黄秋葵果胶理化特性的研究

Physicochemical Properties of Okra Pectin

以商品柑橘果胶为对照,研究黄秋葵果胶的理化特性及果胶质量浓度、加热温度、pH值、蔗糖质量浓度和CaCl2质量浓度等因素对黄秋葵果胶黏度的影响。结果表明:黄秋葵果胶总半乳糖醛酸含量为86.68%,酯化度为75.45%,溶解度为82%,pH值为4.63,属于弱酸性高酯果胶;黄秋葵果胶的黏度随着加热时间的延长而下降,但其热稳定性优于商品柑橘果胶;黄秋葵果胶的黏度与其质量浓度、蔗糖质量浓度均成正相关,与加热温度成负相关,而随pH值、CaCl2质量浓度的增大呈先上升后下降的趋势,表现出一般果胶的黏度特性。黄秋葵果胶的黏度及热稳定性能优于商品柑橘果胶,是一种优质果胶。

Using commercial citrus pectin as control for comparison, the physicochemical properties of okra pectin and the impact of pectin concentration, temperature, pH, sucrose concentration, calcium chloride concentration and other factors on the viscosity of okra pectin were studied. The results showed that the total galacturonic acid of okra pectin was 86.68%, esterification degree was 75.45%, solubility was 82%, and pH was 4.63. It was a weakly acidic and high methoxyl pectin. Its viscosity gradually decreased with increasing heating time, but its heat stability was better than that of commercial citrus pectin. The viscosity of okra pectin was positively correlated with its concentration and sucrose concentration but negatively correlated with temperature, displayed an initial increase and a subsequent decrease with increasing pH and calcium chloride concentration, and showed the general viscosity properties of pectin. The viscosity and heat stability of okra pectin were superior to those of commercial citrus pectin, and thus it was a kind of pectin with high quality.