Image analysis study of the perimysial connective network,and its relationship with tenderness and composition of bovine meat

Image processing method was developed to predict beef tenderness, collagen and lipids contents. The study was carried out on the semimembranosus muscle (SM). Images of SM slices were acquired under visible and ultraviolet lighting. In this work statistical technique was implemented as a method to relate the distribution of intramuscular connective tissue (IMCT), characterized by image analysis, to sensory tenderness evaluated by a trained panel and collagen and total lipids contents assessed chemically. Using Multiple Linear Regression (MLR) combining visible and ultraviolet lighting, IMCT image parameters were found to be good predictors of beef tenderness (R² = 0.89), collagen and lipids contents (respectively R² = 0.82 and R² = 0.91).     

Consumer assessment of beef palatability from four beef muscles from USDA Choice and Select graded carcasses

Consumer sensory analysis was conducted to determine differences in beef palatability between two quality grade categories [Upper 2/3 (Top) Choice and Select] and four muscles [longissimus lumborum (LL), gluteus medius (GM), serratus ventralis (SV), and semimembranosus (SM)]. Generally, tenderness, flavor, and overall liking scores were more desirable for Top Choice compared to Select, regardless of muscle. Consumers rated LL as more tender (P < 0.05) than SV and SM, but similar to GM (P = 0.52). Overall and flavor acceptability were similar (P > 0.05) between LL, GM, and SV, regardless of quality grade. Consumer overall liking was most highly correlated with flavor liking (r = 0.85). When tenderness was acceptable, flavor and juiciness played a major role in determining overall acceptability. Overall liking of GM and SV from Top Choice carcasses was superior to LL from Select carcasses and comparable to LL from Top Choice carcasses.     

Application of exogenous enzymes to beef muscle of high and low-connective tissue

Exogenous enzymes tenderize meat through proteolysis. Triceps brachii and Supraspinatus were randomly assigned to the seven enzyme treatments, papain, ficin, bromelain, homogenized fresh ginger, Bacillus subtilis protease, and two Aspergillus oryzae proteases or control to determine the extent of tenderization (Warner–Bratzler shear and sensory evaluation) and mode of action (myofibrillar or collagen degradation). Sensory evaluation showed improvement (P < 0.0009) for tenderness and connective tissue component and all except ginger had a lower shear force than the control (P < 0.003). Ginger produced more off-flavor than all other treatments (P < 0.0001). Only papain increased soluble collagen (P < 0.0001). Control samples were only significantly less than ficin for water soluble (P = 0.0002) and A. oryzae concentrate for salt soluble proteins (P = 0.0148). All enzyme treatments can increase tenderness via myofibrillar and collagenous protein degradation with no difference among high and low-connective tissue muscles.     

Trained sensory perception of pork eating quality as affected by fresh and cooked pork quality attributes and end-point cooked temperature

The present study evaluated individual and interactive influences of pork loin (n = 679) ultimate ph (pH), intramuscular fat (IMF), Minolta L∗ color (L∗), Warner-Bratzler shear force (WBSF), and internal cooked temperatures (62.8 °C, 68.3 °C, 73.9 °C, and 79.4 °C) on trained sensory perception of palatability. Logistical regression analyses were used, fitting sensory responses as dependent variables and quality and cooked temperature as independent variables, testing quadratic and interactive effects. Incremental increases in cooked temperature reduced sensory juiciness and tenderness scores by 3.8% and 0.9%, respectively, but did not influence sensory flavor or saltiness scores. An increase of 4.9 N in WBSF, from a base of 14.7 N (lowest) to 58.8 N (greatest) was associated with a 3.7% and 1.8% reduction in sensory tenderness and juiciness scores, respectively, with predicted sensory tenderness scores reduced by 3.55 units when comparing ends of the WBSF range. Modeled sensory responses for loins with pH of 5.40 and 5.60 had reduced tenderness, chewiness, and fat flavor ratings when compared with responses for loins with pH of 5.80 to 6.40, the range indicative of optimal sensory response. Loin IMF and L∗ were significant model effects; however, their influence on sensory attributes was small, with predicted mean sensory responses measurably improved only when comparing 6% and 1% IMF and L∗ values of 46.9 (dark) when compared with 65.0 (pale). Tenderness and juiciness scores, were related to a greater extent to loin WBSF and pH, and to a lesser extent to cooked temperature, IMF and L∗.     

