WB Shear Force Research Articles

Carcass characteristics, physicochemical traits, texture and microstructure of young and spent quails meat

The purpose of the study was to compare young (6-wk-old) and spent (52-wk-old) Japanese quail in terms of body weight, carcass characteristics, and some meat quality traits. Whole carcasses were dissected, pectoral muscles and leg muscles were sampled for determination of basic chemical composition and L*a*b* color parameters, while m. pectoralis major was sampled for texture and microstructure traits. Age of quails had a significant effect on body weight, carcass weight, carcass yield, pectoral muscle, abdominal fat and skin with subcutaneous fat, and carcass remainders contents in eviscerated carcass. Spent quails had significantly higher intramuscular fat content in pectoral and leg muscles and protein content in breast muscle, and also lower content of water in breast and leg muscles than young quails. Slaughter age significantly affected lightness (L*) and redness (a*) of pectoral muscles, as well as texture traits (except for cohesiveness) and microstructure of m. pectoralis major, except for thickness of perimysium and endomysium. Regardless of age, quail sex had an effect on the carcass traits studied (except for leg muscle content), intramuscular fat content of pectoral and leg muscles, water content of leg muscles and yellowness of pectoral muscle. In addition, a significant effect of quail sex was found on cutting work, springiness, chewiness and marked microstructural characteristics, except for vertical fiber diameter. The interaction between age and sex was significant for most slaughter and microstructural characteristics and also WB-shear force of m. pectoralis major, and L*, b* pectoral muscles. Higher fatness of carcasses, higher intramuscular fat in meat, and poorer textural and microstructural characteristics of m. pectoralis major spent Japanese quail indicate poorer fulfillment of most consumers' requirements compared to carcasses and meat of young quails.

Gestational nutrient restriction under extensive grazing conditions: Effects on muscle characteristics and meat quality in heavy lambs

We evaluated maternal undernutrition effects induced by a lower natural pasture allowance (gestation days 30–143) on histological-biochemical and meat traits in muscles Semitendinosus, cranial Gluteobiceps and Supraspinatus from 200-day old male and female lambs. Maternal undernutrition increased oxidative and reduced glycolytic fibers in all muscles (P ≤ 0.01). Maternal undernutrition reduced the diameter of glycolytic fibers in the cranial Gluteobiceps of exclusively female lambs (P = 0.05) and reduced the diameter of oxidative fibers in the Supraspinatus of exclusively male lambs (P = 0.02). Maternal undernutrition increased lipid content in the Supraspinatus of females (P = 0.001), reduced lactate content (P = 0.03) and WB shear force (P = 0.02) in the Semitendinosus of females, and increased cooking losses in the Semitendinosus of males (P = 0.0069). In conclusion, gestational nutrient restriction induced fetal programming effects on muscle characteristics of lambs. Moreover, our study demonstrates that maternal undernutrition influences muscle and meat characteristics in a sex and muscle-dependent way.

Comparison of some meat and liver quality traits in Muscovy and Pekin ducks

ABSTRACT The objective of the study was to compare Muscovy and Pekin ducks for proximate analysis, colour attributes, tenderness, meat microstructure, and content of some minerals in meat and liver. The material of the study was sexed 51 Muscovy ducks and 47 Pekin ducks. At the end of the rearing period, 40 birds were selected for dissection. Duck genotype influenced the content of water, protein, fat, collagen, zinc, iron, haematin, and redness, chroma, hue angle, WB shear force, muscle fibre diameter and density of the breast muscle, and also protein, fat, magnesium, iron, haematin content, WB shear force and lightness of the leg muscle. The sex of ducks had an impact on the content of water, protein, fat, potassium, copper, on redness, chroma and muscle fibre diameter of breast muscle, and on water, protein, fat, sodium, potassium, magnesium and copper in liver content of the leg muscle. The genotype-sex interaction was significant for water, protein and sodium content, redness, chroma of breast muscles; for water, protein, sodium, magnesium and haematin content, redness and chroma of leg muscles; and for phosphorus content in the liver. Muscovy ducks had more favourable chemical composition and poorer tenderness and microstructural characteristics compared to the meat of Pekin ducks.

