精制对魔芋葡甘聚糖及其与κ-卡拉胶复配凝胶性质的影响

本论文主要研究魔芋葡甘聚糖（Konjac glucomannan，KGM）的精制条件及精制前后的KGM与κ-卡拉胶复配凝胶的理化性质和结构表征，并进一步解析KGM的理化性质与其复配体系凝胶特性之间的相关性。结果表明，KGM的最佳精制条件为:乙醇浓度为60%，溶胀时间为2 h，溶胀温度为50 ℃；在此精制条件下的KGM的葡甘聚糖含量、粘度、亮度和白度分别增加了34.43%、128.55%、17.94%和28.29%，其与κ-卡拉胶复配体系的凝胶强度、硬度、咀嚼性和胶着性分别显著提高了47.39%、60.47%、55.44%和45.87%（P < 0.05），复配体系的氢键作用力增强，凝胶网络结构更加平滑紧密；相关性分析结果表明，精制后KGM的葡甘聚糖含量、粘度、色泽、气味是提高复配体系凝胶特性等品质的关键因素。本论文为开发高凝胶强度的KGM与卡拉胶复配凝胶的研究提供了一种高效简单的精制KGM的方法，并为后续精制KGM的工业化生产奠定了理论基础。

Effects of Refining on Konjac Glucomannan and Gel Properties of Its Blend with κ-Carrageenan

Refined conditions of konjac glucomannan (KGM), physicochemical properties and structural characterization of KGM before and after refining and its blend with κ-carrageenan were explored in this study. Furthermore, the correlation between physicochemical properties of KGM and gel properties of the blend was also determined. The result showed that refined conditions of KGM were as follows: Refined ethanol concentration 60%, swelling time 2 h, swelling temperature 50 ℃. With this treatment, the glucomannan content, viscosity, brightness and whiteness of KGM were increased by 34.43%, 128.55%, 17.94% and 28.29%, respectively. Gel strength, hardness, chewiness and gumminess of its blend with κ-carrageenan were significantly increased by 47.39%, 60.47%, 55.44%, and 45.87%（P < 0.05）, respectively. The best gel properties of the blend were obtained with the enhanced hydrogen bond force, smoother and tighter gel network structure. In addition, physicochemical properties of KGM e.g. glucomannan content, viscosity, color and flavor were considered to be the key factors to improve quality of the blend gel. This study could provide an efficient and simple refined method for development of KGM and carrageenan blend with high gel strength, and lay a theoretical foundation for the industrial production of refined KGM in future.