National Beef Market Basket Survey - 2006: External fat thickness measurements and separable component determinations for beef from US retail establishments.

A market basket survey for beef retail cut composition at the retail level (four stores each from two chains in each city) was conducted in 11 US cities from January to March 2006. Beef cuts (n=17,495) were measured for external fat thickness with cuts from the chuck (0.05cm), round (0.05cm), and miscellaneous (0.04cm) having less (P<0.05) fat than cuts from the loin (0.11cm) and rib (0.11cm). Beef cuts (n=1327) were separated physically into separable components with round cuts having more (P<0.05) separable lean (96.63%) than chuck cuts (86.81%) and miscellaneous cuts (86.18%), which had more (P<0.05) separable lean than loin cuts (84.53%) with rib cuts (69.34%) having the lowest (P<0.05) separable lean. Chemical fat from the separable lean differed (P<0.05) between each cut category: round cuts (3.71%), miscellaneous cuts (4.99%), loin cuts (5.60%), chuck cuts (6.90%), and rib cuts (8.61%). Ground beef samples (n=235), with declared lean/fat percentages ranging from 73/27 to 96/4, had overall chemical fat values of 13.41% and moisture values of 67.42%. This survey documents the current beef retail cut and ground beef composition, which is helpful to those who need this information for various dietary and marketing purposes.

Enhanced efficiency of a capillary-based biosensor over an optical fiber biosensor for detecting calpastatin.

A capillary-based optical biosensor has been developed to detect calpastatin, an indicator of meat tenderness. Longissimus muscle samples (n=11) were extracted from beef carcasses at 0 and 48h post-mortem. These samples were assayed for calpastatin by traditional laboratory methods and with a newly developed capillary tube biosensor as well as for Warner-Bratzler shear force (WBSF) and crude protein and the responses were compared. Additionally, the response from the capillary-based biosensor was compared to a previously developed optical fiber biosensor. When the 0 and 48h sampling periods were combined, the capillary tube biosensor was moderately accurate in predicting calpastatin activity (R(2)=0.6058). There was less variation in the 0h capillary tube biosensor compared to the 0h pre-column (P=0.006) and post-column optical fiber biosensors (P=0.047), therefore the capillary tube biosensor is a more precise system of measurement. This research further advances the development of a calpastatin biosensor and makes online assessment one step closer to reality.

Correlation between a novel calpastatin biosensor and traditional calpastatin assay techniques.

An optical fiber biosensor to detect calpastatin has been investigated as a preliminary step in developing tenderness detection instrumentation. Longissimus dorsi samples were taken from beef carcasses (n=21) at 0, 24, 36 and 48h postmortem. Muscle homogenates were assayed for calpastatin activity using traditional methods and an optical fiber biosensor. Warner-Bratzler shear force was also performed on a steak from each carcass at 14d postmortem. Results demonstrated that the measurements with highest correlation between traditional calpastatin assays and optical biosensor readings were taken at 48h postmortem (r=0.597, P< or =0.01), suggesting that this is the best time for use of this biosensor in an on-line grading system. This research further advances the development of a calpastatin biosensor and would be useful in laboratory determination of the presence of biologically active calpastatin concentrations.

Conjugated linoleic acid content of beef differs by feeding regime and muscle.

The project objective was to determine the CLA content of three muscles (Longissimus lumborum, LD; Semimembranosus, SM; Triceps brachii, TB), in both raw and cooked states, in cattle finished on pasture or with grain supplements. Cattle were randomly assigned to one of four finishing regimens; pasture (n=11), pasture with grain supplement (n=11), pasture with grain supplement containing soyoil (n=12), and feedlot (n=12). In the raw state, TB had higher (P<0.05) CLA than LD or SM on a mg/g sample basis. Total CLA was higher (P<0.05) in the soyoil diet when compared to the other three feeding regimes on a mg/g sample basis and when expressed as mg/g fat in both raw and cooked analyses. Pasture inclusion produced higher levels (P<0.05) of total CLA than the feedlot diet on a mg/g fat basis for cooked samples while maintaining acceptable eating quality.

National beef tenderness survey - 2006: Assessment of Warner-Bratzler shear and sensory panel ratings for beef from US retail and foodservice establishments.

