No abstract

Our objective was to determine the relationship between heifer carcass maturity and beef palatability of the longissimus lumborum (LM) and biceps femoris (BF). Left sides of A (n = 30), B (n = 30), and C (n = 30) maturity heifer carcasses under 30 mo of age by dentition were used. Carcasses were selected to ensure similar marbling scores across maturity groups (Small to Modest). Beef strip loins (LM) and outside rounds (BF) were obtained from these carcasses. Steaks were used to measure color stability, lipid oxidation (thiobarbituric acid reactive substances; TBARS), Warner-Bratzler shear force (WBSF), soluble and insoluble collagen, and consumer sensory perceptions. Heifer carcass maturity did not affect pH, fluid loss, WBSF, or collagen content of LM or BF steaks (P > 0.29). In LM and BF steaks, a maturity × day of retail display interaction occurred for TBARS, in which B maturity steaks had lower levels of lipid oxidation compared with A and C maturity steaks from the fourth day to the end of the retail display (P < 0.01). Nevertheless, LM steaks from B maturity carcasses tended to have lower overall acceptability (P = 0.08) and juiciness (P = 0.09) than steaks from C maturity carcasses, but steaks from B and C maturity carcasses did not differ from LM steaks obtained from A maturity carcasses. No differences in tenderness or flavor were observed due to maturity (P > 0.24). Similarly, maturity had no effect on sensory characteristics of BF steaks (P > 0.30). In conclusion, our results indicate that advanced physiological maturity does not decrease palatability of strip loin or outside round steaks from carcasses of heifers under 30 mo of age.

Identifying non-allergenic, natural water binders to increase beef patty juiciness and extend shelf life would be beneficial to the beef industry. The objective of this study was to determine the effect of integrating water binders into beef hamburger patties on cooking yield, shelf life, and pH. Five water binder treatments were added at 2% of the meat block. Treatments included potato extract, citrus fiber, dried refried beans, and potato peel, or no binder (control). Six batches of each treatment were made and two patties from each batch were analyzed for each parameter. Fluid yield and lipid oxidation were measured on cooked, frozen (210 days), and reheated patties. Raw patties were used to evaluate color, fluid loss, and lipid oxidation over four days of retail display. Patties containing citrus fiber improved reheat yield (P = 0.03) and overall yield (P < 0.01). Citrus patties had the lowest pH (P < 0.01) at 5.45. On day 0 and day 4 of retail display, patties containing a water binder treatment had less lipid oxidation than the control patties (P < 0.01). Additionally, the cooked, frozen, and reheated patties, had less lipid oxidation when containing a water binder treatment than the control patties (P < 0.01). Citrus fiber improved water retention in reheated patties, and all water binders delayed lipid oxidation in raw, cooked, frozen, and reheated patties. Increasing patty juiciness and delaying lipid oxidation will improve consumers’ eating experience of reheated, precooked patties in settings such as school or hospital cafeterias.

No abstract

ObjectivesThe study objectives were to compare the deep (D) vs. superficial (S) portions of the beef top round (NAMI #169A PSO1), semimembranosus (SM) muscle, for tenderness, lipid oxidation, and color.Materials and MethodsTo simulate the retail setting, USDA Choice top rounds (n = 12) were purchased from a commercial food distributer and delivered to the University of Idaho Meat Science Laboratory under refrigeration. Top rounds were aged for 21 to 24 d from their pack date prior to removing the SM for subsequent analysis. Four steaks were cut from each SM proximally to distally. To account for steak location, steaks were systematically assigned to one of the following analyses; Warner-Bratzler Shear Force (WBSF) measurement, lipid oxidation using the Thiobarbituric Acid Reactive Substances (TBARS) method, subjective and objective color analysis on the whole steak to calculate color uniformity (two-toning), and subjective and objective color of a steak separated into D and S portions. The separating cut was made approximately two inches from the superficial edge of the steak. After cutting, WBSF steaks were cooked on clamshell grills to an internal temperature of 71°C. Steaks were then chilled overnight before 6 cores were sheared perpendicular to the muscle fiber direction on a WBSF machine. Steaks were sampled and evaluated for TBARS on Days 0 and 4 of retail display, while color was evaluated subjectively and objectively on Days 0, 1, 2, 3, and 4 of retail display. Steaks used for TBARS and color analysis were placed on white Styrofoam trays, overwrapped with an oxygen permeable PVC film, and displayed in a glass-fronted retail display case at 3°C for 4 d to simulate retail display. Data were analyzed using the mixed models procedure of the Statistical Analysis System (SAS Institute, Inc., Cary, NC) and significance was determined at P < 0.05.ResultsMean Warner-Bratzler shear force values were lower (P = 0.0012) in the S (4.2 kg) than the D (5.2 kg) portion of the SM. On Day 0, D and S portions had similar TBARS values (0.172 vs. 0.118 mg MDA/kg Meat); yet, by Day 4, the D portion had substantially greater TBARS values than the S portion (0.497 vs. 0.194 mg MDA/kg Meat; treatment × day of retail display interaction, P < 0.0001). The D portion was lighter (higher L*; P < 0.0001) colored than the S portion. Furthermore, the D portion became less red compared to the S portion during simulated retail display (treatment × day of retail display interaction; P < 0.0001). The whole steak had greater levels of two-toning initially, as well as throughout the 4 d of retail display, compared to the D and S portions (treatment × day of retail display interaction; P < 0.0001). Therefore, cutting top round steaks into a D and S portion would result in the steaks being more uniform in color. Additionally, the S portion has longer shelf-life as well as improved tenderness compared to the D portion.ConclusionIn conclusion, the S portion may be able to generate a premium compared to the whole steak at the retail level because of its superiority in color to the D portion and more uniform color compared to the whole steak.