No abstract

No abstract

No abstract

No abstract

Twenty-eight Merino Precoce suckling lambs raised under confinement in the Mediterranean semi-humid dryland of Central Chile were studied to evaluate meat quality and major carcass characteristics. Animals were grouped by slaughter weight (10 and 15 kg) and sex (7 males and 7 females in each weight group). The average commercial and true dressing percentages were 53 and 55%, the average ribeye area was 11.7 cm 2 , and the average dorsal fat thickness was 1.5 mm. The largest retail yields were those of the leg and shoulder, at 38 and 22%, respectively. The tissue composition of the leg was 58% muscle, 23% bone, 12% fat, 3.6% residues, and 3% shrink loss. The tissue composition of the shoulder was 57% muscle, 23% bone, 11% fat, 3.7% residues and 3.2% shrink loss. The average chemical composition of the fresh meat was 67% moisture, 19% protein, 13% ether extract, and 1.3% ash. Sensory panel evaluation indicated that almost all the sensory characteristics were within the ideal range, and the acceptability panel evaluation indicated that 15 kg lambs produced the most acceptable meat. Slaughter weight had the most significant effect on carcass and meat quality. These results confirm that Merino Precoce suckling lambs yield high-quality carcasses and highly acceptable meat.

Per capita meat consumption in Chile is 89.1 kg per year in 2014, of which approximately 25 kg are beef. Some 50% of the beef consumed is imported as vacuum packaged meat from two species, Bos taurus, produced mainly in Chile, Argentina and Paraguay, and Bos indicus, which comes mainly from Brazil and Paraguay. The latter two countries account for the highest levels of beef imports in Chile. The objective of this investigation was to study and compare the fatty acid profiles of beef from Bos Taurus from Chile and Bos indicus from Paraguay and Brazil. Samples of vacuum packaged Longissimus dorsi muscle tissue were collected from private companies, two Chilean, three Paraguayan and two Brazilian. The fatty acid profiles were determined by GLC according to standardized regulations. There were differences in the fat profiles of the analyzed meats, mainly in the content of saturated and monounsaturated fatty acids. Brazilian and Paraguayan beef had similar fat compositions, with higher saturated fat content and lower monounsaturated fat content than the Chilean beef. The saturated and monounsaturated fat contents in the Chilean beef were similar. All the analyzed beef samples had a low content of trans and polyunsaturated fats.

It is well known that beef produces volatile molecules. In this work, the detection of volatiles released by post-mortem bovine fast-twitch muscles (Musculus longissimus dorsi and Musculus cutaneus trunci) was done using GC/MS-SPME (gas chromatography/mass spectrum-solid-phase microextraction). The releases of volatile molecules were modeled against three factors (rigor-mortis, animal age and oxidative capacity) using a chemometrics approach (experimental design and partial least squares regression). The GC/MS-SPME technique produced more than 30 reproducible chromatographic peaks, but only 13 were associated significantly with two factors (rigor-mortis and animal age). The volatile profile was composed mainly of alcohols, aldehydes and alkanes. The factor "animal age" was the main variable related to the release of volatile molecules. The results strongly suggest that the release of volatile molecules change according to post-mortem metabolism and the animal age.Un enfoque quimiométrico para analizar moléculas volátiles emanadas por músculos bovinos post-mortem de contracción rápida RESUMEN Es conocido que la carne produce moléculas volátiles. En este trabajo, la detección de moléculas volátiles emanadas por músculos bovinos post-mortem de contracción rápida (Musculus longissimus dorsi y Musculus cutaneus trunci) fue realizada usando GC/MS-SPME. Las emanaciones de las moléculas volátiles fueron modeladas contra tres factores (rigor-mortis, edad del animal y capacidad oxidativa) usando un enfoque quimiométrico (diseño experimental y regresión de mínimos cuadrados parciales). La técnica GC/MS-SPME produjo más de 30 picos cromatográficos reproducibles, pero solo 13 fueron asociados significativamente con dos factores (rigor-mortis y edad del animal). El perfil volátil estuvo compuesto principalmente por alcoholes, aldehídos y alcanos. El factor "edad del animal" fue la principal variable relacionada con la emanación de las moléculas volátiles. Los resultados sugieren fuertemente que la emanación de moléculas volátiles cambia de acuerdo al metabolismo post-mortem y la edad del animal.