魔芋胶对甘薯淀粉流变学特性及粉条品质的影响

Effect of Konjac Gum on Rheological Properties of Sweet Potato Starch and Qualities of Starch Noodles

摘要:

研究多糖胶对淀粉糊化特性、老化特性、流变学特性及粉条食用品质的影响，为改善粉条品质提供理论指导。该文选择甘薯淀粉为原料，加入不同比例的魔芋胶，通过快速粘度仪（RVA）测定淀粉与魔芋胶复配体系粘度的变化来考察体系的糊化特性；用X衍射仪测定结晶度，评价体系的长期回生情况；通过流变仪考察魔芋胶对淀粉凝胶体系粘弹性的影响；最后评价魔芋胶对粉条食用品质的改善效果。结果表明：魔芋胶能够显著降低甘薯淀粉的糊化温度，提高粘度、崩解值和回生值，显著抑制淀粉的长期回生。甘薯淀粉/魔芋胶复配体系为屈服-假塑性流体，并且随着魔芋胶添加量的增加，屈服应力τ0、稠度系数K增加，流体指数n减小，复配体系有更好的粘弹性。甘薯淀粉和魔芋胶按质量比为8.5:1.5制备的粉条食用品质最佳。

Abstract:

To provide theoretical guidance for improving the qualities of starch noodles, the effect of konjac gum (KGM) on the pasting, retrogradation, rheologicalpropertiesofsweet potato starch (SPS)and the qualities of sweet potato starch noodles were investigated. The viscosity of the mixture of SPS and KGM was assayed by rapid viscosity analysis (RVA) so as to analyse the pasting properties of the mixture system.The crystallinity was measured by X-ray diffractometer to evaluate the long-term retrogradation of the system. The effect of KGM on the viscoelasticity of the system was investigated by rheometer. The effect of KGM on the qualities of starch noodles was evaluated.The results showed thatKGM reduced the pasting temperature, increased the viscosity, breakdown and setback, and inhibited the long-term retrogradation of starch significantly. The complex SPS/KGM was yield-pseudoplasticity system with better viscoelasticity, with the increasing of the proportion of KGM, the yield stress and consistency coefficient increased, while the flow behavior index decreased. Overall, a mixture of sweet potato starch and konjac gum (8.5:1.5 g/g) proved to be the most optimal proportion.