Pulmonary arterial pressure in fattened Angus steers at moderate altitude influences early postmortem mitochondria functionality and meat color during retail display

Pulmonary hypertension is a noninfectious disease of cattle at altitudes > 1524 m (5,000 ft). Mean pulmonary arterial pressures (PAP) are used as an indicator for pulmonary hypertension in cattle. High PAP cattle (≥ 50 mmHg) entering the feedlot at moderate elevations have lower feed efficiency as compared to low PAP cattle (< 50 mmHg). The impact of pulmonary arterial pressure on mitochondrial function, oxidative phosphorylation (OXPHOS) protein abundance, and meat color was examined using longissimus lumborum (LL) from high (98 ± 13 mmHg; n = 5) and low (41 ± 3 mmHg; n = 6) PAP fattened Angus steers (live weight of 588 ± 38 kg) during early postmortem period (2 h and 48 h) and retail display (day 1 to 9), respectively. High PAP muscle had greater (P = 0.013) OXPHOS-linked respiration and proton leak-associated respiration than low PAP muscles at 2 h postmortem but rapidly declined to be similar (P = 0.145) to low PAP muscle by 48 h postmortem. OXPHOS protein expression was higher (P = 0.045) in low PAP than high PAP muscle. During retail display, redness, chroma, hue, ratio of reflectance at 630 nm and 580 nm, and metmyoglobin reducing activity decreased faster (P < 0.05) in high PAP steaks than low PAP. Lipid oxidation significantly increased (P < 0.05) in high PAP steaks but not (P > 0.05) in low PAP. The results indicated that high PAP caused a lower OXPHOS efficiency and a greater fuel oxidation rates under conditions of low ATP demand in premortem beef LL muscle, this could explain the lower feed efficiency in high PAP feedlot cattle compared to low PAP counterparts. Mitochondrial integral function (membrane integrity or/and protein function) declined faster in high PAP than low PAP muscle at early postmortem. LL steaks from high PAP animals had lower color stability than those from the low PAP animals during simulated retail display, which could be partially attributed to the loss of muscle mitochondrial function at early postmortem by ROS damage in high PAP muscle. Pulmonary arterial hypertension could also decrease type I/type II muscle fiber ratio in skeletal muscle, which needs to be investigated further.

Metabolomics of meat color: Practical implications

Objective: Meat is biochemically active, and the various pre-and post-harvest processes can affect meat quality. Metabolomics is a valuable tool to elucidate metabolite changes in meat. The overall goal of this study was to provide an overview of various techniques, data analysis, and application of metabolomics in meat color research. Results: Both targeted and non-targeted approaches have been used to determine metabolite profiles in meat. Researchers use gas-, liquid-chromatography, and nuclear magnetic resonance platforms to separate molecules. Metabolomics is used to characterize muscle-specific differences in color stability, meat tenderness, the impact of aging on meat color, and to determine metabolite profile differences between normal-pH and dark-cutting beef. Color stable muscles have more glycolytic metabolites than color labile muscles. Conclusion: The use of metabolomics has greatly enhanced our understanding of metabolites' role in meat quality. There are challenges in data analysis; thus, there is a need for multiple platforms in order to obtain comprehensive metabolite libraries specific to food. Metabolomics in combination with wet-laboratory techniques can provide novel insights on the relationship between postmortem metabolism and meat color.

Effect of Dietary Curcumin Supplementation on Duck Growth Performance, Antioxidant Capacity and Breast Meat Quality

This study aimed at examining the effects of curcumin supplementation on growth performance, antioxidant capacity, and meat quality of ducks. To investigate these effects, 600 healthy ducks were randomly assigned to four treatment groups with 10 replicates pens, and each pen contained 15 ducks. Ducks were fed a diet containing curcumin at levels of 0, 300, 400, and 500 mg kg−1 in different groups. The results demonstrated that curcumin supplementation is beneficial to the growth performance (p < 0.05) of ducks and antioxidant capacity (p < 0.05) of duck meat. In addition, dietary curcumin raised the meat quality of ducks, improving the meat color, increasing water-holding capacity, and inhibiting lipid and protein oxidation. In conclusion, the present study provides important insights into both the nutrient and qualities of ducks, finding that a dietary inclusion of 400–500 mg/kg of curcumin (kg−1) has the greatest effect.

