Meat Quality Assessment Research Articles

Lamb Meat Quality Assessment by Support Vector Machines

The correct assessment of meat quality (i.e., to fulfill the consumer’s needs) is crucial element within the meat industry. Although there are several factors that affect the perception of taste, tenderness is considered the most important characteristic. In this paper, a Feature Selection procedure, based on a Sensitivity Analysis, is combined with a Support Vector Machine, in order to predict lamb meat tenderness. This real-world problem is defined in terms of two difficult regression tasks, by modeling objective (e.g. Warner–Bratzler Shear force) and subjective (e.g. human taste panel) measurements. In both cases, the proposed solution is competitive when compared with other neural (e.g. Multilayer Perceptron) and Multiple Regression approaches.

Use of supplementary tryptophan to modify the behavior of pigs1

Three experiments were conducted to investigate the short-term use of supplementary Trp on the behavior of grow/finish pigs. Three levels of dietary Trp were used, representing the standard requirement for growth (control), twice (2x), and 4 times (4x) the control amount. In Exp. 1, pigs were fed the diets for 7 d, during which observations were made of their general behavior (time budget), aggression within the group of familiar pigs, and response to a startling auditory stimulus. Behavior effects were evident during the period of supplementation for both the 2x and 4x diets. During the treatment period, pigs fed supplemental Trp spent more time lying (P = 0.04) and less time eating (P = 0.05) than pigs fed the control diet. Although the response of the animals to the startling stimulus was to become alert and stand, similar behavioral effects caused by supplemental Trp also were evident after the startling stimulus (P < 0.01). Based on these observations, the subsequent studies retained the same dietary levels of Trp and incorporated a 3-d feeding of diets before behavior testing. In Exp. 2, pigs were fed the experimental diets for 3 d before being regrouped with unfamiliar pigs on the same diet. Subsequent aggression was affected by Trp supplementation, in that high levels of dietary Trp decreased the total duration of fighting by approximately 50% (P = 0.03). Supplemental Trp had no effect on the number of fights, and there were no differences between the 2 levels of supplemental Trp on any behavior. In Exp. 3, pigs were exposed to specific handling tests on the farm and meat quality assessments after being fed the experimental diets for 3 d. There were no differences among dietary treatments for any of the meat quality characteristic variables measured. The only behavioral or physiological difference observed among the treatments was a slower movement of pigs fed the 4x Trp treatment than control or 2x Trp-fed pigs in a minimal-forced situation (P = 0.04). Response to confinement on a scale, an electric prod, and movement in general did not differ among treatments. High levels of Trp may result in animals avoiding stressful situations if possible, but they seem to have no effect on responses to stressors that animals may experience in a forced situation.

Meat quality of fully or partly outdoor reared pigs in organic production

Outdoor production on pasture is considered an option in organic pig production. The aim of the present trial was to study the influence of feeding strategies combining outdoor and indoor rearing on pig meat quality. The experiment was carried out with 245 pigs in 5 replicates, and commenced following weaning at day 52. Five treatments were compared: 1) pigs fed ad libitum and reared indoors with access to an outdoor concrete area (In-A); 2) pigs fed restrictively on pasture until 40 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-40A); 3) pigs fed restrictively on pasture until 80 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-80A); 4) pigs reared on pasture and fed restrictively during the whole period of growth (Out-R); and 5) pigs reared on pasture and fed ad libitum during the whole period of growth (Out-A). All pigs had free access to roughage (clover-grass silage/fresh clover grass). Restrictive feeding in the weight range from weaning to 40 kg body weight (In-40A) resulted in a reduced daily gain; however, following transfer to indoor facilities and ad libitum feeding these pigs compensated in growth and the overall daily gain did not differ from the In-A control pigs. Pigs fed restrictively from weaning to 80 kg body weight were unable to compensate completely following transfer to indoor facilities. Out-R pigs had the lowest overall daily gain, while In-A pigs and Out-A pigs had similar daily gain. Meat quality assessments were performed on longissimus dorsi (LD) samples from a subsample of 100 pigs (2 castrates and 2 female pigs from each treatment in each replicate). Compared to meat from either ad libitum treatments (In-A and Out-A), meat from Out-R and In-80A pigs was less red due to a lower pigmentation, and had a higher ratio of polyunsaturated:saturated fatty acids. In addition, Out-R female pigs had numerically (6–10 Newton) higher shear force than In-A and Out-A. Treatments did not affect the concentration of α-tocopherol of meat. Introducing a finishing period with free access to concentrates following 40 kg body weight until slaughter prevented the deterioration in meat quality. However, a finishing period following 80 kg body weight was not sufficient. In conclusion, ad libitum feeding in the organic production system gave superior meat quality compared to a restrictive feeding strategy. However, including a finishing period indoors with ad libitum feeding of concentrates may prevent the detrimental effect of restrictive feeding on meat quality.

