Effect Of Soy Protein Isolate On The Sensory Quality Of Milk Cheese

In this study,fresh milk as raw material,direct investment type mixed lactic acid as the main starter cultures,propionic acid bacillus fee type as the secondary starter cultures to make two kinds of cheese,stomatal cheese and non-porous blend cheese.In the mixed cheese added different ratio of soybean protein isolated to explore the influence on its sensory quality.In cheese ripening process,a series of parameters of cheese quality were detected,and the content of protein in cheese was detected by electrophoresis analysis.Detecting its amino acid quantity timely,when the two types of cheese completely mature.Collecting the volatile compounds in two kinds of milk cheese by micro extraction technology.In order to effectively collect the aroma components and their contents in milk cheese,the gas phase mass spectrometry can be used in the experiment.At the end of the experiment,the effect of the incorporation of soy protein isolate on the sensory quality of milk cheese was explored by combining the experimental data with the personal identification.1.Detecting the cheese quality parameters of adding soybean protein isolated,the results showed that the water holding capacity of milk cheese could be improved under the action of soy protein isolate.Cheese hardness and chewing ability decreased with the increase of soybean protein content,while the elasticity and coagulation of cheese had no significant change.Through the experimental data,it can be known that in two kinds of milk cheese,the water content of cheese and the content of soy protein isolate are positively correlated,while the hardness,the degree of chewing and the content of soy protein isolate are negatively correlated.2.Electrophoresis analysis data showed that the protein molecules mixed cheese containing two molecular segments(35Da,53Da),their moisture content and cheese chewing and hardness,have very high relevance.In two kinds of cheese,the two protein molecules were negatively correlated with the hardness and the degree of chewing,but the water content of cheese was positively correlated.3.Micro extraction and gas chromatography mass spectrometry showed that the flavor substance is given priority to with acids,and esters are the second.The incorporation of soy protein isolate can significantly reduce the content and type of the acids,but the relative content of ketone substance increased significantly in the milk cheese,when excessive mixed with soybean protein isolated and inhibiting the production of ketone substance,When the doping amount of protein was 4%,the smell of milk cheese is greatly reduced,more strong milk fragrance.4.Through the senses come to the conclusion,when the soybean protein content is greater than 4%,the milk cheese taste more and more rough,and the milk fragrant decrease,the bean flavor increases.Comprehensive consideration,in order to get a good taste of milk cheese,protein content should be controlled at 4%.Through the analysis of many related parameters,analyzed the influence of soybean protein on the quality of cheese,by gel electrophoresis method,studied the inner correlation between texture of cheese and soybean protein isolated.Using the method of solid phase microextraction gas phase mass spectrometry instrument,studied the improvement of cheese flavor added the soybean protein isolated.Finally,through the analysis of the cheese senses,forming an evaluation system and ultimately determined the best proportion of soy protein isolate in the milk cheese.