Effect of Supplementary Levels of Rumen-Protected Lysine and Methionine on Growth Performance, Carcass Traits, and Meat Quality in Feedlot Yaks (Bos grunniens)

Yak, a unique bovine species on the Qinghai-Tibetan Plateau, has provided pastoralists with the basic materials of production and life for thousands of years. Existing literature showed that yak meat is of high nutritional value for humans whereas the growth performance is relatively low. As it has been demonstrated, lysine and methionine are the two key limiting amino acids in ruminants. Therefore, this study was conducted to investigate the effect of supplementary levels of rumen-protected lysine (RPL) and methionine (RPM) on growth performance, carcass traits, and meat quality in feedlot yaks. Thirty-two male yaks, with initial body weight (IBW) of 237.5 ± 13.99 kg were randomly assigned to four dietary treatments (n = 8), including control group (CON; basal diet without adding rumen-protected amino acid (RPAA)), low RPAA supplementation group (Group Low; basal diet supplemented with RPL (30.0 g/animal/day) and RPM (7.5 g/animal/day)), medium RPAA supplementation group (Group Medium; basal diet supplemented with RPL (50.0 g/animal/day) and RPM (12.5 g/animal/day)), and high RPAA supplementation group (Group High; basal diet supplemented with RPL (70.0 g/animal/day) and RPM (17.5 g/animal/day)). The average daily gain was increased linearly (p < 0.001) and quadratically (p < 0.01) while feed to gain ratio was decreased linearly (p < 0.001) and quadratically (p < 0.001) with the increasing RPAA supplementation, and the average daily gain was higher while feed to gain ratio was lower in RPAA than CON (p < 0.001). Meat color L* values and b* were decreased linearly (p < 0.01) with the increase of RPAA supplementation, and b* was lower in RPAA than CON (p < 0.05). Meat color a* value was increased linearly (p < 0.05) with the increasing RPAA supplementation, and a* was higher in RPAA than CON (p < 0.05). The 24 h drip loss and shear force were decreased quadratically (p < 0.01) with the increasing RPAA supplementation, and drip loss and shear force values were lower in RPAA than CON (p < 0.05). The glycine concentration in longissimus dorsi (LD) increased linearly (p < 0.05) with the increasing RPAA supplementation. These results demonstrated that both the growth performance and meat quality characteristics were improved in feedlot yaks as an effect of the dietary supplementation with RPL and RPM, and the medium supplementary level is recommended, since it showed the most promising results.

Effects of Calcium Salts on the Physicochemical Quality of Cured Beef Sausages during Manufacturing and Storage: A Potential Calcium Application for Sausages with Alginate Casings

The impacts of adding calcium chloride (CaCl2) and calcium lactate (CaLac) with different concentrations (0%, 0.2%, 0.4%, and 0.7%) on the physicochemical properties of cured beef sausages were investigated in this study. Meat color, pH, lipid oxidation, and cooking loss were measured at respective manufacturing stages (ground beef, raw chopped batter, and after cooking). Additionally, meat color, pH, lipid oxidation, nitrosylhemochrome, residual nitrite, and texture profiles of vacuum-packaged sausages were evaluated during seven days of storage. Compared with the control (no Ca added), both calcium salts resulted in deteriorative color and texture properties, and promoted pH decline, cooking loss, and lipid oxidation of sausages during manufacturing and storage. However, increased calcium salt addition led to the reduction of residual nitrite over time. Compared to CaCl2 addition, 0.2–0.4% CaLac resulted in greater redness and oxidative stability and softer texture. These results may be useful when considering calcium salt additions in sausages, for the purpose of co-extruded sausages coated with alginate where Ca salts are used to form the casing during the co-extrusion of the sausages.

