Research On The Effect Of Sous Vide Cooking On The Flavor Characteristics And Quality Of Duck Meat

Duck meat has the characteristics of high protein,low fat and low cholesterol,and is deeply loved by consumers.At present,duck meat products on the market are mainly processed by traditional cooking methods,the product varieties are relatively monotonous and many quality problems are found.With the rapid development of China’s economy and people’s demand for diversified and convenient diet,sous vide cooking products have attracted wide attention.The technology has a broad development prospect because the temperature is lower and can be precisely controlled,and the product’s controllability and stability are improved.With the research object of duck meat,this study analyzes the effects of sous vide cooking conditions and salt pre-curing treatment on the flavor characteristics,physicochemical properties and texture quality of duck meat,also the quality differences of duck meat between sous vide cooking and traditional cooking methods.The result will provide theoretical basis for the development and production application of duck meat products.The specific research results are as follows:（1）The effect of heating temperature and heating time on the quality of duck meat was studied.The optimum cooking conditions of sous vide cooking method were determined by sensory evaluation combined with GC-MS and OAV analysis:heating temperature of 70℃and heating time of 10 h.Under this condition,the samples has the highest scores of fatty aroma and umami taste,lower scores of off-flavor with boiling and duck smell,the highest content of flavor substances,and higher OAVs of characteristic flavor components such as hexanal and nonanal.Through the flavor combination and omission experiments,it was confirmed that the characteristic flavor components of sous-vide duck meat under the optimal cooking conditions were hexanal,octanal,nonanal,cis-4-decenal,decanal,2,4-decanedienal,pentanal,（E）-2-octenal and so on.（2）The effects of salt pre-curing process parameters（salt concentration,curing temperature,curing time）on the flavor characteristics,physicochemical indexes and texture quality of sous vide cooked duck meat was studied by single factor combined with response surface optimization test method.The best curing conditions were obtained as follows:the curing time was 8.h,the curing temperature was 7.5℃,and the salt concentration was 11.7%.Under these conditions,the overall sensory acceptance of duck meat is 8.59,and the duck meat had the best appearance,the moderate content of NaCl.Salt curing treatment can increase the content of odor-active compounds including penatal,heptanal,octanal,（E）-2-nonenal,cis4-decenal,decanal,2,4-decadienal,and the concentration of nucleotides in duck meat significantly improved.（3）To explore the quality differences among sous vide cooking,sous vide combined with microwave cooking and traditional cooking methods（steaming,boiling,microwave,roasting）in duck meat.The sensory evaluation results showed that the meaty flavor of duck meat prepared inboiling,microwave and roasting methodswas relatively higher,the duck meat in sous vide cooking had the highest scores of fatty and umami flavors,the samples in steaming method were rich in juiciness,and the samples in sous vide combined with microwave cooking were higher in kokumi flavor.The characteristic aroma components of duck meat in different processing methods were analyzed by Principal Component Analysis（PCA）.Results indicated that roasting,sous vide cooking,boiling and microwave heating were clustered separately,and the difference was significant.Steaming and the combined heating method were similar and the differences were slight.At the same time,gas chromatography-ion mobility spectrometry（GC-IMS）was used to determine the volatile flavor of duck meat in different processing methods.The "nearest neighbor" fingerprint analysis was carried out by Euclidean distance.Significant differences in volatile components were found from 6 different processing methods.The overall aroma profile of sous vide cooked samples was close to those of microwave.The overall aroma profile of the combined heating samples was close to those of roasting.The total amount of free amino acids in microwave processed duck meat was the highest,and followed by boiled duck samples.The total concentration of the nucleotides in samples prepared with sous vide cooking,steaming,and microwave treatment was higher than others.The quality of different cooking treatment was different.The color and the appearance quality are better.In general,the samples in sous vide cooking had suitable hardness,moderate elasticity,small shear force,high tenderness and relatively good taste.The total content of free amino acid in the 6 different processing methods was not significantly different.The samples in sous vide cooking,steaming,and microwave treatment had relatively higher amounts of nucleotides than other processing groups.Sous vide cooking and sous vide combined with microwave cooking duck meat had moderate brightness,better color and appearance quality,lower hardness,moderate elasticity,better appearance quality and relatively better taste.