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Meat quality in the m. longissimus thoracis (LT) associated with decreased muscle temperature early post-mortem was investigated using ten Angus crossbred steer carcasses. LT chill rate of each carcass right side was increased by removing superficial subcutaneous fat and associated muscles. LT muscles were removed at 24 h post-mortem and divided into halves with the posterior portion analyzed immediately and the anterior portion analyzed after 14 days post-mortem ageing. Denuding the LT decreased its temperature by 2 °C at 3 h post-mortem and decreased intramuscular lactate concentration, sensory panel tenderness score, a*, b* and chroma values, and proportion of oxymyoglobin and increased proportions of metmyoglobin and deoxymyoglobin at day 2 post-mortem without affecting intramuscular pH, or cooked LT shear force. Small shifts in early post-mortem muscle temperature can alter the extent of anaerobic glycolysis, influencing early retail display color and sensory tenderness, emphasizing the importance of proper early post-mortem management of carcasses in controlling beef quality.

The efficacy of thermal activation of residual proteolytic enzymes on shear force and deformation of 72 beef supraspinatus (SS) and rectus femoris (RF) muscles was tested using multi-stage sous-vide cooking (M-SV; 1 h at 39 °C, 1 h at 49 °C, 4 h at 59 °C), single-stage sous-vide cooking (S-SV; 4 h at 59 °C), and waterbath cooking (22 min at 70 °C, to 59 °C). Two storage conditions (1 week at 2 °C; 2 weeks at -1.5 °C) followed, then meat was reheated to and tested at 55 °C. Shear force decreased by 17-21% with S-SV (P 0.001) and appeared to affect both myofibrillar and collagen components, likely through heat activation of cathepsin BL and 20S proteasome. A further 5-6% increase was realized with M-SV (P: SS = 0.006, RF = 0.12) affecting primarily the myofibrillar component, likely from calpain-2 activation. The degree of deformation increased with sous-vide cooking in general (P 0.001). No meaningful effects of post-cooking storage were found (P 0.05).

An image analysis method for identifying marbling on exposed boneless pork loin surfaces was developed, solving the problem of influences from uneven lean colour. Comparing results from RAW and JPEG images of the mid-loin pork chop showed that, except at very high marbling levels, estimation of %IMF (intramuscular fat) was similar with both image types (R2 = 0.72 and 0.74 respectively). Marbling calculated from JPEGs was positively related to %IMF, but also diverged as %IMF increased. Estimations of %IMF at the mid-loin chop from JPEGs of external loin sites showed marbling on the posterior face to be the most strongly related (r = 0.72, P

This study examined if different color intensities of dark-cutting beef carcasses (Dark B4/Moderate B4) were similar in quality to normal (N) carcasses of a lower marbling score. The eating quality from abnormal (AB) dark-cutting carcasses (normal pH) was also evaluated to determine if AB should receive the same penalty as classic (CL) dark-cutting carcasses in the Canadian grading system. B4-grade carcasses, regardless of dark color intensity, exhibited increased toughness and greater off-flavor than N carcasses of a lower marbling score. Additionally, AB and borderline (BD) carcasses were tougher than N. The CL dark cutters, albeit similar in tenderness to N carcasses, had greater off-flavor and less beef flavor intensity. Downgrading B4 carcasses one quality grade based on the marbling score, with no further carcass demerits, is likely not sufficient, and further devaluations of dark cutters may be warranted. As well, AB and BD carcasses were of lower quality compared to N carcasses and, therefore, deserve some economic penalty.

A series of studies was performed to develop and test a method adaptable for early automated sorting of pork bellies based on firmness. Flattened and non-flattened, bone-in, skin-on primal bellies were fed skin-down, caudal end foremost on to a horizontal (0°) or raised (30°) conveyor with an adjustable nosebar (o = 14 mm). The drop angle, after 24 cm of belly had passed the nosebar, was strongly correlated with subjective floppiness (r = 0.77–0.82; P ≤ .0001) and moderately correlated with fat thicknesses (r = 0.47–0.67; P ≤ .0001). On a 0° conveyor, drop angle relationships were generally weakest for non-flattened bellies, but moderate and similar for flattened bellies at 0°, as well as for both flattened and non-flattened bellies at 30°. The method appears to show promise for commercial production use. Further work is required on the impact of belt speed, firmness categorization, and the relationship to the current bar bend research method.

