A comparison of fatty acid percentages and mass, sensory attributes, and volatile aroma compounds for segregating beef quality grades

Journal of Animal Science · 2025-01-01 · 4 citations

We hypothesized that combining sensory flavor attributes, volatile aroma compounds (VAC), and fatty acid composition would better separate beef quality grades than fatty acid composition alone. Select, Choice, Prime, and Grass-fed ribeye rolls (n = 6 per group) were purchased from a local distributor, so production conditions or cattle type were unknown. Select cooked beef steaks ranked lowest for Beef Flavor, Bloody/Serumy, Brown/Roasted, and Umami (P ≤ 0.048). Prime steaks had greater values than other steak types for the VAC 2-methyl-butanal, 2-methyl-propanal (2MP), 3-methyl-butanal (3MB), and 3-hydroxy-2-butanone (3H2B) (P ≤ 0.025). There was a significant, positive correlation of 3MB and 3H2B with Beef Flavor (P ≤ 0.05), and 2MB, 3MB, and 2MP were significantly, positively correlated with Brown/Roasted (P ≤ 0.05). Principal component analysis (PCA) that included fatty acid percentages indicated that all positive flavor attributes clustered with 2MP and 3H2P, Grass-fed, and Prime. A PCA analysis that included mg fatty acid/100 g muscle (i.e., fatty acid mass) segregated all positive flavor attributes and all fatty acids with Grass-fed and Prime steaks, but VAC were not in the same quadrant. Fatty acid percentages, sensory attributes, and VAC were analyzed by partial least squares discriminant analysis (PLS-DA) with Beef Flavor Identity as the dependent variable. Fatty acid composition alone could not completely segregate beef types. Analysis by PLS-DA with fatty acid percentage or mass, combined with sensory attributes and VAC, indicated that all beef types were distinctly separated. We conclude that the combination of sensory attributes, VAC, fatty acid composition better separate beef quality types than fatty acid percentages or mg fatty acid/100 g muscle alone.

Oleic acid concentration in bovine adipose tissues: impact on human health, sensory attributes, and genetic regulation

Frontiers in Animal Science · 2024-01-29 · 11 citations

Fatty acids are important components of foods derived from livestock species, as they contribute to the healthfulness and benefits of beef and beef products. Oleic acid (18:1n-9) is the most highly regulated and most abundant fatty acid in animal tissue. The greatest risk factor for cardiovascular disease (CVD) is low circulating high-density lipoprotein cholesterol (HDL-C), and consumption of beef naturally enriched with oleic acid increases plasma HDL-C concentrations in men and women. Oleic acid is synthesized by the activity of stearoyl-coenzyme A (CoA) desaturase (SCD). In cattle, SCD activity and SCD1 gene expression are highest in adipose tissue depots, followed by skeletal muscle, intestinal mucosa, and the liver. Early studies demonstrated that the concentration of oleic acid beef contributes to positive flavor attributes, but this finding has been difficult to replicate in more recent studies. Including grain (especially corn) in the finishing diets of cattle is essential for the upregulation of SCD1 expression and activity. The measurement of SCD activity is technically difficult, but quantifying SCD gene expression or the concentration of palmitoleic acid (16:1n-7) in beef often provides insight into SCD activity. DNA polymorphisms in SCD1 , the sterol regulatory element binding protein-1, the fatty acid synthase, and the growth hormone are associated with oleic acid concentration in the muscle of Japanese Black cattle, indicating a strong genetic component to the regulation of fatty acid composition of beef.

