Abstract: ‘Daohuaxiang 2’, ‘Liaoxing’ and ‘Yanfeng’ rice stored at 4, 30, and 70 ℃ were selected to investigate the effects of storage temperature on the functional properties of rice protein like protein solubility, water-holding capacity, oil-holding capacity, foaming properties, and emulsifying properties. The results showed that for each storage temperature, the water-holding capacity and foaming activity of rice protein generally decreased, while the oil-holding capacity generally increased with storage time. The foam stability of ‘Daohuaxiang 2’ and ‘Liaoxing’ rice proteins increased generally during storage. However, ‘Yanfeng’ rice protein showed a downward trend. During storage at 4 ℃, the emulsion stability of all three rice proteins decreased. The solubility and emulsifying activity of ‘Daohuaxiang 2’ and ‘Liaoxing’ proteins showed a downward trend, while those of ‘Yanfeng’ rice protein increased significantly (P < 0.05). The solubility of all three rice proteins decreased, while the emulsifying activity and emulsion stability increased significantly during storage at 30 ℃ (P < 0.05). During storage at 70 ℃, the solubility of all three rice proteins and the emulsion stability of ‘Liaoxing’ rice protein decreased significantly (P < 0.05), while the emulsifying activity of ‘Daohuaxiang 2’ rice protein showed an overall upward trend. Collectively, The functional properties of proteins in the three rice cultivars changed significantly during storage at different temperatures.

Key words: rice; storage; protein; functional properties