Quality traits of pork semimembranosus and triceps brachii muscles sourced from the United States and Mexico.

The study included fresh pork semimembranosus (SM, n=289) and triceps brachii (TB, n=283) muscles sourced from meat packers of Mexico and the USA. Samples were analyzed for moisture, protein, and fat content, pH, shear force (WBSF), cook loss, water holding capacity (WHC), instrumental color, emulsion capacity (EC) and stability (ES), and consumer sensory ratings. SM from the USA had lower WBSF (P<0.05) than that from Mexico (26.7 vs. 29.7N), higher WHC (44.7 vs. 38.4%; P<0.05) and a better appearance, as indicated by its lower h* (52.3 vs. 56.6; P<0.05) and higher C* (23.1 vs. 21.3; P<0.05). Consumer acceptance of SM was similar (P>0.05) across countries. TB from Mexico had higher (P<0.05) fat content (2.5 vs. 2.0%), lower (P<0.05) WBSF values (32.0 vs. 36.9N), and received more positive ratings by Mexican consumers (87.1 vs. 81.7%) than its US equivalent. In general, US pork exhibits better technological properties, while country of origin has less effect on consumer acceptability.

A survey of Mexican retail chain stores for fresh U.S. pork.

An overview of fresh US pork in the Mexican market was achieved by surveying fresh US pork packages (n=342) for sale in five Mexican cities. Data on cut, primal/sub-primal from which the cut was sourced, subcutaneous and seam fat thicknesses, marbling scores, and presence of bone were collated. The most prevalent identifiable retail cuts were milanesa (thin slice of pork, breaded or non-breaded) and trozos (diced pork) derived primarily from the leg and accounting for 68% of the total US pork on sale. Over 90% of the retail cuts were trimmed to 3.2mm or less of external fat and the average marbling score was 2.26. Differences in distribution and fat measures were observed with chain, location and socio-economic status of clientele indicating potential for a targeted marketing approach in Mexico.

Prediction equations for Warner-Bratzler shear force using principal component regression analysis in Brahman-influenced Venezuelan cattle.

A database consisting of 331 beef animals (Brahman-crossbred) was used to determine the multivariate relationships between carcass and beef palatability traits of Venezuelan cattle and to develop prediction equations for Warner-Bratzler shear force (WBSF). The first three principal components (PC) explained 77.53% of the standardized variance. Equations were obtained for each sex class and the total variability observed in WBSF could be explained by its orthogonal regression with carcass weight (CW), fat cover (FC), fat thickness (FT), and skeletal maturity (SM). Prediction equations were: WBSF(steers)=3.566+0.003(CW)-0.033(FC)-0.015(FT)+0.0004(SM); WBSF(heifers)=4.824+0.002(CW)-0.229(FC)+0.096(FT)-0.064(SM); WBSF(bulls)=3.516+0.009(CW)+0.154(FC)-0.129(FT)-0.006(SM). A higher proportion of the variation was explained by the PC when variables of greater weight were selected to define each PC. The equation set presented herein could become an important tool to improve the Venezuelan carcass grading system.

Comparison of physical, chemical, and sensorial characteristics between U.S.-imported and Northwestern Mexico retail beef.

To compare beef from Northwestern Mexico (NMEX) and that imported from the United States in physical-chemical (PC) and sensory traits, samples of ribeye (m. Longissimus dorsi thoracis, LDT) and knuckle (m. Vastus lateralis, VL) of Mexican (64 LDT; 51 VL) and U.S. (28 LDT; 25 VL) origin were purchased randomly from select retail stores located in 3 cities of NMEX. PC evaluation measured contents of moisture, fat and cholesterol, Warner-Bratzler shear force (WBSF), pH, CIE L*, a*, and b*, cooking loss, and normalized fatty acid profile (FAP). Trained panelists evaluated raw and cooked samples for 2 and 6 different organoleptic traits, respectively. Mexican and U.S.-imported LDT steaks did not differ (P>0.05) in PC traits. VL samples differed in L*, b*, hue*, WBSF, and fat content by country of origin (COO). The WBSF for cooked VL samples from the United States was lower (P < 0.05) and fat content was greater (P<0.05) than those for NMEX steaks. The FAP varied between muscles; Mexican LDT had a higher content of C18:0, while VL from the United States had a higher proportion of polyunsaturated fatty acids (PUFA) and a higher PUFA/Saturated ratio (P<0.05). Although sensory traits tended to be rated higher for Mexican LDT and VL steaks, no statistical differences with U.S.-imported samples were detected (P > 0.05). Results indicated that domestic and U.S. retail steaks sold in the NMEX are similar in eating quality and PC, whereas differences observed in FAP deserve further attention from a nutritional standpoint.

