Regulation mechanism of lotus root juice quality: From the perspective of interaction between cell wall polysaccharides and polyphenols

Lotus root juice contains a large amount of colloidal substances including polysaccharides, which leads to low juice yield and difficulty in clarifying during the juice extraction process. This paper was aimed to explore regulation mechanism of lotus root juice quality from the perspective of interaction between cell wall polysaccharides and poly-phenols by a series of spectroscopic methods. Results indicated that the uniformity of chelating agent soluble polysaccharide (CSP) was high, with the minimum molecular weight of 7.17 × 10⁴ Da. UV, fluorescence spectrum and infrared spectrum showed that there was non-covalent interaction between cell wall polysaccharide and polyphenol through hydrogen bond and hydrophobic interaction. And the specific type of cell wall polysaccharide and metal ions as well as pH values could all influence these interactions. Meanwhile, the interaction could significantly improve antioxidant activity of cell wall polysaccharide (p < 0.05). Finally, the color and stability of simulated lotus root juice were optimal at pH 7 and a ratio of 1:3 for polysaccharides and polyphenols. Our results could provide theoretical basis for deep processing of lotus root products.