Abstract:

The insoluble dietary fiber(IDF) in Rhodomyrtus tomentosa fruits was prepared by water method and enzymatic modification extraction, respectively. Scanning electron microscopy(SEM), Fourier transform infrared spectrometer(FT-IR), X-ray diffraction(XRD), and other methods were used to characterize their physicochemical characteristics. The inhibitory effects of R. tomentosa fruits IDF at each protein glycation stages as well as the adsorption capacity to advanced glycation end-products(AGE) were evaluated. The results indicate that the IDF prepared by water extraction method(WIDF) presented higher content of water, fat, protein and ash. The extraction yield of R. tomentosa fruits IDF by enzymatic modification extraction method(EIDF) was 67.43%, which was lower than that of water extraction method. The functional groups of IDF prepared by these two methods were similar, whereas the EIDF presented a lower comparative crystallinity at 29.32%. The rough surface, loose structure and holes were observed in EIDF. As the mass concentration of EIDF was 2 g/L, the contents of fructosamine and carbonyl compounds in glycation system were (1.98±0.25) mmol/L and (21.75±1.17) μmol/g, with fluorescence intensity of β-amyloid protein at (5.26±0.14)×10⁶ and AGE inhibitory rate at (18.15±0.73)%, respectively, and the anti-glycation capacity of EIDF was better than that of WIDF. As the concentration of EIDF was 10 g/L, 33.28% of AGE could be adsorbed.

Key words: dietary fiber, enzymatic modification, fructosamine, advanced glycation end product, adsorption