Gil Marta, Ramírez Jorge A, Pla Marcial, Ariño Beatriz, Hernández Pilar, Pascual Mariam, Blasco Agustín, Guerrero Luis, Hajós Gyöngyi, Szerdahelyi Emöke N, Oliver Maria Ángels
IRTA Institut de Recerca i Tecnologia Agroalimentàries, Centre de Tecnologia de la Carn, Granja Camps i Armet, 17121 Monells, Girona, Spain.
Meat Sci. 2006 Jan;72(1):121-9. doi: 10.1016/j.meatsci.2005.06.014. Epub 2005 Aug 22.
The effect of selection for growth rate on the degradation of the myofibrillar proteins and on meat texture properties of rabbit longissimus muscle at two ageing times (1 and 7 days) was studied as well as its effect on the proteolytic potential of the muscle. Two groups of contemporary animals (20 rabbits per group), one selected for growth rate (S) for 14 generations and the other unselected control group (C) were compared. The control group was formed from the offspring of the embryos belonging to the 7th generation and was compared with selected animals belonging to 21st generation. Myofibrillar protein degradation was studied by SDS-PAGE electrophoresis (12.5% and 4-15% polyacrylamide gels) followed by densitometric analysis of the pherograms. Texture properties were evaluated by Warner-Bratzler (WB) test and Texture profile analysis (TPA). The activities of proteolytic enzymes calpains and cathepsins and of their inhibitors were determined in the muscle at 24h. Densitometric analysis of the pherograms of samples aged 7 days showed an extra 30kDa band and the disappearance of a band with higher molecular weight than the myosin heavy chain with respect to samples aged 24h in both groups of rabbits. TPA results showed that cohesiveness was significantly lower in meat at 7 days than at 24h (P<0.0001), whereas springiness and chewiness presented a clear tendency to be lower at 7 days than at 24h (P=0.0646 and P=0.0764, respectively). Regarding the genetic type, S animals presented higher hardness and chewiness than C rabbits. Shear firmness (WB test) was significantly (P<0.0001) higher for S group, whereas no significant differences in shear force and area were found. No significant effect (P>0.05) of ageing time was detected using WB test. Selection for growth rate did not affect the activities of proteolytic enzymes or their inhibitors.
研究了生长速率选择对兔背最长肌在两个成熟时间（1天和7天）的肌原纤维蛋白降解、肉质地特性的影响，以及对肌肉蛋白水解潜力的影响。比较了两组当代动物（每组20只兔子），一组为经过14代生长速率选择的（S组），另一组为未选择的对照组（C组）。对照组由第7代胚胎的后代组成，并与第21代的选择动物进行比较。通过SDS-PAGE电泳（12.5%和4-15%聚丙烯酰胺凝胶）研究肌原纤维蛋白降解，随后对电泳图谱进行光密度分析。通过Warner-Bratzler（WB）试验和质地剖面分析（TPA）评估质地特性。在24小时时测定肌肉中蛋白水解酶钙蛋白酶和组织蛋白酶及其抑制剂的活性。对7天龄样品电泳图谱的光密度分析显示，两组兔子中，相对于24小时龄样品，均出现一条额外的30kDa条带，且一条分子量高于肌球蛋白重链的条带消失。TPA结果表明，7天时肉的内聚性显著低于24小时时（P<0.0001），而弹性和咀嚼性在7天时明显有低于24小时时的趋势（分别为P=0.0646和P=0.0764）。关于遗传类型，S组动物的硬度和咀嚼性高于C组兔子。S组的剪切硬度（WB试验）显著更高（P<0.0001），而剪切力和面积未发现显著差异。使用WB试验未检测到成熟时间的显著影响（P>0.05）。生长速率选择不影响蛋白水解酶或其抑制剂的活性。