Establishing tenderness thresholds of Venezuelan beef steaks using consumer and trained sensory panels.

The tenderness thresholds for ribeye steaks at 2d postmortem were found by using sensory trained (n=734 steaks) and consumers panel data (55 ribeye steaks and 296 consumers). Also, consumers' perceptions of sensory attributes of beef steaks were assessed to establish their relationships and to determine acceptability levels. The tenderness threshold obtained by regression analysis from trained panelists was 37.98N (3.87kg). Customer satisfaction of 81% was obtained when beef steaks had Warner-Bratzler shear force values (WBSF) less than 40.13N (4.09kg), suggesting that 40.13N could be considered as a tenderness threshold to segregate tough from tender steaks, for Venezuelan beef consumers. According to correlation and regression analyses, consumers focused on flavor to assign their overall liking score. Results suggest that consumers are able to detect changes in tenderness of steaks with different WBSF and that flavor drives customer satisfaction when the beef tenderness is acceptable.

Predicción del rendimiento en cortes de carniceríade bovinos venezolanos / Predicting beef carcass cutability in venezuelan cattle

Datos de cortes obtenidos de ganado bovino (hasta 1197 observaciones) fueron utilizados para desarrollar ecuaciones de predicción del rendimiento en cortes de valor (RCD), Porcentaje de hueso (PHUESO) y recortes de grasa (PGRASA). La condición sexual (CONSEXUAL) explicó el 43 por ciento y 30 por ciento de la variación en RCD y PGRASA, respectivamente. La mayor parte de la variación (>50 por ciento) en RCD, PHUESO y PGRASA no pudo ser explicada por su regresión lineal simple sobre cualquiera de los 13 rasgos de la canal considerados. Las variables incluidas para el análisis de regresión fueron CONSEXUAL, peso en canal (PCANAL), espesor de grasa dorsal (ESPEGRASA), área del ojo del lomo (AOL), porcentaje de grasa interna (GPR), acabado y conformacion. Las mejores ecuaciones fueron: RCD por ciento: 47,564 +2,281(CONSEXUAL) +0,003(PCANAL) -0,302(ESPEGRASA) +0,211(AOL) -1,237(GPR) +0,219(ACABADO) –0,659(CONFORMACION) (R2: +0,629; Cp-Mallows:8); PHUESO: por ciento 17,077 –0,749(CONSEXUAL) –0,005(PCANAL) -0,097(ESPEGRASA) -0,064(AOL) -0,402(GPR) +0,2(ACABADO) +0,272 (CONFORMACION) (R2: 0,387; Cp-Mallows: 8); PGRASA por ciento: 9,628 +0,345(ESPEGRASA) -0,162(AOL) +1,733(GPR) -0,725(ACABADO) –0,134(CONFORMACIÓN) (R2: 0,80; Cp-Mallows: 5,74). Es necesario, en futuras experiencias validar las ecuaciones obtenidas antes de su recomendación y uso comercial.

