Research On The Extraction Of Pork Lipase And The Effect Of Pork Lipase On Meat Flavor

Lipases widely exist in animals, plants and micro-organisms. It hydrolyzedlong chain-fatty acid glyceride into glycerol and long chain fatty acids. It was animportant industrial enzyme. At present, the method for efficient extraction ofendogenous lipase was still in the stage of exploration. And adding endogenouslipase in order to improve the meat flavor of the research was still in theexploratory stage. Previous studies showed that adding microbial lipase onmeat flavor had a certain degree of influence. But, the flavor and the effect werenot significant. Therefore, this topic designed an efficient extraction method ofendogenous lipase, and studied the effect of endogenous lipase of meat flavor.The experiment used cold fresh pork as a raw material. Adipose tissue made ofcrude enzyme solution. The comparison of extraction of pork endogenous lipasewith three methods of PEG2000/(NH4)2SO4aqueous two-phase systemextraction and reverse micelles extraction and combination of aqueoustwo-phase extraction and chitosan precipitation in this paper. Further optimizethe extraction conditions for each method by the orthogonal experiment. Theoptimized condition was gained: mass fraction of PEG200025%, mass fractionof (NH4)2SO412%, pH6.5, chitosan concentration of2.5mg/mL. Under thecondition of aqueous two phase extraction and chitosan precipitation phasecombination, lipase extraction rate was97.83%, the maximum distributioncoefficient5.209, multiple purification was7.74.For pork endogenous lipase, the optimum conditions are as follows: theoptimum temperature was37℃, the optimum pH was6.5, the optimum timewas40minutes. And under this condition, the lipase had a better stability. Onthe basis of the enzymatic properties, single factor and orthogonal experiments were designed to determine the best conditions added the endogenous lipase ofmeat: single factor and orthogonal experiments were designed to determine thebest conditions for adding the endogenous lipase of meat: the role of time was40min, the amount of enzyme was10.0mL/25g, and the role of temperature was37℃.This experiment selected electronic nose to detect the meat flavor ofprocessed pork samples and blank samples. After adding the pork endogenouslipase, the sensor response analysis showed that: sulfur compounds, organicsulfur compounds, aromatic ingredients and ethanol ingredients have increasedsignificantly. PCA analysis and LDA analysis results showed that: electronicnose effectively distinguished between the flavor of processed pork samplesand blank samples. After endogenous lipase decomposition, the pork generatedadditional volatile components than those blank samples. In some extent, thepork endogenous lipase effectively improved the aroma of pork.