In order to investigate the effects of different preparation methods on Semen coicis resistant starch, the structural properties and prebiotic effects of autoclaving treatment-purified S. coicis resistant starch (GP-SRS3), ultrasonic-autoclaving treatment-purified S. coicis resistant starch (UP-SRS3), enzyme-autoclaving treatment-purified S. coicis resistant starch (EP-SRS3) and microwave-moisture treatment-purified S. coicis resistant starch (MP-SRS3) were studied compared to high-amylose maize starch (HAMS). Fourier transform infrared spectroscopy and Solid-state 13C NMR spectroscopy showed all of SRS3 displayed B-type crystallite structure, furthermore, MP-SRS3 and UP-SRS3 showed higher degree of ordered structure and degree of double helical structure compared to other samples. Field emission scanning electron microscopy showed MP-SRS3 displayed deeply layered strips and UP-SRS3 exhibited some cavities. Moreover, S. coicis resistant starch could promote the growth of Bifidobacteria adolescentis better compared to high-amylose maize starch, among these samples. MP-SRS3 exhibited best prebiotic effect, which was possible attributed to its rough surface and double helix structure. B. adolescentis displayed a higher survival rate to the simulated gastrointestinal tract environment in SRS3 medium than that in high-amylose maize starch medium, especially MP-SRS3 and UP-SRS3, which partly contributed to its strips and cavities. Overall, MP-SRS3 could be regarded as a potential prebiotic to promote the growth of B. adolescentis for its structural trait.
Keywords: Bifidobacteria adolescentis; Preparation method; Semen coicis resistant starch; Structural characteristics.
Copyright © 2017. Published by Elsevier B.V.