Beef from retail and foodservice establishments in 11 US cities was evaluated using Warner-Bratzler shear (WBS) and consumer evaluation panels. Postmortem aging times ranged from 3 to 83d for retail and 7 to 136d for foodservice with mean aging times of 22.6d and 30.1d, respectively. For retail, the three cuts from the round - top round, bottom round, and eye of round - had the highest (P<0.05) WBS values compared to cuts from the chuck, rib, and loin. Top loin steaks had the lowest (P<0.05) WBS value compared to ribeye and top sirloin foodservice steaks. Retail bone-in top loin, top loin, ribeye, T-bone, and porterhouse received the highest (P<0.05) ratings by consumers for overall like and like tenderness. Quality grade had little or no effect on foodservice sensory evaluations. Improvements in round tenderness are needed to increase consumer acceptability.

RAPID COMMUNICATION: Impact of contemporary light sources on oxidation of fresh ground beef.

Meat color is considered one of the driving factors in consumer purchasing decisions. The objective of this study was to determine the impact of 2 different lighting sources on color and lipid oxidation of ground beef patties in a controlled environment. USDA Select top rounds ( = 20) were processed to produce ground beef at 2 different fat levels (5 and 25%) and made into patties (113.4 g). Patties were packaged with oxygen permeable polyvinyl chloride, assigned to one of three lighting treatments (low UV fluorescent [FLO], light emitting diode [LED], and no light [DRK, negative control]), and placed within deli cases at 5°C. Patty removal for evaluation occurred on retail display d 1, 3, 5, and 7. Objective color measurements were obtained using a HunterLab MiniScan 45/0 LAV. These values were utilized to determine myoglobin redox forms as a measure of myoglobin oxidation. Additionally, thiobarbituric acid reactive substances (TBARS) were measured to indicate lipid oxidation. Objective color measurement for a* (redness), decreased for all light treatments by retail display day ( < 0.0001). Oxymyoglobin values for all light treatments decreased daily but showed no differences between treatments until d 5 ( < 0.0001) where DRK > LED > FLO. Conversely, metmyoglobin values increased daily ( < 0.0001), but showed no differences between treatments until d 5 where FLO > LED > DRK. TBARS values increased by day for each fat percentage ( < 0.0001) with 5% fat patties having higher TBARS values indicating great oxidation occurring in the phospholipids than adipose tissues. Results indicate that light treatment affected discoloration and metmyoglobin formation in ground beef patties LED lighting may lead to increased meat quality shelf life in a retail setting.

Beef muscle isolation has no detrimental effect on premium ground beef programs.

This experiment evaluated whether isolating certain muscles from the chuck for retail sale and excluding them from ground beef mix changes the number of days that ground chuck is acceptable to consumers. Chucks were harvested from twenty-four beef steers, and were allocated to either traditional or innovative fabrication methods. Resulting ground beef patties were stored in retail simulation conditions for 7days to determine color and oxidative stability. Raw patties were analyzed for thiobarbituric acid reactive substances (TBARS), oxymyoglobin concentration, objective color by Minolta Chromameter, and by a trained sensory panel for odor, color and percent discoloration. No differences (P>0.05) were observed between traditional and innovative style patties for TBARS, sensory odor or color, or oxymyoglobin concentration. Minolta Chromameter readings revealed more substantial fading (P<0.05) in traditional patties compared with innovative style patties. This study demonstrated that removing certain muscles from the ground chuck mix does not cause detrimental consequences in resulting ground chuck patties.

Tenderness assessments of top loin steaks from retail markets in four U.S. cities.

The purpose of this study was to evaluate the tenderness of beef loin steaks from retail markets in 4 U.S. cities. Beef top loin steaks ( = 1,613) were obtained for Warner-Bratzler shear force (WBSF), slice shear force (SSF), and consumer sensory determinations. Personnel at 4 universities (California Polytechnic State University, Colorado State University, University of Missouri, and Texas A&M University) conducted the study over a 12-mo period. Enhanced/blade-tenderized top loin steaks had the lowest ( < 0.05) WBSF and SSF values, whereas nonenhanced top loin, bone-in steaks had the highest ( < 0.05) WBSF and SSF values. Enhanced/blade-tenderized top loin steaks received the highest ( < 0.05) ratings by consumers for palatability scores, whereas nonenhanced top loin, bone-in steaks had the lowest ( < 0.05) consumer panelist ratings. The USDA quality grade did have an effect ( < 0.05) on the tenderness of nonenhanced steaks but did not affect ( > 0.05) steaks that were enhanced/blade tenderized. The WBSF values and consumer sensory values for top loin steaks were comparable to the 2010 National Beef Tenderness Survey, signifying that no drastic changes in tenderness have occurred due to changes in antemortem or postmortem conditions.