The effects of the myostatin g+6723G>A mutation on carcass and meat quality of lamb

This study evaluated the effects of the myostatin g + 6723G > A mutation on carcass and meat quality traits of lamb (AA: n = 5; AG: n = 8; GG: n = 9). Dressing percentage was positively affected by the mutation with homozygotes for the mutation having the highest yield. Regarding carcass composition, there was a significant increase in the proportional weights of the loin and hindquarter muscles. Objective meat quality traits of the M. longissimus lumborum (LL) and M. semimembranosus (SM) were not significantly affected. For the SM, toughness (shear force and compression) tended to be lowest for homozygotes for the mutation. The myostatin g + 6723G > A mutation did not affect sensory meat quality traits of grilled steaks for the LL, but resulted in a significant improvement in eating quality for the SM. Given the number of animals in this study, the robustness of the outcome of this study with regard to the effects on meat quality and its causes requires further investigation.     

Effects of hot boning and moisture enhancement on the eating quality of cull cow beef

The effects of chilling method and moisture enhancement were examined for improving eating quality of semimembranosus (SM) and longissimus lumborum (LL) from 62 cull beef cows. Chilling method included hot boning muscles after 45 to 60 min postmortem or conventional chilling for 24 h. Moisture enhancement included 1) a non-injected control (CONT) or injection processing (10% of product weight) using 2) Sodium Tripolyphosphate/salt (Na/STP), 3) Sodium Citrate (NaCIT), 4) Calcium Ascorbate (CaASC), or 5) Citrus Juices (CITRUS). Chilling method by moisture enhancement treatment interactions (P < 0.09) were due to decreased hue, chroma and sarcomere length values in hot boned vs. conventionally chilled product (SM and LL) for CaASC vs. other moisture enhancement treatments. Chilling method by moisture enhancement treatment interactions (P < 0.05) were due to decreased shear force and increased tenderness in conventionally chilled vs. hot boned LL using CaASC vs. Na/STP. Moisture enhancement can improve tenderness of cull cow beef depending on combinations of chilling method and moisture enhancement treatments used.     

Carcass measurements and meat quality of Turkish Merino,Ramlic, Kivircik,Chios and Imroz lambs raised under an intensive production system

Effect of breed on carcass measurements and meat quality characteristics were investigated by using 46 lambs from Turkish Merino, Ramlic, Kivircik, Chios and Imroz breeds. Chios and Imroz carcasses had smaller values for carcass quality characteristics. Breed had no significant effect on pH at 45 min and 24 h post-mortem, water holding capacity and cooking loss. Kivircik and Imroz lambs had lower Warner Bratzler shear force values than those of Ramlic and Turkish Merino lambs (P < 0.01). Meat samples from Kivircik lambs had the highest redness value. Differences among breeds for sensory characteristics, except tenderness were not significant. Tenderness scores given to meat samples of Kivircik lambs were significantly higher (P < 0.01) than those of Turkish Merino, Ramlic and Imroz lambs. Indigenous Kivircik breed, which had high carcass quality as those of improved breeds, might be considered for production of better quality meat in Marmara Region of Turkey.     

Thermal effects on chicken and salmon muscles: Tenderness, cook loss, area shrinkage, collagen solubility and microstructure

The objective of this study was to gain insight into the mechanisms underlying heating-induced tenderness in muscle food products by comparing tenderness changes in chicken breast (Pectoralis major) and salmon (Oncorhynchus gorbuscha) during high-temperature treatment. Relationships among changes in chicken breast and pink salmon muscle were investigated for tenderness, cook loss, area shrinkage, collagen solubility and microstructure. Small white muscle samples (D 30 mm×H 6 mm) cut from pink salmon fillets and chicken breast were sealed in small aluminum containers (internal dimension: D 35 mm×H 6 mm) and heated in an oil bath at 121.1 °C for different time intervals up to 2 h to simulate various thermal process durations. The changes in salmon tenderness had 4 phases (rapid toughening, rapid tenderizing, slow toughening and slow tenderizing), while that of the chicken breast only had 2 phases (rapid tenderizing and slow tenderizing). Twenty minutes was found to be a critical heating time in which >85% collagen was solubilized and shear force reached a minimum. Cook loss and area shrinkage were significantly (P<0.05) correlated with shear force change for both the salmon and chicken, while collagen solubility was only significant for the chicken.     

