Study on the Properties and Structure of Rice Starch-Monoglyceride Complexs

To slow down the aging of rice starch during food processing, rice starch-monoglyceride complexes were prepared by heating pasting method, and the effects of three monoglycerides, glycerol monolaurate(GML), glycerol monopalmitate (GMP) and glycerol monostearate (GMS), on the physicochemical and structural properties of the complexes were investigated. The pasting properties, thermal properties, short-range ordering and crystalline structure of the complexes were determined by RVA, DSC, FTIR and XRD. The results showed that different monoglycerides had significant effects on the complex index (P<0.05), and the complex index was GMP>GMS>GML. The solubility, precipitation rate, regeneration value and short-range orderliness of the complexes were significantly lower compared with the original rice starch (P<0.05), and there were also significant differences between the complexes (P<0.05). Among them, rice starch-glycerol monopalmitate had the lowest precipitation rate, regeneration value and short-range orderliness of 25.58%, 281.7 cP and 0.58, respectively. Differential scanning calorimetry and X-ray diffraction analysis revealed that the starch changed from A-type crystalline structure to V-type crystalline structure after compounding with monoglycerides. The above results indicated that the addition of monoglycerides could retard starch aging to some extent, and the rice starch-glycerol monopalmitate complexes were more effective in inhibiting starch aging.