Influence of wholesale lamb marketing options and merchandising styles on retail yield and fabrication time.

Lamb carcasses (n = 94) from five packing plants, selected to vary in weight class and fat thickness, were used to determine retail yield and labor requirements of wholesale lamb fabrication. Carcasses were allotted randomly according to weight class to be fabricated as whole carcasses (n = 20), three-piece boxes (n = 22), or subprimals (n = 52). Processing times (seconds) were recorded and wholesale and retail weights (kilograms) were obtained to calculate retail yield. Subprimals were fabricated into bone-in retail cuts or boneless or semi-boneless retail cuts. Retail yield for subprimal lamb legs decreased from 85.3 +/- .6% for bone-in to 68.0 +/- .7% for a completely boneless retail product. Correspondingly, processing times increased from 126.1 +/- 5.4 s to 542.0 +/- 19.2 s for bone-in and boneless legs, respectively. For all subprimals, retail yield percentage tended to decrease and total processing time increase as cuts were fabricated to boneless or semi-boneless end points compared with a bone-in end point. Percentage retail yield did not differ (P > .05) among whole carcass, three-piece box, and subprimal marketing methods. Total processing time was shorter for subprimals (P < .05) than for the other two marketing methods.

Subprimal purchasing and merchandising decisions for pork: relationship to retail value.

To assess retail value and profitability, cutting test data were obtained in a simulated retail cutting room for boxed pork subprimals, bone-in loins (n = 180), boneless loins (n = 94), Boston butts (n = 148), fresh hams (n = 28), and boneless hams (n = 23). Processing times (seconds) and retail weights (kilograms) were used to determine relative value. Cutting style affected (P < .05) value differential (US$/subprimal) for bone-in and boneless loins. When cutting styles within subprimals were pooled, value differential was affected (P < .05) by purchasing specification for bone-in loins, boneless loins, Boston butts, and inside fresh hams. Processing bone-in loins to a boneless end point produced a greater (P < .05) value differential and percentage of gross margin than a bone-in retail end point. Bone-in loins fabricated to a boneless retail end point produced a greater (P < .05) value differential and percentage of gross margin than boneless loins fabricated to the same end point. The increase in retail value can be attributed to the increased number and weight of retail cuts produced from bone-in loins. The thick, boneless loin cutting style produced a greater (P < .05) value differential and percentage of gross margin as a result of a lower (P < .05) cost of fabrication and increased value of retail cuts than the thin, boneless cutting style. In general, boneless pork cutting methods were more profitable than bone-in cutting methods regardless of subprimal.

Subprimal purchasing and merchandising decisions for pork: relationship to retail yield and fabrication time.

Boxed pork was obtained to represent four different purchase specifications (different anatomical separation locations and[or] external fat trim levels) common in the pork industry to conduct a study of retail yields and labor requirements. Bone-in loins (n = 180), boneless loins (n = 94), and Boston butts (n = 148) were assigned randomly to fabrication styles within subprimals. When comparing cutting styles within subprimals, it was evident that cutting style affected percentage of retail yield and cutting time. When more bone-in cuts were prepared from bone-in loin subprimals, retail yields ranged from 92.80 +/- .61 to 95.28 +/- .45%, and processing times ranged from 222.57 +/- 10.13 to 318.99 +/- 7.85 s, from the four suppliers. When more boneless cuts were prepared from bone-in loin subprimals, retail yields ranged from 71.12 +/- 1.10 to 77.92 +/- .77% and processing times ranged from 453.49 +/- 8.95 to 631.09 +/- 15.04 s from the different loins. Comparing boneless to bone-in cuts from bone-in loins resulted in lower yields and required greater processing times. Significant variations in yields and times were found within cutting styles. These differences seemed to have been the result of variation in supplier fat trim level and anatomical separation (primarily scribe length).

