Distinctions in structure, rheology, antioxidation, and α-glucosidase inhibitory activity of ß-glucans from different species.

ABSTRACT

To investigate the distinctions between ß-glucans from different species, Lentinula edodes ß-glucan (LG), yeast ß-glucan (YG), and oat ß-glucan (OG) were extracted with hot water and determined as ß-d-glucopyranose form by HPLC and FT-IR analysis. The molecular weight (Mw) of LG, YG, and OG was 670 kDa, 341 kDa, and 66 kDa, respectively. Scanning electron microscopy exhibited different micro surfaces of three ß-glucans and the relative crystallinity of YG was the highest (29.8 %), followed by that of LG (23.2 %) and OG (20.3 %) determined by X-ray diffraction. Congo red analysis and atomic force microscopy showed that LG and YG have triple helical structures. The apparent viscosity, storage modulus (G'), and loss modulus (G") of ß-glucans were increased with the increase of Mw. DPPH·, ABTS+·, HO·, and reducing power assays showed that ß-glucans from different species exhibited different antioxidant activities, and the DPPH· scavenging rate of 2 mg/mL LG reached >80 % higher than that of YG and OG. The α-glucosidase inhibitory activity of OG was better than YG and LG. In summary, ß-glucans from different species have different structures, physicochemical properties, and physiological functions, which provides theoretical evidence for the precise processing and utilization of ß-glucan.