Effect of ageing time on consumer-perceived quality of Italian Simmental beef

The aim of the experiment was to provide an objective indication on the optimal ageing time of meat from Italian Simmental (IS) young bulls, the most important commercial category of the breed. The research was carried out on 10 young bulls slaughtered at the average weight of 688 kg (SE: 7.3 kg). The right side of each carcass was stored for 7 days and the left one for further 7 days, at normal refrigeration temperatures. At the end of the ageing period, the sides were sampled at the loin for meat pH, color, cooking loss and shear force measurement. A central location, affective test involving 74 consumers was carried out to measure the degree of liking for grilled beef aged 7 or 14 days. The pH and color parameters were not significantly affected by the duration of post-mortem storage, while cooking loss increased (31.4 vs 32.6%; P<0.05) and shear force values diminished (56.7 vs 46.8 N; P<0.01) when ageing time increased from 7 to 14 days. The degree of liking by the untrained respondents for the two types of cooked meat was different, considering that consumers gave the highest hedonistic scores to beef aged 14 days. Tenderness was the sensory attribute that allowed the best discrimination between beef stored for periods of different length. In fact, while the difference between 14-day-aged and 7-day-aged beef for flavour ratings (7.0 vs 6.9) did not reach the threshold of significance, the former meat was perceived as significantly finer than the latter regarding tenderness (6.5 vs 5.6; P=0.01) and marginally preferred in overall terms (6.9 vs 6.5; P=0.07). The classification test, carried out at the end of the quantitative test by asking consumers to select from a list the most appropriate attributes describing the stimuli associated with meat consumption, confirmed the effectiveness of texture attributes in ranking different-aged beef acceptability. In fact, the number of ticks reported for chewiness and juiciness descriptors were different for the two types of meat: the 14-day-aged beef was perceived as easier to chew (57 vs 34 ticks) and juicier (42 vs 24) than the shortest-aged beef. Ageing for 14 days should be recommended as a process control point for the beef industry to improve consumer acceptance of IS young bull beef.