Tough aged meat presents greater expression of calpastatin, which presents postmortem protein profile and tenderization related to Nellore steer temperament

Eighteen Nellore steers were classified as either excitable (high index) or calm (low index) temperament, and high or low WB Shear Force (SF) in Longissimus lumborum at 16 days postmortem, with a subset assigned to four groups: HTHS–high temperament and SF (n = 5); HTLS–high temperament and low SF (n = 4); LTHS–low temperament and high SF (n = 4); LTLS–low temperament and SF (n = 5). Only the second calpastatin peak was detected at 48 h in the all samples, and the calpastatin activity only differed (P < .05) between shear force groups. High WBSF groups had greater expression of CAST gene (P < .05) in the high and low temperament. Western blots showed a calpastatin fragmentation pattern very particular to each group with high molecular weight bands present in the HTHS. Temperament was not a determinant factor in postmortem proteolysis variation. However, greater WBSF aged meat from high temperament animals had greater calpastatin activity and less calpastatin fragments formed during the postmortem period analyzed.

Effects of probiotics and sex on physicochemical, sensory and microstructural characteristics of broiler chicken meat

The aim of the study was to determine the effects of probiotic preparations Pro-Biotyk Em-15 and EMFarma™ and sex on proximate chemical composition, physicochemical properties of breast and leg muscles, sensory properties (including texture) and microstructural characteristics of pectoralis major muscle in Ross 308 broiler chickens. The study used 48 carcases – 12 from males and 12 from females fed no probiotics, and 12 from males and 12 from females receiving the EM probiotics. At 42 days, the chickens receiving EM preparations had significantly higher WB-shear force of pectoralis major muscle, whereas the leg muscles contained significantly less water and fat and had higher pH24 value. Regardless of the treatment, males exhibited significantly higher springiness, chewiness, as well as significantly lower yellowness (b*), fibre perimeter, horizontal (H) fibre diameter and fibre cross section area of pectoralis major muscle when compared to females. In turn, male leg muscles had significantly higher fat content compared to female leg muscles. The genotype × sex interaction was significant for the content of water, protein and fat, and for electric conductivity (EC24) of leg muscles.HighlightsProbiotics did not improve the quality of chicken meat.The influence of sex on the quality of chicken meat was varied.

Mechanical texture profile of Hanwoo muscles as a function of heating temperatures

BackgroundCooking temperature and consequently doneness of beef muscles are most important for the palatability and consumer acceptability. Current study assessed the response of mechanical texture of Hanwoo muscles as a function of cooking temperature at different ageing days. Six muscles (Psoas major (PM), Longissimus thoracics (LT), Gluteus medius (GM), Semimembranosus (SM), Biceps femoris (BF) and Triceps brachii (TB)) were collected from each 10 Hanwoo steers. Warner-Bratzler WB-shear force (WBSF) and texture profile analysis (TPA) texture profiles were determined after 3 or 21 days of chiller, and randomly assigned to four groups; non-cooked, cooked at 55, 70 or 85 °C.ResultsToughness of WBSF and TPA hardness of Hanwoo muscles were presence in the order of LT = PM = GM = SM < BF = TB (p < 0.001) for non-cooked raw muscle, and PM < LT = GM = SM < TB=BF (p < 0.001) for cooked meat aged for 3 days. WBSF linearly increased in 3 days aged meats after cooked at a higher temperature (P < 0.05). On the other hand, toughening of the muscles were significantly (P < 0.05) differed at various temperature when muscles were aged for 21 days. WBSF of PM and LT muscles were significantly increased at a higher cooking temperature, while other muscles (i.e., GM, SM, BF, TB) showed the lowest values at 70 °C. In the case of TPA hardness, the effect of cooking temperature was very less in the toughness of the muscle (P > 0.05).ConclusionTaken together, these findings clearly showed that the toughness of the muscle highly depends and varies upon the temperature and ageing of the muscle. Moreover, the effect of cooking temperature was very limited on aged muscles. The results mirror the importance of cooking temperature for objective measurements which ultimately estimate sensory tenderness and other quality traits.