Carcass fabrication yield (%) data (up to 1197) of Venezuelan cattle were collected to develop prediction equations of boneless, closely trimmed cuts (high plus medium-valued) (YCV), bone percentage (PBONE), and fat trimmings (PFAT). The sex condition (SEXCON) explained 43% and 30% of the variation on YCV and PFAT, respectively. The majority of the variation (50% or more) on YCV, PBONE, and PFAT could not be explained by its simple linear regression over any of the 13 carcass traits considered. The variates included for the regression analysis were SEXCON, Carcass Weight (CWEIGHT), Back Fat Thickness (BACKFAT), Loineye Area (LEA), Internal Fat Percentage (IFP), FINISH and CONFORMATION. The best equations were: YCV%: 47.564 +2.281(SEXCON) +0.003 (CWEIGHT) -0.302( BACKFAT) +0.211(LEA) -1.237(IFP) +0.219 (FINISH) -0.659 (CONFORMATION) (R2: 0.629; Mallow´s-Cp: 8); PBONE: %17.077 -0.749(SEXCON) -0.005 (CWEIGHT) -0.097(BACKFAT) -0.064(LEA) -0.402(IFP) +0.2 (FINISH) +0.272(CONFORMATION) (R2: 0.387; Mallow´s-Cp: 8); PFAT%: 9.628 +0.345(BACKFAT) -0.162(LEA) +1.733(IFP) -0.725(FINISH) -0.134(CONFORMATION) (R2: 0.80; Mallow´s-Cp: 5.74). The equation set presented here in must be subjected to practical and statistical validation.

Effect of oat's soluble fibre (ß-glucan) as a fat replacer on physical, chemical, microbiological and sensory properties of low-fat beef patties.

This study evaluated the effect of adding oat fibre source of ß-glucan (13.45%) on physical, chemical, microbiological and sensory traits of low-fat (<10%) beef patties as compared to 20% fat control patties. Significant (p<0.05) improvements in cooking yield (74.19%), and retentions of fat (79.74%) and moisture (48.41%) of low-fat patties were attributed to the water binding ability of ß-glucan. Because of larger water retentions moisture contents of raw and cooked low-fat patties were higher (p<0.05) than those of the control patties. Cholesterol content was similar across formulations. Low-fat and control beef patties remained stable in microbiological quality during 60days frozen storage. Low-fat patties were found to be of lower degree of likeness in the taste but juicer than control (p<0.05). Besides appearance, tenderness and colour were not affected by the addition of oat's soluble fibre. Oat fibre can be used successfully as a fat substitute in low-fat beef patties.

Characterization of beef semimembranosus and adductor muscles from US and Mexican origin.

The purpose of this study was to compare the chemical composition and sensory characteristics of two beef muscles (semimembranosus, SM and adductor, AD) from the inside round of Mexican and US origins. Inside rounds were obtained from 20 Mexican bull carcasses, representing beef of Mexican origin. Forty-vacuum packaged USDA Choice and Select inside rounds were purchased from a local trader, representing US beef. Muscles were analyzed for chemical composition, Warner-Bratzler shear force (WBSF), cooking loss percentage, instrumental color, textural profile, and consumer acceptability. Muscles imported from the US contained more intramuscular fat, had higher cooking loss percentages, lower shear force values, and higher consumer ratings for overall desirability than Mexican counterparts (P<0.05). Choice and Select beef samples had similar WBSF values (P>0.05). Consumers found differences in juiciness and tenderness ratings between the two muscles, with the SM being tougher and less juicy than the AD (P<0.05).

Mineral content of longissimus dorsi thoracis from water buffalo and Zebu-influenced cattle at four comparative ages.

The longissimus dorsi thoracis (LDT) of 64 water buffalo and 68 Zebu-influenced cattle was used to determine the mineral content variation (mg/100g of fresh tissue) according to species, age (7, 17, 19 and 24 months-of-age, MOA) and gender (steers and bulls). Buffalo LDT had higher concentrations of K, Mn, Fe, Zn and Cu at weaning (P<0.05). Phosphorous content was higher (P<0.05) at post-weaning ages. Mineral profile was affected by age without clear trends; the Na and K contents increased at 24 MOA. The age×species, age×gender and species×gender interactions affected (P<0.05) Fe content that ranged from 1.74 to 2.56mg/100g fresh tissue. Meat from both species contributes with more of 25% of K, P, Fe and Zn of the daily requirement for an adult.

