| The study and application of fat replacers have been developed deeply overseas, but the study level of fat replacers in our country remains mainly in the stage of research, with little application. This study aimed at preparing a whey protein-based fat replacer, of which90%particle diameter were lower than10μm. This fat replacer was called particulate protein gel fat replacer (FR).In this paper, whey protein concentrate (WPC80) was used as raw material. The method of preparation of fat replacer FR was determined by single factor experiments and orthogonal experiment. The method of preparation of FR was as follows:the concentration of WPC80was100mg/mL, the pH was7.0, the concentration of anhydrous calcium chloride was5mg/mL, and the concentration of xanthan gum was3mg/mL. This protein solution was heated at80℃for30min (without mixing), cooled in the ice-bath immediately and pelletized for15min, then the fat replacer FR was prepared.The characteristics of commercial fat replacer60MP, raw materials WPC80, WPI90and FR included emulsibility, emulsion stability, creaming stability, solubility, and thermal stability were measured respectively. The results showed that the solubility and thermal stability of WPC80were decreased by denaturation of heat treatment, the emulsibility, emulsion stability and creaming stability of WPC80were increased by denaturation of heat treatment. The product FR had stronger effectiveness of emulsifier than WPC80.The low fat Stirred yogurt was prepared by60MP, WPC80, FR separately at different substitution rates of fat. The substitution rates of fat were0%,25%,50%,75%and100%. The determination of the syneresis rate, apparent viscosity, texture and the sensory evaluation were conducted. The conclusions were as follows:in the low fat stirred yogurt, relativant to fullfat and nonfat contrast, the syneresis rate of low fat yogurt which contained FR as fat replacer decreased significantly (P<0.01) and the apparent viscosity increased significantly (P<0.01). The result of sensory evaluation showed that:the firmness and consistency of low fat yogurt increased significantly (P<0.01). When fat substitution rate of FR reached100%, the sensory evaluation score of mouth feeling texture feature decreased. The optimum substitution rates of fat were75%,25%and75%for60MP, WPC80, FR respectively. FR reached the same level of the external homogeneous product as60MP in the aspect of fat substitute rate. |
