David Pethick

Australian producers can enhance animal performance and profitability by selecting for lean meat yield and eating quality attributes using Australian Sheep Breeding Values (ASBVs). However, the impact of selecting for these traits on the consumer-perceived eating quality of a large range of lamb cuts has not been explored. From 824 lambs, eight cuts (knuckle, leg, loin, outside, rack, rump, shoulder, topside) were collected, along with the loin and topside from an additional 2288 animals (n = 3119 animals). Samples were assessed by untrained consumers (n = 18,720) for tenderness, juiciness, flavour liking and overall liking. Selection for increased lean meat yield had mainly a negative impact on the eating quality of several cuts within the Terminal sire type. Selection for improved eating quality through increased loin intramuscular fat content (IMF) improved the eating quality of the loin, rack, outside and leg cuts, primarily within the Terminal sire type. Improving eating quality through selection for reduced shear force at five days ageing (SF5) also improved consumer sensory perception of all cuts except the knuckle and outside. The improvement in eating quality through selection for increased IMF and reduced SF5 was not fully accounted for by the phenotypic traits of loin chemical IMF and Warner-Bratzler shear force, suggesting that these breeding values are impacting eating quality through additional mechanisms. Simultaneous selection for improved lean meat yield and eating quality demonstrated minimal effects on consumer sensory scores, implying the Australian sheepmeat industry can produce high-quality, lean products to consistently meet consumer expectations.
•Selection for increased intramuscular fat improved consumer eating quality.•Selection for reduced shear force improved consumer eating quality.•Greater impact of lean meat yield breeding values in Terminal sire type.•Minimal effect of selecting for lean meat yield and eating quality on sensory traits.

The Australian pork industry has been seeking a rapid and non-destructive way to predict pork chemical components and eating quality. In this study, near-infrared spectroscopy (NIRS) and nuclear magnetic resonance (NMR) were applied to fresh pork Longissimus thoracis et lumborum (LTL) and Semimembranosus (SM) with the aim to build prediction models for intramuscular fat (IMF) content, collagen content and solubility, pH, and sensory attributes, namely tenderness, juiciness, liking of flavor and overall liking as well as investigate the effects of chemical components on pork eating quality. Results showed that the NIRS output, which was a predicted IMF content calibrated for the IMF of lamb, correlated with the chemically analyzed IMF content across both muscles. In LTL, NMR parameter p2f was weakly correlated with IMF and pH. For the LTL, NMR parameters p21 and p22 were related to sensory tenderness, while T22 was correlated with the liking of flavor. In both muscles, the collagen content and pH were related to all sensory attributes, and IMF was related to the liking of flavor. The chemical properties of SM were weakly correlated with those of LTL. The NIRS and NMR weakly predicted the pork chemical components and sensory properties, but more studies are required to improve the accuracy.

The impact of increasing lean meat yield (LMY) on consumer eating acceptance and its association with intramuscular fat (IMF) of lamb products was evaluated. Consumer sensory scores (overall liking, tenderness, juiciness, flavour liking) of the loin and topside were obtained from 3119 lambs, in addition to the knuckle, leg, outside, rack, rump and shoulder from a subset of these animals (n = 824). LMY indicators included GR tissue depth (measured 110 mm from dorsal midline of 12th rib), whole carcass and section (fore, saddle, hind) computed tomography (CT) lean% and cut weight of the loin and topside (as a percentage of the total carcass weight). Loin IMF was measured on all animals, with topside, outside, rump and shoulder IMF obtained from a subset of animals. Linear mixed models demonstrated a reduction in eating quality with increasing LMY in all cuts (P < 0.05) except the knuckle and leg. The impact on eating quality varied depending on the method used to estimate LMY, with the strongest association observed when using CT lean% measures, particularly section CT lean% from which the cut was taken. The effect of LMY on consumer eating quality was fully driven by IMF within the loin and rump cuts (P > 0.05) but only partially in the rack, outside and shoulder (P < 0.05). Results confirm the importance for simultaneous selection of LMY and IMF as key drivers of sheepmeat eating quality and the importance for the inclusion of on-line predictions of LMY in eating quality grading systems.

The European beef carcass grading scheme prioritizes meat yield over consumer eating experience, in contrast to the Meat Standards Australia (MSA) grading scheme, which is more focused on eating quality. The Italian-French beef production system, mostly characterized by young bulls and heifers imported from France and then fattened within Italian specialized fattening units, has been underexplored using the MSA grading system. This study examines the impact of animal sex on performance, MSA traits, and predicted MSA quality scores (MQ4 and MSA index) using carcasses from an Italian commercial abattoir. It also assesses how animal performance and MSA traits influence predicted beef eating quality. A Random Forest classifier demonstrated high performance with an accuracy of .98, a specificity of .99, and a sensitivity of .97 after 10-fold cross-validations, confirming key traits such as hot carcass weight, European carcass grading scheme fatness score, and general muscular characteristics as being significantly different due to sex. Entire males had greater muscle development, whereas females had notably higher MSA marbling scores, MQ4 scores, and MSA index (P < .05). Furthermore, categorizing the MSA index into 2 classes and applying a similar Random Forest classifier approach revealed that MSA marbling was the primary factor influencing variability of the MSA index. These findings suggest that beef cuts from females may better meet consumer expectations when using the MSA grading scheme in Europe, making them a suitable category for premium beef branding. Grading carcasses from entire male animals for sensory quality is also important, as it demonstrates their potential to produce good-quality beef with a higher lean meat yield; however, their sensory quality tends to be lower than that of heifers and this is in part reflected by their lower marbling score resulting from reduced intramuscular fat deposition.

