Analysis On Characteristic Flavors In Jinhua Ham And The Correlation With Hydrolysis And Oxidation Of Lipids

Jinhua ham has a very strong flavor and is one of traditional dry-cured products in China. Flavor is the most important index of dry-cured hams. A lot of flavor components are produced from oxidation of lipids. Proper oxidation could generate a satisfactory flavor while peroxidation will bring unpleasant taste, even destroy the quality of ham.In this paper Jinhua ham was chosen as raw material with SDE, SPME, fluorescence spectrophotometer, Near-infrared spectroscopy and other technologies to study the flavor components, hydrolysis and oxidation of lipids. Main results were obtained as follows:In this study, we established a qualitative and quantitative method of characteristic flavors and identified 57 flavor compounds totally. The changes of flavors content were also tested by SDE. Dodecane was used as internal standard. The results showed that aldehydes content is relatively high, followed by hydrocarbons and carboxylic acids. Besides, others such as furans play an important part in the overall flavor of Jinhua ham though in low amount.The activities of hydrolysis lipase of Jinhua ham were also studied. Results showed that activities of acid lipase, neutral lipase and phospholipase continual declined during processing. The residual activity accounted for 39.82 percent, 6.54 percent and 10.04 percent of green ham respectively at ferment middle. Negative liner correlation existed between aldehydes and carboxylic acids content in Jinhua ham and activities of phospholipase with the equations of Y=37.65-0.06X and Y=28.33-0.05X, and R coefficients of -0.88975 and -0.71413 respectively.Based on research of lipids oxidation in Jinhua ham, a mathematical model for ham quality detection was established by Near-infrared spectroscopy, taking peroxide value and water content as testing indexes. Predictive values were close to the measured values by chemical methods and correlation coefficient were 0.99091 and 0.93537 respectively. It indicated that NIR analysis could be used for detecting the quality of Jinhua ham rapidly during processing.