魔芋葡甘聚糖与大豆分离蛋白复合凝胶作用研究

Studies on the Composite Gelation between Konjac Glucomannan and Soybean Protein Isolate

以魔芋葡甘聚糖(KG)与大豆分离蛋白(SPI)作为基材,系统研究两者间的复合凝胶作用保持SPI为2.0％,复合凝胶随KG浓度从0.8％增至2.5％,凝胶强度不断上升;凝胶失水率直线下降;凝胶松弛度也逐渐下降;而粘着性则在KG浓度为1.5％时达最大值。在SPI为0—3.0％范围内,随SPI的增加,复合凝胶粘着性和失水率皆逐渐上升;在6.0％范围内,凝胶松弛度变化较小,此后迅速上升;而凝胶强度则随SPI增加光增强,当SPI为2.0％时达最大值,此后逐渐下降。KG的添加,对复合凝胶颜色无明显影响,凝胶保持浅黄色;而随SPI的添加,凝胶则逐渐由乳白色转为浅黄色、黄色,当SPI>3.0％后,凝胶褐色逐渐加深。根据氯化钠和脲对复合凝胶强度的影响,推断复合凝胶中以氢键作用为主。

A systematic research is conducted on the composite gelation between konjac glucomannan (KG) and soybean protein isolate (SPI) . With SPI concentration kept at 2.0% , when KG increased from 0.8% to2.5% , gel strength also increased continuously; gel dehydration ratio was straight falling; gel relaxation decreased gradually, and when KG at 1.5%, the gel adhesiveness was the strongest. Keeping KG at 1.5%, gel adhesiveness and dehydration ratio both increase with SPI increasing from 0 to 3.0% ; Gel relaxation only showed a little change while SPI below 6.0% , hut if beyond, it would increase rapidly; With SPI increasing, gel strength increased initially, and then reached the maximum at 2.0% , after than decreases gradually. It did not show any effect on gel color with KG increasing, and the gel maintained light yellow. But with SPI increasing, the gel color changed gradually from milky while to light yellow and yellow; after SPI > 3.0% , the gel color gradually become brown. From the effect of sodium chloride and urea on composite gel strength, it can be deduced that hydrogen bonding is the main action in the composite gel system.