Eating quality of commercially processed hot boned sheep meat

The aim of this work was to establish consumer perceptions of the eating quality of commercially processed hot boned sheep meat. The eating quality scores for tenderness, flavour, juiciness, and overall liking of grilled m. longissimus thoracis et lumborum (LL) were derived from untrained consumers. The animals used in this experiment were sourced from three different properties and were of various ages, breed, and sex, and had been on various quality pastures. All carcases were subjected to immobilisation, spinal discharge and high voltage electrical stimulation and boned within 2 h of slaughter. All LL samples were frozen after boning according to the system applied at the abattoir and samples kept for consumer assessment and measurement of meat quality. The results showed, on average carcases entered rigor at high temperatures with a pH of 5.95 at 29.3 °C. With an average sarcomere length of 1.68 μm, some shortening was evident and there was a significant difference between lots in sarcomere length ( P < 0.05). A large percentage (82%) of samples had a pH greater than 5.8 at the time of freezing. All samples taken for shear force analysis exceeded a recommended threshold for acceptable table meat of 49 N and there was no significant difference between lots ( P > 0.05). Only 13.5% of the samples met the ‘good everyday’ requirement following sensory assessment and there were significant differences between lots for eating quality traits ( P < 0.05). This work clearly shows that the application of effective electrical stimulation is not sufficient to ensure that hot boned sheep meat will be suitable as a table meat. These findings highlight the need for the inclusion of other intervention techniques.