Occurrence of conjugated linoleic acid in longissimus dorsi muscle of water buffalo (Bubalus bubalis) and zebu-type cattle raised under savannah conditions.

Lipid extracts from longissimus dorsi muscles of 64 water buffaloes and 68 zebu-type cattle were used to quantify the amount (mg/g of lipids) of total conjugated linoleic acid (CLA), CLA isomers c9, t11 and t10, c12 and linoleic acid (LA), according to species (buffaloes and cattle), age (slaughter groups at 7, 17, 19 or 24 months of age) and gender (bulls and steers). The effects of gender and age were significant (P<0.05) but marginal. Comparisons of lipid extracts from buffaloes vs. cattle showed that total CLA (1.83 vs. 1.47 mg/g), CLA c9, t11 (1.27 vs. 1.01 mg/g) and CLA t10, c12 (0.56 vs. 0.47 mg/g) isomers as well as the CLA/LA ratio (0.10 vs. 0.07) were higher (P<0.05) in buffalo lipids. Considering the sparingly low lipid concentrations (<2 g/100 g of fresh muscle) none of the meat species should be considered a significant source of CLA.

Composición mineral del músculo longissimus crudo derivado de canales bovinas producidas y clasificadas en Venezuela / Mineral composition of raw longissimus muscle derived from beef carcasses produced and graded in Venezuela

A total of 145 beef carcasses derived from cattle produced under tropical conditions in different regions of Venezuela were graded by the current grading system. Rib (longissimus) samples were excised, trimmed to zero fat cover and subjected to spectrophotometric analyses to examine the variation in ash, macro- and micro-mineral contents, according to the beef carcass grade. The analysis of variance indicated that the Venezuelan carcass grade did not affect significantly the ash or individual mineral content of the raw longissimus muscle; only the Na content tended to decrease (P < 0.10) as the beef carcass quality decreased from grade AA to grade C. Overall means +/- standard deviations are given for ash percentage (1.06 +/- 0.16) and content (mg/100g) of Ca (2.77 +/- 1.57), Mg (21.62 +/- 3.11), P (211.4 +/- 35.88), Na (76.06 +/- 30.88), K (243.81 +/- 63.93), Fe (1.93 +/- 0.58), Zn (4.13 +/- 0.82), Cu (0.084 +/- 0.041) and Mn (0.026 +/- 0.016). It was concluded that the variation in mineral composition of beef longissimus observed for this sample of tropical beef cattle, cannot be attributed to the Venezuelan carcass grade.

[Comparative proximal and mineral analysis of iguana,poultry and beef meats]. / Análisis comparativo proximal y de minerales entre carnes de iguana, pollo y res.

Raw meat samples from iguana, poultry and beef cattle specimens were used to compare proximal (g/100 g) and mineral (mg/100 g) composition. Iguana meat was obtained by dissecting whole specimens (Iguana iguana) captured at a ranch (n = 20). Thighs and breasts were separated from broiler (either chilled or frozen) carcasses (n = 20), and deboned to represent chicken meat samples, whereas 2.5-cm-thick longissimus (ribeyes) steaks were removed from carcasses and frozen to represent beef of several breed types (n = 20). The one-way analysis of variance performed by the least squares method (LS Means) showed specie affected significantly (p > 0.05) all composition variables under study. Moisture content did not differ between iguana and chicken meats (74.7 y 74.9%, respectively) whereas beef samples had the lowest water content (73%) (p < 0.01). LS means for protein content showed beef samples (22.3%) were highest (p < 0.05) in this nutrient, iguana meat being intermediate (20.8%). Chicken meat presented the highest amount of total lipids (7.75 +/- 0.20 g/100 g) (p < 0.01) followed by iguana (3.49 +/- 0.12 g/100 g) and beef (2.57 +/- 0.20 g/100 g). Ash and most individual minerals were more concentrated in iguana meat, except for K and Zn that were more abundant in beef samples. Non-significant differences in Mg, Na, Cu or Mn contents were detected between chicken and beef samples. It was concluded that iguana meat could be an alternate source of protein and minerals as compared to those of traditional meat species.

