海藻酸钠高甲氧基果胶复合体系凝胶特性的研究

Studies on the Gelling Properties of Sodium Alginate-High Methoxyl Pectin System

研究了海藻酸钠 高甲氧基果胶复合体系的凝胶特性及pH值、凝胶温度和时间对其凝胶特性的影响.结果表明:海藻酸钠和高甲氧基果胶具有协同作用,且体系的凝胶强度、持水性、凝固点和融点与两种胶的质量比、胶体总质量分数、pH值、凝胶温度和时间密切相关.随海藻酸钠/果胶质量比增加,体系凝胶强度和凝胶融点增加,并在取得最大值后又下降,而持水性与凝固温度则变化不大;在pH3 0～3 5,体系可形成性能较好的凝胶,而当pH>4 20时,不能凝胶,pH还对凝胶融点有影响,而对凝固点影响不大;随凝胶温度升高,体系凝胶强度显著下降,凝胶融点也下降;在15℃凝胶6h,体系即可形成稳定的凝胶体.

A study on the gelling properties of sodium alginate-high methoxyl pectin systems and the effect of pH, gelling temperature and time on them were conducted. The results showed that sodium alginate could interact with high methoxyl pectin to form gels and the gelling properties such as gel strength, water-holding ability, the melting point and solidifying point of the mixture depended on the factors like the ratio of sodium alginate to pectin, total concentration of polysaccharide, pH value, gelling temperature and time. The gel strength and melting point of the mixture increased with the increase of the ratio of sodium alginate to pectin, and decreased after peaking, while sodium alginate/pectin ratio had little effect on the water-holding ability and solidfying point. At pH 3.0 to 3.5, it formed the gel possessed better properties, but gelling could not occur at pH above 4.20; pH value also affected the melting point of the gel but had no effect on its solidfying point. The gel strength and melting point of the mixture decreased when the gelling temperature increased and gelling could not happen at temperature above 28 ℃. After 6 h at 15 ℃, the two mixture could form firm gel.