Predicting meat quality, especially dark, firm and dry meat, as well as muscle fat prior to slaughter, presents a challenge in practice. Medical as well as high-frequency ultrasound applications can be utilized to predict body composition and meat quality aspects. Ultrasounds are non-invasive, rapid-to-operate in vivo and show high correlations to the animal production traits being estimated. Farm animal ultrasounds are used to predict intramuscular fat content in the beef cattle industry. Challenges are identified in applying ultrasound technology to detect glycogen content in farm animals due to a wide range of fat, muscle and water composition. Other technologies and methods are reported in this literature review to overcome issues in the practicability and accuracy of ultrasound technology when estimating muscle glycogen levels in cattle. The discussion of other tools such as hyperspectral imaging, microwave sensor technology and digital infrared thermal imaging were addressed because of their superior accuracy in estimating moisture and fat components.

Untrained consumer-determined sensory scores of tenderness, juiciness, flavour liking, and overall liking possess a level of dependency due to poorer consumer ability to discriminate between these traits. Given that overall liking is strongly correlated to all traits, this study evaluated the contributions of sensory traits to the overall liking scores of Australian lamb. Tenderness, juiciness, flavour liking and overall liking of a range of lamb cuts were assessed by untrained Australian consumers (n = 18,720) following Meat Standards Australia protocols. The most important contributor to lamb overall liking was flavour liking (44.7%), followed by tenderness (28.3%) and juiciness (27.0%) (P < 0.05; R = 0.88). The contribution of the sensory traits to overall liking varied between meat quality categories, although the contribution of juiciness varied minimally. The contribution of flavour liking to overall liking became more important as loin intramuscular fat content increased. Whilst small differences in the contribution of tenderness and juiciness were present between cooking methods, untrained consumers evaluated overall liking in a similar manner regardless of cut type, demonstrating consumers' inherent ability to consistently evaluate meat products.

This study evaluated the impact of high oxygen modified atmosphere packaging (MAP) in four different combinations, 80 % oxygen and 20 % carbon dioxide (MAP80), 40 % oxygen, 20 % carbon dioxide and 40 % nitrogen (MAP40(20CO2)), 40 % oxygen, 60 % carbon dioxide (MAP40(60CO2)), and vacuum skin packaging (VSP) under different retail display times (3 or 8 days) on the sensory scores of lamb meat. Untrained consumer sensory scores for overall liking, tenderness, juiciness and liking of flavour were assessed on the M. longissimus lumborum (loin) and M. semimembranosus (topside) of 144 lambs. In general, MAP40(20CO2) samples received higher sensory scores than MAP80 (P < 0.05). While the high carbon dioxide MAP mixture MAP40(60CO2) scored similar to MAP80 (P > 0.05). Therefore, MAP40(20CO2) minimised the detrimental effects on eating quality and is a viable alternative to the widely used MAP80. However, the highest eating quality scores were still obtained with VSP (P < 0.05).

The current sheep Meat Standards Australia (MSA) model is a pathways system designed to improve the overall eating quality of Australian lamb, yet it is unable to predict individual consumer-based eating quality scores for specific cuts. This paper describes the methodology of using consumer sensory scores to create an objective composite eating quality prediction score linked to individual quality grades for different cuts. This methodology accounts for objective carcass measures that are being commercialised within the industry, such as intramuscular fat percentage and a measure of lean meat yield percentage. The model demonstrated that through utilising these carcass grading traits, an eating quality prediction can be made with an accuracy of 75 % and 72 % for the grill and roast cooking method respectively, however individual consumer variation remained substantial. The model will allow the supply chain to allocate cuts to different marketing strategies (branding) based on their eating quality performance whilst also reducing the chances of consumers being offered products that do not meet their expectations.

Cet article est une synthèse d’une session consacrée à la recherche sur le persillé ou le gras intramusculaire chez le bœuf et l'agneau présentée lors du congrès annuel de la fédération européenne des sciences animales (EAAP) à Florence du 1er au 4 septembre 2024. Une vue d'ensemble du développement du persillé a été présentée insistant sur les rôles de la génétique en termes de prolifération et de localisation des adipocytes intramusculaires et de croissance musculaire, ainsi que sur le rôle de la nutrition et de l'âge de l'animal durant la finition. L'avènement de nouveaux outils de mesure en ligne du taux de gras intramusculaire a conduit au développement d'un nouveau modèle australien des normes de la viande pour prédire la qualité sensorielle de la viande d'agneau sur la base de l'équilibre entre le rendement en viande maigre et le taux de gras intramusculaire. D'autres technologies basées sur la chimie des lipides du tissu musculaire, telles que la spectrométrie de masse à ionisation par évaporation rapide (REIMS), sont très prometteuses pour classer les pièces de viande cuites selon leur flaveur et leur qualité globale attribuée par les consommateurs. Enfin, la détermination chimique du taux de gras intramusculaire est proposée comme la meilleure méthode pour étayer les futurs systèmes de classement des carcasses qui est actuellement basé sur l'évaluation visuelle du persillé.