[Moisture, total lipids and fatty acids in raw longissimus muscle from Venezuelan cattle]. / Contenido de humedad, lípidos totales y ácidos grasos del músculo longissimus crudo de bovinos en Venezuela.

Randomly selected groups of slaughter cattle, crossbreds of dairy (n = 14) and zebu (n = 131) types were classified by age (2.5, 3.0, 3.5 and 4.0 yr., estimated by dentition), and carcass fatness (as described by different criterion, including marbling levels) to study variation in moisture (M), lipid (L), and fatty acid (FA) contents (g/100 g of fresh tissue) of longissimus muscle trimmed to zero fat cover. Overall means +/- standard deviations per 100 g of raw product for M and L were 73.9 +/- 1.36 and 2.9 +/- 1.04, respectively. Analyses of variance by the least squares (LS) method showed age, breed type, marbling, backfat thickness and carcass finish affected (p < 0.05) fatty acid (FA) profiles. The oldest cattle group (4 yr. or older) trended to present a lower intramuscular lipid content (2.72 g/100 g) and showed the highest (2.04) unsaturation (unsaturated/saturated FA) index (p < 0.05). Breed type had little effect on the FA profile. Comparison of LS means showed intramuscular concentrations of myristic and linolenic acids were slightly higher in samples from dairy types (p < 0.05). Carcasses with poor, "patch-like" fat distribution, showed muscles with the highest (0.16) polyunsaturated/saturated FA index (p < 0.05). Unsaturation indexes for trimmed beef samples with the prevailing marbling levels (1.76 for "Traces" to 1.92 for "Devoid") show a clear predominance of unsaturates, relatively larger than that estimated from compositional FA data reported for the same cut in the United States.

Crossbreeding dual-purpose cattle for beef production in tropical regions.

Six breed types groups of six steer calves each were used to observe differences in growth and carcass traits: F1 Brown Swiss (F1BS), F1 Holstein (F1HO), F2 Brahman (F2BR), F2 Criollo Rio Limon (F2CRL), purebred Criollo Rio Limon (CRL), and Perija Mosaic (PMO). After 404 days of grazing, the heaviest F1BS and F2BR steers were different from F1HO and CRL counterparts (p < 0.05) in slaughter weight. F2BR dressed higher and had better muscle conformation scores than F1BS, F1HO, F2CRL and CRL (p < 0.05). F1BS had the thickest backfat (0.5 cm) but only differed (p < 0.05) from F1HO (0.3 cm). Rib eye area, marbling score, carcass maturity, quality or yield grade, boneless cut percentages, bone percentage or percent trimmable fat did not vary among breed types. All steers were within the A maturity level and graded Standard. Results indicate the importance of feeding dual-purpose steers to heavier weights to please industry preferences.

[Effects of salting, cut type, and initial simmering temperature on protein and fat contents of meat broths: I. Beef]. / Efecto de adición de sal, tipo de corte y temperatura inicial de cocción sobre el contenido de proteínas y lípidos en caldos de carne: I. Carne de vacuno.

A 2 x 2 x 4 factorial design was used to study variation of protein and fat contents in beef broths as affected by cut type (flank, shank), salt treatments (addition of salt to the medium, no salt), and initial temperatures of simmering (25, 70, 75, and 100 degrees C). Flank portions yielded slightly more protein (0.29 g/100 mL) and had three-fold less fat (0.39 g/mL) than those of shank (0.25 and 1.12 g/mL, respectively) (P < 0.05). No linear relationship of temperature and amount of extractable components was observed, but it was clear that the greatest protein extraction was accomplished when meat was immersed in cooking water at boiling point (P < 0.05). In general, salting of water reduced fat content of beef broths. However, a significant Salting x Cut type interaction showed this effect was only present in shanks (P < 0.05). Conversely, the reducing effect (P < 0.05) of salting on amount of protein extracted from flank was not observed in shanks. Based on these data, we conclude that larger amounts of protein and less fat could be transferred from meat pieces to the medium by immersing beef in salted water at the boiling point.

