Studies On Fat-mimetic Made Out Of Puraria Lobate Starch

With puraria lobate starch, the optimal condition for preparation of fat-mimetic by carboxymethylation and methylation, the physical properties feasibility in food and security, were investigated in the paper. The results were gained as below.For carboxymethylation, with starch concentration of 12%, the mol ratio of monochloroacetic acid to starch AGU of 0.7 and sodium hydroxide to starch AGU of 1.4, reacting at 45 C for 1.5h, the highest DS was gained as 1.42.For methylation, with ethyl concentration of 30%, the ratio(v/w) of ethyl solvent to starch of 8 and DMS to starch of 0.5 and 30% sodium hydroxide to starch of 0.55, reacting at 50癈 for 1 .Oh, the highest DS was gained as 0.41.Carboxymethyl starch appeared as buff powder, and its granules were more abnormitical than native starch. While methylstarch appeared as ivory-white and half-solid substance. Its granules which conglutinated with one another, were lubricity in the surface, and had no full granules in some places .The coating characteristic of fat-mimetics made by carboxymethylation was not so good as margarine, while those made by methylation was very similar to margarine, and all increasing with the increase of DS . When completely mixed with water, the fat-mimetics produced by carboxymethylation could easily soluble in cold or hot water, while the fat-mimetics produced by methylation had a poor solubility in cold water and a high solubility in hot water. The freeze-thaw stability and water holding capacity of the fat-mimetics produced by both methods were very high.When the fat-mimetics were used to substituted fat in pork sausages, the fat-mimetics produced by carboxymethylation were mixed with water with starch /water ratio of 1: 4. When the fat in pork sausages was substituted with the fat-mimetics made out of carboxymethylation and methylation by 25% and 50%, the quality of fat reduced products had no significant difference from normal products. Among the products made out with the fat-mimetics produced by carboxymethylation, the product made out of carboxymethylated starch with a DS of 0.57 had the best quality, while the product made out of methylated starch with a DS of 0.41 had the best quality among the products made out with the fat-mimetics produced by methylation.The toxicity evaluation experimentation of puraria lobate starch based fat-mimetics showed that acute LDso of carboxymethylation starch-based and methylation starch-based fat-mimetics were higher than 15 000 mg/(kg.d), they could be considered as safe substance .