Effects of feeding whole-grain triticale and sex on carcass and meat characteristics of common pheasants

The aim of the present research has been to determine the effect of replacing a part of commercial compound feed with whole triticale grain on the body weight (BW), body measurements, feed conversion ratio (FCR), carcass composition and meat quality of pheasants. The study involved 80 one-d-old common pheasants. From 71 to 112 d of rearing, two diets were administered: a complete commercial diet ad libitum for control pheasants and restricted amounts of a commercial diet (50%) and whole triticale grain (50%) for experimental pheasants. Each treatment consisted of 4 replications, 10 birds each. Introducing whole triticale grain did not cause significant changes in BW, body measurements, feed intake and FCR. The carcasses of 112-d-old pheasants fed whole triticale grain diet showed a significantly lower breast muscle content (%) and a significantly higher content of skin with subcutaneous fat and carcass remainders (p < .05). Breast muscles of pheasants fed commercial compound feed and whole triticale grain exhibited significantly higher hardness, chewiness and gumminess, more palmitic acid and zinc, as well as significantly less sodium, water, linoleic acid, paullinic acid, heptadeconoic acid. There were also significant changes in water and protein, the content of fatty acids in leg muscles, except for myristic acid, pentadecanoic acid, arachidonic acid and nervonic acid. Irrespective of the type of diet, males showed a significantly higher body weight, body measurements and carcass weight, and their breast muscles demonstrated significantly higher WB shear force and the amounts of protein, linoleic acid, potassium, phosphorus, magnesium and zinc.

Comparação das características de carcaça e qualidade da carne de suínos Black Slavonian em função da duração do período de engorda

O objetivo deste estudo foi analisar a possibilidade de encurtar o período de engorda do porco Black Slavonian sem deteriorar a qualidade da carne. A pesquisa foi realizada em 30 porcos Black Slavonian divididos em dois grupos iguais, A e B, de acordo com a duração do período de engorda: 18 e 12 meses, respetivamente. Os porcos foram criados em sistema extensivo (pastagens, bosques). Durante o ano, os porcos foram alimentados com uma mistura de cereais (50% de milho, 30% de cevada, 10% de aveia, 10% de soja) que foi suplementada com alfafa durante o período de crescimento vegetal; durante o inverno, os porcos foram alimentados com feno de alfafa. No final do período de engorda, os porcos foram abatidos num matadouro comercial. Foram obtidos dados de carcaça e qualidade da carne: peso da carcaça, comprimento da carcaça, espessura muscular e de gordura subcutânea dorsal, bem como comprimento e circunferência do presunto, pH45 dos músculos semimembranoso e longissimus dorsi, cor da carne (CIE L * a * b *) e perda por gotejamento pelo método EZ drip. Os porcos do grupo B apresentaram carcaças significativamente mais leves e mais curtas, caracterizadas por uma gordura subcutânea dorsal menos espessa que os porcos do grupo A. O comprimento e a circunferência do presunto não foram afetados pela duração do período de engorda. Por outro lado, os resultados mostraram que o encurtamento do período de engorda deteriorou significativamente alguns traços importantes da qualidade da carne, sobretudo a perda por gotejamento e os valores CIE L* da carne no grupo B. A carne dos porcos deste grupo também se apresentou menos tenra do que a carne dos porcos do grupo A, como mostrado por valores de força de cisalhamento WB (N) significativamente maiores.

Evaluation of the Technological Suitability of Beef Muscles: M. Semitendinosus, M. Semimembranosus, Mm. Psoas Major And Minor as Entire Primal Cuts in the Production Of Raw Fermented Meats With Regard to the Raw Pork Products

