Muscle-specific color stability in fresh beef from grain-finished Bos indicus cattle.

OBJECTIVE: To investigate the color and oxidative stabilities of longissimus lumborum (LL) and psoas major (PM) muscles from grain-finished Bos indicus cattle in Brazil. METHODS: The LL and PM muscles were obtained 24 h post-mortem from eight (n = 8) Nellore bull carcasses, fabricated into 1.5-cm steaks, aerobically packaged, and stored at 4°C for nine days. Steaks were analyzed for myoglobin concentration, pH, instrumental color, metmyoglobin reducing activity (MRA) and lipid oxidation. RESULTS: The LL steaks exhibited greater (p<0.05) redness, color stability, and MRA than their PM counterparts on days 5 and 9. The LL and PM steaks demonstrated similar (p>0.05) lightness and yellowness on days 0, 5, and 9. On the other hand, PM steaks exhibited greater (p<0.05) myoglobin concentration, pH, and lipid oxidation than their LL counterparts. CONCLUSION: These results indicated that muscle source influenced the color and oxidative stabilities of beef from grain-finished Bos indicus animals. These results highlighted the necessity of muscle-specific strategies to improve the color stability of beef from grain-fed Bos indicus cattle.

Color attributes and oxidative stability of longissimus lumborum and psoas major muscles from Nellore bulls.

The influence of muscle source on color stability of fresh beef from purebred Bos indicus cattle was investigated. Longissimus lumborum (LL) and psoas major (PM) muscles obtained from twelve (n=12) Nellore bull carcasses (24h post-mortem) were fabricated into 2.54-cm steaks, aerobically packaged, and stored at 4°C for nine days. Steaks were analyzed on day 0 for proximate composition and myoglobin concentration, whereas pH, instrumental color, metmyoglobin reducing activity (MRA), lipid oxidation, and protein oxidation were evaluated on days 0, 3, 6, and 9. LL steaks exhibited greater (P<0.05) redness, color stability, and MRA than PM counterparts. On the other hand, PM steaks demonstrated greater (P<0.05) myoglobin content, lipid oxidation, and protein oxidation than LL steaks. These results indicated the critical influence of muscle source on discoloration of fresh beef from Bos indicus animals and suggested the necessity to engineer muscle-specific strategies to improve color stability and marketability of beef from Bos indicus cattle.

Differential abundance of sarcoplasmic proteome explains animal effect on beef Longissimus lumborum color stability.

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.

Sex-specific effect of ractopamine on quality attributes of pork frankfurters.

Our objective was to determine the effect of dietary ractopamine and immunocastration on the quality attributes of pork frankfurters. Gilts (GT), surgically castrated male pigs (SR) and immunologically castrated male pigs (IM) were fed diets containing 7.5 ppm ractopamine (RAC) or no ractopamine (CON) for 21 days prior to harvest. Deboned hams were manufactured into frankfurters, and physico-chemical parameters, instrumental color and texture, and sensory attributes were evaluated. Ractopamine increased (P<0.05) L* (lightness) in SR, whereas it decreased (P<0.05) lightness in IM and GT. While ractopamine increased (P<0.05) a* (redness) in GT, a reverse (P<0.05) trend was observed in SR. With respect to instrumental texture, ractopamine increased (P<0.05) hardness, resistance, and springiness in IM, cohesiveness and springiness in GT, and shear force in SR. These results indicated that ractopamine exerted sex-specific effects on frankfurter quality. Swine industry may adopt sex-specific dietary strategies to optimize the quality of further processed meat products.

Physico-chemical and sensory attributes of low-sodium restructured caiman steaks containing microbial transglutaminase and salt replacers.

Our objective was to examine the physico-chemical and sensory attributes of low-sodium restructured caiman steaks containing microbial transglutaminase (MTG) and salt replacers (KCl and MgCl2). Trimmings from caiman carcasses were processed into restructured steaks with or without MTG and salt replacers; the five treatments were CON (1.5% NaCl), T-1 (1.5% NaCl+1% MTG), T-2 (0.75% NaCl+1% MTG+0.75% KCl), T-3 (0.75% NaCl+1% MTG+0.75% MgCl2), and T-4 (0.75% NaCl+1% MTG+0.375% KCl+0.375% MgCl2). T-4 demonstrated the greatest (P<0.05) succulence and the lowest (P<0.05) values for cooked hardness, springiness, and cohesiveness. The greatest (P<0.05) purchase intention was for T-3. Furthermore, T-3 and T-4 were similar (P>0.05) to controls in salty flavor. Our findings suggest that the combination of MTG, KCl, and MgCl2 can be employed as a suitable salt reduction strategy in restructured caiman steaks without compromising sensory attributes and consumer acceptance.