Protein kinetics in callipyge lambs.

The objectives for this experiment were to determine the effect of the callipyge phenotype on protein kinetics. We studied callipyge and normal lambs (n = 37) at 5, 8, and 11 wk of age (n = 4 to 7/ group) to determine how protein kinetics are altered by this trait. Total protein, DNA, and RNA and calpastatin activity were measured in five skeletal muscles and in the heart, kidneys, and liver, and protein accretion rates were calculated. At 8 wk, the fractional synthesis rates of proteins in these tissues were measured in vivo using a primed, continuous 8-h infusion of [2H5]phenylalanine. Fractional rates of protein degradation were estimated by differences. At 5 wk of age, muscle weights, protein mass, protein:DNA, RNA:DNA, and calpastatin activity were higher (P < .05) for callipyge, and protein mass differences continued to increase through 11 wk. At 8 wk, fractional rates of protein synthesis and degradation were lower (P < .05) in callipyge than in normal lambs. The organs of callipyge lambs exhibited reduced growth at 11 wk. Thus, enhanced muscle growth seems to be maintained in callipyge lambs by reduced protein degradation rather than increased protein synthesis. However, we cannot exclude the possibility that the initial onset of the callipyge condition may be caused by an increase in the fractional rate of protein synthesis.

Beef customer satisfaction: trained sensory panel ratings and Warner-Bratzler shear force values.

Trained sensory panel ratings and Warner-Bratzler shear force (WBS) values from the Beef Customer Satisfaction study are reported. Carcasses were chosen to fit into USDA quality grades of Top Choice (upper two-thirds of USDA Choice), Low Choice, High Select, and Low Select. A trained, descriptive attribute panel evaluated top loin, top sirloin, and top round steaks for muscle fiber tenderness, connective tissue amount, overall tenderness, juiciness, flavor intensity, cooked beef flavor intensity, and cooked beef fat flavor intensity. Four steaks from each of the three cuts from each carcass were assigned randomly to one of four cooking endpoint temperature treatments (60, 65, 70, or 75 degrees C) for WBS determination. For all trained panel measures of tenderness and WBS, regardless of USDA quality grade, top loin steaks were rated higher than top sirloin steaks, which were rated higher than top round steaks (P < 0.05). There were significant interactions between USDA quality grade and cut for most of the trained sensory panel traits: USDA quality grade influenced ratings for top loin steaks more than ratings for top round steaks or top sirloin steaks. Three interactions were significant for WBS values: USDA quality grade x endpoint temperature (P = 0.02), USDA quality grade x cut (P = 0.0007), and cut x endpoint temperature (P = 0.0001). With the exception of High Select, WBS values increased (P < 0.05) for each grade with increasing endpoint temperature. Choice top loin and top round steaks had lower (P < 0.05) WBS values than Select steaks of the same cut; however, only Top Choice top sirloin steaks differed (P < 0.05) from the other USDA grades. As endpoint temperatures increased, WBS values for top sirloin steaks increased substantially compared to the other cuts. When cooked to 60 degrees C, top sirloin steaks were closer to top loin steaks in WBS values, when cooked to 75 degrees C, top sirloin steaks were closer to top round steaks in WBS values. Simple correlation coefficients between consumer ratings and trained sensory muscle fiber tenderness, connective tissue amount, overall tenderness, juiciness, flavor intensity, and cooked beef fat flavor were significant (P < 0.05), but values were low. While relationships exist between consumer and trained sensory measures, it is difficult to predict from objective data how consumers will rate meat at home.

Beef customer satisfaction: role of cut, USDA quality grade, and city on in-home consumer ratings.