[Cholesterol content in longissimus muscle beef from slaughter cattle in Venezuela]. / Contenido de colesterol en el músculo longissimus de bovinos venezolanos.

An observational study was conducted with 149 cattle, raised under tropical conditions of Venezuela (mostly grassfed), to study the relationships of sex class (62 bulls, 67 steers, 20 heifers), age by dentition (2.5; 3.0; 3.5 and 4.0 yr), physiological maturity (A or B), cattle type (17 Dairy or 132 Zebu type crossbreds), Venezuelan carcass grade (Optima, Excelente, Selecta or Superior), marbling level (four levels from "None" to "Small quantity"), carcass fat cover (four level: "Even", "Uneven", "patch-like" and "Devoid") and subcutaneous fat thickness (SFT) over the ribeye (1 = 0.1-0.2 cm; 2 = 0.3-0.4 cm; 3 = 0.5-0.9 cm and 4 = > 1.0 cm) on cholesterol content (mg/ 100 g wet weight) of longissimus muscle. Cholesterol content, as determined colormetrically, did not vary in response to the differences in sex class, age, maturity level, carcass grade, marbling level or SFT represented in the present survey. However, cattle type affected (P = 0.08) cholesterol content. Least square means analysis showed that dairy type contained 12.2 mg more of cholesterol/100 g of muscle than Zebu type. The overall mean (+/- SD) muscle cholesterol for the kind of cattle sampled herein (66.6 +/- 16 mg/100 g) was not considered to be different from those of cattle fed in other latitudes.

Fatty acid composition of subcutaneous adipose tissue from male calves at different stages of growth.

The objective of this investigation was to compare fatty acid composition of calves from Bos taurus and Bos indicus cows across different stages of growth. Hereford (H) and Brahman (B) embryos were transferred to H or B cows (n = 58) to produce purebred Brahman (BB), purebred Hereford (HH), Hereford x Brahman (HB), and Brahman x Hereford (BH) offspring. Calves were castrated at 2 to 3 wk of age. Before weaning (210 d of age), calves were fed native grasses. After weaning, calves were fed a concentrate diet in dry-lot pens. Adipose tissue was obtained by biopsy at two times: at weaning during forage feeding and 3 mo after weaning when placed on feed. A third sample was collected from the fed steers at slaughter (approximately 430 d of age). Samples obtained by biopsy and after death were collected from the perianal region. Fatty acid composition for each sample was determined as the normalized percentage area means from the duplicate measures. Generally, BB calves grew slowest and BH steers grew fastest (P < .05). The BH steers exhibited 15 and 20% heavier (P < .05) carcasses per day of age than H-sired steers and BB steers, respectively. Adipose tissue samples from calves from Brahman sires or dams were less saturated (P < .05) than samples from calves from Hereford sires or dams. Differences in degree of unsaturation primarily were due to the percentages of monounsaturated fatty acids (MUFA). As calves became older, MUFA increased markedly, polyunsaturated fatty acids increased slightly (due to inverse, nearly proportional changes in 18:2 and 18:3), and saturated fatty acids decreased by 10 percentage units (P < .001). Thus, adipose tissue from Brahman and Hereford purebred and crossbred calves became markedly more unsaturated early postweaning; this change was less dramatic in the purebred Hereford calves.

[Factors affecting the cooking of longissimus muscle beef from Venezuela cattle]. / Factores que afectan la culinaria de bistés del músculo Longissimus de bovinos venezolanos.

