Selection of muscles as indicators of tenderness after seven days of ageing

Study of the Warner-Bratzler shear force, sensory analysis and sarcomere length as indicators of the tenderness of sun-dried beef

Sun-dried beef is a frequently consumed and valued product in Brazil, however, there have been no scientific studies on its texture. To assess the tenderness of sun-dried beef, an instrumental analysis (Warner-Bratzler Shear Force; WBSF), a sensory analysis (Quantitative Descriptive Analysis; QDA) and the sarcomere length (SL) were used as indicators. Significant differences were observed among the sun-dried beef samples. Sample 3 (composed of sun-dried meat purchased at three fairs from Region 3 in the city of João Pessoa-PB) was considered the most tender by the assessors, with a score of 6.7, and its WBSF analysis revealed a maximum value of 2.70 kgf. Additionally, this sample exhibited the highest SL value (1.89 µm). Samples 1 and 2 (composed of sun-dried meat purchased at three fairs from Regions 1 and 2, respectively, in the city of João Pessoa) exhibited very similar tenderness values (WBSF and QDA) but differed in their SL values, which suggested that sample 2 was the least tender. In conclusion, these results demonstrate that the studied parameters are complementary and can be used as tenderness indicators for sun-dried beef. However, although the difference was beyond the detection limit of the assessors and the texturometer, the SL analysis appears to have been the most effective.

Effect of low- and high-forage diets on meat quality and fatty acid composition of Alentejana and Barrosã beef breeds

This study investigated the effects of genotype and diet on meat fat composition and palatability obtained from Alentejana (AL) and Barrosã (BA) breeds. Herein, 20 males from each breed allocated at 11 months of age were fed ad libitum a low-forage diet or a high-forage diet and slaughtered at 18 months of age. Trained sensory panel analysis found that the longissimus lumborum (Ll) muscle from BA had higher tenderness, juiciness and overall acceptability scores than the AL breed. The highest scores for those attributes were observed in the BA breed fed the high-forage diet. Regarding the semitendinosus (St) muscle, breed was a source of variation of tenderness scores. In contrast to the Ll muscle, the highest tenderness scores for the St muscle were observed in the AL breed. The intramuscular fat (IMF) content was positively correlated with tenderness, juiciness and overall acceptability in Ll muscle and negatively correlated with flavour in the St muscle. The levels of 14:0 and 16:0, 16:1c9, 18:1c9 and 18:1c11 were positively correlated to juiciness, tenderness and overall acceptability in the Ll muscle. These correlations were not observed in the St muscle, which may be related to its low IMF content. Nonetheless, negative correlations were observed for the St muscle between flavour and 14:0, 16:0 and 18:0 FA contents.The IMF varied widely in the Ll but not in the St muscle. The latter had higher levels of 16:1c9 and trans fatty acids (∑TFA) in the BA than in the AL breed. Regarding the Ll muscle, the BA had higher amounts of 14:0, 16:0, 16:1c9, 18:0, 18:1c9, 18:1c11, saturated fatty acids (∑SFA), cis monounsaturated fatty acids (∑cis MUFA), ∑TFA and n-3 polyunsaturated fatty acids (∑n-3 PUFA) than the AL breed. The diet exerted an influence on the IMF content and on the levels of 14:0, 16:0, 16:1c9, 18:0, 18:1c9, 18:1c11, ∑SFA, ∑cis MUFA and ∑TFA in both Ll and St muscles. Moreover, the levels of ∑n-3 PUFA in the Ll muscle and 18:2n-6, 20:4n-6, ∑n-6 PUFA and ∑PUFA in the St muscle were influenced by diet. The results obtained in this study, with two Portuguese breeds, confirm that genetic background plays a major role in the determination of meat eating quality.