马铃薯抗性淀粉消化前后的益生作用与结构变化

制备与纯化得到马铃薯抗性淀粉及消化抗性淀粉，研究其益生作用与结构变化。结果表明：马铃薯抗性淀粉及消化抗性淀粉对双歧杆菌和乳酸杆菌都有显著的增殖作用，对大肠杆菌和产气荚膜梭菌有强抑制作用，对粪肠球菌、梭状杆菌、兼性细菌没有影响；它们的发酵液总酸度增大，说明它们能被肠道益生菌发酵利用；马铃薯抗性淀粉经消化处理后比表面积增加，经发酵后比表面积更大；马铃薯抗性淀粉的平均聚合度较之原淀粉显著变小，马铃薯抗性淀粉或消化抗性淀粉发酵后的平均聚合度降低；马铃薯抗性淀粉经消化前后的晶型均为B型，其抗性淀粉及消化抗性淀粉发酵后的晶型都转变为A型，微晶度、亚微晶度及总结晶度较之发酵前都明显降低。

Probiotic Functions and Structural Changes of Potato Resistant Starch before and after Digestion

Potato resistant starches before and after in vitro digestion were made and purified. Their probiotic functions
and structural changes were intensively studied. The results demonstrated that the undigested and digested resistant
starches had good proliferative effects on bifidobacterium and lactobacillus, but inhibitory effects on Escherichia coli
and Clostridium perfringens, and no influence on Enterococcus faecalis, Corynebacterium fusifome or facultative bacteria.
The increase in total acidity after fermentation demonstrated that both these resistant starches could be utilized by intestinal
probiotics. After digestion, the resistant starch had increased specific surface area, which was further increased after in vitro
anaerobic fermentation. In comparison with the native starch, average degree of polymerization of the resistant starch was
decreased significantly and along with the digested resistant starch, was further reduced after fermentation. Both the resistant
starch and its digestion product in vitro were type-B crystals. After fermentation, the crystal type became type A, and
the degrees of microcrystallization and submicrocrystallization as well as total crystallinity were obviously decreased
compared with those measured before fermentation.