To explore the impact of the physicochemical properties by different organic acid with heat treatments on konjac glucomannan (KGM), the konjac hydrosol was selected as the research object, and the viscosity, relative molecular mass, rheological behaviors, Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM) under the heat treatment by ascorbic acid, lactic acid, malic acid, citric acid were studied. The results showed that, compared with the control group, the viscosity and relative molecular mass of citric acid decreased significantly in the citric acid group, which were 80.52% and 94.70%, respectively. Moreover, when the shear rate was 12.6 s-1, the apparent viscosity of citric acid treatment decreased by 62.45%, G′ and G″ decreased by 86.52% and 64.62% individually with the angular frequency of 8.58 rad/s. According to FT-IR and SEM, though the acid and heat treatment could destroy its microstructure, occurring the chaotic laminated thin-walled structure, the main chain and the repeat unit structure of KGM was not affected even though the hydrogen bond and glucosidic bond were weakened. Therefore, during the process to KGM, different organic acid can be used to control the rheological behavior and broaden its application scope in food, medical and materials. and in food, medicine and materials.
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