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.

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.

Investigation of muscle-specific beef color stability at different ultimate pHs

Objective: This study was aimed to investigate the muscle-specific beef color stability at normal and high ultimate pHs.Methods: The impact of muscle (Longissimus lumborum [LL] vs psoas major [PM]) and pH (normal ultimate pH [Np] vs high pH dark cutting beef [Hp]) on color stability, indicated by basic color traits, metmyoglobin reducing activity (MRA) and oxygen consumption (OC), as well as the lipid oxidation, were determined over 7 days of display at 4°C.Results: Hp-LL had the highest pH (6.92), followed by Hp-PM (6.01), Np-PM (5.76), and Np-LL (5.52). Hp-LL had increased (p<0.05) a^*, chroma and % oxymyoglobin during display. Hp-LL also had the highest metmyoglobin (MMb) reducing activity and OC among all the samples, thus, the greatest color stability, although very dark throughout storage, with lowest values for lightness (L^*) and yellowness (b^*). Np-LL also exhibited relatively high color stability, as a result of its lower % MMb and OC and higher MRA than psoas muscle samples. The 0.2 unit difference of the pH between Hp and Np psoas muscle, resulted in the difference of the color intensity, not the color stability. Interestingly, high pH psoas muscle (Hp-PM) did not have better color stability than Np-PM, and in fact had lower color stability than even Np-LL. The similar level of OC and lipid oxidation cannot explain the difference in color stability between Hp-PM and Np-LL.Conclusion: The Hp does not always show better color stability compared with Np beef, which depends on the muscle type. The balance of MRA and OC is important to keep the color in great intensity and stability in the meantime.

The Applicability of Total Color Difference ΔE for Determining the Blooming Time in Longissimus Lumborum and Semimembranosus Muscles from Holstein-Friesian Bulls at Different Ageing Times

This study was conducted to determine the optimal blooming time in beef muscles based on ΔE, and to analyze the effects of muscle type and ageing time on beef color and blooming. Beef color was determined on freshly cut longissimus lumborum (LL, n = 8) and semimembranosus (SM, n = 8) muscles on days 1, 9, and 14 of ageing during 60 min blooming at 5 min intervals. It was found that ΔE0, representing the difference in color between freshly cut muscles and subsequently analyzed samples, supported the determination of the optimal blooming time, which varied across ageing times (15, 20, 25 min for the LL muscle, and 10, 15, 20 min for the SM muscle on days 1, 9, and 14 of ageing, respectively). Beef color was affected by both muscle type and ageing. The values of color parameters increased between days 1 and 9 of ageing. The results may have practical applications because beef should be presented to consumers and restaurant owners approximately 25 min after cutting, when its color has fully developed.

PSV-32 Pulmonary arterial pressure in cattle influences beef color during retail display

Pulmonary hypertension is a noninfectious disease of cattle at altitudes &gt; 1524 m (5,000 ft). Mean pulmonary arterial pressures (mPAP) ≥ 50 mmHg is used as an indicator for pulmonary hypertension in cattle. Meat quality attribute, such as color, critically influencing consumer purchase decision, is economically significant. However, the effect of pulmonary arterial pressures (PAP) on postmortem beef color has not been investigated. To examine this, instrumental color, metmyoglobin reducing activity (MRA), and lipid oxidation of aged strip loins (longissimus lumborum; LL) steaks from high PAP (98±13; n = 5) and low PAP score (41±3; n = 6) fattened Angus steers (i.e., live weight of ~600 kg) were evaluated during simulated retail display (day 1, 3, 5, 7, 9). A split-plot design was used to analyze the effects of PAP score and display day on instrumental color, MRA, and lipid oxidation. Data analysis was performed using R with the lme4 package as a mixed model, where PAP score (high or low), display day, and their interactions were the fixed effects, and random effect was individual steer. Differences between least square means (P &lt; 0.05) were determined by Tukey’s multiple comparisons. An interaction (P &lt; 0.05) between PAP score and display day for redness (a* value), chroma, hue, and MRA was observed. The LL steaks from high PAP score animal had lower (P &lt; 0.05) redness, chroma, and hue, than from low PAP score steer on day 9. A main effect (P &lt; 0.05) of display day on lipid oxidation of was observed, with lipid oxidation increasing as display days increased. The results of current study indicated that the LL steaks from steers with high PAP score have lower color stability than those from steers with low PAP score during simulated retail display. Research partially supported by USDA-NIFA grant: 2018-67015-28241.