현수방법이 한우육질에 미치는 영향

본 연구는 현수방법이 한우 육질에 미치는 영향과 근육간 육질특성 차이에 영향을 주는 요인을 평가하기 위해 수행되었다. 총 18두 한우 거세우의 좌도체와 우도체를 순차적으로 tendaerstretch(TS) 처리하고, 다음날 양 도체의 longissimus(LD), semimembranosus(SM), tricepsbrachii(TB)을 발골하여 7일 동안 숙성하였다. 관능검사는 한국식 바베큐(BBQ)와 서양식 스테이크(Grill) 방법으로 360명을 대상으로 실시하였고, 동시에 전단력, 보수력, 가열 감량, 근절길이와 근내 조지방 함량을 측정하였다. 소비자 맛 지수는 도체 육질등급이 높은 경우 LD는 높았으나(P < 0.05), TB는 차이가 없었다. 한편, SM은 Grill의 경우에만 높은 듭급이 높은(P < 0.05) 값을 없었다. 이 결과는 높은 도체 육질등급은 LD의 경우 맛이 우수하다는 것을 증명하나, SM과 TB의 맛은 대변하지 못한다는 것을 시사한다. Tenderstretch는 TB의 관능 특성 및 물리적 육질 특성에는 영향을 미치지 않았고, 다른 근육의 가열 감량에도 영향을 미치지 않았다. 한편, 이 현수 방법은 LD와 SM의 근절길이와 맛 지수를 증가(P < 0.05) 시키고 전단력을 감소(P < 0.05) 시켰다. 이 결과는 시료가 7일 동안 냉장 숙성되었다는 점을 고려할 때, 결체조직의 약화와 관련되었다는 것을 시사하고 있다. 도체 육질등급에 따른 현수방법의 특별한 효과는 대부분 육질 특성에는 관찰되지 않았으나, tenderstretch된 SM의 맛 지수가 처리를 하지 않은 LD와 동하였다. 이 결과는 소비자들이 tenderstretch한 우둔을 불고기 형태로 소비했을 경우 등심과 같은 맛을 느낄 수 있다는 것을 의미한다. 소비자 맛 지수와 기계적 육질 측정치와의 상관관계에서, LD의 경우 근내지방과 유의적(P < 0.05) 상관관계를 보였고, SM의 경우는 근절길이와 유의적(P < 0.05) 관계를 보였다. 이 결과는 근육에 따라 맛을 대변할 수 있는 예측 요인이 다르다는 것을 시사한다. SM의 경우 보수력과 가열 감량이 높은 음의 상관관계를 보여, 보수력과 가열 감량과의 관계를 잘 나타내고 있으나, 다른 근육에서는 높은 상관도가 관찰되지 않았다. 소비자가 느끼는 맛 차이를 포함하여 실험실적 측정요인을 이용한 근육간 별별력 검사를 하였을때 약 77%의 확률에서 분류되었다. 근육간 차이에서 가장 큰 요인은 맛지수였고, 가열 감량과 근절길이도 큰 요인으로 작용했다. 이 결과는 전단력 측정의 절대치와 맛과의 관계는 근육에 따라 다르다는 것을 나타내며, 근육간 맛 차이는 전단력보다 가열 감량과 근절길이가 설명력이 높다는 것을 나타냈다. 본 연구 결과는 Tenderstretch는 우둔과 같은 비인기부위의 맛 지수를 높이는데 유용한 방법이고, 기계적인 육질측정 방법이 국내 소비자 맛 지수를 예측하는데 한계가 있다는 것을 시사한다. The current study was conducted to determine the effect of suspension method on satisfaction level of Korean consumers and objective meat quality traits in Hanwoo longissimus dorsi(LD), triceps brachii(TB) and semimembranosus(SM) muscles. Eighteen Hanwoo steers were slaughtered and alternative sides were hung either by pelvic bone(TS) or Achilles tendon(Al). Sensory characteristics, WB-shear force, sarcomere length, water-holding capacity, saroomere length and cooking loss were determined after a 7-d chiller ageing. Higher carcass quality grade received significantly(p < 0.05) greater eating quality for LD, but the grade did not affect eating quality for both TB and SM. TS did not influence objective and subjective meat quality for TB, but that significantly(P < 0.05) improved eating quality for LD and SM. The most noticeable result was that when SM was tenderstretehed, eating quality was equivalent to that of nonna1ly hung LD. In relationship between objective and subjective meat quality assessments, eating qualty for LD had a significant(P < 0.05) relationship with intramuscular fat content, while that for SM was greatly(P < 0.05) related to saroomere length. The current study indicated that pelvic hanging was an effective way to improve eating quality both LD and SM, and carcass quality grades did not greatly reflect eating quality of SM and TB. The data also implied that instnunental measurements poorly estimated the satisfaction level of Korean conswners.

The Effect of Feeding a Milk Diet Versus Concentrate and Hay Diet on the Meat Quality and Fatty Acid Profile of Lambs

The object of this study was to compare carcass and meat quality characteristics of conventionally reared lambs with others reared solely on milk. Eighteen crossbred lambs weaned at 5 weeks of age were randomized within each sex into 2 groups. The first group was fed reconstituted whole milk and the second, commercial lamb pellets and hay. Both diets were offered ad libitum for 9 weeks. Animals were subsequently slaughtered under standard commercial conditions. Samples of shoulder joint were taken for dissection and meat quality assessment was made using the 6 - 12 rib section of the Longissimus doris th muscle. Lambs on the concentrate and hay diet had significantly larger reticulo-rumens, livers and generally were less fat (p < 0.01) than milk-fed lambs. Dietary treatment had little effect on meat quality. Lambs reared on the milk diet contained higher proportion of unsaturated fatty acids in subcutaneous fat than lambs fed concentrate and hay. The milk diet did not appear to produce the typical pale colour in lambs as might be expected from studies on veal production.

