Research On Tenderizing Methods Of Aging Sika Meat

Venison is suitable for human consumption which has tonic effect. Its nutritionalvalue is higher. It is with the characteristics of high protein, low fat, low cholesteroland easy digestibility. It is delicious and has the reasonable nutrition structure. Nowthe main economic purpose of deer breeders is to take antlers. The raising years arelong, meat quality and taste is poor, so the utilization of the aging sika deer meat isnot high and theoretical study on the development and processing of the venisonproducts is lagging behind. In this paper, we studied the tenderizing effects of agingvenison by physical methods （ultrasound, high pressure）, chemical methods （salts,organic acids） and exogenous enzymes methods （bromelain, papain, trypsin）. Wecompared the tenderizing effects of three methods, optimized the best tender methodand process parameters. This study applied the ideas and theoretical basis forimproving the edible quality of aging sika meat and laid the practical foundation forthe development of high-quality venison products.1. Ultrasonic and ultra-high pressure methods were used to treat aging venison.The variation of MFI, CSP, pH, texture properties, cooking loss and protein changeswere studied and comprehensive effect of venison tenderization were evaluated. Theresults showed that （1） ultrasonic and high pressure treatment can play the role oftenderization to venison, improve the organizational structure, reduce the hardness、chewiness and cooking loss of venison and change myofibrillar fragmentation extentand CSP.（2） the optimal conditions of ultrasonic method are power200W, treatingtime15min. The tenderization effect is better under these conditions, the hardness ofvenison can be reduced by31.5%, the chewiness decreased by nearly50%andcooking loss decreased by7.5%; venison has not reached maturity, the hardness,elasticity didn’t change significantly, the chewiness decreased within1-3d aftertendering treatment; we can see that venison protein degraded by SDS-PAGE, butvenison tenderization by ultrasound is not entirely caused by the degradation ofprotein.（3） the optimal conditions of ultra-high pressure are pressure400MPa,pressing time6min. The tenderization effect is better under these conditions, thehardness of venison can be reduced by about53%, chewiness decreased by74.9%,cooking loss decreased by24.4%; we can see that venison protein degradedsignificantly by SDS-PAGE when pressure is higher than300MPa.2. CaCl₂, Na2CO3, sodium polyphosphate, citrate were used to treat aging venison. The variation of MFI, CSP, pH, texture properties, cooking loss and proteinchanges were studied and comprehensive effect of venison tenderization wereevaluated. The results showed that CaCl₂、Na₂CO₃、sodium polyphosphate, citratetreatment all can increase MFI, CSP and pH, improve the texture properities,significantly reduce hardness, chewiness and cooking loss. But the use of chemicaltenderization agent need to moderate, or it is easy to give meat adverse effects, suchas color, flavor, etc; After comparing the tenderizing effect of four agent, we obtainedthat the best aging venison tenderization agent is CaCl₂. The optimal amount is2%and placing time is2d. The tenderization effect is better under these conditions, thehardness of venison can be reduced by31.3%, the chewiness decreased by52.1%andcooking loss decreased by11.8%; venison protein degraded differently because ofdifferent agent, we can see significant difference by SDS-PAGE, venison proteintreated by CaCl₂degraded significantly.3. Bromelain, papain and trypsin were used to treat aging venison. The variationof MFI, CSP, collagen heat solubility, texture properties, cooking loss and proteinchanges were studied and comprehensive effect of venison tenderization wereevaluated. The results showed that bromelain, papain and trypsin can play the role oftenderization to venison, increase MIF, CSP, collagen heat solubility, improve venisontexture properities, decrease hardness, chewiness and cooking loss significantly. Butthe amount of enzyme need to moderate, over-give meat products have adverseconsequences, such as color, shape, etc., and follow-up processing is inconvenience;the best exogenous protease of venison tenderization is papain, the optimalconcentration is50-150U/g, soaking for40-80min and the pH of tender agent isbetween6.0-8.0, the tenderization effect is better under these conditions; venisonprotein degraded differently because of different enzyme, we can see significantdifference by SDS-PAGE, venison protein treated by papain degraded significantlywhen the concentration was the same as bromelain and trypsin; the effect of pH toprotein degradation was greater when the enzyme was papain; the extent of proteindegradation increased, proteins of small relative molecular and polypeptides weregenerated as the immersion time prolonged. Therefore, to prevent over-tenderized, weneed to control the immersion time.4. Four tendering methods （ultrasound, CaCl₂, ultra-high pressure, papain）wereused to treat venison. The comparation of MFI, CSP, collagen heat solubility, pH,texture properties and cooking loss were studied and optimized the best tenderizingmethod. The results showed that papain method is a better tender method of aging deer meat. The hardness and chewiness of venison reducted significantly, respectivelydecreased by65.4%and71.2%; CSP increased about50%, collagen heat solubilityincreased by3times, cooking loss decreased by about40%.5. Factor analysis was used to comprehensive evaluate the quality of tendervenison and three initial common factors （texture factor F₁, sensory factor F₂andnutritional factor F₃） were obtained. The variance contribution rates of three initialcommon factors were36.678%,27.044%and21.728%. Based on the results of factoranalysis, we used comprehensive factor scorea as the dependent variable, the amountof enzyme （Z₁）, pH （Z₂） and immersion time （Z₃） as the independent variable to carryout Box-Behnken response surface analysis and established the regression equation:Y=0.59+0.34X₁+0.092X₂+0.39X₃+0.10X₁X₂+0.34X₁X₃+0.074X₂X₃0.59X₁²0.40X₂²0.27X₃²From this equation, we got the optimal tender process parameters: the amount ofenzyme217.00U/g, pH7.19, tender time78.89min.