Effect of High Pressure, Calcium Chloride and ZnO-Ag Nanoparticles on Beef Color and Shear Stress

This study investigates how the use of a combination of high-pressure treatment, steak marination and active packaging influences beef color and shear stress. A 2 × 2 × 2 × 3 factorial design was applied, including pressure, marination, packaging and storage time. Many significant interactions among factors were found, but the effects of pressure and marination were so high that the effect of packaging was almost undetectable. Independent of storage type, pressurized treatments presented higher values for both L* and hab than unpressurized treatments, and independent of pressure application, the increase in L* and hab with storage time was higher for marinated treatments than for unmarinated treatments. In unpressurized samples, marination provoked an increase in L*, a* and hab and a decrease in C a b ∗ , whereas in pressurized samples, marination had no effect on color. Pressurized samples always showed higher values for shear stress (on average 71% higher) than unpressurized samples.

Relationships of a Detailed Mineral Profile of Meat with Animal Performance and Beef Quality

The mineral profile of beef is a subject of human health interest, but also animal performance and meat quality. This study analyzes the relationships of 20 minerals in beef inductively coupled plasma-optical emission spectrometry (ICP-OES) with three animal performance and 13 beef quality traits analyzed on 182 samples of Longissimus thoracis. Animals’ breed and sex showed limited effects. The major sources of variation (farm/date of slaughter, individual animal within group and side/sample within animal) differed greatly from trait to trait. Mineral contents were correlated to animal performance and beef quality being significant 52 out of the 320 correlations at the farm/date level, and 101 out of the 320 at the individual animal level. Five latent factors explained 69% of mineral co-variation. The most important, “Mineral quantity” factor correlated with age at slaughter and with the beef color traits. Two latent factors (“Na + Fe + Cu” and “Fe + Mn”) correlated with performance and beef color traits. Two other (“K-B-Pb” and “Zn”) correlated with beef chemical composition and the latter also with carcass weight and daily gain, and beef color traits. Beef cooking losses correlated with “K-B-Pb”. Latent factor analysis appears be a useful means of disentangling the very complex relationships that the minerals in beef have with animal performance and beef quality traits.

Effects of Finishing Diet and Packaging on Longissimus Dorsi Color

ObjectivesMeat color is extremely influential in purchasing decisions as consumers associate a bright-red color with freshness. The type of finishing diet can influence beef color. Previous studies have shown that grass-finished cattle have darker muscle color than grain-finished cattle. With the use of modified atmospheric packaging (MAP), beef purveyors are able to vary the gas compositions within a package and enhance beef color. However, limited studies have determined the effects of modified atmospheric packaging on grass-finished beef color. The objective of this study was to determine how finishing diet and packaging type affects the color of the longissimus dorsi (LD) muscle.Materials and MethodsDuring the stocker period, all of the cattle were on a forage diet. Cattle were then randomly assigned to either a conventional grain-based diet or an alfalfa pasture diet for finishing. Both conventionally and pasture-finished cattle were fed for 91 d. Cattle were slaughtered on the same day at a commercial beef processing facility under normal conditions and chilled for approximately 30 h. After grading, one strip loin from each carcass was collected and transported to Oklahoma State University. At 11 d postmortem, one steak (n = 60) from each strip loin was vacuum packaged and randomly assigned to display. Those steaks were then randomly assigned to PVC, HiOx-MAP (80% oxygen and 20% carbon dioxide), or CO-MAP (0.4% carbon monoxide, 69.5% nitrogen, and 30% carbon dioxide) packaging and were displayed under retail conditions for 5 d. Muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were all analyzed by a trained panel (n = 6). MD was evaluated only on d 0 and MC and SD were scored once every 24 h for 0, 1, 2, 3, and 4 d. Lipid oxidation was measured by thiobarbituric acid reactive substances (TBARS) assay on d 4. Data were analyzed using the Mixed Procedure of SAS.ResultsThere was a significant display day by finishing diet by packaging interaction (P < 0.05) for muscle color and surface discoloration. There was also a significant finishing diet by packaging interaction (P < 0.05) for muscle darkening. Steaks packaged in HiOx-MAP remained the most stable in color and the brightest cherry-red colored throughout display time (P < 0.05) compared with other packaging types. PVC was the most discolored (P < 0.05) on d 3 and 4 when compared to HiOx-MAP and CO-MAP with the grain-finished PVC packaged steaks showing the most discoloration on d 4. Pasture-finished steaks packaged in CO-MAP displayed the darkest colored muscle (P < 0.05) on d 0. Steaks packaged in PVC had a higher amount of lipid oxidation (P < 0.05) compared with other packaging types.ConclusionThese results indicate that HiOx-MAP more effectively maintains the desired beef color of bright cherry-red for pasture-finished beef. The results also indicate that the use of appropriate packaging type can minimize the losses due to discoloration of steaks from either grain or grass-finished beef.