Abstract The aim of the study was to evaluate the technological suitability of selected beef muscles: m. semitendinosus (BST), m. semimembranosus (BSM), mm. psoas major and minor (BPM) as entire primal cuts in the production of raw fermented meats, compared to the raw pork rump (RSR) and loin (RSL), widely known in the Podlasie region. The 4-week maturation was conducted by the same traditional method in a genuine ripening room, and the texture, colour and sensory parameters of the pork and beef products were compared. The lowest water activity (0.89 and 0.83), pH (5.16 and 4.75) as well as the highest WB shear force (8.50 and 19.96 kG/cm2) and TPA hardness (52.12 and 199.24 N) were found in the ready-to-eat RSL and BST, respectively. The RSR and BPM were characterized by the lowest values of WB shear force (7.63 and 9.49 kG/cm2), TPA hardness (48.17 and 105.18 N) and TPA chewiness (8.39 and 32.68 N), as well as the highest grades for overall impression (4.50 pts), cross-section colour (4.60 pts), structure (4.60 pts), tenderness (4.30 and 4.70 pts) and flavour desirability (4.60 pts) in the sensory evaluation while the RSL and BPM were the juiciest (4.60 and 4.70 pts). The a* values and chroma showed an increase in redness during the first 2 weeks of beef aging and during the entire aging period in the pork products. The most significant colour differences were found for BSM, BST and BPM products (ΔEL*a*b*=6.48, 5.27 and 4.24, respectively).

The interaction between ractopamine supplementation, porcine somatotropin and moisture infusion on pork quality

Ninety six crossbred pigs were used in a 4×2×2 experiment to determine the influence of management strategy, moisture infusion and ageing on pork quality. The treatments were i) management strategy (MS) during the last 28days pre-slaughter (Control: conventional diet; Ractopamine (Rac): porcine somatotropin (pST); and combined (Rac+pST): Rac for 28days and pST for the final 14days), ii) moisture infusion (MI) (0% and 10%) and iii) ageing period (24h and 7days). L* was decreased by pST and Rac+pST, followed by Rac and then the Control MS. Shear force was increased by Rac and Rac+pST but not by either pST or the Control MS. MI decreased L* and shear force while ageing for 7days increased L* and yellowness, and decreased drip loss and WB shear force. MI or ageing for 7days improved sensory pork quality. The results from this experiment indicated that as expected MI and ageing can be used to improve pork quality.

Effect of post-mortem handling conditions on the quality of spent hen meat curry

Study was performed to determine the effect of post-mortem handling conditions on the physico-chemical and sensory attributes of spent hen meat curry. Breast cuts of spent hens were subjected to different postmortem handling conditions before cooking viz; made into small cuts and cooked within 1-2h of slaughter (condition1), made into small cuts and cooked after 4-5h of slaughter (condition2), made into small cuts immediately after slaughter, stored at 4 ± 1°C for 12h and then cooked (condition3), stored at 4 ± 1°C for 12h, made into small cuts and cooked (condition4). The pH of meat just before cooking due to different stages of rigor development under various conditions differed accordingly. Observed differences in temperature of meat just before cooking were because of different postmortem handling condition variations viz:1,2,3,&4. The associated post mortem changes under different postmortem handling conditions before cooking led to significant variation in Water holding capacity, Water Soluble Protein, Salt Soluble Protein, cooking yield, moisture percentage before cooking and after cooking and also WB shear force value. In general, sensory scores were higher for conditions4 and 1 as compared to conditions2 and 3. Results revealed that quality attributes of spent hen meat curry can be improved by following proper post-slaughter handling and processing conditions. To get meat curry of good sensory quality, meat should be cooked preferably within 1-2h of slaughter or after 10-12h of storage of intact carcass at 4 ± 1°C. Cuts should be made just before cooking but cooking after 4-5h of slaughter should be avoided.

Objective Meat Quality and Volatile Components as a Function of Cooking Temperature in Beef Longissimus lumborum