Effects of Polyunsaturated Fatty Acids Supplementation on the Meat Quality of Pigs: A Meta-Analysis

Polyunsaturated fatty acids (PUFAs) supplementation has been widely discussed as a strategy for improving meat quality in pig production, but the effects are inconsistent. This meta-analysis was performed to comprehensively evaluate its effects on the meat quality and growth performance of pigs. We searched the PubMed and the Web of Science databases (articles published from January 1, 2000 to October 16, 2020) and compared PUFAs-supplemented diets with control diets. We identified 1,670 studies, of which 14 (with data for 752 pigs) were included in our meta-analysis. The subgroup analysis was classified as PUFA source [conjugated linoleic acid (CLA) or linseed], concentration (high or low concentration), and initial stage (growing or finishing pigs). Our analysis found that PUFA supplementation increased the intramuscular fat (IMF) content (WMD = 0.467%, 95% CI: 0.312–0.621, p &lt; 0.001), decreased the meat color L* (WMD = −0.636, 95% CI: −1.225 to −0.047, p = 0.034), and pH 24 h (WMD = −0.021, 95% CI: −0.032 to −0.009, p &lt; 0.001) but had no influence on drip loss, meat color a* and b*, pH 45 min, and growth performance. CLA supplementation improved IMF content (WMD = 0.542%, 95% CI: 0.343–0.741, p &lt; 0.001) and reduced meat color b* (WMD = −0.194, 95% CI: −0.344 to −0.044, p = 0.011). Linseed supplementation increased IMF content (WMD = 0.307%, 95% CI: 0.047–0.566, p = 0.021), decreased meat color L* (WMD = −1.740, 95% CI: −3.267 to −0.213, p = 0.026), and pH 24 h (WMD = 0.034, 95% CI: −0.049 to −0.018, p &lt; 0.001). We discovered an increase on the IMF content in both high and low concentration PUFA supplementation (WMD = 0.461%, 95% CI: −0.344 to −0.044, p &lt; 0.001; WMD = 0.456%, 95% CI: 0.276–0.635, p &lt; 0.001). Furthermore, we also found the effects of PUFA supplementation on meat color L* and pH 24 h are concentration- and stage-dependent. PUFA supplementation can improve the meat quality of pigs, which mainly emerges in greatly increasing IMF content.

Frozen/thawed meat quality associated with muscle fiber characteristics of porcine longissimus thoracis et lumborum, psoas major, semimembranosus, and semitendinosus muscles

To evaluate the relationship between muscle fiber characteristics and the quality of frozen/thawed pork meat, four different muscles, M. longissimus thoracis et lumborum (LTL), M. psoas major (PM), M. semimembranosus (SM), and M. semitendinosus (ST), were analyzed from twenty carcasses. Meat color values (lightness, redness, yellowness, chroma, and hue) changed due to freezing/thawing in LTL, which showed larger IIAX, IIX, and IIXB fibers than found in SM (P < 0.05). SM and ST showed a significant decrease in purge loss and an increase in shear force caused by freezing/thawing (P < 0.05). Compared with LTL, SM contains more type IIXB muscle fibers and ST had larger muscle fibers I and IIA (P < 0.05). PM was the most stable of all muscles, since only its yellowness and chroma were affected by freezing/thawing (P < 0.05). These results suggest that pork muscle fiber characteristics of individual cuts must be considered to avoid quality deterioration during frozen storage.

Color and Marbling as Predictors of Meat Quality Perception of Argentinian Consumers

In Argentina, color and intramuscular fat are the main attributes of raw beef quality; however, it is necessary to clarify how consumers use them, in order to establish different marketing strategies. Consumer preferences are affected by multiple factors. Thus, the objective of the present study was to identify the Argentinian consumer’s choice behavior regarding beef color and fat content. An online survey was carried out in Argentina. It inquired about socio-demographic characteristics, purchase and consumption habits and beliefs, showing pictures related to color, marbling and the amount of fat. Choice behavior was evaluated by asking why consumers chose a particular picture out of the ones shown. Several Kruskal–Wallis tests evaluated the different hypotheses. Three different decision trees using the CHAID analysis method were created. Multifactorial analysis was carried out for clustering consumers. Regarding consumer beliefs, 90% of the respondents agreed with the sentence, “The two main characteristics defining beef quality at purchase time are meat color and marbling”. Socio-demographic characteristics affected purchase habits and beliefs; they also affected perceptions about meat color and marbling. It was possible to build three consumer groups for future marketing strategies: “hedonic” focused on a pleasing sensory experience, “appearance” prioritized the visual aspects, and the “health-conscious” consumers were interested in their healthy nutrition.