Comparison of the effects of production and processing parameters on the eating quality of lamb

Abstract

While many separate research studies have investigated the effect of production and processing factors on eating quality of lamb, the relative impact of these parameters has been difficult to ascertain. In this study, the effect of eighteen production and processing factors on the eating quality of Welsh Lamb was compared, using meat from 624 lambs and assessments by 1920 UK consumers. Four experimental trials provided a balanced assessment of production and processing factors: muscle, breed type, lamb gender, ageing, finishing diet, season, carcase hanging and packaging method. The effect of other parameters was assessed using the combined data: farm type, individual farm, liveweight gain, abattoir, slaughter date, carcase weight, carcase conformation, carcase fat grade, age at slaughter, and transport time. The Meat Standards Australia protocol for consumer panels was used to provide a consistent methodology for comparing the effect on palatability of different treatments and factors and the interactions between them. The three factors that had the most significant effect on consumer sensory quality were muscle, season and individual farm. While the differences between muscles are well known, the effects of season within the 1st year and individual farm have not been widely reported. Meat from mid-season lambs received the highest scores for sensory quality while differences in sensory quality between meat from different farms were pronounced and unexplained; further research is needed to evaluate the role of genetics and/or microflora. Younger age and higher intramuscular fat content also gave improved eating quality, with gender and conformation grade having a small effect. Of the postslaughter factors, ageing to 14 or 21 days, gave significantly better eating quality than 7 days ageing, as did hanging “cross-legged” and vacuum packing, compared with Achilles hanging and modified atmosphere packaging, respectively. There was a significant muscle × hanging method interaction, with the greatest effect of “cross-legged” hanging observed in the loin. There was no significant effect of lamb finishing diet, abattoir, preslaughter daily liveweight gain or transportation time on any of the consumer sensory scores. The main factors tested that provide practical scope for improving the eating quality of lamb were ageing of the meat, carcase hanging and meat packaging. If the reasons for inter- and intra-farm differences in lamb quality can be elucidated, this may provide further management tools for improving the quality and consistency of lamb quality.