RESUMO
The sarcoplasmic proteome of beef Longissimus lumborum demonstrating animal-to-animal variation in color stability was examined to correlate proteome profile with color. Longissimus lumborum (36 h post-mortem) muscles were obtained from 73 beef carcasses, aged for 13 days, and fabricated to 2.5-cm steaks. One steak was allotted to retail display, and another was immediately vacuum packaged and frozen at -80°C. Aerobically packaged steaks were stored under display, and color was evaluated on days 0 and 11. The steaks were ranked based on redness and color stability on day 11, and ten color-stable and ten color-labile carcasses were identified. Sarcoplasmic proteome of frozen steaks from the selected carcasses was analyzed. Nine proteins were differentially abundant in color-stable and color-labile steaks. Three glycolytic enzymes (phosphoglucomutase-1, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate kinase M2) were over-abundant in color-stable steaks and positively correlated (P<0.05) to redness and color stability. These results indicated that animal variations in proteome contribute to differences in beef color.
Assuntos
Qualidade dos Alimentos , Carne/análise , Proteínas Musculares/biossíntese , Músculo Esquelético/metabolismo , Pigmentos Biológicos/biossíntese , Retículo Sarcoplasmático/metabolismo , Matadouros , Animais , Bovinos , Armazenamento de Alimentos , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/biossíntese , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/metabolismo , Proteínas Musculares/análise , Músculo Esquelético/enzimologia , Músculo Esquelético/crescimento & desenvolvimento , Fosfoglucomutase/biossíntese , Fosfoglucomutase/metabolismo , Pigmentos Biológicos/análise , Estabilidade Proteica , Piruvato Quinase/biossíntese , Piruvato Quinase/metabolismo , Reprodutibilidade dos Testes , Retículo Sarcoplasmático/química , Retículo Sarcoplasmático/enzimologia , Eletroforese em Gel Diferencial BidimensionalRESUMO
Dietary ractopamine improves pork leanness, whereas its effect on sarcoplasmic proteome has not been characterized. Therefore, the influence of ractopamine on sarcoplasmic proteome of post-mortem pork Longissimus thoracis muscle was examined. Longissimus thoracis samples were collected from carcasses (24 h post-mortem) of purebred Berkshire barrows (n=9) managed in mixed-sex pens and fed finishing diets containing ractopamine (RAC; 7.4 mg/kg for 14 days followed by 10.0 mg/kg for 14 days) or without ractopamine for 28 days (CON). Sarcoplasmic proteome was analyzed using two-dimensional electrophoresis and mass spectrometry. Nine protein spots were differentially abundant between RAC and CON groups. Glyceraldehyde-3-phosphate dehydrogenase and phosphoglucomutase-1 were over-abundant in CON, whereas serum albumin, carbonic anhydrase 3, L-lactate dehydrogenase A chain, fructose-bisphosphate aldolase A, and myosin light chain 1/3 were over-abundant in RAC. These results suggest that ractopamine influences the abundance of enzymes involved in glycolytic metabolism, and the differential abundance of glycolytic enzymes could potentially influence the conversion of muscle to meat.