Preparation And Toxicological Assessment Of Starch Phosphate Monoester

Nature starch is a kind of reproducible resources, and it is the product of plants' photosynthesis. It can be extensively used both in life-activity and in industrial production because of the attributes of nature starch. But there are many deficiencies that it is hard to dissolve in cold water, easy to dehydrate, bad film-forming, low shear resistance and weak stability, etc. So it is necessary to modify the nature starch's attributes to make it suitable to production.Before and after the corn starch was modified by phosphate, the physical and chemical properties such as paste transparency, retrogradation, freeze-thaw stability , viscosity, solubility, and swelling power were studied. According to the requirements of The Toxicological Evaluation Procedure and Method of Food Safety, the acute toxicity test and the genetic toxicity test were carried out in starch phosphate monoester(SPM). At last, the SPM was added to set-style yoghourt, and the qualities of the yoghourt were studied.The degree of substitution (DS) of the SPM had been confirmed to be 0.0138±0.0001. Infrared spectrometry showed that there were peaks at the corresponding area, which indicated that the corn starch had undoubtedly introduced the groups of P=O and P-O-C.The paste's transparency of the SPM was 4.8 times of that of the nature starch. The freeze-thaw stability of the nature starch had been improved greatly. The starch's solubility and dilating capability had increased by 6.5 times and 1.8 times respectively after being modified. And the viscosity of the starch had been enhanced much, and fell sharply with the accretion of the shearing rate, which showed the characters of pseudoplastic fluid.Acute Toxicity Test: No visible symptom was observed and no death occurred in mice administrated orally with SPM during the acute toxicity experiment. The medium lethal dose of SPM on mice was more than 10.00g/kg body weight, which indicated there was actually no toxicity according to the standard of toxicity grade classification.Genotoxicology: In Ames test with plate infiltration, SPM showed no mutagenic effects. In mice erythrocyte micronucleus test, no significant difference was observed between SPM treatment groups and negative control group both in the rate of micronucleus in polychromatic erythrocytes(PEC) and the ratio of PEC to mature erythrocyte, which also implied that SPM had no mutagenic effects. Mice sperm malformation test showed that the abnormal sperm rate in treatment group was not different significantly from control group, indicating SPM is of no genetic toxicity.At last, the application of SPM in the yoghourt was discussed. When addition volume of starch was 0.2～0.5%, SPM showed very good effects.