Pig carcass quality and pH&lt;sub&gt;1&lt;/sub&gt; values of meat

The data on 964 pig carcasses were examined with the objective to determine the relationship between a high carcass lean meat content in currently used pig hybrids and deterioration of the quality traits important for further processing of meat. The average slaughter weight of pigs was equal to 106.2 &amp;plusmn; 0.417 kg. Lean meat percentage determined by the FOM instrument with the average value of 54.50 &amp;plusmn; 0.139% was used as the main quantitative carcass trait. For the assessment of meat quality, the pH&lt;sub&gt;1&lt;/sub&gt; value (average 6.15 &amp;plusmn; 0.011) was used in the same way as in the system of breeding animals&amp;rsquo; progeny testing. The relationship between the mentioned traits is characterised by the low correlation coefficient r = &amp;ndash;0.13. This result was further confirmed by correlations determined between pH&lt;sub&gt;1&lt;/sub&gt; and loin, shoulder and ham percentages (r = &amp;ndash;0.33, r = &amp;ndash;0.13 and r = &amp;ndash;0.12, respectively). These relationships are rather surprising as the studies from the beginning and the first phase of realization of hybridisation programmes usually emphasized that the increasing lean meat content in carcass was connected with the higher incidence of negative side effects. Our conclusions are also in agreement with the results of the separate analysis of carcasses with pH&lt;sub&gt;1&lt;/sub&gt; above 5.8 and equal to or lower than 5.8. The carcasses with pH&lt;sub&gt;1&lt;/sub&gt; referring to less favourable technological properties of meat showed somewhat higher average values characterising carcass meat content but the differences between the groups were small and insignificant. We were not able to find any relationships between higher meat contents in carcasses and less favourable pH&lt;sub&gt;1&lt;/sub&gt; values when the carcasses were classified according to meat content. &amp;nbsp;

Development of an enzyme immuno assay for the determination of porcine haptoglobin in various body fluids: testing the significance of meat juice measurements for quality monitoring programs

Quantification of haptoglobin (Hp), an acute phase protein, in blood is presently discussed as being useful to monitor animal health. We developed an enzyme immuno assay (EIA) which is specific for porcine Hp, is not impaired by hemolytic samples and is sufficiently sensitive to be applied in meat juice. Hp was purified from porcine serum by affinity chromatography on hemoglobin Sepharose followed by gel filtration. A specific rabbit antiserum was obtained. In a competitive approach, biotinylated porcine Hp was used as tracer and incubated with Hp standard or sample in microtiter plates. The limit of detection was 0.02 mg/l, parallelism of sample dilutions was proven; recovery of Hp added to serum samples was 96.4±4.7%. The coefficients of intra and inter-assay variation were 3.3 ( n=5) and 10.2% ( n=16), respectively. Hp was reliably quantified in blood serum and plasma, whole blood, saliva and meat juice. For healthy pigs of different ages (4 weeks and 6 months), mean Hp concentrations of about 0.5–0.7 mg/ml were observed. To test the significance of Hp measurements in other matrices, samples were obtained from fattening pigs or from slaughter pigs. Blood serum or plasma was collected in parallel. In whole blood, Hp concentrations were about 40% lower than in plasma, but were closely related ( n=24, r=0.85, P<0.001). Saliva Hp concentrations ranged between 0.3 and 3.0 μg/ml and were marginally related with blood plasma concentrations ( n=93, r=0.35, P<0.001). From 106 hybrid slaughter pigs (100–110 kg) blood and muscle samples (diaphragmatic pillar, d.p.; m. brachiocephalicus, m.b.) were collected. Meat juice was obtained after freezing and thawing. Concentrations were 0.39±0.5 mg/ml in serum and 0.04±0.06 mg/ml in meat juice. Hp concentrations in blood were closely correlated with those in d.p. juice ( P<0.001, r=0.750) and m.b. juice ( P<0.001, r=0.776). In view of the many reports on Hp measurements being predictive for animal health even in the subclinical range, we conclude that Hp quantification in meat juice might be useful to assess meat quality at slaughter and further along the processing chain in terms of animal health.

Sodium Chloride (0.8 M) as a Better Protein Extractant for Fish Meat Quality Assessments

ABSTRACT:The extractability of proteins by NaCl, KCl, and LiCl as affected by different ionic strengths and pH was compared to determine the best protein extractant. The individual proteins in the extracts were identified by electro‐phoresis. The optimum ionic strength (IS) at pH 7.0 for the protein extractability (PE) of NaCl, KCl, and LiCl were 0.8, 0.9, and 1.0, respectively. The PE of NaCl and KCl declined as pH changed from 6.0 to 8.0, whereas an opposite effect was observed for the LiCl. The NaCl had the highest PE, followed by LiCl and KCl. The maximum number of proteins (15 bands) was found at the optimum IS of each salt. However, the resolution and clarity of the protein bands were better in the NaCl extracts.

