The effects of feeding benzoic acid and/or active dry yeast (Saccharomyces cerevisiae) on fatty acid composition, sensory attributes, and retail shelf-life of beef longissimus thoracis

Fifty-nine Angus-cross steers (492 ± SD 36 kg) were arranged in a randomized complete block design and assigned to the following dietary treatments for the final 106 days of the finishing phase: no supplementation (CON), 0.5% benzoic acid (ACD), 3 g/steer/d active dry Saccharomyces cerevisiae (YST), or both [0.5% benzoic acid and 3 g/steer/d S. cerevisiae (AY)]. Steers were slaughtered at a commercial facility where longissimus thoracis (IMPS #107 Beef Rib) samples were retrieved and evaluated for fatty acid composition, sensory attributes, and shelf-life during a simulated retail display period. Data (N = 57) were analyzed using dietary treatment as a fixed effect, blocking weight at the beginning of the study as a random effect, and steer as the experimental unit. Muscle pH and proximate composition (moisture and intramuscular lipid) for longissimus samples were not different (P ≥ 0.39) among dietary treatments. Most fatty acid profile values and calculations were not different among dietary treatments (P ≥ 0.10); however, the n-6:n-3 ratio differed (P = 0.01), with ACD samples having lower n-6:n-3 compared with CON and YST samples while AY samples were intermediate and not different from other dietary treatments. The trained sensory panel did not detect differences among dietary treatments (P ≥ 0.23) for juiciness, beef flavor intensity, or off-flavor intensity; however, they did score AY samples as chewier than ACD samples with CON and YST samples intermediate and not different from other dietary treatments. Yet, tenderness was not different when scored by trained panelists (P = 0.10) or measured instrumentally (P = 0.21). Total color change tended to differ (P = 0.09) during the 12-d simulated retail display period with AY samples experiencing less color change compared with YST samples, while CON and ACD samples were intermediate and not different from other dietary treatments. Lipid oxidation (as measured with TBARS) tended to differ (P = 0.08) following the 12-d simulated retail display period with ACD and AY samples experiencing lower levels of oxidation compared with CON, while YST samples were intermediate and not different from other dietary treatments. Overall, these results suggest there were no negative impacts on meat quality when finishing steers were supplemented with either benzoic acid or S. cerevisiae, and there may even be advantages for fatty acid composition and oxidative stability when steers were supplemented with benzoic acid.

A Meta-Analysis of Essential Oils Use for Beef Cattle Feed: Rumen Fermentation, Blood Metabolites, Meat Quality, Performance and, Environmental and Economic Impact

The objective of this study was to see how dietary supplementation with essential oils (EOs) affected rumen fermentation, blood metabolites, growth performance and meat quality of beef cattle through a meta-analysis. In addition, a simulation analysis was conducted to evaluate the effects of EOs on the economic and environmental impact of beef production. Data were extracted from 34 peer-reviewed studies and analyzed using random-effects statistical models to assess the weighted mean difference (WMD) between control and EOs treatments. Dietary supplementation of EOs increased (p < 0.01) dry matter intake (WMD = 0.209 kg/d), final body weight (WMD = 12.843 kg), daily weight gain (WMD = 0.087 kg/d), feed efficiency (WMD = 0.004 kg/kg), hot carcass weight (WMD = 5.45 kg), and Longissimus dorsi muscle area (WMD = 3.48 cm2). Lower (p < 0.05) ruminal concentration of ammonia nitrogen (WMD = −1.18 mg/dL), acetate (WMD = −4.37 mol/100 mol) and total protozoa (WMD = −2.17 × 105/mL), and higher concentration of propionate (WMD = 0.878 mol/100 mol, p < 0.001) were observed in response to EOs supplementation. Serum urea concentration (WMD = −1.35 mg/dL, p = 0.026) and haptoglobin (WMD = −39.67 μg/mL, p = 0.031) were lower in cattle supplemented with EOs. In meat, EOs supplementation reduced (p < 0.001) cooking loss (WMD = −61.765 g/kg), shear force (WMD = −0.211 kgf/cm2), and malondialdehyde content (WMD = −0.040 mg/kg), but did not affect pH, color (L* a* and b*), or chemical composition (p > 0.05). Simulation analysis showed that EOs increased economic income by 1.44% and reduced the environmental footprint by 0.83%. In conclusion, dietary supplementation of EOs improves productive performance and rumen fermentation, while increasing the economic profitability and reducing the environmental impact of beef cattle. In addition, supplementation with EOs improves beef tenderness and oxidative stability.

The Relationship between Lipid Content in Ground Beef Patties with Rate of Discoloration and Lipid Oxidation during Simulated Retail Display

The relationships between the lipid content, lipid oxidation, and discoloration rate of ground beef during a simulated retail display were characterized in this study. A total of 276 batches of ground beef were manufactured with inside rounds and subcutaneous fat from 138 beef carcasses at different targeted levels of lean:fat. There was a total of four different targeted grind levels during the manufacture of the ground beef, and the lipid content for the samples used in this study ranged from 2% to 32% total lipid. Fatty acid composition was determined based on subcutaneous fat, whereas the proximate composition of moisture and total lipids, instrumental color, visual discoloration, and lipid oxidation measured as thiobarbituric acid reactive substances were evaluated on ground beef patties during 7 days of simulated retail at 4 °C display under LED lights. Analysis for the correlation and the creation of linear regression models indicated that lipid content played a more critical role in the discoloration rate compared to lipid oxidation and fatty acid composition. Lipid oxidation could be more reliably predicted by lipid content and instrumental color compared to visual discoloration. Overall, ground beef formulated with greater lipid content is expected to experience greater rates of lipid oxidation and discoloration during retail display.