Mezgebo Gebrehawerya B, Monahan Frank J, McGee Mark, O'Riordan Edward G, Marren Declan, Listrat Anne, Picard Brigitte, Richardson R Ian, Moloney Aidan P
School of Agriculture and Food Science, University College Dublin, D04V1W8 Dublin, Ireland.
Teagasc, Animal & Grassland Research and Innovation Centre, Grange, Dunsany, Co., C15PW93 Meath, Ireland.
Foods. 2019 Jul 23;8(7):278. doi: 10.3390/foods8070278.
The biochemical and organoleptic characteristics of the longissimus thoracis muscle from suckler bulls ( = 56) finished on a concentrate-based system (C) or raised in a pasture-based system (P) incorporating 99 (P99), 162 (P162) or 231 days (P231) of grazing prior to indoor finishing on the concentrate-based diet were investigated. Age at slaughter increased with increasing period at pasture. Intramuscular fat concentration was lower ( < 0.001) for P99 than for C, P162 and P231 bulls, which did not differ. Soluble collagen proportion was lower ( < 0.01) for P162 and P231 than for P99 and C bulls. Collagen cross-link content was higher ( < 0.05) for P231 than for P99 and C bulls and for P162 than for C bulls. The proportion of type I muscle fibres was higher ( < 0.01) for P231 and P162 than for P99 and C bulls. Sensory tenderness was higher ( < 0.001) for C and P162 than for P99 and P231 bulls and overall liking was higher ( < 0.01) for C than for P99 and P231 bulls but similar to P162 bulls. Extending the grazing period to 162 days did not negatively influence the sensory qualities of beef compared to the intensive concentrate-based system.
研究了在以精料为主的饲养体系（C）中育肥的56头哺乳公牛的胸最长肌，以及在以牧草为主的饲养体系（P）中育肥的公牛的胸最长肌的生化和感官特性。在以牧草为主的饲养体系中，室内精料育肥前的放牧天数分别为99天（P99）、162天（P162）或231天（P231）。屠宰年龄随在牧场饲养时间的增加而增加。P99组公牛的肌内脂肪浓度低于C组、P162组和P231组公牛（P<0.001），后三组之间无差异。P162组和P231组公牛的可溶性胶原蛋白比例低于P99组和C组公牛（P<0.01）。P231组公牛的胶原蛋白交联含量高于P99组和C组公牛（P<0.05），P162组公牛的胶原蛋白交联含量高于C组公牛（P<0.05）。P231组和P162组公牛的I型肌纤维比例高于P99组和C组公牛（P<0.01）。C组和P162组公牛的感官嫩度高于P99组和P231组公牛（P<0.001），C组公牛的总体喜好度高于P99组和P231组公牛（P<0.01），但与P162组公牛相似。与集约化精料饲养体系相比，将放牧期延长至162天对牛肉的感官品质没有负面影响。
