Influence of O/W emulsion on gelatinization and retrogradation properties of rice starch

Abstract An investigation was conducted into the effects of micro- and nano-emulsion on gelatinization and retrogradation of rice starch (RS). According to the results, the addition of emulsion contributed to the decline in the maximum viscosities, gelatinization enthalpy and a restriction on granular swelling during the gelatinization process of RS, and reduce the final gel strength of RS. During storage at 4 °C of the starch gel, the addition of emulsion was discovered to reduce the gel firmness and water mobility of RS gels during cold storage. The crystallinity of RS was found to be reduced from 11.59% to 6.81% after storage at 4 °C for 14 days. The microstructure of RS gel with emulsion was observed to be denser and more uniform compared with that of RS without emulsion after cold storage. As indicated by the result of starch retrogradation, emulsion was capable to prevent the interactions between starch molecules, retain the compact structure of starch gel, and decline the mobility of starch intra-granular water. These findings suggested that the addition of emulsion inhibited the short- and long-term retrogradation of RS, and promoted the application of emulsion in the starchy foods.