A survey was conducted to study variation in cookery traits of beef longissimus in Venezuela. Cattle originated from the main beef producing regions of the country (n = 274) provided steaks to study the effects of cattle type (Zebu-dairy, Zebu), Sex (bull, steer, heifer), age by dentition (estimated chronological age of 2, 3 and 4 yr), maturity levels (A, B,C) and marbling scores (none, traces, slight). Cookery traits were affected (P > .05) by marbling and maturity. Steaks with "traces" of marbling cooked faster and had more cooking losses (P < 0.05) than steaks with marbling amounts described as "slight" or "none". Steaks derived from the more mature, "C" cattle, required lesser time (i.e., 14 min) and retained 3 g/100 g more weight during cooking than those from younger ("A" and "B") maturity groups. Beef from bulls and steers typified as Zebu-dairy, lasted more in reaching the cooking endpoint (70 degrees C) than that from Zebu counterparts Regardless of age or cattle type, steaks from heifers cooked more rapidly than those from bulls and steers. These results call attention to some of the important sources of variation of cookery traits of beef and afford guidelines for meal planning.

[Experiences during training of a group for tasting bovine meat at an industrial refrigerated abattoir in Venezuela]. / Experiencias en el entrenamiento de un panel de degustación de carne vacuna a nivel de un matadero frigorífico industrial venezolano.

During three months, a group of people (meat consumers and active personnel) of a Venezuelan packing house were asked to assign discretionary scores to a sample of 103 beef longissimus steaks in order to familiarize them with the score sheet and to their future job as panelists. Scores assigned to 37 steaks by seven candidates that assisted regularly to these preliminary sessions (out of 12 attendants), were subjected to Analysis of Variance (ANOVA) to determine variability among judges before training. The whole group (n = 12) potential candidates from both sexes, and ranging between 25 and 45 years, were interviewed and pre selected for formal training. Triangle tests were used as selection tool and allowed for dismissing two of them. Training reinforced acquaintance with test procedures and improved natural abilities, sensitivity and memory for test attributes by using an 8-point descriptive scale to describe samples differing in fiber tenderness, amount of connective tissue, overall tenderness, juiciness, and flavor intensity. After 2 mo. of training (5 h weekly) the first panel performance evaluation (PPE) was conducted over 4 days with 3 sessions per day and 3 samples per session with 9 different samples. Data for each candidate were subjected to one-way ANOVA and F-ratio served as criteria to rank candidates' ability for describing each attribute. Panelist 7 and 8 rated last and were excused to conform an 8-member panel. The panel evaluated 300 samples during a 6-mo period and a second PPE was conducted. The second PPE revealed changes in relative ranking positions. Data from the first 40 (out of 300) samples were subjected to ANOVA for testing score (panelist) variability after training. A significant effect of panelist was detected before (P < .05) and after (P < .001) training, but a much greater variability became apparent in untrained candidates. Mean separation for trained panelist only differed in decimal units within the same points or adjacent points of the scale. Results validated methodologies used for panel training and the panel capability for sensorial evaluation of non-processed beef.

Comparison of the fatty acid composition of subcutaneous adipose tissue from mature Brahman and Hereford cows.

The fatty acid composition of adipose tissue was measured in 37 mature Brahman and 32 mature Hereford cows to determine breed effect. Diet was held constant among all cows. When biopsied, cows were on oats and native cool-season annual pastures of good quality. Real-time ultrasound measurements of subcutaneous fat were taken at three locations (between the 12th and 13th rib, at the rump, and at the perianal region) to determine overall fatness. Overall fat thickness from these measurements was 1.3 cm for Brahman cows and 1.7 cm for Hereford cows (P < .01). Subcutaneous adipose tissue biopsy samples were collected from the perianal region, and fatty acid composition was determined using a gas chromatograph. Fatty acids were expressed in both normalized (area percentage) and gravimetric (grams/100 grams of fresh tissue) formats. In addition to greater overall subcutaneous fat thickness, Hereford cows contained 5 g more of fatty acids per 100 g of fresh adipose tissue than Brahman cows (P < .05). Subcutaneous adipose tissue from Hereford cows was higher (P < .01) in total saturated fatty acids and lower in mono- and polyunsaturated fatty acids than subcutaneous adipose tissue from Brahman cows. Compositional differences remained when breeds were compared by analysis of covariance at a common body fatness. The data suggest a genetic basis for the differences in fatty acid composition of Brahman and Hereford cows.