Recovering value from dark cutting carcasses (Canada B4) was investigated by examining twelve muscles in the loin, fore- and hindquarters of atypical (AT, pH 5.8), borderline (BD, 5.8 pH 6.0) and classic (CL, pH 6.0) dark cutting carcasses. Subjective and objective colour, purge loss, and colour stability were measured over 4 days of retail display. Forequarter muscles from all dark cutting carcasses were not different from those of normal Canada AA carcasses, suggesting that forequarter muscles may be preferentially harvested for sale through normal retail outlets. None of the adductor, biceps femoris, gluteus medius, and semitendinosus muscles in the AT carcasses were dark and all had retail display colour stability comparable to that of normal steaks, indicating that these muscles in these carcasses are undervalued. Sorting of dark cutting carcasses by longissimus thoracis pH or a* and b* values will allow for value to be recovered from atypical dark cutting carcasses.

The development of non-destructive methodologies based on Hyperspectral Imaging (HSI), Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) techniques to determine quality characteristics of fresh meat has been reviewed in this study. It has been focused primarily on research published in the last decade, and has placed particular attention on the instrumentation, data acquisition and main applications of each technique, finding a wide variety of possibilities for systems and methodologies as well as evidence of accurate and promising results. Most samples analysed were pork and beef, followed by lamb and chicken, with few studies on fresh meat from rabbit and duck. The overall evaluation is that work has been performed primarily in an experimental way but generally still lacks real application in the meat industry. In that respect, these non-destructive techniques should be improved, especially regarding speed, price and influence of external factors.

This study aimed to evaluate a novel three-step sous-vide (SV) method on bacterial growth and diversity, and its relationship to product storage life. Vacuum-packed naturally contaminated steaks were sequentially cooked at 39 °C (1 h), 49 °C (1 h), and 59 °C (4 h), then stored at -1.5 and 2 °C for 28 d, with a single-step SV at 59 °C for 4 h for comparison. None of the seven indicator bacteria tested proliferated (P .05) after incubation at 39 or 49 °C; microbial diversity was also unaffected. Bacterial load was reduced (P .05) by up to 5 log units with both (P .05) SV methods. The odour of all steaks remained acceptable on d 28. Unexpectedly, during storage, Pseudomonas, not lactic acid bacteria, dominated the microbiota on steaks cooked by either SV method, likely due to the temperature shift-induced lag phase and/or heat sensitivity of psychrotrophic bacteria. In conclusion, the three-step SV did not lead to bacterial proliferation or compromise the storage life of cooked products.

Pork bellies (n = 198) were scanned with dual energy X-ray absorptiometry (DXA). Visible and near-infrared reflectance (Vis-NIR) spectra were collected from the lean (latissimus dorsi), subcutaneous fat and intermuscular fat layers. Belly-flop angle and subjective belly scores were collected as measures of pork belly softness. Vis-NIR spectra from a single fat layer could explain between 72.7 and 81.1% of the variation in pork belly softness (43.6–72.4% in validation set). The combination of the lean and subcutaneous layers improved the calibration model fit to 79.7–99.9% (66.3–71.5% in validation set). The DXA estimates explained 62.3% of variation in pork belly softness (65.2% in validation set). Results indicated that DXA and NIR technologies could potentially be utilized for pork belly softness sorting in the pork industry.

Canada B4 beef carcasses are penalized because the longissimus thoracis (LT) at the grade site (12–13th ribs) is darker than the color threshold for normal bright cherry-red beef. Previous studies have shown that not all B4 carcasses have pH > 6.0; therefore, the relationship between LT pH and meat quality was investigated by collecting thirty half-carcasses comprised of the following: ten Canada AA (AA, control), ten B4 with LT pH > 6.0 (CL, classic), and ten B4 with LT pH

7 páginas, 2 figuras, 3 tablas., NIRS potential to estimate the proportion of PUFA and their biohydrogenation products in adipose tissues from cattle fed sunflower or flaxseed was tested. Immediately after skinning, perirenal and subcutaneous fat samples from 63 steers were collected, scanned intact at 37 degrees C and 33 degrees C, respectively, over a NIR spectral range from 400 to 2498 nm using benchtop equipment and then analyzed for fatty acid composition. NIRS calibrations in perirenal fat showed high predictability for total and major omega - 6 and omega - 3, conjugated linolenic acids, t,t-conjugated linoleic acids (CLA), non-CLA dienes and trans-monounsaturated fatty acids, with R-2 (RMSECV, %) of 0.88-0.89 (0.16-0.20), 0.89-0.91 (0.07-0.08), 0.86-0.89 (0.01-0.09), 0.82 (0.07), 0.89 (0.46) and 0.86-0.88 (0.87-1.29), respectively. NIRS predictions in subcutaneous fat were less reliable, probably due to lower fatty acid variability. The results show NIRS to be a useful technique for the early, fast and relatively inexpensive estimation of proportions of fatty acids with potential human health effects in cattle perirenal fat., Financial support received from the AAFC-Peer Review Program and the Alberta Meat and Livestock Agency is gratefully acknowledged. Dr. N. Prieto acknowledges the receipt of a research contract from the Spanish National Research Council (CSIC) and the European Social Fund under the program JAE-Doc “Junta para la Ampliación de Estudios”.

