不同冻融次数对猪肉品质的影响

研究不同冻融次数(0、1、3、5、7次)对猪背最长肌肉品质特性的影响,分析猪肉冻融过程中食用品质特性、全质构特性、脂肪氧化(硫代巴比妥酸值)以及肌浆蛋白和全蛋白含量的变化。结果表明:随着反复冻融次数的增加,解冻汁液流失率、加压失水率和蒸煮损失率随之显著增加,到冻融7次时解冻汁液流失率已达到13.24%,加压损失率达到36.77%,蒸煮损失率达到31.77%;亮度(L*)、黄度(b*)增加,红度(a*)减少,到冻融7次时L*值达到58.46,b*值达到13.25,a*值降低到11.68;pH值和剪切力值先增大后减少。硫代巴比妥酸值随冻融次数的增加显著增加。猪肉肌浆蛋白和肌肉全蛋白含量在反复解冻-冻融过程中降低。反复冻融严重降低了猪肉的品质,且随着冻融次数的增加,对猪肉品质的影响越严重。

Effects of Different Freezing and Thawing Cycles on Pork Quality

This study was designed to explore the effects of freeze-thaw cycles (0, 1, 3, 5 and 7 cycles) on quality
characteristics of pork longissimus muscle (LM). The changes in eating quality, full textural properties, fat oxidation
(thiobarbituric acid-reactive substances, TBARS), and sarcoplasmic protein and total protein contents of repeatedly frozenthawed
pork were analyzed. The results showed that with an increase in the number of freeze-thaw cycles, thawing loss (TL),
pressurized water loss rate (WL) and cooking loss (CL) increased significantly. TL, WL and CL increased to 13.24%, 36.77%
and 31.77%, respectively after the seventh freeze-thaw cycle; L* and b* values increased to 58.46, 13.25, respectively, and
a* value decreased to 11.68. pH and shear force (SF) increased at the initial stage and then decreased. TBARS significantly
increased with increasing number of freeze-thaw cycles. The contents of sarcoplasmic protein and total protein decreased
during freeze-thaw cycles. All these results demonstrated that freeze-thaw cycles decreased the meat quality of pork muscle
significantly and this effect was positively related to the number of freeze-thaw cycles.