Mesona chinensis polysaccharide regulates the gelatinization behavior of rice starch

The Chinese traditional dessert “Black Bean Jelly” is a gelatinous food, formed mainly by the interaction of Mesona chinensis polysaccharide (MCP) and starch. In this study, the changes in rice starch (RS)-MCP composite gels during the gelatinization process were investigated. The results showed that the addition of MCP promoted the gelatinization of starch, leading to a decrease in the pasting temperature of starch, while the gelatinization enthalpy exhibits a trend of initially increasing and then decreasing. Furthermore, MCP increased the particle size and irregularity of starch, with the D50 value and the difference between D [4, 3] and D [3, 2] both increased. Elevated temperatures resulted in an increase in swelling power (SP), causing starch granules to swell and rupture significantly. Additionally, at a constant temperature, an increase in MCP concentration caused the aggregation of starch granules. The binding of MCP to amylose was crucial for gel formation, MCP decreased the content of leached amylose and enhanced the degree of binding between RS and MCP. Gaussian fitting results suggested that the strength of the intermolecular hydrogen bonding between MCP and RS was strengthened with MCP addition. Moreover, MCP promoted the transformation of free water to bound water. This study offers theoretical insights into the formation of MCP-starch-based gel products.