氧化魔芋葡甘露聚糖对脱乙酰魔芋葡甘露聚糖凝胶特性的影响

Effect of oxidized konjac glucomannan on gel properties of deacetylated konjac glucomannan

将氧化魔芋葡甘露聚糖(oxidized konjac glucomannan,OKGM)与脱乙酰魔芋葡甘露聚糖(deacetylated konjac glucomannan,DKGM)共混制备复合凝胶(D、D-K、D-O-30、D-O-60、D-O-90、D-O-120),探讨不同氧化程度OKGM对DKGM基凝胶的持水性、凝胶强度、溶胀率、冻融稳定性、质构特性和流变学特性等凝胶特性的影响。结果表明,与空白组(D组)相比,OKGM能降低凝胶的白度,提高凝胶的溶胀率和冻融稳定性;D-K和D-O-30组的凝胶强度比D组低,而D-O-60、D-O-90和D-O-120组的凝胶强度高于D组;OKGM能降低凝胶的硬度,D-O-30、D-O-60、D-O-90和D-O-120组高于D组和D-K组的弹性,D-O-30组的咀嚼性最小;动态流变表明,复合凝胶是弱凝胶;红外光谱分析表明,OKGM会改变体系氢键的作用强度;经扫描电镜观察发现,OKGM能缩小凝胶网络孔洞大小和缩短片层距离。综上,可通过添加氧化修饰的魔芋葡甘露聚糖调节DKGM凝胶的性能,以适应其在食品生产中的应用。

Composite gels(D,D-K,D-O-30,D-O-60,D-O-90,D-O-120) were prepared by blending oxidized konjac glucomannan(OKGM) with deacetylated konjac glucomannan(DKGM).The effects of different oxidation levels of OKGM on the gel properties such as water holding capacity,gel strength,swelling rate,freeze-thaw stability,and textural and rheological properties of DKGM-based gels were investigated.Compared with the control group(group D),OKGM addition reduced the whiteness but improved the swelling rate and freeze-thaw stability of the composite gels.The gel strength of the D-K and D-O-30 groups was lower than that of the D group,while the gel strength of the D-O-60,D-O-90 and D-O-120 groups was higher than that of the D group.OKGM reduced the hardness of the composite gels.D-O-30,D-O-60,D-O-90 and D-O-120 groups were more elastic than the D and D-K groups.The chewiness of the D-O-30 group was the least.Dynamic rheology showed that the composite gels were weak gels.The results of the infrared spectroscopy showed that OKGM addition changed the strength of hydrogen bonds in the system.According to the scanning electron microscope,OKGM addition reduced the pore size of the gel network and shortened the distance between the lamellae.In conclusion,the properties of DKGM gel were adjusted by OKGM addition for adapting its application in food production.