The present paper describes the effect of cooking temperature on objective meat qualities and volatile components in beef longissimus lumborum. Twenty samples of lumbar vertebrae longissimus muscle from Australian Black Angus (grain-fed and chiller aged for 29 d) were screened. Samples were cooked at 50, 70 or <TEX>$90^{\circ}C$</TEX> in a pre-heated water bath for 1 h and uncooked raw samples were used as control. The results revealed that elevating the heating temperature from 50 to <TEX>$90^{\circ}C$</TEX> led to a significant (p<0.05) increase in WB-shear force, total energy required for WB-shear force, cooking loss, pH and soluble collagen content, whereas a significant (p<0.05) linear decrease in protein solubility was observed. The results also revealed that the WB-shear force at <TEX>$70^{\circ}C$</TEX> was significantly (p<0.05) lower than that observed at <TEX>$50^{\circ}C$</TEX> and <TEX>$90^{\circ}C$</TEX>. However, the effect of temperature on cooking loss and protein solubility was notably (p<0.05) higher at <TEX>$70^{\circ}C$</TEX>. The detectable volatile components were mostly produced from fat oxidation, and temperature effects on the generation of volatile components were significantly (p<0.05) greater for aldehydes (hexanal, benzaldehyde, nonanal and octanal) than for ketones and hydrocarbons (hexane, benzene, decan, toluene and 3-methylnonane).

Effect of Transportation and Low Voltage Electrical Stimulation on Meat Quality Characteristics of Omani Sheep

The aim of this study was to determine the effects of road transportation during the hot season (36 oC) and low voltage electrical stimulation on meat quality characteristics of Omani sheep. Twenty intact male sheep (1-year old) were divided into two equal groups: 3 hrs transported or non-transported. The transported group was transferred to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 300 km. The non-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 3 days prior to slaughter. Blood samples were collected from the animals before loading and prior to slaughter in order to assess their physiological response to stress in terms of hormonal levels. Fifty percent of the carcasses from each group were randomly assigned to low voltage (90 V) at 20 min postmortem. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length, myofibrillar fragmentation index and colour L*, a*, b* were measured on samples from Longissimus dorsi muscles collected 24 hrs postmortem at 2-4 oC. The transported sheep had significantly (P&lt;0.05) higher cortisol adrenaline, nor-adrenaline, and dopamine levels than the non-transported group. Muscles from electrically-stimulated carcasses had significantly (P&lt;0.05) lower pH values, longer sarcomere length, lower shear force value, higher expressed juice, myofibrillar fragmentation index and L* values than those from non-stimulated ones. Transportation significantly influenced meat quality characteristics of the Longissimus dorsi muscle. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than non-transported sheep. This study indicated that pre-slaughter transportation at high ambient temperatures can cause noticeable changes in muscle physiology in sheep. Nevertheless, meat quality of transported sheep can be improved by electrical stimulation post-slaughter.

Effects of transportation during the hot season and low voltage electrical stimulation on histochemical and meat quality characteristics of sheep longissimus muscle

The effect of transportation during the hot season (42 °C) and low voltage electrical stimulation on physiological, histochemical and meat quality characteristics of Omani sheep was studied. Forty intact male sheep were divided into two equal groups: 3 h transported or non-transported. The non-transported group remained in holding pens for 48 h prior to slaughter, while the transported group was transported 300 km (approximately 3 h) in an open truck under solar radiation on the day of slaughter. Blood samples were collected from the animals before loading and prior to slaughter. Fifty percent of the carcasses from each group were randomly assigned to low voltage (90 V) at 20 min postmortem. Temperature and pH decline of the left longissimus thoracis muscle were monitored. Ultimate pH, WB-shear force, sarcomere length, myofibrillar fragmentation index (MFI), expressed juice, cooking loss and color L⁎, a⁎, b⁎ were measured on samples from both sides muscles collected at 24 h postmortem at 3–4 °C. The transported sheep had significantly higher plasma cortisol ( P < 0.01), adrenaline, nor-adrenaline and dopamine concentrations ( P < 0.05) than non-stimulated animals. Electrical stimulation resulted in a significantly ( P < 0.05) more rapid pH fall in muscle during the first 12 h after slaughter. Muscles from electrically-stimulated carcasses had significantly ( P < 0.05) lower pH values, longer sarcomere length, lower shear force value, higher expressed juice, MFI and lighter L⁎ than those from non-stimulated ones. The muscle samples from the transported sheep had significantly ( P < 0.05) smaller and lower proportion of Types I and IIA fibers than those from the non-transported group. This study indicated that pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep. Electrical stimulation improved meat quality characteristics, which indicate that meat quality of transported sheep can be improved by electrical stimulation.

