Mechanism of bridging and interfering effects of tea polyphenols on starch molecules

The effect of tea polyphenols (TP) on the rice starch (RS) was investigated and the interaction mechanism between TP and RS was further analyzed. TP exhibited a remarkable capacity to affect the processing properties (including the texture property and color) of RS in cold rice cake. Meanwhile, TP exhibited a significant effect on the solubility, swelling power, gelatinization property, rheological property, gel property, and microstructure of RS. Furthermore, according to the molecular dynamics simulation using epigallocatechin gallate (EGCG) and two parallel short-chain glucose (SGS) as a testing model, EGCG could interact with two SGS chains by hydrogen bonds, and could change the SGS-wound form and molecular force (including intra- and intermolecular hydrogen bonds) in heating and cooling period. All results suggested that TP had the obvious effects on starch food by affecting its gelatinization and retrogradation. Practical applications There are many kinds of starch food, which are important energy sources for the human body. However, during the processing and storage periods, the unfavorable changes in the starch property may cause the quality deterioration of starch food, which can affect the taste, nutrition, and sale of starch food. In the present study, tea polyphenols (TP) were used as supplement fortified in starch to affect the color, taste, and quality of starch food, and the action mechanism of molecular interaction was also revealed. The present study suggested that TP showed the potential value to ameliorate the quality of starch food and extended its shelf life during its processing and storage in the food industry.