LONGISSIMUS LUMBORUM QUALITY OF LIMOUSIN SUCKLER BEEF IN RELATION TO AGE AND POSTMORTEM VACUUM AGEING

The aim of the research was to evaluate the influence of calf age on proximate composition, fatty acid composition and mineral contents, as well as postmortem ageing under vacuum on the inherent properties of musculus longissimus lumborum of Limousin suckler beef aged to 6, 7 or 8 months. The moisture, protein, fat, and ash content, fatty acid composition, mineral concentrations and intrinsic properties (pH, electrical conductivity, drip and cooking loss, shear force, and CIE colour parameters) were determined. The calf age significantly (P <= 0.05) correlated with an increased protein content and energy value of meat and decreased water: protein proportion. Moreover, increased age correlated with higher concentrations of Mg (P <= 0.01), Zn and Fe (P <= 0.05) and reduced concentrations of Cu (P <= 0.05). The fatty acid composition was similar irrespective of calf age, with the exception of CLA content, which was significantly (P <= 0.01) reduced in older animals. Muscles of calves aged 6 months were significantly lighter, less red, and showed the most significant drip loss compared to the muscles of older animals. There was no significant (P>0.05) interaction between calf age and postmortem ageing for the intrinsic properties analysed. Postmortem ageing under vacuum resulted in a significant decrease (P <= 0.05) in the shear force of meat (irrespective of the age of the calves). The lack of significant differences, especially with regard to the meat pH, shear force, fatty acid composition, and with the significantly higher content of protein and major elements (Fe, Mg and Zn) in relation to the slaughter age, indicates the validity of increasing the duration of fattening of the Limousin calves reared with their mothers on the pasture until the age of 8 months, which is a maximum in this category.