Preliminary investigations on the effects of ageing and cooking on the Raman spectra of porcine longissimus dorsi

The influence of ageing and cooking on the Raman spectrum of porcine longissimus dorsi was investigated. The rich information contained in the Raman spectrum was highlighted, with numerous changes attributed to changes in the environment and conformations of the myofibrillar proteins. Predictions equations for shear force and cooking loss were developed from the Raman spectra of both raw and cooked pork. Good correlations and standard errors of prediction were obtained for both WB shear force and cooking loss, with the raw and the cooked samples showing almost identical results R 2 = 0.77, root mean standard error of prediction (RMSEP)% of mean = 12% for shear force; R 2 = 0.71, RMSEP% of mean = 10% for cooking loss. The Raman spectra were also able to predict the extent of cooking that occurred within the pork ( R 2 val = 0.94, RMSEP% of range = 5.5%). Raman spectroscopy has considerable potential as a method for non-destructive and rapid determination of pork quality parameters such as tenderness. Raman spectroscopy may provide a means of determining changes during cooking and the extent to which foods have been cooked.

Effect of fiber type on postmortem proteolysis in longissimus muscle of Landrace and Korean native black pigs

The current study was conducted to characterize objective meat quality, fiber type and their relations to postmortem proteolysis in longissimus muscle of Landrace and Korean native black (KNP) pigs. Longissimus muscles from each 10 market-weighted male pigs were removed after conventional slaughtering and chilling procedures, and aged for 1 or 7 days at 4 °C to determine WB-shear force, objective meat color, proportion of myosin heavy chain I (MyHC I), intramuscular fat content and rate of proteolysis by a proteomics approach. KNP had a significantly ( p < 0.05) higher content of MyHC I, and that concurred with greatly ( p < 0.05) higher intramuscular fat content and Hunter a ∗ value, and significantly ( p < 0.05) lower drip loss than those seen in Landrace. One-dimension SDS-PAGE indicated that GAPDH, troponin I and creatine kinase were prominent proteolytic products during chiller ageing. By applying a gel-based proteome analysis, 26 proteins were identified, which showed different degradation properties during ageing between the breeds. Biopsied sample revealed that myosin regulatory light chain 2, myosin light chain isotype v/sb, fatty acid-binding protein and albumin were expressed at a greatly higher level for KNP, but their relation to fiber type (or genetic background) is unclear. It was particular noticeable that different actin isoforms showed various degradation behavior during ageing time.

Variation in the response to manipulation of post-mortem glycolysis in beef muscles by low-voltage electrical stimulation and conditioning temperature

The aim of this study was to investigate how manipulation of glycolytic rate by post-mortem processing conditions influences quality of aged beef of two bovine muscles of different physiological character, longissimus dorsi (LD) and adductor (AD). Post-mortem glycolysis was manipulated by low-voltage electrical stimulation (LV-ES) of half carcasses and by chilling rate of the muscles. Multivariate statistical analysis was used to visualise the data, while ANOVA was used to identify significant effects and interactions. As expected there was a significant effect of LV-ES on the pH decline in the first hours post-mortem in both muscles. Moreover, significant effects of LV-ES on WB shear force measured 2 and 8 days after slaughter were observed for LD at both chilling temperatures, while for AD no effect on WB shear force was observed. Furthermore, the results revealed a large individual variation in the response of LV-ES on both pH decline and WB shear force, and this variation did not always correlate for the two responses. Some animals showed no response of LV-ES on pH decline, but still had an improved WB shear force, and vice versa. The results from this study indicate that there probably are other mechanisms than accelerated pH decline and prevention of cold-shortening, by which LV-ES can affect meat tenderness.