Effect of ractopamine–HCl supplementation for 28 days on carcass characteristics,muscle fiber morphometrics,and whole muscle yields of six distinct muscles of the loin and round

This study evaluated the effects of ractopamine–HCl (RAC) supplementation on carcass characteristics, muscle fiber morphometrics, and tenderness. Thirty-four steers (2 groups, 4 replicates) were fed RAC or carrier for 28 days prior to harvest. Seventy-two hours postmortem, the Longissimus lumborum (LL), Gracilis (GRA), Vastus lateralis (VL), Rectus femoris (RF), Semimembranosus (SM), and Adductor (ADD) were dissected from each carcass. Commodity weight, denuded weight, and muscle dimensions were collected. RAC supplementation tended to affect dressing percentage (P = 0.15) and muscle firmness (P < 0.15), and significantly affected lean maturity (P < 0.05) and marbling score (P < 0.05). With the exception of the LL and GRA (P < 0.05), RAC had no effect on muscle dimensions. RAC did not influence the tenderness of vacuum-packaged, aged steaks as measured by Warner–Bratzler shear force. Muscle fiber size within the six muscles was unchanged (P > 0.05) by RAC. Thus, RAC improves carcass parameters without a negative impact on tenderness.     

Effects of genotype and slaughter weight on the meat quality of Criollo Cordobes and Anglonubian kids produced under extensive feeding conditions

Physicochemical and organoleptic characteristics of meat (longissimus muscle) from Criollo Cordobes (CC) and Anglonubian (AN) suckling kids were analysed to determine the effects of genotype and slaughter weight. Forty suckling entire male kids, 20 CC and 20 AN were assigned to two age/slaughter weight groups (I: 60 + 2 days old and ?11 kg, and II: 90 + 2 days old and >11 kg). Colour, shear force and cholesterol levels of meat were affected by breed. Tenderness decreased and cholesterol increased with age/slaughter weight. Fatty acid profiles were affected primarily by genotype. The sensory attributes were perceived as medium-high intensity, and meat from CC and AN goat kids was valued as tender. However, initial tenderness and connective tissue varied with genotype. The main effect due to the increase in age/slaughter weight was a decrease in tenderness (initial and overall), as observed for instrumental shear force.     

Associations of sire estimated breeding values and objective meat quality measurements with sensory scores in Australian lamb

The impact of selecting for lean meat yield using breeding values for increased eye muscle depth (PEMD) and decreased fat depth (PFAT) on the consumer acceptance of lamb meat was evaluated. Consumer sensory scores (tenderness, juiciness, flavour, odour, overall liking) were obtained for the longissimus lumborum (loin) and semimembranosus (topside) muscles of 1471 lambs. On average loin samples were more acceptable for consumers. Sensory scores increased with higher IMF levels, with lower shear force levels, and when animals were younger and less muscular. Increasing PEMD decreased tenderness, overall liking and flavour scores in both muscles, and decreasing PFAT reduced tenderness within the loin samples only. This negative impact of PEMD and PFAT is not solely driven through the phenotypic impact of IMF and shear force on sensory scores. Our results confirm the growing concerns that selecting for lean meat yield would reduce consumer eating quality, and highlight that careful monitoring of selection programmes is needed to maintain lamb eating quality.     

Carcass and meat quality characteristics of Brahman cross bulls and steers finished on tropical pastures in Costa Rica

Forty-eight male calves (3/4 Brahman × 1/4 Charolais) were used to determine carcass cutability and meat tenderness of Longissimus lumborum (LL), Gluteus medius (GM), Semitendinosus (ST) and Psoas major (PM) steaks from lighter weight carcasses of bulls and steers castrated at 3, 7, or 12 mo of age grown under tropical pasture conditions. Steaks from steers had lower (more tender) LL Warner–Bratzler shear force (WBSF) values than those from bulls. Steaks from steers castrated at 3 mo had lower GM WBSF than those from bulls. For PM steaks, those aged 28 d had lower WBSF than those aged 2 d. Steaks aged 28 d had the lowest LL and GM WBSF and steaks aged 2 d had the highest LL, GM, and ST WBSF. Castration at younger ages is recommended because it provides improvement in LL and GM tenderness over bulls with no differences in carcass traits or subprimal yields.     

