Study On Making Fat Mimetic With Corn Starch

Fat mimetic can imitate fat physical and organic properties when used in low-fat foods without high calorie They satisfied consumers with both delicious foods and health It was investigated in the study based on rheology that made fat mimetic with corn starch by acidic hydrolysis and enzyme hydrolysis respectively , and applied them in low-fat mayonnaise to imitate full-fat mayonnaise through adjusting rheological properties.Corn starch was hydrolyzed with acid. The optimum technological parameters were 80% alcohol , 6%hydrochloric acid , 5 hours of reacting time and 80C of reacting temperature The starch hydrolyzing rate was 27.5%, and the average diameter of starch granule was about 5 i.~ m remaining crystalline form.Puzyme was selected from four kinds of hydrolytic enzymes using SEM . Mediate temperature a -amylase (95 57U/g) hydrolyzing of starch provided porous or cavernous granule surface readily discernible, while the size changed little ; it was hardly no change on granule after hydrolyzed by P -amylase (52 13U/g) and gucoamylase(5597U/g) ; but hydrolyzed by Puzyme(gucoamylase 9403U/g+pullulanasel5000U/g) granule size obviously reduced with undistinguished hole . The quadratic rotary combination design was used to find out the optimal hydrolyzing condition , whose result were pH4.3 , 60 C (reaction temperature) , 10% (starch concentration) , 2m1/l OOg (starch)(enzyme concentration) , 12 hours (reaction time ) . The starch hydrolytic rate was 38.32% , and the average diameter of starch granule was about 3 i?m , which exhibited crystallinity characteristic as determined by X-ray.Applied in low-fat mayonnaise . The full-fat rheological model conform to the Bingham formula: T-T fl B?S . The removal rate of fat was determined as 60%. considering viscosity change combined with sensory evaluation . The removal of fat from mayonnaise affected its stability and rheological properties, so we used the three factors orthogonal design to find out the optimal combination of technological parameters were 3% agar, 1: 6 as the rate ~f starch to water, 4% emulsifier. The stability was 94.97% . 2% Xamthan Gum was added which made low-fat and full-fat mayonnaise have similar physical properties . After 20 times freeze-thaw cycles , there was a little separated water in 18 times cycles , which proved it to nave excellent freeze-thaw stability.Postgraduate:Cai Chun guangMajor:Food science Tutor : vice-prof.Ma Ying...