The Effect of Increased Pork Hot Carcass Weights and Varying Chop Thicknesses on Consumer Visual Appearance and Purchase Intent Ratings of Top Loin Chops

ObjectivesThe objective of this study was to evaluate the effect of increased pork hot carcass weights on consumer visual acceptability and purchase intent ratings of top loin chops cut to various thicknesses in a price labeled versus unlabeled retail display scenario.Materials and MethodsPigs in this study were intentionally raised to reach heavier hot carcass weights when compared to industry standards. Pork loins (N = 200) were collected from 4 different hot carcass weight groups: a light weight (LT; less than 111.8 kg), medium-light weight (MLT; 111.8 to 119.0 kg), medium-heavy weight (MHVY; 119.1 to 124.4), and a heavy weight (HVY; 124.4 and greater). Loins were fabricated into 4 pairs of chops of specified thicknesses (1.27, 1.91, 2.54, and 3.18 cm) at Day 7, 8, or 9 postmortem. For each chop loineye area, length and width were measured. One chop from each specified thickness was then randomly assigned to be packaged with a label containing package price and weight information. The other paired chop was packaged without a label. Consumers (N = 393; 8 per panel) from the Manhattan, KS, area assessed chops from each weight group × thickness combination in both labeled and unlabeled scenarios. Chops were assessed on a 0 to 100 continuous line scale for desirability and purchase intent. Consumers were also able to indicate “yes” or “no” if the chop was either desirable and if they would purchase the chop.ResultsAs hot carcass weight increased, there was an increase in loineye area and chop length, with chops from HVY carcasses having greater (P < 0.05) loineye areas and lengths compared to all other weight treatments. For both appearance and purchase intent ratings, chops from HVY carcasses were given higher (P < 0.05) ratings compared to LT chops. Additionally, consumers gave greater (P < 0.05) appearance ratings to thicker cut chops. There was a hot carcass weight × chop thickness interaction (P < 0.05) for the percentage of consumers that indicated the chop was desirable overall. Regardless of hot carcass weight treatment, chops with a thickness of 1.27 cm had the lowest (P < 0.05) percentage of consumers indicate they were desirable overall. Within the LT and MLT weight treatments, chops with a thickness of 1.91 and 2.54 cm were similar (P > 0.05) with the greatest (P < 0.05) percentage of consumers who indicated they were desirable. Within the HVY weight treatment, chops with a thickness of 2.54 cm had the greatest (P < 0.05) percentage of consumers who indicated they were desirable. A greater (P < 0.05) percentage of consumers indicated “yes” they would purchase chops cut to a thickness of 2.54 cm compared to all other thicknesses. Additionally, there was a greater (P < 0.05) percentage of consumers who indicated they would purchase chops that were unlabeled compared to chops labeled with weight and pricing information.ConclusionThese results indicate that carcass weight and chop thickness can affect consumer preference and purchasing decisions. Thus, both should be considered by retailers when marketing fresh pork top loin chops.

Characterizing Pork Quality of Carcasses with an Average Weight of 119 Kg

ObjectivesBetween 1995 and 2018, average hot carcass weight of U.S. pork carcasses increased from 82 kg to 96 kg, which is an increase of approximately 17%. At current rates, pork carcasses in the U.S. will weigh on average, 105 kg by the year 2030 and over 118 kg by 2050. Although this represents an increase in throughput efficiency due to increases in economy of scale, projecting continued increases in the future raises some concerns. Therefore, the objective was to characterize pork quality of carcasses ranging from 78 to 145 kg with a mean weight of 119 kg.Materials and MethodsCarcass composition, such as hot carcass weight (HCW), back fat depth and loin depth were measured on 666 carcasses. Additionally, loin quality measurements, such as pH, loin instrumental and visual color, and iodine value of clear plate fat were measured on approximately 90% of the total population. Ham quality, 14 d aged loin and chop quality measurements, and loin chop slice shear force (SSF) were evaluated on approximately 30% of the total population. Finally, myosin heavy chain fiber type determination was completed on approximately 50 carcasses selected from carcasses ranging from 97 to 133 kg. The slope of regression lines and coefficients of determination between hot carcass weights and quality traits were calculated using the REG procedure in SAS and considered significantly different from 0 at P ≤ 0.05.ResultsAs HCW increased loin depth (b1 = 0.2496, P < 0.0001), back fat depth (b1 = 0.1374, P < 0.0001), loin weight (b1 = 0.0345, P < 0.0001), chop weight (b1 = 1.6626, P < 0.0001), and ham weight (b1 = 0.1044, P < 0.0001) increased. There was a decrease in estimated lean (b1 = –0.0751, P < 0.0001) and iodine value (b1 = –0.0923, P < 0.0001) as carcass weight increased, however, HCW only accounted for ≤ 24% (R2 = 0.24) of the variation in estimated lean and iodine value. Additionally, there were no significant differences in gluteus medius pH (b1 = 0.0009, P = 0.30) or instrumental lightness (b1 = 0.0301, P = 0.15), redness (b1 = –0.0036, P = 0.73) or yellowness (b1 = 0.0058, P = 0.57) of the ham as carcass weight increased. As carcass weight increased, 1 d loin instrumental yellowness (b*) increased (b1 = 0.0092 P < 0.01), however HCW only explained 1% of the variation in b*. Heavier carcasses were more tender (decreased SSF of chops cooked to 71°C, (b1 = –0.0674, P < 0.0001), although HCW only explained 9% of the variation in SSF. Total cook loss of chops used for SSF determination decreased as HCW increased (b1 = –0.0512, P < 0.0001), and HCW explained 15% (R2 = 0.15) of the variation in total cook loss. There were no significant differences in fiber type percentage, type 1 (b1 = –0.0170, P = 0.81), 2a (b1 = –0.0786, P = 0.23), 2x (b1 = –0.0201, P = 0.80), or 2b (b1 = 0.1224, P = 0.37), or fiber type area, type 1 (b1 = –26.6331, P = 0.22), 2a (b1 = –40.7257, P = 0.07), 2x (b1 = –46.9459, P = 0.25), or 2b (b1 = –26.2537, P = 0.38) as HCW increased.ConclusionDue to the lack of variation explained by HCW (≤ 15%), pork quality traits are not expected to be compromised as HCW continues to increase. The results suggest that increasing HCW to 119 kg did not have detrimental effects on pork quality attributes.

