Physicochemical Characterization of a Low-Molecular-Weight Fructooligosaccharide from Chinese Cangshan Garlic (Allium sativum L.)

A novel low-molecular-weight fructooligosaccharide (LMWF) from garlic (Allium sativum) was isolated and identified. The structure and physicochemical properties of the LMWF were determined by chemical and spectroscopic methods, size-exclusion chromatography, atomic force microscopy (AFM), dynamic rheometry, and differential scanning calorimetry (DSC). The results showed that the LMWF was a neo-ketose with a molecular weight of 1770 Da. The LMWF had a (2,1)-linked beta-D-Fruf backbone with (2,6)-linked beta-D-Fruf side chains, and it was mainly composed of fructose. The branch degree was 18.1%, and the intrinsic viscosity was 3.06 mL/g. The spherical particles of the LMWF were observed by AFM, and their size was relatively uniform. With an increase in the water content, the peak temperature (T-p), onset temperature (T-o), and endset temperature (T-c) increased, while the gelatinization enthalpy (Delta H-gel) decreased. The LMVVF was more stable at a water content of 10%.