139 Metabolic regulation of intramuscular adipose tissue development

Journal of Animal Science · 2024-09-01

Abstract Acetate arguably is the most important substrate for de novo fatty acid biosynthesis in bovine adipose tissue. However, including glucose in incubation media in vitro strongly stimulates fatty synthesis from acetate; additionally, glucose carbon is essential for triacylglycerol synthesis from acetate. Our laboratory is unique in that we utilize bovine intramuscular (i.m.) and subcutaneous (s.c.) adipose tissue explants dissected from beef longissimus muscle immediately post-exsanguination to study bovine adipose tissue metabolism. Four decades ago, using this experimental technique, we established that glucose is a primary substrate for fatty acid biosynthesis in i.m. adipose tissue. Recent research in our laboratory has addressed the hypothesis that acetate and/or long-chain fatty acids (LCFA) differentially affect lipid filling of i.m. and s.c. adipose tissue. We had previously demonstrated that, whereas s.c. adipose tissue is highly responsive to isoproterenol (a non-selective ß-adrenergic agonist), i.m. adipose tissue is relatively refractory to isoproterenol. This subsequently was confirmed in our laboratory utilizing primary cultures of bovine s.c. and i.m. adipocytes. We currently are focusing on the G-coupled protein receptors-43 (GPR43) and GPR120. Several previous studies from our laboratory have documented GPR43 expression in i.m. and s.c. adipose tissue, and we more recently demonstrated GPR120 expression in bovine adipose tissues. Acetate is a ligand for GPR43, whereas LCFA are ligands for GPR120. The binding of ß-adrenergic agonists to ß-adrenergic receptors increases the production of cyclic adenosine monophosphate (cAMP), whereas binding of acetate and LCFA to GPR43 and GPR120, respectively, decreases cAMP production. Thus, binding of circulating acetate and LCFA to their respective GPR receptors putatively should lead to increase lipid filling of bovine adipose tissues. A current study from our laboratory demonstrated that acetate had no effect on forskolin-stimulated cAMP production in i.m. or s.c. adipose tissue explants unless the culture medium also included oleic acid (18:1n-9). A subsequent study confirmed that oleic acid and palmitic acid (16:0), but not acetate, strongly depressed forskolin-stimulated cAMP production in s.c. adipose tissue explants; oleic and palmitic acid were much less effective in depressing cAMP production in i.m. adipose tissue explants. Unusually, GPR43 expression was detected in neither s.c. adipose tissue nor i.m. adipose tissue in our most recent study, whereas GPR120 expression was readily detected in both adipose tissue types. We conclude the following from these recent studies: LCFA binding to GPR120 is more effective than acetate binding to GPR43 in promoting lipid filling in bovine adipose tissue; and LCFA binding to GPR120 putatively would promote greater lipid filling in s.c. adipose tissue than in i.m. adipose tissue.

Assessment of Vascular Function in Response to High-Fat and Low-Fat Ground Beef Consumption in Men

Nutrients · 2023-03-15 · 3 citations

Red meat is stigmatized as an unhealthy protein choice; however, its impacts on vascular function have not been evaluated. We aimed to measure the vascular impact of adding either low-fat (~5% fat) ground beef (LFB) or high-fat (~25% fat) ground beef (HFB) to a habitual diet in free-living men. Twenty-three males (39.9 ± 10.8 years, 177.5 ± 6.7 cm, 97.3 ± 25.0 kg) participated in this double-blind crossover study. Assessment of vascular function and aerobic capacity were measured at entry and in the last week of each intervention and washout period. Participants then completed two 5-week dietary interventions (LFB or HFB; 5 patties/week) in a randomized order with a 4-week washout. Data were analyzed via 2 × 2 repeated-measures ANOVA (p < 0.05). The HFB intervention improved FMD relative to all other time points, while lowering systolic (SBP) and diastolic blood pressure (DBP) relative to entry. Neither the HFB nor the LFB altered pulse wave velocity. The addition of either low- or high-fat ground beef did not negatively alter vascular function. In fact, consuming HFB improved FMD and BP values, which may be mediated by lowering LDL-C concentrations.