Novel fibre typing technique for meat quality assessment

Novel fibre typing technique for meat quality assessment

Review: The Role of Collagen in Meat Tenderness

Meat tenderness is a major factor affecting the consumers’ assessment of meat quality. Collagen is an abundant connective tissue protein and is a contributing factor to variation in meat tenderness and texture. It is found in three specific regions in muscle and in various forms and types. Collagen molecules are bound together through intermolecular crosslinks that help provide structure and strength. These crosslinks are initially reducible, but over time are replaced by mature, thermally stable, and less soluble crosslinks. These mature crosslinks, rather than the total amount of collagen, are the key factors in collagen-related toughness. The proportion of mature to reducible crosslinks increases with age, resulting in older animals that often have less tender meat than younger animals. Collagen crosslinks are also affected by growth rate, nutrition, and genetics. Collagen plays major roles in cooked meat as well. As collagen fibrils are heated during cooking, they shrink, resulting in a fluid loss and less tender meat. They also act to hold muscle fibers together after shrinkage. Post-mortem degradation of collagen and the use of collagenases appear to play a role in providing the desired tenderness and texture by altering the connective tissue structure. Collagen is very important in maintaining acceptable texture; however, high amounts of crosslinks can greatly decrease tenderness and consumer acceptability.

Variation of the sensory quality within the m. longissimus thoracis et lumborum of PSE and normal pork

This study evaluated the variation in instrumental and sensory meat quality within the m. longissimus thoracis et lumborum of carcasses with normal and PSE meat. Out of 80 slaughtered pigs, respectively, 9 and 7 carcasses were selected with a pH30 value > or=5.80 (normal pork) and a pH30 value <5.80 (PSE pork). Instrumental and sensory meat quality measurements were performed at three locations on these carcasses: longissimus thoracis (LT), longissimus thoracis et lumborum: (LTL—mid-loin) and longissimus lumborum (LL). Meat of the thoracis site (LT) was paler, but more favourable for pH45, cooking loss, juiciness, tenderness and preference scores than meat of the mid-loin part. The lumborum site (LL) was more or less in between the other two locations for meat quality, but closer to the LTL than the LT site. The meat quality variation within the m. longissimus thoracis et lumborum followed a similar pattern for normal and PSE carcasses. It can be concluded that the mid-loin part is best suited as a reference place for meat quality assessment, if one wants to eliminate carcasses with unacceptable meat.

Meat quality of steers finished on autumn grass, grass silage or concentrate-based diets

The objective of this experiment was to determine the effect of varying the proportions of autumn grass and concentrates and grass silage and concentrates on the quality of meat from cattle with similar rates of carcass growth. Fifty continental crossbred steers were assigned to five treatments. The experimental diets offered were (1) grass silage ad libitum plus 4 kg concentrate (SC), (2) 1 kg hay plus 8 kg concentrate (CO), (3) 6 kg grass dry matter (DM) plus 5 kg concentrate (CG), (4) 12 kg grass DM plus 2.5 kg concentrate (GC) and (5) 22 kg grass DM (GO). The experiment lasted 85 days after which all animals were slaughtered. The right side m. longissmus dorsi was excised from all animals 24 h post slaughter for assessment of meat quality. Treatments SC and CO resulted in animals with whiter ( P<0.05) subcutaneous and kidney/channel fat than all other treatments. There was an interaction ( P<0.05) between ageing time and treatment with treatment GC having higher ( P<0.05) tenderness, texture and acceptability values after 2 days ageing, but not after 7 or 14 days ageing. It is concluded that supplementing grass with low levels of concentrate produced the most tender and acceptable meat at 2 days post mortem, but that further ageing eliminated all treatment effects on eating quality of beef.