An in-home beef study evaluated consumer ratings from moderate-to-heavy beef users as influenced by cut (top loin, top sirloin, and top round steaks), USDA quality grade (Top Choice, Low Choice, High Select, and Low Select), and city (Chicago, Houston, Philadelphia, and San Francisco). Consumers (n = 2,212) evaluated each steak for overall like (OLIKE), tenderness (TEND), juiciness (JUIC), flavor desirability (DFLAV), and flavor intensity (IFLAV) using 23-point hedonic scales (23 = like extremely, extremely tender, extremely juicy, like extremely, and an extreme amount of flavor; 1 = dislike extremely, not at all tender, not at all juicy, dislike extremely, and no flavor at all). A USDA grade x cut interaction existed for OLIKE (P < .05). Consumers rated top loin steaks highest (P < .05) in OLIKE and ranked Top Choice highest of all steaks (P < .05). Within the top loin, consumers were not (P > .05) able to distinguish OLIKE differences between Low Choice and High Select or between High Select and Low Select. For OLIKE, top sirloin was rated intermediate (P < .05) of the three cuts, and consumers were not able to detect (P > .05) USDA quality grade differences. For OLIKE, top round was the lowest-rated (P < .05) cut. However, consumers preferred (OLIKE, P < .05) Top Choice to the other USDA grades offered. Grade and city interacted to affect TEND, JUIC, DFLAV, and IFLAV. The cut x city interaction was significant for all palatability attributes. Cut and city affected customer satisfaction more than USDA quality grade. Tenderness and flavor were important and equal contributors to OLIKE, r = .85 and r = .86, respectively.

National Beef Quality Audit: survey of producer-related defects and carcass quality and quantity attributes.

To assess the then-current population of fed beef cattle for quality defects, the federally inspected beef steer and heifer slaughter in 28 packing plants was surveyed during a 3-mo period (October to December 1991). Data were collected over the course of 1 d of production at chain speed. Carcasses were selected randomly to include 50 and 10% of each lot on the slaughter floor and in the cooler, respectively. Slaughter floor defects evaluated were brand location and size, degree of bruising, grubs and injection sites, condemnation of offal, and the presence of mud and horns. USDA grade factors and other data were collected in the cooler. The distribution of hot-iron brand scars on the hide for the sample was as follows: cattle with no brand, 55.0%; cattle with butt brands, 29.9%; cattle with side brands, 13.8%; and cattle with shoulder brands, .8%. In addition, 83.3, 85.6, 76.6, 97.3, 99.9, and 99.8% of the carcasses had no superficial bruising in the chuck, rib, loin, round, brisket, and other areas of the carcass, respectively. The incidence of viscera condemnations for livers, lungs, tripe, and total viscera were 19.2, 5.1, 3.5, and .1%, respectively. Means for the carcass traits were as follows: USDA yield grade, 3.1; hot carcass weight, 344.7 kg; adjusted fat thickness, 1.5 cm; longissimus muscle area, 83.4 cm2; kidney, pelvic, and heart fat, 2.2%; USDA quality grade, high Select; marbling score, Small-minus; and overall maturity, A69.

Beef customer satisfaction: cooking method and degree of doneness effects on the top loin steak.

The objective of this research was to evaluate the consumer-controlled factors of cooking method and degree of doneness on Top Choice, Low Choice, High Select, and Low Select top loin steaks. The in-home product test was conducted in Chicago, Houston, Philadelphia, and San Francisco. Consumers (n = 2,212) evaluated each top loin steak for overall like (OLIKE), tenderness (TEND), juiciness (JUIC), flavor desirability (DFLAV), and flavor intensity (IFLAV) using 23-point hedonic scales. Respondents in San Francisco and Philadelphia cooked their top loin steaks to lower degrees of doneness than those in Chicago and Houston. Outdoor grilling was the most common method of cookery for top loin steaks in all cities. Consumers had the highest preference for Top Choice steaks (P < .05) and the lowest preference for Low Select steaks (P < .05). Consumer OLIKE scores were the highest (P < .05) for steaks cooked to a medium rare or lesser degree of doneness. Consumers preferred (P < .05) medium and well done or more degrees of doneness over medium well. The interaction of city x cooking method was significant for all steak palatability attributes. The differences in consumer preparation techniques among cities present challenges for the beef industry to develop market-specific promotional campaigns.

Beef customer satisfaction: cooking method and degree of doneness effects on the top sirloin steak.

