Research On Content Change Of Hexanal And Hexanoic Acid Of Rabbit Meat Under Different Processing Methods And Its Correlation With Fatty Acid Oxidation

Rabbit meat offers excellent nutritional value and is one of the ideal meat for consumers to routinely consume.However,most consumers in China believe that rabbit meat has a special odor after cooking,which greatly affected the consumption of rabbit meat and restricted the development of China’s rabbit industry.Therefore,it is of great practical significance and social value to study the special odour of rabbit meat.In this study,a method for determination of rabbit meat odor substance hexanal and hexanoic acid was established.The content change of odor substance hexanal and hexanoic acid under different processing methods was explored.And finally,the correlation between the content change of hexanal & hexanoic acid and fatty acid oxidation was discussed,in order to provide theoretical basis for the study of rabbit meat odor and to provide theoretical support for further research on odor removal of rabbit meat.The main conclusions of this paper are as follows:(1)A method for determination of hexanal & hexanoic acid in rabbit meat was established.The optimization of equilibrium condition for the headspace vial was carried out through single factor experiment.Experimental data has shown that a good headspace balance can be achieved when the saturated NaCl aqueous was added to the meat sample,and then equilibrating at a temperature of 70 ℃ for 15 min.The feasibility of the HS-GC method was verified by methodology.Results show that this method is accurate and suitable for determination of hexanal & hexanoic acid in rabbit meat.(2)The existence of hexanoic acid in rabbit meat was confirmed by solvent extraction coupled with gas chromatography analysis.The HS-GC method was used to determine the content of hexanal & hexanoic acid in raw rabbit meat.Hexanal detected in rabbit meat was in the range of 49.62 ~ 67.73 μg/kg;Hexanoic acid detected in rabbit meat was in the range of 10.32 ~ 14.92 μg/kg.OAV analysis showed that hexanoic acidand hexanal have a direct effect on rabbit meat odor.(3)The content change of odor substance hexanal & hexanoic acid under different processing methods(stewing,baking,microwave heating and frying)was characterized using the HS-GC method,respectively.Results show that the four kinds of processing methods have a significant impact on the content of hexanal & hexanoic acid.We found that concentrations of hexanal & hexanoic acid would first increase and then decrease during stewing and baking processing.While concentrations of hexanal & hexanoic acid would gradually increase during the microwave heating process.Yet during frying processing,concentrations of hexanal & hexanoic acid would go down sharply from the very beginning and reduce to the minimum content at the end of frying.(4)We found that flavor precursor in rabbit meat will degrade or interaction with each other due to the effect of heat,and then newly formed hexanal & hexanoic acid will occur despite the loss of hexanal & hexanoic acid due to heat volatilization.(5)We explored the content change of oleic acid(C18:1 n-9c),linoleic acid(C18:2n-6),linolenic acid(C18:3 n-3)and arachidonic acid(C20:4 n-6)in rabbit meat under different processing methods(stewing,baking and microwave heating).Results showed that the content of selected unsaturated fatty acids in rabbit meat gradually decreased with the prolongation of processing time.Among the three kinds of hot processing methods,baking contributed greatest to the destruction of the selected unsaturated fatty acids while microwave heating contributed the least.(6)The correlation between the content change of hexanal & hexanoic acid and fatty acid oxidation was discussed.Pearson correlation analysis showed that the content of hexanal & hexanoic acid and the content of selected unsaturated fatty acids were negatively correlated under different processing methods,but the correlation is not very significant.In addition,compared with linolenic acid(C18:3 n-3)and arachidonic acid(C20:4 n-6),the formation of hexanal & hexanoic acid during thermal processing might be more closely linked with the thermal degradation of oleic acid(C18:1 n-9c)and linoleic acid(C18:2 n-6).