Abstracts - Process et Technologies

The importance of fat infiltration in meat for organoleptic quality has recently been demonstrated once again. As a result, marbling is a key area of research for INTERBEV (the French bovine meat interbranch organisation) with the aim of improving meat quality for consumers. An action plan has been set up and the Institut de l'Elevage (IDELE) has developed a measurement grid for INTERBEV enabling slaughterers to measure this criterion. The marbling level of French carcasses measured with this method has not yet been studied. The objective of this study is to take stock of marbling levels in French breeds and to identify the links between carcasses characteristics (age, weight, conformation, fatness) and marbling. The aim of the study is to provide the meat industry with references to help it meet consumer demands, particularly from an organoleptic point of view.

The role of marbling in beef and lamb quality - development, importance, measurement, harmonisation
This session, presented at the EAAP meeting in Florence on September 2nd, 2024, described research on marbling or intramuscular fat in beef and lamb. An overview of marbling development was presented with the important roles of genetics in terms of intramuscular adipocytes proliferation and location and muscle growth, along with the role of nutrition and animal age during finishing. The advent of new tools to measure intramuscular fat on-line has led to the development of a new Meat Standards Australian model to predict the eating quality of lamb based on balancing lean meat yield and intramuscular fat. Other technologies based on general lipid chemistry of muscle tissue such as Rapid Evaporative Ionisation Mass Spectrometry (REIMS) shows great promise to classify both flavour liking and the overall quality grade given by consumers to cook beef cuts. Finally, chemical intramuscular fat is proposed as the best method for underpinning future carcass grading schemes that currently use visual appraisal of marbling.

Marbling is defined as fat infiltration between muscular fibers. Some recent studies confirm the positive impact of this criterion on the overall palatability of meat. This is why INTERBEV (the interbranch of the meat industry) has chosen to work on this criterion to meet consumer’s expectations in terms of organoleptic quality. An action plan has been drawn up on this topic and the measurement of marbling is the first step to be taken. It’s important to be able to measure this criterion to better understand how to manage it. In addition, the interbranch is proposing that slaughterhouses measure marbling to measure marbling to complete the other parameters (such as conformation, fatness score, carcass weight,…) that already exist, in order to better meet consumer expectations. IDELE (the French livestock institute) has developed a French grid, adapted to the French context to assess marbling levels. The grid has been tested in slaughterhouse and performances are satisfying. The grid has therefore been validated by IDELE and INTERBEV and an interbranch agreement supervises marbling measurements and defines how the grid is to be used. Studies are underway to improve reliability and efficiency of marbling measurements in vivo and on carcasses thanks to new technologies (artificial intelligence).

In Australia, quality assessment of the beef rib eye according to AUS-MEAT chiller assessment and MSA standards provides a means of describing saleable meat characteristics. One of the characteristics visually assessed is the amount of marbling. In Europe, a growing interest to evaluate the amount of marbling in beef rib eye is observed among slaughterhouses. Objective measurement technologies ensuring consistent, precise and standardised grading which can be adopted by the beef industry has in recent years become more and more important. The Q-FOM^TM Beef camera is an objective equipment that predicts the marbling score and chemical intramuscular fat percentage (IMF%). This paper summarises the prediction accuracy and precision of MSA marbling and chemical IMF% by the Q-FOM^TM Beef camera in Australian beef carcasses, quartered at 10th-13th rib, and European beef carcasses, quartered at the 4th-6th rib. The Q-FOM^TM Beef is highly accurate and predicts the MSA marbling score with a precision of approximately 50 MSA marbling points and chemical IMF 1.3% at both quartering sites. These results are important for both European and Australian beef industries. The Q-FOM^TM Beef camera is commercially available and suited for grading both at grading stations and in chiller.

For European abattoirs, the preferred carcass grading site is the 5th rib and cutting between the 10th and the 13th rib as in Australia is not desired as it could lead to a lower economic value of the carcass. Consequently, the aim of this study was to compare marbling, meat color and fat color grading scores on M. longissimus thoracis et lumborum at the 5th and the 10th thoracic vertebrae. The impact on beef eating quality prediction using the Meat Standards Australia (MSA) grading scheme was then evaluated for cull cows, which produce most of the beef consumed in France. Carcasses from 208 French cattle, mainly Limousine cows, were graded according to the Australian Beef Chiller Assessment System (ABCAS) used to implement the MSA system and its European equivalent, the 3G system. There was no significant difference between the 5th rib and the 10th rib in marbling score, and therefore in muscle global quality scores (MQ4) and in carcass MSA index calculated from the marbling values of the 5th or the 10th ribs. However, meat color was significantly darker and fat color significantly more yellow at the 10th rib than at the 5th rib. In France, marbling must be evaluated at the M. longissimus thoracis et lumborum at the 5th thoracic vertebrae according to the current interprofessional grid. The results of this study suggest that it could technically be carried out at this level according to MSA/3G standards for research on cattle breeds in Europe. However, further investigation and adjustments would be required for other critical carcass MSA/3G scores (such as rib fat thickness) when using European carcass quartering practices. 

Effect of the position of the gun on the brain damage caused by the captive bolt when stunning cattle
The impact of the position of the stun gun brain damage was studied in 19 cattle. The aim was to define a reliable method of damaging the Ascending Reticular Activating System (ARAS), which is strongly involved in consciousness. The positions tested were two positions located at the intersection of the diagonals between the animal's eye and the base of the opposite horn (Low position: Eye-hornB; High position: Eye-hornH) and two positions located in the middle of the line going from the top of the head to the line connecting the animal's two eyes (Low position: MedianB; High position: MedianH). When using the Eye-HornB position, the bolt usually passed below the brain. The Eye-HornB and Eye-HornH positions were influenced by the shape of the head. The MedianB and Eye-HornH positions resulted in damage to the ARAS in approximately half and three-quarters of the animals, respectively. The MedianH position produced satisfactory damage to the ARAS (within the target zone: 95% of the animals; at the limit of the target zone: 5% of the animals). The disadvantages of the latter position are a potentially too caudal position in some animals and the greater difficulty to use outer canthi of the eyes as a landmark. In conclusion, placing the gun 1 cm lower than the MedianH position, or about 2 to 3 cm higher than the Eye-hornH or MedianB positions, maximises the probability of damaging the ARAS, while limiting the risk of a too caudal position.