Effect of Postmortem Metabolic Rate on Meat Color

The current study was conducted to evaluate carcass characteristics, objectives and sensory meat qualities of Hanwoo longissimus muscle as affected by ultimate pH. Twenty-four steers and bulls (556±53 kg and 0.63±0.32 cm for live weight and backfat thickness, respectively) were used. As there was a linear relationship (r = 0.77) between lean meat color and ultimate pH, cattles were thus segregated into normal (pH 5.8, n = 11) groups. Normal pH group had significantly (p<0.05) higher carcass weight, marbling score and backfat thickness than those for high pH group, while fat color and lean meat color were inverse. In principle component analysis for co-ordinates of DFD and normal meats, fat color, lean meat color, texture, time to pH 6.2 and pH at 24 h postmortem were associated with the positive range of the first factor (67.5%) while backfat thickness marbling score and temperature at 24 h were placed in negative values. The rate constant of decline in pH (pH k) did not differ between the two groups, implying that initial pH (i.e., pH at slaughtering) differed between two groups. Contour mapping of pH k between pH at 1 and 24 h postmortem indicated that high pH k was related to lower pHs at 1 and 24 h postmortem. This suggested that the high pH cattles (i.e., DFD cattle) resulted from their own potential. Although the time to reach pH 6.2 was significantly (p<0.05) shorter for normal meat (i.e., 3.2 h) than that for DFD one (i.e., 19.8 h), there were no significantly differences in both WB-shear force and sensory attributes. Given that the experimental animals were sampled from a similar group, which implies a similar myoglobin pigment content, the current data suggested that pre- and post-slaughter animal handling likely had a significant effect on ultimate pH and consequently meat color of Hanwoo longissimus muscle, and also small animals with lower marbling score and backfat thickness had a higher risk for DFD meat.

Effect of Transportation at High Ambient Temperatures on Physiological Responses, Carcass and Meat Quality Characteristics in Two Age Groups of Omani Sheep

The aim of this study was to determine the effects of short road transportation in an open truck during hot season on live weight shrink, physiological responses, and carcass and meat quality of Omani sheep at 6 and 12 months of age. Thirty-six male sheep, 18 of each age group, were used. Age groups were assigned randomly to transported and not-transported groups. The transported group was transported to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 100 km. The average temperature during transportation was 37°C. The not-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 48 h prior to slaughter. Blood samples were collected from sheep before loading and prior to slaughter via jugular venipuncture to assess their physiological response to transport in relation to hormonal levels. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length and colour L*, a*, b* were measured on samples from longissimus dorsi, biceps femoris and semitendinosus muscles collected at 24 h postmortem at 1-3°C. Live weight shrinkage losses were 1.09 and 1.52 kg for 6 and 12 month transported sheep, respectively. The transported sheep had significantly (p<0.05) higher cortisol, adrenaline, noradrenaline, and dopamine concentration levels prior to slaughter at both ages than the not-transported sheep. Transportation significantly influenced meat quality characteristics of three muscles. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than not-transported sheep. Age had a significant effect on meat quality characteristics of Omani sheep. These results indicated that short-term pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep.

유기셀레늄강화버섯 폐배지의 급여수준에 따른 거세한우 채끝육의 육질특성

The current study was conducted to investigate the effect of organic selenium in mushroom cultured media (MCM) on beef quality. Each five of 20 Hanwoo steers(20 - 24 month, approximately 613 kg) were assigned to four levels of the selenium content(O.l, 0.3, 0.6, 0.9 dry matter based ppm), and the feeding treatments were enforced for 12 weeks. The results showed that m. longissimus from the 0.1 ppm feeding supplementation had greatly higher intramuscular fat content than other treatments(13.1 %). In meat color, the 0.1 ppm treatment showed the lowest lightness(CIE <TEX>$L^*$</TEX>)(P< 0.05) and had a tendency to have lower redness(CIE <TEX>$a^*$</TEX>). The treatment had no noticeable effect on moisture, protein, and ash content, cooking loss, water-holding capacity and purge loss. The 0.3 ppm treatment resulted in the toughest meat(assessed by WB-shear force) with 4.54 kg / inch', while other groups showed a similar toughness ranging from 3.3 to 3.7 kg/ inchl . Sensory characteristics in juiciness and flavor intensity had a tendency of increasing as organic selenium concentration increased, but tenderness was not influenced by the contents. The result indicated that the organic selenium feeding affects meat qualities to different extent, and further study is required to examine anti-oxidant effect of selenium in vivo.