Biochemical and sensorial evaluation of intact and boned broiler breast meat tenderness during ageing

Meat tenderness is the main characteristic demanded by consumers and is affected by rigor mortis development and proteolysis activities, both of which occur during carcass refrigeration. In this work, we demonstrate that broiler breast fillet tenderness can be further increased and its extension depends on whether or not meat is excised from the carcass. Post-harvest samples taken from 0 to 72 h after slaughtering and kept refrigerated at 2 ± 2 °C were evaluated for tenderness by myofibrillar fragmentation index determination, shear force analysis and sensorial testing. The 24 h post-harvested intact samples were 30.6% more tender than excised samples and 41.7% more tender than control samples (p ? 0.05). The myofibrillar fragments index was 13.2% higher in intact samples than in deboned fillet (p ? 0.05) and a sensory test showed that the 24 h intact samples were of major acceptability. Our results demonstrated that tenderness was best achieved with intact breast fillet samples stored at 2 ± 2 °C for 24 h.     

Effects of dry,vacuum, and special bag aging; USDA quality grade; and end-point temperature on yields and eating quality of beef Longissimus lumborum steaks

This study evaluated the effects of three aging methods: (dry (D), wet (W), and special bag (SB)); two quality grades [USDA Choice((≥ Small⁵⁰ marbling) and Select); and two cooked end-point temperatures (62.8 °C and 71.1 °C) on physico-chemical traits of instrumental tenderness, color, and sensory properties of Longissimus lumborum beef muscle. Dry-aged loins had higher (P < 0.0001) weight loss than W or SB aged loins. However, D and SB aged loins had similar (P > 0.05) combined losses. W aged loins had higher (P < 0.01) L* values than D or SB aged loins. Warner–Bratzler shear force of steaks was not affected (P > 0.05) by aging method or quality grade but increased (P < 0.0001) as end-point temperature increased. Sensory panel evaluation also showed no effect (P > 0.05) of aging method or quality grade on myofibrillar tenderness, juiciness, connective tissue amount, overall tenderness or off flavor intensity. Steaks cooked to 62.8 °C were juicier (P < 0.05) than those cooked to 71.1 °C. Neither D nor SB aging had advantages over W aging.     

Relationship between collagen characteristics,lipid content and raw and cooked texture of meat from young bulls of fifteen European breeds

Variations in texture were determined for 10 day aged raw and cooked Longissimus thoracis (LT) muscle from 436 bulls of 15 European cattle breeds slaughtered at an age of 13–16 months. Variations in texture were related to differences in pH 24 h post-mortem, sarcomere length, collagen characteristics and lipid content. The shear force of cooked meat samples varied from 43.8 to 67.4 N/cm². Simmental, Highland and Marchigiana cattle had the highest shear force values and Avileña-Negra Ibérica, Charolais, Casina and Pirenaica cattle had the lowest values. Cooked meat toughness showed a weak negative correlation to lipid content (P < 0.001) but no correlation to collagen characteristics. Raw meat texture measured by compression correlated positively (P < 0.001) with total and insoluble collagen. In conclusion, collagen characteristics showed correlation to raw meat texture but not to cooked meat toughness of LT muscle in European young bulls.     

Effects of chilling methods and hot-boning on quality parameters of M. longissimus lumborum from Bos indicus Nelore steer

To study the effects of chilling methods and hot-boning on quality parameters of M. longissimus lumborum (LL) of Nelore steers, sixteen left-carcass sides were electrically stimulated and the LL muscles were hot-boned and chilled at − 20 °C (HBVFC) or 0 °C (HBO). Eight control left-carcass sides were cold-boned (AT). All muscles were vacuum-packaged and aged at 0 °C for 14 d. Shear force and tenderness of the AT-treated muscles were not different from HBO-treated muscles. The shear force values of the HBVFC muscles were higher after 7 and 14 d post-mortem (pm) compared to those of the AT muscles, but there was no difference from the HBO muscles. Aging did not reduce the shear force values of the HBVFC muscles. The purge losses of the HBVFC muscles were higher than those of the HBO and AT muscles. The HBVFC muscles were less tender than the HBO and AT muscles at 14 d pm.     

