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Composition and eating quality of beef from young male dairy cattle derived from different production systems assessed by standard and rapid spectroscopic methods
University College Cork
The objective of this thesis was to assess the eating quality of beef from young male Holstein-Friesian (HF) and Jersey×Holstein-Friesian (JEX) dairy cattle from different production systems. Bulls were slaughtered at 15, 19 and 22 months, after finishing on diets differing in energy content. Longissimus thoracis (LT), Semitendinosus (ST) and Gluteus medius (GM) muscles were assessed primarily from bulls. Effects of carcass suspension method and ageing time on eating quality were also investigated. Standard eating quality variables assessed were post-mortem pH-temperature window, ultimate pH, colour, WarnerBratzler variables (WBSF, WB-slope, WB-area), cooking loss, intramuscular fat (IMF), moisture and protein content, collagen characteristics, fatty acid (FA) composition and sensory attributes. Raman spectroscopy (RS) and near infrared spectroscopy (NIRS) were explored as rapid methods to predict eating quality characteristics. The JEX breed type had superior eating quality to HF, while their FA profiles were similar. Slaughter age affected collagen characteristics. Higher energy diets produced beef with relatively better eating quality, but a less healthy FA profile than mainly forage diets. However, amount of concentrates in the first or second grazing season had limited effects on meat quality traits. Quality varied between muscles and the interaction between muscle and production system was significant for IMF content and FA profile. Eating quality of LT was superior but FA profile was inferior to GM and ST. Steer beef had superior eating quality to bull beef. Compared to Achilles tendon suspension (AS), Pelvic suspension (PS) improved tenderness up to 7 days of ageing and accelerated ageing processes. Both RS (1300-2800 cm-1) and NIRS (400-1900 nm) showed considerable potential for assessing physico-chemical quality traits from young male dairy beef, with RS demonstrating enhanced prediction performance. Consistent and significant correlations were also obtained among technological, compositional, sensorial and nutritional quality traits for dairy beef.
Physico-chemical quality traits , Sensory evaluation , Dairy breeds , Young bulls , Beef , Production system , Tenderness , Eating quality , Fatty acids , Muscle type , Castration , Pelvic suspension , Raman spectroscopy , Near infrared spectroscopy
Nian, Y. 2017. Composition and eating quality of beef from young male dairy cattle derived from different production systems assessed by standard and rapid spectroscopic methods. PhD Thesis, University College Cork.