高压对食品胶溶液流变特性的影响

 经高压处理后，卡拉胶、琼胶、高甲氧基果胶、海藻酸钠、黄原胶和瓜尔豆胶等六种食品胶溶液的粘度变化不同。卡拉胶和琼胶溶液的粘度显著增加，高甲氧基果胶、海藻酸钠和瓜尔豆胶溶液的粘度变化较小，而黄原胶溶液的粘度明显降低。动态粘弹性测量表明，卡拉胶和琼胶溶液的贮藏模量（G′）在高压处理后明显减小，而且G′变得小于G″，这表明卡拉胶和琼胶溶液的弹性变小。高甲氧基果胶、海藻酸钠和瓜尔豆胶溶液的损耗正切值（tan δ=G″/G′）在处理后几乎没有变化，黄原胶溶液的tan δ略微减小。高压处理后食品胶溶液流变特性的不同变化表明，高压处理对食品胶的影响因其种类、胶分子的结构和胶在水溶液中的构象而异。文中对造成这些变化差异的可能原因进行了探讨。

PRESSURE EFFECT ON RHEOLOGICAL PROPERTIES OF FOOD GUM SOLUTIONS

The rheological properties of food gum solutions(carrageenan,agar,high methoxyl pectin,sodium alginate,xanthan and guar gums)after high pressure treat were investigated.After the treatment,the viscosity of the solutions changes very differently.The viscosity of carrageenan and agar solutions increases,that of high methoxyl pectin,sodium alginate and guar gum solutions dose not change very much,and that of xanthan gum solutions decreases.Experimental results show that the storage moduli(G′)of carrageenan and agar solutions became smaller and their G′ are smaller than their G″ after the treatment.The loss tangents(tan δ=G″/G′)of high methoxyl pectin,sodium alginate and guar gum solutions after the treatment are almost the same as that before the treatment.All the results above indicate that the pressure effects on the solutions depend on gum structures,The possible reasons were discussed in the paper.