Cyanidin inhibits adipogenesis in 3T3-L1 preadipocytes by activating the PLC-IP3 pathway

Cyanidin is the most abundant anthocyanin found in red-purple plants and possesses anti-obesity properties. However, its mechanism of action in adipocytes remains unknown. The objective of this study was to elucidate how cyanidin inhibits adipocyte formation in 3T3-L1 preadipocytes. Cells were cultured in adipogenic differentiation medium supplemented with cyanidin and examined for adipogenesis, cell viability, and adipocyte gene expression using Oil Red O staining, MTT assay, and RT-qPCR. Real-time Ca²⁺ imaging analysis was performed in living cells to elucidate cyanidin's mechanism of action. The results demonstrated that cyanidin (1-50 μM) supplementation to the adipogenic medium inhibited adipogenesis by downregulating adipogenic marker gene expression (PPARγ, C/EBPα, adiponectin, and aP2) without affecting cell viability after 4 days of treatment. Stimulation of cells with cyanidin (30-100 μM) increased intracellular Ca²⁺ in a concentration dependent manner with peak calcium increases at 50 μM. Pretreatment of cells with the phospholipase C (PLC) inhibitor U73122, inositol triphosphate (IP₃) receptor blocker 2-APB, and depletion of endoplasmic reticulum Ca²⁺ stores by thapsigargin abolished the Ca²⁺ increases by cyanidin. These findings suggested that cyanidin inhibits adipocyte formation by activating the PLC-IP₃ pathway and intracellular Ca²⁺ signaling. Our study is the first report describing the mechanism underlying the anti-obesity effect of cyanidin.

Antimicrobial Interventions to Reduce Shiga Toxin-Producing Escherichia coli (STEC) Surrogate Populations on Beef Striploins Intended for Blade Tenderization

ObjectivesBlade tenderization (BT) is used in the beef industry to improve tenderness of steaks prepared from subprimals but can translocate surface pathogens to the interior of meat. Application of antimicrobial solutions on the surface of subprimals prior to blade tenderization can reduce the risk of translocation of surface microorganisms. The objectives of this research were: 1) evaluate the efficacy of antimicrobial interventions applied to inoculated (surrogate Escherichia coli) beef striploins prior to blade tenderization; and 2) examine the transfer of E. coli from inoculated striploins to subsequent non-inoculated subprimals.Materials and MethodsThe anterior portion of whole muscle beef striploins (30.48 cm) were inoculated (lean side) across a 10 cm band with an approximately 8.00 log CFU/mL cocktail containing non-pathogenic, rifampicin-resistant surrogate STEC strains (BAA-1427, BAA-1428, BAA-1429, BAA-1430, and BAA-1431). The inoculated striploins were sprayed with (1) levulinic acid (5.0%) + sodium dodecyl sulfate (0.50%) (LVA+SDS), (2) peroxyacetic acid (2000 ppm; PAA; FCN 1666), (3) acidified sodium chlorite (1200 ppm; ASC), or (4) lactic acid (4.5%; LA) by passing through a spray cabinet and blade tenderized, along with an inoculated, non-sprayed control (CON). To evaluate the potential for cross-contamination of subsequent subprimals, an inoculated striploin (for each treatment) was blade tenderized followed by a non-inoculated beef striploin. For each striploin, surface and subsurface samples (2.54 cm wide) were collected from three different locations including the anterior, middle, and posterior end of each striploin. A total of 30 striploins across three replications were randomly assigned to treatment stratification. Sponge samples were also collected from the blade tenderizer (plate of the blade unit and blades) after each treatment group. Data were analyzed using Proc Mixed (SAS Inst., v.9.4; Cary, NC) as a completely randomized split-plot design. Microbial counts for all samples were log transformed and then analyzed for the main effects of antimicrobial treatment, location (anterior to posterior and surface or interior), and their interaction. Differences were considered significant at α ≤ 0.05.ResultsPAA was more effective in reducing E. coli populations (1.80 log CFU/g; P ≤ 0.05) and had lowest recovery of the microorganism from the striploin subsurface compared to other treatments, followed by LVA+SDS (1.00 log CFU/g). E. coli populations gradually decreased (P ≤ 0.05) on the surface and subsurface as sampling moved anterior to posterior. However, E. coli populations were similar (P > 0.05) on the posterior end of inoculated striploins and the anterior end of the subsequent, non-inoculated striploins, indicating transfer of microorganisms from one striploin to the following striploin. E. coli populations of 3.03 log CFU/cm2 and 2.47 log CFU/cm2 were recovered from the plate of the blade unit and the blades of the blade tenderizer. E. coli populations recovered from the plastic plate (3.46 log CFU/cm2) and blades (2.87 log CFU/cm2) of the blade tenderizer were the similar (P > 0.05) for all treatment groups except for PAA (1.41 log CFU/cm2 and 0.97 log CFU/cm2, respectively).ConclusionThese results showed that PAA and LVA+SDS can be used to improve the safety of blade tenderized beef.

