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Anthocyanins and polysaccharides interaction on gut barrier function
thesisposted on 18.10.2021, 14:46 by Wenyi FuWenyi Fu
Anthocyanin-containing foods are beneficial against chronic diseases. Anthocyanins exist as acylated and complexed with other macronutrients such as carbohydrates and proteins in the food matrix. Isolated anthocyanins are unstable and can be easily destabilized by environmental factors (pH, light, temperature). Furthermore, the colonic concentration of isolated anthocyanins is low compared to when in a food matrix. Complexation is a technique used to stabilize anthocyanins. This study aims to investigate which polysaccharides can stabilize the isolated anthocyanins from purple potatoes and enhance the colonic concentration of anthocyanins via complexation. The health benefits of anthocyanin-polysaccharide complexes were also evaluated in vivo. The different polysaccharides used were pectin, inulin, starch, cellulose, and their mixture in equal proportions. Pectin exhibited the best binding capacity with anthocyanins (anthocyanin-pectin complex; APC).
APC retained more anthocyanins compared to other complexes after the simulated upper GI digestion. The electrostatic interaction of APC quantified by zeta potential showed that anthocyanins were positively charged, and pectin was slightly negatively charged under pH 2.0 condition. The increased particle size of APC was observed indicating the agglomeration between particles. The physical surface structure of APC was changed after complexation compared to APM (anthocyanin-pectin mixture) as observed by SEM. The stability of anthocyanins in APC was better at pH 3, 5 and 7 and showed higher temperature tolerance than isolated anthocyanins. Furthermore, APC significantly decreased LPS-induced increase in gut permeability in Caco-2 cell model. APC restored the gut barrier function in vivo by reducing gut permeability and increasing mucus thickness in a DSS-induced colitis mouse model. APC also increased the total short-chain fatty acids especially butyrate concentration. In conclusion, APC enhanced the stability of isolated anthocyanins and improved the gut barrier function compared to isolated anthocyanins.