Preparation of Rice Starch Malate and Its Improvement on the Quality Characteristics of Noodles

In order to investigate the effects of different degrees of substitution (DS) on physicochemical properties of rice starch malate and on the quality of noodles, rice starch malate with different degrees of substitution (DS=0~0.603) was prepared. The solubility, swelling, gelatinization and rheological properties of rice starch malate were investigated, as well as its improvement effect on the cooking characteristics, texture characteristics and sensory characteristics of noodles. The results indicated that a new absorption peak appeared at a spectral wavenumber of approximately 1720 cm⁻¹ on the infrared spectrum curve of malic acid starch esters. After esterification, the solubility of starch significantly increased (P<0.05), while the swelling property decreased. The results of gelatinization and rheological experiments showed that the addition of low-substituted starch (DS=0.141~0.442) significantly reduced (P<0.05) the peak viscosity, decreased the storage modulus G' and loss modulus G" of malic acid starch esters, while the addition of highly substituted starch (DS=0.603) was not conducive to improving the gelatinization and rheological properties of malic acid starch esters. Correlation analysis was used to comprehensively analyze the relationship between some physicochemical properties of malic acid starch esters (solubility, swelling, and gelatinization characteristics) and the quality of noodles (cooking characteristics, texture characteristics, and sensory characteristics). Rice starch malate could significantly enhance the overall quality of noodles. In this experiment, the best noodle quality was obtained when the degree of substitution was 0.442 for wheat flour preparation.