Heat Mitigation Strategies for Finishing Beef Cattle During the Summer in the Southeastern United States Reduces Heat Load and Improves Weight Gain, but does not Influence Meat Quality

ObjectivesThe objective of this research was to determine the effect of heat mitigation strategies on meat quality when finishing cattle under heat stress conditions.Materials and MethodsForty-five Angus crossbred steers (446 ± 23 kg) were blocked by weight and randomly assigned to 1 of 3 finishing environments: shaded with fan (CWF), shaded without fan (CNF), or outside no shade (OUT). For 92 d steers were individually fed a corn-based total mixed ration and were weighed every 3 wk. Environmental monitors (Kestrel Instruments) were used to quantify heat load index (HLI) and accumulated heat load units (AHLU). When the first treatment group averaged 613 kg all steers were harvested. Carcass quality and yield data were collected 24 h postmortem. Strip loins were removed from the right side of each carcass at 24 h postmortem, vacuum packaged, and aged (2 ± 1°C) for 5 d. Strip loins were then fabricated into 2.54-cm steaks anterior to posterior. The first steak was designated for proximate analysis, followed by two steaks for slice shear force (14 and 21 d aging), two steaks for other analyses, and the remaining 7 steaks were randomly assigned to shelf life (SL) for 6 d following 28 d of wet aging. Steaks were vacuum packaged and held (2 ± 1°C) for their respective days of aging. After 28 d, shelf life steaks were opened, placed in Styrofoam trays with PVC overwrap, and placed in retail display cases (1 ± 2°C). Steaks were frozen (–20°C) once they reached their assigned day of wet aging or simulated shelf life. Objective color L* (lightness), a* (redness), b* (yellowness), and isobestic wavelengths were recorded daily (± 2 h). Hue, chroma, DE, and deoxymyoglobin (%Dmb), oxymyoglobin (%Omb), and metmyoglobin (%Mmb) were calculated. Data were analyzed using a mixed model (JMP v.13; SAS) and means were separated using LSmeans at a = 0.05.ResultsEnvironmental monitors showed that CWF and CNF had lower HLI and AHLU (P < 0.01) than OUT. Final weights were greater for CWF than OUT (P = 0.02) while CNF was similar (P ≥ 0.17) to both. Similar results were observed for hot carcass weights where CWF > OUT (P = 0.03), and CNF was similar to both (P ≥ 0.23). Treatment differences were not observed for USDA yield grade (P = 0.38), dressing percent (P = 0.93), kidney pelvic heart fat (P = 0.89), ribeye area (P = 0.47), backfat thickness (P = 0.49), marbling score (P = 0.71), overall maturity (P = 0.92), or subjective lean color (P = 0.16). No differences in fat color scores were observed between CNF and OUT (P = 0.95) while CWF were whiter (P ≤ 0.04) than both. Protein analysis showed CWF had more protein than OUT (P = 0.01) while CNF was similar to both (P ≥ 0.90). No differences were observed for lipid content (P = 0.99), ash (P = 0.39), or moisture (P = 0.92). Treatment nor day of aging effected slice shear force (P = 0.45 and P = 0.53, respectively). While treatment differences were not observed for a*, b*, hue, chroma and DE (P = 0.51, P = 0.65, P = 0.18 P = 0.57, and P = 0.57, respectively). Treatment values for L* were lighter for CNF than CWF (P = 0.04), while OUT was similar to both (P ≥ 0.14). There were no differences for %Dmb, %Omb, and %Mmb (P = 0.24, P = 0.32, and P = 0.39, respectively) among the treatments.ConclusionResults indicate that heat stress mitigation is a viable method to improve weight, however, does not impact the quality of the meat.

