Studies On Fat Replacer From Oat Bran

The hydrocolloidal compositions separated from oat bran displays high viscosity, good holding water capacity and smooth in texture. These compositions are rich in soluble fiber, principallyβ-glucan. The hydrocolloidal products displays the properties of coconut cream, butter, palm oil and some saturated fat, and is useful for the texture to substitute partial fat in the food system. There are many researches about oat bran or oatβ-glucan used as fat replacers in Western sausage, cheese, meatballs, mayonnaise, frozen desserts. Good results are received according to compare low fat samples containing oat bran or oatβ-glucan to full fat samples. The aim of this paper is to prepare fat replacer by extracting oat bran hydrocolloid (OBH) from oat bran, and to use the fat replacer to substitute partial fat in ice-cream.Firstly, the making method of fat replacer from oat bran was studied. The main manufacture way of oat bran fat replacer( OBFR) was by extracting the hydrocolloid from oat bran and partially hydrolyzing the starch. The yield of OBFR is 39.3% and theβ-glucan content is 8.8% when the optimum process conditions were as follows: solid-liquid ratio of 1:15, extraction temperature of 80℃, extraction time of 30min, 4.8-6.4u/g enzyme, enzymolysis time of 10min.Drying methods affected the solubility of the product markedly. The solubility of the product made by freeze-drying was better than by spray-drying. Comparing with the OBFR made without enzymolysis, smooth surface was observed in the SEM images of OBFR made by treatment ofα-amylase. More than 90% particle size distribution of OBFR was less than 8.8μm, and average particle size was 4.4μm which meant the product could be used as fat replacer to simulate the mouthfeel of fat.The rheological properties ofβ-glucan, maltodextrin-β-glucan blends and maltodextrin-oat protein blends, and the main ingredients which make up OBFR were studied. The results showed that as the temperature or share rate increased, the viscosities ofβ-glucan at different concentration, maltodextrin-β-glucan blends and maltodextrin-oat protein blends were decreased. 2% concentration ofβ-glucan with maltodextrin or oat protein could develop gelatin. OBFR was a shear-thinning liquid, which could develop weak gelatin at the concentration of 10%, and the viscosity of which decreased significantly as much as 90% when the temperature reached 80℃.OBFR andβ-glucan were used to replace fat in preparation of low-fat ice cream. The overrun, thaw ratio, texture and rheological properties of ice cream were studied. The results of organoleptic investigation and fuzzy mathematical analysis showed that comprehensive scores of the ice cream containing 1% concentration ofβ-glucan or 2% concentration of OBFR were similar with full-fat sample, and the samples containing other different concentration ofβ-glucan or OBFR were acceptable.