超声波解冻对猪肉品质的影响

Effect of Ultrasonic Thawing on the Quality Characteristics of Frozen Pork

以20℃静水解冻为对照组,5种不同超声波功率(100、200、300、400、500 W)解冻为处理组,研究超声波解冻对猪肉品质及加工特性的影响。结果表明:与对照组相比,超声波处理可以缩短猪肉的解冻时间,但汁液损失较大,随着超声波功率的增大,猪肉的蒸煮损失率增大,200 W超声波处理组猪肉的压榨保水性高于其他处理组;与对照组相比,除100 W超声波处理组外,不同超声波功率解冻处理均能显著降低猪肉的pH值和亮度值(L~*)(P<0.05),且随着超声波功率的增大,各处理组样品的pH值和L~*均呈降低趋势;500 W处理组猪肉的剪切力值显著低于对照组(P<0.05),且随着超声波功率的增大,各处理组样品的剪切力逐渐降低;对照组样品的横向弛豫时间T23峰面积显著低于500 W超声波处理组(P<0.05),各超声波处理组样品的T23峰面积比随着超声波功率的增大而增加;样品中水溶性蛋白质和盐溶性蛋白质的含量随着超声波功率的增大均呈下降趋势。200 W的超声波解冻功率是既能缩短解冻时间,又能减少猪肉品质降低的最佳功率。

The aim of this study was to investigate the effect of ultrasonic thawing on pork quality and processing characteristics. Still water thawing （20 ℃） was used as control group, while ultrasonic thawing at five different powers （100, 200, 300, 400 and 500 W） were used as treatment group. The results showed that ultrasonic treatment shortened thawing time but increased thawing loss compared with the control group. Cooking loss increased with ultrasonic power, and the water-holding capacity of 200 W ultrasonic treatment was higher than the other treatment groups. But pH value and L＊ value were significantly lower in all treatment groups except the 100 W group than the control group （P 〈 0.05）, and they were inversely correlated with ultrasonic power. Ultrasonic treatment at 500 W caused a significant increase in shear force in comparison with the control group （P 〈 0.05）, and the shear force decreased with increasing ultrasonic power. Moreover, the transverse relaxation T23 peak area ratio in the control group was significantly lower than in the 500 W ultrasonic treatement group （P 〈 0.05）, and this parameter increased with ultrasonic power. Water-soluble and salt-soluble protein contents both decreased with the increase in ultrasonic power. The above results demonstrated that an ultrasonic power of 200 W was the optimal thawing condition to not only shorten thawing time but also lessen the deterioration of pork quality.