Influence of Utilizing Breast Meat Afflicted with Woody Breast Myopathy on Sausage Textural Properties

ObjectivesWoody breast (WB) myopathy reduces the utility and value of breast meat for the broiler industry. It is hypothesized that WB meat may be included in comminuted products to increase utility and ultimately add value to the broiler industry. Information on the textural and quality characteristics that WB inclusion has on further processed products is limited in the literature. The objective of this research was to evaluate the quality of sausage made with WB meat of varying degrees of severity.Materials and MethodsFor each of three replications, broiler breast meat (normal, moderate WB, and severe WB) and chicken abdominal fat were obtained from a commercial poultry processor. Breast meat was coarse ground (19-mm) and combined with fat (targeting 15%) to produce 10-kg batches representing 25, 50, and 100% moderate WB meat, 25, 50, 100% severe WB meat, and a 100% normal control. The batches were then re-ground (4.8-mm), mixed for 1 min with 1.5% salt, and stuffed into 35-mm natural casings. Links were placed in individual bags, cooked to 70°C in a water-bath, and allowed to cool to room temperature before hardness, cohesiveness, springiness, gumminess, and chewiness were evaluated using texture profile analysis. Individual sausage links were weighed before and after cooking and cook loss was calculated. Data were analyzed using SAS version 9.3 with a fixed effects design with replication as a random effect.ResultsSausage hardness tended to be softer (P = 0.06) as WB inclusion rate and severity increased. Cohesiveness and springiness values were similar between treatments (P = 0.53, P = 0.95, respectively). Gumminess decreased (P < 0.05) as severity and inclusion of WB increased indicating a lack of bind, which was further supported by the decline in chewiness (P < 0.05). The raw 25% moderate WB and 50% severe WB sausage links were similar in lightness values (L*) to the normal sausage links. In cooked sausage, 25% and 50% inclusion of WB meat regardless of severity were similar in lightness values (L*) compared to the 100% normal formulations.ConclusionWith no difference in cook loss (P = 0.08), the data presented indicates that moderate and severe WB meat can be included in the formulation of linked sausages to increase utility and value of broiler WB meat.

Evaluation of Pearl Millet With and Without Soybean Hull Supplementation for Forage-Finished Beef Production Systems

ObjectivesThe objective of this research was to evaluate pearl millet, a warm-season annual grass, with and without soybean hull supplementation for forage-finished beef production systems in the Southeast.Materials and MethodsEach year, 32 Angus-crossbred steers (339 ± 40 kg) were randomly assigned to one of four finishing treatments. Treatments were arranged in a 2 × 2 factorial and included two varieties of pearl millet, ‘Tifleaf 3’ (PM) and ‘Exceed’ brown mid-rib (BMR), and two levels of soybean hull supplementation, 0 and 0.75% of body weight d–1. Steers were on treatments for 90 and 84 d during the summers of 2017 and 2018, respectively, at the University of Georgia Department of Animal and Dairy Science Beef Research Unit located near Eatonton, GA. Shrunk weights were taken at initiation and termination of the finishing period and average daily gains (ADG) were calculated. At the end of the finishing period, steers were harvested under USDA inspection and carcass data was collected 24 h postmortem from the right side of each carcass. Striploins were then removed from the right side, vacuum packed, and allowed to age for 21 d prior to fabrication. Striploins were fabricated into 2.54-cm steaks and allocated to meats proximate (n = 1), 0 through 7 d of simulated shelf life (n = 8), trained sensory panel (n = 2), and instrumental tenderness analyses (n = 2). All data were analyzed using PROC GLIMMIX in SAS v. 9.4.ResultsSupplementation increased ADG over forage alone (P < 0.01) however, hot carcass weights were increased by supplementation in the PM steers only (P < 0.05). No treatment differences were observed for marbling score (P = 0.61), overall maturity (P = 0.49), 12th rib fat thickness (P = 0.21), ribeye area (P = 0.1668), and subjective fat color (P = 0.93). Objective carcass lean color values for L* and subjective lean color scores were different (P < 0.05). Treatment effects were also observed for carcass lean maturity scores (P < 0.05). No treatment differences were observed for meats proximate analysis (P > 0.05), instrumental tenderness as measured by Warner-Bratzler shear force (P = 0.94), initial and sustained tenderness (P = 0.66 and P = 0.29, respectively), beef and off-flavor intensities (P = 0.83 and P = 0.36, respectively), or juiciness (P = 0.54) as measured by a trained sensory panel. No treatment differences (P > 0.05) were observed for lipid oxidation or color change (Delta E) within any day of simulated shelf life. Calculated values for hue, chroma, and redness were unaffected (P > 0.05) by treatment within day of simulated shelf life.ConclusionResults indicate pearl millet is a viable forage option for forage-finished beef systems and soybean hull supplementation improves animal performance over forage alone with minimal impacts on carcass characteristics, meat quality, and shelf life.