Sensory profiling of textural properties of meat from dairy cows exposed to a compensatory finishing strategy

A compensatory finishing strategy was evaluated to improve the quality of meat from dairy cows. The experiment included ten pairs of Holstein Friesian dairy cows. Each pair was the progeny of the same sire, in the same parity, and approximately at the same number of days in lactation before entering the experiment. Within each pair, one cow was allocated to a compensatory finishing strategy, dried off for 4 days, and further restricted in energy intake for another 17 days followed by 6 weeks of ad libitum feeding. The strategy improved the sensory texture and flavour of both M. longissimus dorsi (LD) and M. semimembranosus (SM). This was supported by lower shear force in both muscles (P < 0.02). The effect can be ascribed to various factors; in LD an increased amount of IMF plays a significant role, whereas in SM an increased protein turnover is suggested to be the dominating factor.     

Assessment of the sensory quality and shelf stability of selected Horro beef muscles in Ethiopia

The objective of this work was to assess sensory quality and retail life of Horro beef muscles in Ethiopia. Six muscles: M. rhomboideus (RM), M. infraspinatus (IS), M. longissimus lumborum (LL), M. semimembranosus (SM), M. biceps femoris (BF) and M. rectus femoris (RF) were considered. Sensory quality of the muscles was rated by a 9-member trained panel for palatability, tenderness, juiciness, amount of connective tissue (ACT), lean color and surface discoloration and measured by Warner-Bratzler Shear Force (WBSF). Retail life of the six muscles were evaluated for CIE 1976 L^∗a^∗b^∗ color values across 6 days. Significant differences (p < 0.05) between muscles for all sensory attributes and WBSF were found. Significant L^∗a^∗b^∗ color values of muscles and USDA quality grades by retail life were found (p < 0.05). Significant correlations (p < 0.05 or p < 0.01) of key parameters were also identified.     

The effect of conditioning period on loin muscle tenderness in crossbred lambs with or without the Texel muscling QTL (TM-QTL)

A Texel muscling quantitative trait locus (TM-QTL) has been identified on chromosome 18, which increases loin muscling, but may also have a negative impact on mechanically-measured loin tenderness in crossbred lambs, depending on conditioning time. This study investigated the influence of a range of conditioning times (3, 5, 7 or 9 days) on the effect of TM-QTL on loin muscle tenderness. Using Texel rams heterozygous for TM-QTL, mated to non-carrier Mule ewes, heterozygous (n = 45) and wild-type (n = 50) crossbred lambs were produced. Weight of the valuable Longissimus lumborum muscle was higher in TM-QTL carriers than non-carriers, when compared at a fixed age (+11.5%; P = 0.038), with the same trend at a fixed carcass weight (+10.2%; P = 0.064). Toughness, measured by shear force, was significantly higher in samples from TM-QTL carriers than non-carriers, after conditioning for 3 days (P = 0.002), 5 days (P = 0.003) or 7 days (P = 0.03), but was not significantly different after 9 days of conditioning (P = 0.32). Compared to non-carrier lambs, the proportion of samples above consumer acceptability thresholds for toughness was greater in the TM-QTL carrier lambs after 3 and 5 days of conditioning, similar at 7 days, but lower at 9 days. The results suggest that the negative effect of TM-QTL on loin tenderness in crossbred lambs can be overcome by conditioning for more than 7 days. Marketing of TM-QTL carrier lambs through companies that use enhanced processing protocols could be beneficial, due to higher loin muscle weights, without negative effects on meat quality.     

Structural and biochemical characteristics of bovine intramuscular connective tissue and beef quality

The aim of the study was to evaluate the impact of structural and biochemical characteristics of muscle intramuscular connective tissue on beef quality. The experimental design was based on three muscles of three breeds sampled as fresh material and cooked at 55 °C (Longissimus thoracis and Semimembranosus) or at 70 °C (Semimembranosus and Biceps femoris) for quality assessment. The results showed that muscle characteristics influence beef quality differently from one muscle to another. In grilled LT, proteoglycan content contributed negatively to juiciness, and intramuscular lipids were linked positively to tenderness, flavour, residues and overall liking scores. In grilled SM, cross-link and lipid contents were involved in beef quality. In BF cooked to 70 °C, perimysial branch points were negatively linked to tenderness. In SM cooked to 70 °C, perimysial area was involved in beef quality. These results should allow a better understanding of the factors involved in background toughness, in juiciness and flavour of meat.