Sistema antioxidante en la carne bovina de diferentes sistemas de producción: Un abordaje a la generación de nuevos biomarcadores de calidad

In Uruguay, beef production is of great economic importance. Production systems range from exclusive use of pastures, pastoral systems with supplementation, confinement and use of concentrates, generating meats with different attributes of nutritional interest. Meat is a complete food in the human diet and of high nutritional quality, due to its high biological value proteins, vitamins, fatty acids and essential minerals of high bioavailability, highlighting heme iron. These can vary with the production system and the post mortem maturation, affecting the quality of the meat. Muscle glycogen, in relation to the stability of iron and changes in myoglobin, would impact the color through maturation. The objective of the work was to study the physicochemical and nutritional components and their changes in long maturation process of beef, from pastoral and feedlot systems, in two types of muscles and their relationship between them as biomarkers of the defense potential of the meat during processing. Meat samples from 30 Aberdeen Angus steers were analyzed, 15 animals were raised and finished in a pastoral system and 15 were finished in a feedlot system. After slaughter, 36 hours post mortem, the cuts of the Longissimus dorsi (LD) and Semimembranosus (SM) muscles were extracted. One portion was frozen without maturing and the other was matured for 60 days in vacuum. The following parameters were measured and determined: pH, color, dry matter, iron, Heme iron, Zinc, Copper, Manganese and glycogen. The data were evaluated using an ANOVA GLM and if there were significant differences, a Tukey-Kramer Test (p<0.05 %) was performed and by ANOVA of one way comparing maturation time for each muscle in each system. Based on the results, it can be stated that the nutritional composition and physicochemical parameters are influenced by the production system, muscle type and maturation process. The muscles presented differences in heme iron, luminosity and glycogen. The SM muscle has a higher content of heme iron and redness, lower glycogen reserves and higher final pH, with no differences at day 0, but yes at day 60. In relation to the production systems, the results reflect significant differences, the feedlot system presented higher values of heme iron, iron, zinc, while Mn was higher in feedlot. In the 60-day maturation, Fe, heme iron, Mn, Zn, color and glycogen decrease in SM, in some cases associated with the pastoral system. The LD muscle was more stable in color and Fe, heme iron content, probably in relation to its lower variation in glycogen content, demonstrating a better defense potential against the oxidative process. The stability of color in long maturation processes depends on the initial Fe and glycogen content, associated with the muscle and the production system, which would be a potential quality biomarker.