Laboratory synthesized meat

Elsevier eBooks · 2023-04-18

The Dose–Response Effect of Docosahexaenoic Acid on the Omega-3 Index in American Football Athletes

Medicine & Science in Sports & Exercise · 2023-01-10 · 14 citations

PURPOSE: American-style football (ASF) players are at increased risk for head injuries and cardiovascular disease. n-3 polyunsaturated fatty acids are cardioprotective, and emerging evidence suggests benefits for protection against head injuries. However, fundamental knowledge of n-3 polyunsaturated fatty acid dosing in athletes such as ASF players remains poorly understood. Therefore, this study investigated the dose-response effect of docosahexaenoic acid (DHA) supplementation in red blood cells (RBC) and as the Omega-3 Index (O3I), in collegiate ASF players throughout a competitive season. METHODS: Sixty-nine ASF players were randomly assigned placebo (corn oil), or 2, 4, or 6 g·d -1 of DHA supplement. Blood samples were collected at eight time points (T1-T8) over 27 wk. RBC were extracted and analyzed by gas-liquid chromatography. Compliant players who had samples collected at all time points were analyzed. A repeated-measures ANOVA was conducted to assess the dose-response effect of DHA over time, and between-group differences at individual time points were assessed by one-way ANOVA followed by Tukey post hoc test. RESULTS: A significant dose and time interaction was found, and all supplement groups had significantly greater DHA in RBC compared with placebo from T2-T8 ( P < 0.05). Athletes receiving 6 g·d -1 of DHA had the greatest O3I, relative to other groups, and the O3I reached steady state by 15 wk. The 6 g·d -1 group surpassed >8% on the O3I at approximately twice the rate of the 4 g·d -1 group (8 vs 15 wk). CONCLUSIONS: Our findings provide important fundamental knowledge demonstrating a dose-response incorporation of DHA into RBC membranes up to 6 g·d -1 . Furthermore, 6 g·d -1 of DHA can be used to rapidly achieve a desired O3I (>8%) in athletes in only 8 wk.

ß-adrenergic agonists and muscle growth

Elsevier eBooks · 2023-08-30

GPR120 Gene expression and activity in subcutaneous and intramuscular adipose tissues of Angus crossbred steers

Journal of Animal Science · 2023-01-01 · 2 citations

We hypothesized that media long-chain fatty acids (LCFA) would more greatly depress cyclic adenosine monophosphate (cAMP), glycerol, and free fatty acid (FFA) concentrations in subcutaneous (s.c.) adipose tissue than in intramuscular (i.m.) adipose tissue via G protein-coupled receptor 120 (GPR120). The GPR120 receptor binds to LCFA, which reduces cAMP production, thereby causing a depression in lipolysis. Fresh ex vivo explants of s.c. and i.m. adipose tissue from the fifth to eighth longissimus thoracic rib muscle section of 8, 22-mo-old Angus crossbred steers were transferred immediately to 6-well culture plates containing 3 mL of Krebs-Henseleit buffer/Hepes/5 mM glucose. Samples were preincubated with 0.5 mM theophylline plus 10 μM forskolin for 30 min, after which increasing concentrations of acetate or propionate (volatile fatty acids, VFA) (0, 1, 5, and 10 mM) in the absence or presence of 100 µM oleate (18:1n-9) or 100 μM palmitate (16:0) (LCFA) were added to the incubation media and incubated an additional 30 min. Main effects of adipose tissue depot (i.m. vs. s.c) and VFA (acetate vs. propionate) for adipose tissue concentrations of forskolin-stimulated cAMP were P = 0.747 and P = 0.106, respectively. The addition of LCFA to the media depressed adipose tissue concentrations of cAMP (P = 0.006) (LCFA main effects). The Tissue × VFA × LCFA interaction was not significant for any dependent variable (P ≥ 0.872). Therefore, concentrations of cAMP, glycerol, and FFA were analyzed separately for i.m. and s.c. adipose tissue by split-plot analysis. Concentrations of cAMP, glycerol, or FFA in i.m. and s.c. adipose tissue were not affected by increasing concentrations of VFA (P ≥ 0.497). Media LCFA had no effect on i.m. adipose tissue cAMP (P = 0.570) or glycerol (P = 0.470) but depressed i.m. adipose tissue FFA (P < 0.001). In s.c. adipose tissue, LCFA decreased concentrations of cAMP (P = 0.042) and glycerol (P = 0.038), but increased FFA concentration (P = 0.026). Expression of GPR120 (P = 0.804) and stearoyl-CoA desaturase (P = 0.538) was not different between s.c. adipose tissue and i.m. adipose tissue. The binding of VFA to the GPR43 receptor depresses cAMP production, thereby attenuating lipolysis, but GPR43 mRNA was undetectable in those adipose tissue samples. These results provide evidence for functional GPR120 receptors in s.c. adipose tissue but question the role of GPR43 in the accumulation of adipose tissue lipids in growing steers.