The effect of increasing carcass weight of finishing boars and gilts on joint composition and meat quality

Two hundred and eighty-eight crossbred (3/4 Landrace × 1/4 Large White) pigs, comprising equal numbers of boars and gilts, were housed in single sex groups from 50 kg liveweight to slaughter at liveweights of 92, 105, 118 and 131 kg (carcass weights of 70, 80, 90 and 100 kg). Sample joints from the left longissimus dorsi muscle were obtained at slaughter for dissection and meat quality assessment. As carcass weight increased there were significant ( p<0.001) increases in eye muscle area and subcutaneous fat content. Lean content decreased ( p<0.001) with increasing carcass weight while intermuscular fat content was not affected. There was a significant interaction between carcass weight and gender with % drip loss in pork from gilts at 100 kg having a higher drip loss than boars and gilts at all other weights. There were small but significant ( p<0.01) reductions in ultimate pH with increasing carcass weight. Cooking loss was also reduced ( p<0.001) at the heavier weights. There was no effect of carcass weight on shear force or on intramuscular fat. Dry matter (DM) and crude protein (CP) contents of m. L. dorsi increased ( p<0.001) at heavier weights while sarcomere length decreased ( p=0.001). Compared with boars, gilts had greater eye muscle area ( p<0.05), more subcutaneous fat ( p<0.001). Meat from gilts in comparison with boars had higher % DM and % CP contents ( p<0.001), higher intramuscular fat content and shear force ( p<0.05). It is concluded that meat quality may be improved when carcass weight is increased from 70 to 100 kg. ©

Impact of the hydrodyne process on tenderness, microbial load, and sensory characteristics of pork longissimus muscle.

Paired, boneless pork loin muscles were obtained from 76 market hogs to evaluate tenderness, meat quality characteristics, sensory attributes, and microbial characterization of pork muscle exposed to the Hydrodyne Process (H) compared with untreated control (C) loin. A subset of 16 paired loins was randomly selected for use in sensory evaluation and microbial characterization. Loins were vacuum packaged and immersed in a heat shrink tank prior to the H treatment. The Hydrodyne treatment exposed the loin to the pressure equivalent of a 150-g explosive, generating a pressure distribution of approximately 703 kg/cm2 at the surface of the samples. Meat quality assessments taken following treatment included subjective color, firmness/wetness, marbling scores (1 to 5 scale), Minolta reflectance and color readings, drip loss, and lipid content. The P-value for statistical significance for main effects and interactions was set at <.05 in all analyses. Administration of H resulted in a 17% improvement in Warner-Bratzler shear force (2.69 vs. 3.24 kg), with the shear force similar at two end-point cooking times (11 and 16 min) corresponding to approximately 75 and 83 degrees C, respectively. No differences between H and C were observed for color score, firmness score, Minolta L, Minolta Y, or drip loss on uncooked samples. The H loins had lower marbling scores (P<.05) and intramuscular lipid (P<.05) content than the paired C loin. Sensory evaluation on the randomly selected (n = 16) paired loins samples showed no improvement in Warner-Bratzler shear force. Sensory panelists were also unable to detect a difference between H and C loins for both initial and sustained tenderness scores. No differences between H and C loins were found for pork flavor, off-flavor, cohesiveness, or number of chews before swallowing, but H loins had a significantly lower juiciness score and more cooking loss than C loins. Microbial analysis results showed no differences in coliform bacteria counts, aerobic plate counts, and no detectable levels of Escherichia coli bacteria in any loins. The findings support the ability of the Hydrodyne procedure to improve tenderness without impacting other muscle quality attributes of pork.

Use of near infrared spectroscopy for beef meat quality assessment: can NIRS measure tissue vitamin E?

Assessment of the quality characteristics of meat is time consuming and, due to the heterogeneity of muscle tissue, is subject to considerable variability. A cheap, fast, accurate and non-destructive method of assessment of meat with the potential to predict subsequent quality, would be useful to the meat industry. Near infra red spectroscopy (NIRS) offers this potential for rapid quality assessment and has been shown to be a valuble tool in the evaluation of a variety of meats (Cozzolino et al 1996)Twenty beef bulls were selected from a commercial herd. Ten bulls (group US) were fed a standard barley-based ration consisting of (g kg–1 DM) barley, 900; GFS Beef 34 protein pellets, 100. Ten bulls (group S) were fed an identical ration supplemented with α-tocopherol acetate (ATA). The average daily intake of these diets was 10 kg DM head-1 d-1 over 100 days prior to slaughter.

