M. longissimus dorsi quality of carcass bulls by marbling the meat of different degree

The objective of this experiment was to verify the hypothesis whether with marked marbling in meat (i.e. higher content of intramuscular fat) the qualitative parameters in beef also change (positively or negatively). Slaughter bulls (340 animals) of different breeds were used in this experiment. Average weight before slaughter ranged from 487 kg to 532 kg. Meat samples were classified according to a 10 points scale; most samples were classified within the marbling degrees 8 (36.18%), 7 (26.47%) and 9 (22.35%) which represent slight, low marbling or just traces of marbling in meat samples, respectively. Few meat samples (0.58% and 1.47%) were classified within marbling degrees 3 and 4, i.e. moderately strong to slightly strong marbling in meat. While evaluating the influence of marbling degree on studied parameters we detected that content of total water decreases linearly from marbling degree 9 (75.75 g per 100 g) to marbling degree 3 (73.15 g. 100 g sup(-1)). We observed a similar decreasing tendency in individual marbling degrees with the content of total proteins, which decreased from 21.95 g per 100 g in marbling degree 9 to 20.30 g per 100 g in marbling degree 3. On the contrary, we noticed a rising linear tendency with high coefficient of significance (P less than 0.01) in values of intramuscular fat that rose to individual marbling degrees as follows: 9- 1.35; 8- 1.86; 7-2.47; 6-3.10; 5 - 3.77; 4 - 3.80; 3 - 5.48 g per 100 g). We registered a certain trend of linear rising in the parameters such as ash content, in which the lowest value recorded was 0.99 g per 100 g) assessed on degrees 9, 8 and 6. Content of loosely bound water decreased almost linearly from marbling degree 9 (34.28 g per 100 g) to marbling degree 3 (32.46 g per 100 g). Worth mentioning is the parameter weight loss in cooked meat that decreased with marbling degree with lower content of intramuscular fat. The highest cooking loss was with the marbling degree 3 (45.85 g per 100 g) and the lowest with the marbling degree 9 (43.31 g per 100 g). Surprising were the findings for the parameter shear force in meat, where results were the most variable. The highest value (5.16 kg) was observed with marbling degree 5 and the lowest one (3.86 kg) with marbling degree 3. We found similar variable results for meat colour as well.