Changes of the main nutritional quality and eating quality in the process of braised pork

The changes of nutritional quality and eating quality of braised pork at the key processing stages,including raw material treatment,cooking wine soaking,frying,stewing,braising,were investigated in order to understand the quality formation of braised pork during processing. The main nutritional quality index,color,texture,and flavor were detected in braised pork during processing by physico- chemical analysis and instrumental analysis. The result showed that the water content in braised pork was decreased,and the protein content had no significant change during the whole processing.The fat content was decreased first then increased and then decreased at the stewing stage.The content of total sugar was increased significantly in the final product.The color of lean meat,fat and skin of braised pork was changed,and L*value in the three parts were significantly decreased( p < 0.05),a*value in three parts was decreased firstly and increased significantly finally( p < 0.05).The b*value of lean meat and the fat part was increased significantly( p < 0.05),while the b*value of the skin part had no significant difference( p > 0.05) in the frond processing points while in the product it was significantly increased( p < 0.05).The results of shear stress and texture analysis showed that the elasticity of lean meat,fat and skin was increased significantly( p < 0.05),while the shear force,hardness were decreased significantly( p < 0.05). Thecohesiveness of lean meat was increased significantly( p < 0.05),and increased in the skin part but not significantly( p > 0.05),and decreased in the fat part.The chewiness of fat part and skin part was significantly decreased( p <0.05),while increased significantly( p < 0.05) in the lean meat. Principal component analysis based on data obtained from the electronic nose showed that expect the second and three,three and four points were different but not significant( p > 0.05),the first three points were significantly different( p < 0.05) with the other processing points.The difference between the fourth processing points with the third,the five and the six processing points was not significantly( p > 0.05),while the other three processing points was significant( p < 0.05),the characteristics of the last 3 processes were similar.