The effect of increasing slaughter weight on the production performance and meat quality of finishing pigs

AbstractA study was made in two parts to establish the production performance potential of pigs taken to heavy slaughter weights (a) in individual housing and (b) in group housing. In experiment 1 96 crossbred pigs, comprised of equal numbers of boars, castrated males and gilts, were housed individually from 50 kg live weight and offered foodad libitumuntil one of four target slaughter weights was reached (70, 80, 90 or 100 kg carcass weight). Detailed dissection and meat quality assessments were performed on sample joints taken from these pigs. There were significant interactions in that boars maintained a high level offood conversion efficiency while this deteriorated at heavier weights for castrated males and gilts. Protein deposition rates (PDR) were estimated to be close to, or in excess of, 200 glday for boars. Daily live-weight gains were similar at all four slaughter weights despite increases (P&lt; 0·001) in daily food intake at the heavier weights. Sample joint contents of lean (P&lt; 0·05) and bone (P = 0·001) decreased while subcutaneous fat content increased (P&lt; 0·001) with increasing slaughter weight. Cooking loss was reduced (P&lt; 0·001) at the heavier weights while other meat quality parameters were not significantly affected by slaughter weight or gender. In experiment 2 288 group-housed boars and gilts were slaughtered at the same four target carcass weights as in experiment 1. Daily food intake, daily live-weight gain and variability in performance were lower for group-housed animals. It is concluded that maximum lean growth lies beyondad libitumfood intake for group-housed pigs of the genotype used in the present study. There are opportunities to take pigs to high slaughter weights with no reduction in daily live-weight gain and concomitant improvements in some aspects of meat quality.

Reference methods for the assessment of physical characteristics of meat

As a spin-off of an OECD Workshop on pork quality, held in Helsinki in 1992, a group of scientists with many years of experience in the field of meat quality assessment convened in February 1993 for the first time, and subsequently in 1994 and 1995, in Kulmbach at the German Federal Centre for Meat Research under the auspices of the OECD research project Management of Biological Resources. Three specific areas were discussed in order to develop internationally accepted reference methods: • • water-holding capacity • • tenderness • • colour of meat. In the autumn of 1997 the methods were brought into their final form at the Meat Industry Research Institute of New Zealand (MIRINZ). They are presented in this paper.

Assessment of commercial lamb meat quality by British and Spanish taste panels

Trained sensory panels in Britain and Spain assessed loin meat from commercial lambs purchased in Spain, which included Welsh lamb (imported from Britain) and two Spanish breeds (Merino and Rasa Aragonesa). The British panel also assessed British lamb purchased in local butcher shops and supermarkets. Sensory panels, in each country, received meat from the same lambs and used their local methods of cooking and assessment. Spanish panels used unstructured line scales to measure lamb odour intensity, tenderness, juiciness, lamb flavour intensity and two hedonic scales of flavour liking and overall liking. The British panel used 8 point category scales with the same attributes. Results from both panels in objective parameters were in agreement, hence showing that different trained sensory panels may arrive at the same conclusion. However, when panellists were allowed to make hedonic judgements (preference), the British panel preferred British lamb and the Spanish panel preferred Spanish lamb. This finding has important consequences for lamb producers who export their lambs and demonstrates that the underlying reasons for different preferences should be investigated. Production variables are discussed in relation to their influence on lamb eating quality and as a way to tailor lamb eating quality attributes familiar to consumers in the importing country.

Differences in natural steroid hormone patterns of beef from bulls and steers.

This investigation gives an overview of the concentrations of naturally occurring androgens, progestogens, corticosteroids, and their precursors and metabolites in meat from bulls and steers. A recently developed gas chromatography-mass spectrometry IGC-MS) method with improved sensitivity for steroid analysis was used. Eighty-two beef samples were analyzed using the GC-MS method. Beef from bulls contained higher concentrations of testosterone, which is an anabolic androgen, and its metabolite epitestosterone (P < .01) and the androgen precursor dehydroepiandrosterone (P < .05) than beef from steers. Beef from steers contained higher (P < .05) concentrations of the basic hormone precursor pregnenolone and cortisol, which is a catabolic corticosteroid, than beef from bulls. A classification of an unknown beef sample to one of the categories (bull or steer) was possible in most cases (>90%) using a masculinity index (MI) that was calculated using the concentrations of testosterone, epitestosterone, and pregnenolone. Because the hormonal status of beef cattle is related to meat quality characteristics, such as tenderness or fat and protein distribution, the MI may contribute to meat quality assessment and meat quality control.