The objective of this research was to evaluate the consumer-controlled factors of cooking method and degree of doneness on Top Choice, Low Choice, High Select, and Low Select top sirloin steaks. The in-home product test was conducted in Chicago, Houston, Philadelphia, and San Francisco. Consumers (n = 2,212) evaluated each top sirloin steak for overall like (OLIKE), tenderness (TEND), juiciness (JUIC), flavor desirability (DFLAV), and flavor intensity (IFLAV) using 23-point hedonic scales. Top sirloin steaks, regardless of city, were consistently cooked to well done or higher degrees of doneness. Dry-heat methods such as outdoor grilling, broiling, and indoor grilling were the most frequent cooking methods used. Four significant interactions existed for OLIKE: USDA quality grade x cooking method (P = .02), city x cooking method (P = .0001), city x degree of doneness (P = .01), and cooking method x degree of doneness (P = .009). Greater differences were found between cooking methods within USDA quality grade than between USDA quality grades within cooking method. Consumers in Houston rated steaks cooked by outdoor grilling higher than those from the other cities, and steaks cooked by indoor grilling were rated the highest among all cooking methods by consumers in Chicago. In Chicago, steaks cooked to more advanced degrees of doneness tended to receive higher ratings, but few differences between degrees of doneness in the other three cities were detected. For outdoor grilling, broiling, and pan-frying, the trend was for OLIKE ratings to decline as degree of doneness increased. The lowest customer satisfaction ratings tended to be given to top sirloin steaks cooked to more advanced degrees of doneness, and consumers most frequently cooked steaks to at least the well done stage. Consumer information programs or the development of postmortem techniques that would ensure acceptable palatability of top sirloin steaks may need to be developed.

Beef customer satisfaction: cooking method and degree of doneness effects on the top round steak.

The objective of this research was to evaluate the consumer-controlled factors of cooking method and degree of doneness on Top Choice, Low Choice, High Select, and Low Select top round steaks. The in-home product test was conducted in Chicago, Houston, Philadelphia, and San Francisco. Consumers (n = 2,212) evaluated each top round steak for overall like (OLIKE), tenderness (TEND), juiciness (JUIC), flavor desirability (DFLAV), and flavor intensity (IFLAV) using 23-point hedonic scales. Stir-frying, braising, and simmering and stewing consistently produced higher consumer attribute ratings. There were clear OLIKE rating differences (P = .0001) for top round steaks among the four cities. The highest ratings were given by consumers in Houston, and the lowest ratings were given by consumers in Philadelphia (P < .05). There were two interactions for OLIKE: USDA quality grade x degree of doneness (P = .002) and degree of doneness x cooking method (P = .02). Higher ratings generally were given to steaks cooked to medium rare or less or to very well degrees of doneness. Stir-frying, braising, and simmering and stewing were preferred at lower degrees of doneness. Customer satisfaction with the top round steak is very dependent on how it is cooked and by whom it is consumed.

Pork loin color relative to sensory and instrumental tenderness and consumer acceptance.

Pork loin color categories were established with the intent of demonstrating differences in eating quality between them. Center-cut boneless pork loins (n=64) were divided into three color classifications. Category A included National Pork Producers Council color standards 1 and 2; category B, 3 and 4; and category C, 5 and 6. L* means for categories A, B, and C were 57.00, 50.24, and 45.54, respectively. Warner-Bratzler shear force values were not affected by category (P>0.05), but were negatively correlated with a* and b* values (P<0.05). The "in-home" portion of this study consisted of 47 households that prepared and evaluated chops randomly distributed by category. Consumers reported differences in liking of juiciness and liking of tenderness (P<0.05) due to color category. Eighty-nine percent of the households participated in a simulated retail display where, 20.8% chose chops from category A, 26.4% from category B, and 52.8% from category C. A trained panel evaluated the cooked chops and perceived category C to be more tender, more juicy, and less dry than both A and B (P<0.05). Consumers responded similarly to the trained panel in their perceptions of tenderness and juiciness.

Prediction of color and pH measurement throughout boneless center-cut pork loins.

Boneless pork loins (N=95) divided into three groupings based on National Pork Producers Council color standards were utilized to characterize changes in color and pH throughout the loin. CIE L(∗), CIE a(∗), CIE b(∗), saturation, and hue angle differed (P<0.05) for color category and chop position. A color category by position interaction (P<0.05) existed only for pH values. These differences in color and pH measures throughout the loin indicate that one measurement may not characterize the entire boneless loin. For all color and pH measures significant orthogonal and polynomial contrasts existed, therefore, separate regression equations were developed for each color category to predict position response. Multiple regression equations were significant for most objective measures of color and pH, but the low R(2) values indicate that these models provide little information as to changes in color and pH throughout the boneless pork loin.