumers of segment 1 (6.8 and 6.7 respectively). The consumers of segment 2 preferred the cultivar without lipoxygenases, BRS 213 (mean of 7.5) while segment 3 preferred the BRS 133 (mean of 7.4). The process of blanching of soybean with bicarbonate solution, grinding with boiling water and pasteurization mitigated the differences between conventional and specialty cultivars and the six cultivars evaluated were suitable for soymilk production.