Consumer Sensory Evaluation of Beef Top Sirloin Cap Steaks from Four USDA Quality Grades

ObjectivesThe objective of this study was to evaluate the influence of quality grade on the palatability of beef top sirloin cap (biceps femoris) steaks.Materials and MethodsFour quality treatments [Prime, Top Choice (Modest and Moderate marbling), Low Choice and Select] were equally represented (n = 15/treatment) from beef top sirloin caps (IMPS # 184D). Sirloin caps were fabricated into 2.5 cm steaks from posterior to anterior following a 28-d aging period and randomly assigned to one of 3 analysis methods: Warner-Bratzler shear force (WBSF), fat and moisture analysis, and consumer sensory analysis. Steaks were cooked on a clamshell grill (Cuisinart Gridler Deluxe, Model GR-150, East Windsor, NJ) to a peak medium (71°C) degree of doneness monitored using a thermometer (Super-Fast Thermopen, ThermoWorks, American Fork, UT). Consumers (N = 118) evaluated each sample for juiciness, tenderness, flavor liking, and overall liking on a 0 to 100-point continuous line scales. Additionally, consumers rated each trait as either acceptable or unacceptable and classified all samples as one of 4 quality levels: unsatisfactory, everyday quality, better than everyday quality, or premium quality. Data were analyzed as a completely randomized design with the fixed effect of quality treatment.ResultsConsumers rated Top Choice, Low Choice, and Select similar (P < 0.05) for overall like, however, Prime rated (P < 0.05) higher than all other treatments. Also, Prime and Top Choice were similar (P > 0.05) for flavor liking, with Low Choice and Select also similar to Top Choice (P > 0.05). There was no difference (P > 0.05) among the quality treatments for tenderness and juiciness ratings. Similar to the rating results, when evaluating the percentage of samples rated acceptable for each palatability trait, no differences (P > 0.05) were found among quality treatments for tenderness, juiciness, and flavor, with all traits rated over 71.5% acceptable. However, a greater (P < 0.05) percentage of Prime samples were rated acceptable overall compared to Low Choice and Select. Additionally, there was no difference (P > 0.05) among the quality treatments for the percentage of samples classified as unsatisfactory. Consumers perceived a similar (P > 0.05) percentage of Top Choice and Low Choice samples at each quality level. Moreover, Prime had a greater percentage (P < 0.05) of samples perceived as Premium Quality than Select. For WBSF, there were no differences (P > 0.05) among treatments. Prime steaks had a similar (P > 0.05) moisture percentage as all other treatments, with Select having the greatest (P < 0.05) percentage of moisture compared to Top Choice and Low Choice. Furthermore, Top Choice and Low Choice had a similar (P > 0.05) percentage of fat, with Prime having the highest (P < 0.05) fat percentage and Select having the lowest (Prime > Top Choice = Low Choice > Select).ConclusionThese results indicate that quality grade has minimal impact on the palatability of beef top sirloin cap steaks. Therefore, food service does not need to pay the extra premiums associated with a higher grading product, as consumers will experience the same eating experience as with lower quality grades.