Consuming High-Fat and Low-Fat Ground Beef Depresses High-Density and Low-Density Lipoprotein Cholesterol Concentrations, and Reduces Small, Dense Low-Density Lipoprotein Particle Abundance

Nutrients · 2023-01-10 · 6 citations

We hypothesized that consumption of high-fat (HF) ground beef (24% fat) would not affect plasma concentrations of high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein (LDL-C), whereas low-fat (LF) ground beef (5% fat) would decrease HDL-C and LDL-C concentrations. In a randomized 2-period crossover, controlled feeding trial, 25 men (mean age and body mass index, 40 years and 31.2) consumed 115-g HF or LF patties, 5/week for 5 weeks with a 4-week washout. The HF treatment increased % energy from fat (p = 0.006) and saturated fat (p = 0.004) and tended (p = 0.060) to depress % energy from carbohydrates. The HF and LF treatments decreased the plasma concentrations of HDL-C (p = 0.001) and LDL-C (p = 0.011). Both ground beef treatments decreased the abundance of HDL3a and increased the abundance of HDL3 (p ≤ 0.003); the LF treatment also decreased the abundance of HDL2b and HDL2a (p ≤ 0.012). The HF and LF treatments decreased the abundance of LDL3 and LDL4 (p ≤ 0.024) and the HF treatment also decreased LDL5 (p = 0.041). Contrary to our hypothesis, the HF treatment decreased plasma HDL-C and LDL-C concentrations despite increased saturated fat intake, and both treatments decreased the abundance of smaller, denser LDL subfractions.

The Effect of Choline and Resistance Training on Strength and Lean Mass in Older Adults

Nutrients · 2023-09-06 · 8 citations

Choline plays many important roles, including the synthesis of acetylcholine, and may affect muscle responses to exercise. We previously observed correlations between low choline intake and reduced gains in strength and lean mass following a 12-week resistance exercise training (RET) program for older adults. To further explore these findings, we conducted a randomized controlled trial. Three groups of 50-to-69-year-old healthy adults underwent a 12-week RET program (3x/week, 3 sets, 8–12 reps, 70% of maximum strength (1RM)) and submitted &gt;48 diet logs (&gt;4x/week for 12 weeks). Participants’ diets were supplemented with 0.7 mg/kg lean/d (low, n = 13), 2.8 mg/kg lean/d (med, n = 11), or 7.5 mg/kg lean/d (high, n = 13) of choline from egg yolk and protein powder. The ANCOVA tests showed that low choline intake, compared with med or high choline intakes, resulted in significantly diminished gains in composite strength (leg press + chest press 1RM; low, 19.4 ± 8.2%; med, 46.8 ± 8.9%; high, 47.4 ± 8.1%; p = 0.034) and thigh-muscle quality (leg press 1RM/thigh lean mass; low, 12.3 ± 9.6%; med/high, 46.4 ± 7.0%; p = 0.010) after controlling for lean mass, protein, betaine, and vitamin B12. These data suggest that low choline intake may negatively affect strength gains with RET in older adults.