不同离子液体处理对豆渣膳食纤维成分变化及物化特性的影响

Changes in Composition and Physicochemical Properties of Okara Dietary Fiber Treated with Different Ionic Liquid

摘要:

为明析离子液体对豆渣膳食纤维成分及物化特性的影响，从而拓宽豆渣在食品中的应用，以富含水不溶性膳食纤维（IDF）的鲜豆渣为原料，研究不同种类离子液体处理后膳食纤维成分变化和物化特性。结果表明：离子液体处理可以显著提高豆渣中水溶性膳食纤维（SDF）含量，其提高效果随着离子液体阳离子基团的延长而减弱，含乙酸根的离子液体的提高效果优于含氯离子的离子液体。1-乙基-3-甲基咪唑乙酸盐的效果最好，可将豆渣中SDF含量从最初5.97×10-2 g/g提高到0.17 g/g，SDF/IDF比值从0.17提高到0.69。离子液体处理改变了豆渣中SDF和IDF的单糖组成，豆渣的微观结构因溶胀而变形，结晶结构遭到破坏。离子液体处理后，豆渣膳食纤维的持水力增加10%，持油力增加16%。离子液体可作为提高豆渣中SDF含量，改善豆渣膳食纤维水合性质的有效途径。

Abstract:

The aim of this study is to determine the effect of ionic liquids (ILs) on the composition and physicochemical properties of okara dietary fiber and to broaden the application of okara in the food industry. Fresh okara containing rich, insoluble, dietary fiber (IDF) was used as raw material to study the changes in composition and physicochemical properties of dietary fiber treated with different ILs. The results showed that soluble dietary fiber (SDF) content of okara increased significantly with ionic liquid treatment. However, this effect waned with the extension of the cationic groups in the IL. The enhancement effect of ILs with acetate groups was better than that of ILs with chloride ion. In all, the largest increase was observed with 1-ethyl-3-methylimidazolium acetate (EAC), where the okara SDF content increased from 5.97×10-2 g/g to 0.17 g/g and the SDF/IDF ratio increased from 0.17 to 0.69. IL treatment also changed the monosaccharide composition of the SDF and IDF, the okara microstructure was damaged due to swelling, and its crystal structure was destroyed. After IL treatment, the water-holding and oil-holding capacities of okara dietary fiber increased by 10% and 16%, respectively. Therefore, IL treatment is an effective approach to increase the SDF content and improve the hydration properties of okara dietary fiber.