In this study, flaxseed gum (FG) was extracted using hot water extraction and ultrasonic-assisted extraction. The yield, molecular weight distribution, monosaccharide composition, structure, and rheological properties of FG were analyzed. The FG yield (9.18) achieved using ultrasound-assisted extraction (this sample was labeled as UAE) was higher than the yield (7.16) achieved with hot water extraction (this sample was labeled as HWE). The polydispersity, monosaccharide composition, and characteristic absorption peaks of the UAE were similar to that of the HWE. However, the UAE had a lower molecular weight and looser structure than the HWE. Moreover, zeta potential measurements indicated that the UAE exhibited better stability. An analysis of the rheological properties showed that the viscosity of the UAE was lower. Thus, the UAE had an effectively better yield of FG, preliminarily modified structure, and rheological properties, and provided a theoretical basis for its application in food processing.
Keywords: flaxseed gum; rheological properties; structural properties; ultrasound-assisted extraction.