Development Of Soybean Protein Isolated Ice Cream And Investigation Of Its Function

With the development of our living standards, products with nutrition and health care functionhave been warmly welcomed by consumers. Healthy ice cream will become the trend ofdevelopment in ice cream industry. Soy protein isolate, due to their processing character and highnutritional value, has been used in the field of biomaterial.In the study, ice cream was prepared byueing soy protein isolate, skim power, cream, stabilizer and emulsifier, then the functions onprevent osteoporosis and hypolipidemic of SPI ice cream were evaluated.The results and conclusions of the study are as follows:The foaming properties, foam stability, emulsification and emulsion stability of differentvarieties of soybean protein isolates were detected. Then they were used to substitute whole milkpowder at levels of20%~50%to produce ice cream. The results showed that viscosity andhardness of ice cream were increased significantly with the level of substitution increased. Theoverrun value of different varieties of soy protein isolates ice cream was different. The overrunvalue of ice cream increased with the level of substitution of soybean protein isolate Ⅰ increasing,moreover it reduced with the level of substitution of soybean protein isolateⅣ increasing. Thetrends of the melting rate were similar in four varieties of soy protein isolate with the level ofsubstitution increasing, the melting rate increased slightly and then decreased rapidly with theincreasing of substitution. The score of the sensory evaluation increased firstly and then loweredwith the level of substitution. The overrun has no correlation with foaming properties, butpositively related with emulsification in a certain viscosity range by the Pearson correlationanalysis. Ice cream with adding SPIⅠ has the proper viscosity, hardness, high overrun and nosoybean pungent taste, SPIⅠ best suit in application in ice cream.The influence of the preferred soybean protein isolate（SPIⅠ） on the quality characteristicsof ice cream was investigated. The viscosity of ice cream mix increased from563maps to4487.5mpa·s with the increase of soybean protein isolate Ⅲ; the overrun of ice cream increasedfirstly and then lowered, the highest overrun and melt rate are obtained by addition level of3%.The viscosity and hardness increased significantly by addition level of6%, the ice cream wasfound to be bed in expansion rate, melting rate and sensory attributes. The ice cream was found tobe good in properties by addition level of5%; the bubble size and distribution were uniform.The effect of stabilizer (Xanthan gum, carrageenans, LBG, CMC) on the quality of SPI icecream was detected by single-factor tests and mixing experiments when adding5%SPI. The results showed that viscosity, hardness of ice cream were increased significantly; the hardness ofice cream with Xanthan gum was the most among the CMC, LBG and carrageenans. Overrun wasincreased before decreasing with the increasing of the amount of stabilizers, CMC improvedoverrun of ice cream most. The melting rate of different varieties of stabilizer was different. Themelting rate of ice cream increased and then decreased with the increasing of the amount ofXanthan gum, it increased at first and then decreased reduced with the increasing of the amount ofCMC, moreover it decreased with the increasing of the amount of carrageenans and LBG;carrageenans gave the best effect on the melt resistance in contrast with the LBG. The hardness ofthe ice cream with Xanthan gum was the most among the stabilizers, then optimize theformulations of carrageenans, LBG, and CMC using D-optimal mixture design with the index ofconsistency index (K), the optimum proportion of carrageenans, LBG and CMC was1：7.9：3.6byexperiments.The formula of SPI ice cream was optimized. The addition levels of SPI, cream, compoundstabilizer, emulsifier had effect on the properties of ice cream, esprcially the overrun. Theorthogonal experiments of central composite rotatable design results indicated that the effect orderof four factors on the overrun was as follows:SPI＞stabilizer＞emulsifier＞cream. The resultshowed that the optimal formula was5.5%SPI,10%cream,0.06%compound stabilizer,0.11%emulsifier. The actual overrun was respectively41.2%. The overrun of ice cream hadsignificantly positive correlation with consistency index of ice cream mix(r=0.560, P＜0.01).Investigate of function research of SPI ice cream. The bone weight, bone transverse diameter,bone mineral, bone organic matrix and uterus index were increased significantly in osteoporosismice, by taking SPI ice cream. With lowering cholesterol levels, as well as raised levels of HDL bytaking SPI ice cream.The microstructure and thermodynamic characteristics of SPI ice cream were studied. Theresult showed that glass temperature of ice cream with5%SPI from-45.7℃to-40℃.The air isunstable with the adding of SPI, however with decrease of emulsifier air in ice cream becomestable.