利用低场核磁共振研究冷却条件对猪肉保水性的影响

    Study on different chilling factors influencing water-holding capacity of pork based on low-field nuclear magnetic resonance (LF-NMR)

    • 摘要: 为了通过水分分布信息,深入了解冷却条件对猪肉保水性的影响,以三元杂交猪为对象,利用低场核磁共振(LF-NMR)技术研究了不同冷却条件下猪肉的水分分布及流动规律。结果表明:冷却猪肉低场核磁共振自旋-自旋弛豫时间T2谱中出现4个水分峰,其横向弛豫时间分别为T20(150~500 μs),T21(1~3 ms),T22(40~50 ms),T23(150~400 ms)。滴水损失、蒸煮损失与T22,T23呈现显著正相关(P<0.01),自由水含量(pT23)与滴水损失的相关系数为0.858。冷却过程中不易流动水(pT22)先增加后减少,自由水(pT23)先减少后逐渐增加。与常规常湿冷却相比,两段式快速冷却使胴体的冷却失重降低了0.3%,高湿冷却使胴体的冷却失重降低了约0.5%,显著提高了保水性(P<0.05)。核磁成像显示,相对湿度95%处理组冷却猪肉表面的自由水比相对湿度80%处理组多。该研究结果对猪肉冷却工艺确定具有一定的指导作用。

       

      Abstract: Obtaining water distribution information can help explain the water-holding capacity of pork. This study investigated water distribution and mobility of M. longissimus dorsi from 32 Duroc×Landrace×Large white pigs under different chilling methods by using low-field nuclear magnetic resonance (LF-NMR). Multi-exponential fitting of the bulk NMR T2 transverse relaxation time data demonstrated that four distinct water populations were T20 (150-500 μs), T21 (1-3 ms), T22(40-50 ms) and T23(150-400 ms). Significant correlation was found between T22, T23 time constant and drip loss, and between T22, T23 time constant and cooking loss (P<0.01), respectively. The strongest correlation was found between pT23 and drip loss (r=0.858). Initial increase and following decrease were observed in the immobilized water (pT22) during the chilling period, but free water (pT23) showed minor decrease followed by moderate increase. Compared with conventional chilling, rapid chilling method resulted in reducing weight loss by 0.3%, and treatment of increasing humidity reduced weight loss by 0.5%. The NMR images showed more free water on the surface of muscle samples in the treatment of relative humidity 95% than the treatment of relative humidity 80%. The results are instructive and meaningful to optimizing chilling parameters in slaughter industry.

       

    /

    返回文章
    返回