Difference in the adhesion of Bifidobacterium breve to lotus seed resistant starch is attributable to its structural performance conferred by the preparation method.

Resistant starch (RS) is a kind of important carbon source for colonic microorganisms. Its structure-function relationship is helpful to understand the mechanism of dietary nutrition in the body. In this paper, lotus seed resistant starches (LRS) prepared by microwave-power method (MP-LRS3-1 and MP-LRS3-2) and water-bath method (WB-LRS3-1 and WB-LRS3-2) were used to determine the structural changes and establish their nutritional interactions with Bifidobacterium breve. The results showed that four types all formed scale- and gully-like surface microstructures, B-type crystal structures, and lightly variable double helix structures. However, greater diffraction peak intensity was observed of MP-LRS3 at 18° and 19° compared with WB-LRS3, and higher crystallinity and tighter double helix were detected in MP-LRS3-1 than others. Meanwhile, MP-LRS3-1 showed the most effective proliferation promoting capability and highest adhesion value to B. breve. It might be related to specific surface microstructure and crystallinity differences of LRS caused by different preparing methods. There was also a positive correlation between the adhesion and the ability to promote proliferation, and it could be speculated this structural difference makes MP-LRS3-1 having highest adhesion ability and the most proliferative effect. This result can provide theoretical bases for improving the metabolism and probiotic action of RS.