高温酸解结合酶法改性制备高品质抗性糊精

Thermal-acid treatment combined with enzymatic modification for high-quality resistant dextrin preparation

抗性糊精因其良好的加工性能与生理功效被广泛应用于各类食品中,但是目前仍存在产品得率相对较低且抗消化性不高等问题。研究者采用高温酸解结合酶法改性的方法制备高品质抗性糊精,优化了工艺条件并分析了不同淀粉酶改性样品的理化性质。结果表明,以玉米淀粉为原料制备抗性糊精相比于复配淀粉具有更高得率,最优反应条件为盐酸浓度0.2%(w/w)、酸解温度170℃、酸解时间2h。相比于淀粉分支酶,采用环糊精葡萄糖基转移酶进行改性处理的作用效果最佳,在4U/g的加酶量下改性12h,所得抗性糊精产率为67.23%。分子量分析和微观形态观察显示,改性后的样品由于糖苷键的变化以及环糊精的产生,形成了更加致密的分子结构,从而阻碍了酶的作用,可能是导致抗消化性提升的主要原因。本研究的成果能够为抗性糊精的高效制备提供新的思路和理论指导。

In this study,high-quality resistant dextrin was prepared by thermal-acid hydrolysis combined with enzymatic modification,and the technological conditions were optimized. The results showed that the yield of resistant dextrin prepared from corn starch was higher than that of compound starch. The optimal reaction conditions were hydrochloric acid concentration 0.2%(w/w),acidolysis temperature 170℃ and acidolysis time 2h. Compared with glucan branching enzyme,the effect of modification with cyclodextrin glucosyltransferase was the best. After being modified by 4U/g cyclodextrin glycosyltransferase for 12h,the yield of resistant dextrin reached up to 67.23%. The molecular size analysis and microstructure observation indicated that the modified samples formed a more compact molecular structure due to the change of glycosidic bond and the production of cyclodextrin,thus hindering the action of enzyme might be the main reason for the improvement of anti-digestibility. This research can provide a new idea and theoretical guidance for the effective preparation of resistant dextrin.