Straadt Ida Krestine, Rasmussen Marianne, Young Jette Feveile, Bertram Hanne Christine
University of Aarhus, Faculty of Agricultural Sciences, Department of Food Science, Research Centre Foulum, P.O. Box 50, DK-8830 Tjele, Denmark.
Meat Sci. 2008 Nov;80(3):722-7. doi: 10.1016/j.meatsci.2008.03.012. Epub 2008 Mar 16.
In order to investigate a possible relationship between integrin degradation and water-holding capacity (WHC), integrin was quantified using western blot, and water mobility and distribution was measured by proton NMR T(2) relaxometry at 24h postmortem in pork (n=30) with a large variation in WHC (drip loss varying from 2.8% to 11.3%). Regression analyses revealed correlation coefficients of r=-0.32 (P=0.08) and r=0.40 (P=0.03) for the correlations between the content of integrin determined by western blot analysis and WHC determined as either drip loss or by NMR, respectively. Water mobility and distribution was also measured in 18 meat samples upon 7 days of aging, which revealed a correlation (r=0.54) between integrin content determined by western blot analysis 24h postmortem and the mobility of the myofibrillar water (T(21) relaxation time) at day 7. In contrast, no correlation could be established between integrin content 24h postmortem and WHC at day 7 determined by NMR as the amount of extramyofibrillar water (T(22) population) (r=-0.01). In conclusion, both visualisation by CLSM and quantification of integrin by western blot analyses of suggested that a strong link between integrin degradation and WHC in pork is questionable, whereas integrin degradation seems to have impact on the succeeding development in the mobility of the myofibrillar water.
为了研究整合素降解与持水能力（WHC）之间可能存在的关系，采用蛋白质免疫印迹法对整合素进行定量分析，并在宰后24小时通过质子核磁共振T(2)弛豫测量法测定猪肉（n = 30）中的水分迁移率和分布情况，这些猪肉的WHC差异较大（滴水损失从2.8%到11.3%不等）。回归分析显示，通过蛋白质免疫印迹分析测定的整合素含量与分别以滴水损失或核磁共振法测定的WHC之间的相关性系数分别为r = -0.32（P = 0.08）和r = 0.40（P = 0.03）。还对18个肉类样品在成熟7天后的水分迁移率和分布情况进行了测量，结果显示宰后24小时通过蛋白质免疫印迹分析测定的整合素含量与第7天肌原纤维水的迁移率（T(21)弛豫时间）之间存在相关性（r = 0.54）。相比之下，宰后24小时的整合素含量与第7天通过核磁共振法测定的作为肌原纤维外水含量（T(22)总体）的WHC之间未发现相关性（r = -0.01）。总之，共聚焦激光扫描显微镜成像和蛋白质免疫印迹分析对整合素的定量分析均表明，猪肉中整合素降解与WHC之间的紧密联系值得怀疑，而整合素降解似乎对肌原纤维水迁移率的后续变化有影响。
