Study On The Processing Technology Optimization And Volatile Components In The Stewed Rabbit Legs

As the material, this experiment selects the Rex hind legs. Through single factor experiment, Box-Behnken test and response surface method, the best curing agent, the recipe of the cuting agent and the process parameters of rabbit legs during the curing and marinating time were determined. And this paper discussed the effects of different curing time on the edible quality of the stewed rabbit legs. Headspace solid phase microextraction gas chromatography-mass spectrometry and electronic nose were used to distinguish and analysis volatile compounds of rabbit legs for adding different amount of pepper, different curing time, different sterilization time and different preservation time. The main conclusions are as follows:Through single factor experiment, Box-Behnken test and response surface method, the best formula for curing agents during the process of stewed rabbit legs was determined. The formula of curing agents includes salt (4%), sugar (5%), star anise (0.5%), pepper (3.7%) and pepper (2%); and the formula of halogen preparation includes salt (3%), sugar (5%), pepper (2%), thirteen-apices (0.3%), monosodium glutamate (1%), pepper (0.5%), cinnamon (0.5%), star anise (0.2%), fennel (0.2%) and kaempferol (0.3%), geraniol (0.15%), cumin (0.05%) and sweet fruit, Amomum Tsao Ko 0.3%. The percentage of the curing agents was that of the quality of rabbit legs, and the percentage of halogen preparation was that of the quality of added water. The curing temperature was 4? and the curing time was 36 h. The marinating time was 15 min. And the best sterilization time of the stewed rabbit leg products was 15 min.The curing time of 24 significantly increased the Red degree (a* value) and Yellow degree (b* value) of the rabbit meat (p<0.01). The curing time of 36 significantly reduced the lightness (L* value) of the rabbit meat (p<0.01) while other curing time had no significant impact (p>0.05) on the Yellow degree (b* value), Red degree (a* value) and lightness (L* value). The pH of meat with a curing time of 48 reduced significantly (p<0.01). Drip loss exhibited a downward trend when the curing time became longer, and the curing time of 36 hours significantly reduced the cooking loss (p<0.01). The curing time of 12 hours,36 hours and 48 hours significantly reduced the shearing force of rabbit meat (p<0.01). Curing can change the color of rabbit meat, improve water holding capacity, improve tenderness, and different curing time on the extent of the impact are different.Results of electronic nose showed that rabbit with different curing time can be identified to some extent. GC-MS results showed that the volatile components included 60 species,24,44,43,44,47 were measured in five groups. The main component of pickled processed flavor substances are mainly aldehydes, hydrocarbons and alcohols, and the most was aldehydes. Pickled flavor components of 36 h has the highest total peak area.Results of electronic nose showed that the addition of pepper had a significant impact on the volatile compounds of stewed rabbit. Results of GC-MS show that chromatographic area of aldehydes, acids and ethers decreased first and then increase when increasing the pepper addition levels. The chromatographic area of hydrocarbon derived from lipid oxidation increased first and then decreased with the increase of addition level of pepper. Chromatographic area of some compounds from Strecker degradation of amino acids and Maillard reaction changed unsteadily. Stewed rabbit with different levels of pepper had the similar volatile compound profiles except volatiles from pepper. Pepper changed the proportion and composition of volatile compounds. Compared with the control group, the new volatile compounds of stewed rabbit, including alcohols, ketones and alkanes, were found. This may due to the addition of pepper. Chromatographic area and variety increased with the increase of pepper addition level. The chromatographic variety obtained the most when the addition level of pepper was 0.30%.Results of electronic nose showed that the stewed rabbit leg with different sterilization time can be identified to some extent. For samples with sterilization time of 0 min,10 min,15 min and 20 min, GC-MS identified 54,41,39 and 36 kinds of volatile compounds. The main volatile compounds were hydrocarbons, esters, alcohols, and acids. The relative content of hydrocarbons and esters increased with the increase of sterilization time, and the relative content of alcohols and acids decreased with the increase of the time of sterilization.Electronic nose was able to distinguish the stewed rabbit leg in different preservation time in a certain degree.43,44,43,43 and 45 kinds of volatile components were detected by GC-MS in the control group and the stewed rabbit legs which were preserved in 10 d,20 d,30 d and 40 d. And the volatile compounds included aldehydes, hydrocarbon, ketone, esters, acids, alcohol, ethers and nitrogen compounds. With the extension of storage time, the relative content of aldehydes and esters increased with increasing storage time; the relative contents of hydrocarbons and alcohols decreased with increase of storage time, the relative contents of acids and ethers basically unchanged.