不同超高压处理对DFD牛肉肉色及货架期的影响OA北大核心CSTPCD

In order to reduce the initial number of microorganisms on the surface of DFD(dark,firm and dry)beef,extend the shelf life of vacuum-packed DFD beef and improve the color of DFD beef,the effects of ultra-high pressure(UHP)treatments at different pressures(200,400 and 600 MPa)and for different periods of time(5 and 10 min)on the shelf life and color of DFD beef were investigated.Vacuum-packed DFD beef was treated by UHP or not(control)and stored at(2±2)℃.After 0,2,4,6,8,12 and 16 days,meat color,apparent images,pH,microbial load and deoxymyoglobin(DMb),oxymyoglobin(OMb)and metmyoglobin(MMb)fractions were measured.The results showed that UHP processing significantly increased the L*,a*,and b* values(P<0.05)of DFD beef,elevated the proportion of OMb,and decreased the proportion of MMb.However,too high pressure(600 MPa)caused DFD beef to show a pink color.The microbial load of DFD beef was reduced significantly by UHP(P<0.05),by 0.6 and 0.8(lg(CFU/g))at 200 MPa,1.1 and 1.3(lg(CFU/g))at 400 MPa,and 1.7 and 2.0(lg(CFU/g))at 600 MPa for beef treated for 5 and 10 min,respectively.UHP effectively inhibited microbial growth in beef during storage.The control group had been spoiled on day 12,and the 200 MPa group reached the threshold of spoilage on day 16,whereas no spoilage was observed in the 400 and 600 MPa groups on day 16.Thus,400 MPa was the optimal pressure to effectively improve the color and simultaneously extend the shelf life of DFD beef.The extension of holding time had no significant effect on meat color or shelf life(P>0.05).Taken together,400 MPa and 10 min were the optimal parameters for UHP treatments of DFD beef,which could improve the meat color of DFD beef while extending the shelf life by at least 5 days.