The Effect of Increased Pork Hot Carcass Weights on Loin Quality and Palatability

ObjectivesThe objective of this study was to evaluate the effects of pork hot carcass weight on loin quality and palatability of top loin chops.Materials and MethodsThe pigs in this study were raised to exceed standard market weights. Pork loins (N = 200) were collected from 4 different hot carcass weight groups: light (LT; less than 111.8 kg), medium-light (MLT; 111.8- 119.1 kg), medium-heavy (MHVY; 119.1- 124.4), and a heavy (HVY; 124.4 and greater). Prior to fabrication, purge loss percentage, instrumental color, subjective color and marbling, and pH were taken for each loin. Following fabrication, chops were assigned to fat and moisture analysis, Warner-Bratzler shear force (WBSF), consumer sensory analysis, or trained sensory analysis. For WBSF, consumer, and trained panels, chops were thawed for 24 h prior to analysis. Chops were cooked on clam-shell style grills and removed from the heat with the internal temperature rising to a peak internal temperature of 71°C. Consumers (N = 197) evaluated each sample for tenderness, juiciness, flavor like, and overall liking on 0 to 100 continuous line scales. Consumers were also able to indicate “yes” or “no” if the chop was acceptable for all palatability traits and overall. Trained panelists evaluated each sample for initial juiciness, sustained juiciness, myofibrillar tenderness, connective tissue amount, overall tenderness, pork flavor, and off flavor on similar 0 to 100 continuous line scales.ResultsLoins from all weight groups differed (P < 0.05) in weight (LT < MLT < MHVY < HVY). No carcass weight effects (P > 0.05) were found for loin instrumental color, subjective color, subjective marbling, purge loss percentage, pH, WBSF, moisture percentage, fat percentage, and drip loss. Carcass weight did not affect (P > 0.05) juiciness or flavor like ratings but did affect (P < 0.05) tenderness ratings and overall liking ratings. Chops from the HVY group were rated as more tender (P < 0.05) compared to chops from the LT weight group. Additionally, chops from the HVY weight group had greater (P < 0.05) consumer overall liking rating compared to chops from both the LT and MLT weight treatments. Hot carcass weight treatment did not contribute (P > 0.05) to the percentage of chops rated acceptable for flavor and overall liking. Chops from the HVY weight carcasses had the greatest (P < 0.05) percentage of chops rated acceptable for juiciness. Chops from LT carcasses had the lowest percentage of chops rated acceptable for tenderness. Trained sensory results also reflected tenderness and juiciness differences among carcass weight treatments. For both initial and sustained juiciness, chops from MHVY carcasses were rated as juicier (P < 0.05) compared to chops from both MLT and LT carcasses. Additionally, chops from the LT hot carcass weight treatment had the lowest (P < 0.05) myofibrillar tenderness ratings. Chops from MHVY and HVY carcasses were similar (P > 0.05) with greater (P < 0.05) overall tenderness ratings compared to chops from LT carcasses.ConclusionThese results indicate that as hot carcass weight increased, there were no negative effects on loin quality, and top loin chops from heavier weight carcasses had improved tenderness and juiciness compared to chops from lighter carcasses. This provides evidence that as the hot carcass weights of pigs in the United States continue to increase there will be no negative effects on quality and palatability.

A multi-laboratory evaluation of a common in vitro pepsin digestion assay protocol used in assessing the safety of novel proteins

Rationale. Evaluation of the potential allergenicity of proteins derived from genetically modified foods has involved a weight of evidence approach that incorporates an evaluation of protein digestibility in pepsin. Currently, there is no standardized protocol to assess the digestibility of proteins using simulated gastric fluid. Potential variations in assay parameters include: pH, pepsin purity, pepsin to target protein ratio, target protein purity, and method of detection. The objective was to assess the digestibility of a common set of proteins in nine independent laboratories to determine the reproducibility of the assay when performed using a common protocol. Methods. A single lot of each test protein and pepsin was obtained and distributed to each laboratory. The test proteins consisted of Ara h 2 (a peanut conglutin-like protein), beta-lactoglobulin, bovine serum albumin, concanavalin A, horseradish peroxidase, ovalbumin, ovomucoid, phosphinothricin acetyltransferase, ribulose diphosphate carboxylase, and soybean trypsin inhibitor. A ratio of 10U of pepsin activity/microg test protein was selected for all tests (3:1 pepsin to protein, w:w). Digestions were performed at pH 1.2 and 2.0, with sampling at 0.5, 2, 5, 10, 20, 30, and 60min. Protein digestibility was assessed from stained gels following SDS-PAGE of digestion samples and controls. Results. Results were relatively consistent across laboratories for the full-length proteins. The identification of proteolytic fragments was less consistent, being affected by different fixation and staining methods. Overall, assay pH did not influence the time to disappearance of the full-length protein or protein fragments, however, results across laboratories were more consistent at pH 1.2 (91% agreement) than pH 2.0 (77%). Conclusions. These data demonstrate that this common protocol for evaluating the in vitro digestibility of proteins is reproducible and yields consistent results when performed using the same proteins at different laboratories.