We explored various dimensional and compositional factors that can influence the perception of pork belly firmness. Bellies from 198 pigs of three different genotypes, two sexes, two slaughter weights and three different diets were recovered and belly firmness was assessed using the belly-flop angle and a 5-point scale subjective measurement. Dimensional and compositional factors were recorded on intact and sheet-ribbed bellies. Subjective belly score was negatively correlated with belly-flop angle (r = − 0.89). Regression analysis accounted for 77 and 83% of the variability in subjective belly firmness and belly-flop angle measurement, respectively. Belly length, weight and width influenced both measures of belly firmness, but these effects were more important for the belly-flop angle. After correcting flop angle using belly length, the effect of belly weight disappeared and the effect of other traits was more like those observed for subjective scoring. Hence, undue effect of belly length should be corrected for if this set-up is to be implemented in commercial plants.

Presumably, dry-ageing enhances flavour attributes of meat by surface desiccation to increase and modify fatty acid content and other organoleptic molecules. However information regarding dry-ageing of fresh pork is limited. To examine the effects of dry-ageing on pork quality, Large White (LW, n = 24) and Large White × Duroc (Duroc, n = 24) barrows were slaughtered and three longissimus thoracis et lumborum sections from each side of the carcass were wet or dry-aged for 2, 7 or 14 d. Dry-aged meat had lower (P0.001) moisture and higher (P0.001) protein content due to higher purge losses (P0.001) when compared with wet aged meat. However no dry-ageing effect (P0.05) was observed on sensory characteristics. The increase in the duration of ageing decreased moisture content and drip loss and increased (P0.001) protein content, purge loss and L*, chroma and hue values. These changes were more accentuated in dry-aged meat (P0.01). Days of ageing dependent increases (P0.001) were observed for instrumental and sensory tenderness and juiciness in both ageing types. Moreover, meat from Duroc barrows had lower (P0.001) moisture and protein content, and higher (P0.01) fat content, L* and hue values. Instrumental and sensory tenderness, juiciness and flavour were higher (P0.01) in meat from Duroc than LW barrows. Increases (P0.01) in flavour intensity and decreases in off-flavour of meat from LW barrows were greater (P0.05) in d 7 than in d 14. Therefore the duration of ageing affected most quality and sensory characteristics, while the changes to quality attributes of dry versus wet-aged pork were attributable to the differences in shrink losses in the present study.

Striping or streaking is a problem in moisture enhanced meats which are injected to low levels. Research was undertaken to determine brine distribution paths and effect of pre-injection thawing rate on brine distribution. Beef rib eyes and eye of rounds were vacuum packed and aged 7 days at 3 °C, then frozen (-35 °C) for a month, thawed either quickly in water (5 h at 12-17 °C) or slowly in air (48 h at 3 °C), injected to 108-110% using a conventional brine containing blue food colouring, chilled overnight, then cut along four planes and photographed for image analysis of % blue, % marbling, and subjective evaluation of brine distribution paths. There were no significant differences in % blue due to treatment. Brine distribution in both muscles was better parallel to fibers than perpendicular to them. A subset of aged rib eyes was injected to 125%. Although brine was more extensively distributed than at lower injection levels, basic patterns remained unchanged.

This study tested the ability of near infrared reflectance spectroscopy (NIRS) to estimate the fatty acid (FA) composition and iodine value (IV) of backfat from carcasses of pigs fed reduced-oil corn dried distillers grains with solubles. NIRS was suitable for screening purposes for the proportions of total saturated, monounsaturated, polyunsaturated, n − 3 and n − 6 FAs and some individual FAs such as C16:0, C18:1, C18:2n − 6 and C18:3n − 3 ( R 2 = 0.80–0.89; RMSECVs, root mean square errors of cross-validation = 0.21–1.37% total FA) in both cold and warm intact backfat samples. This technology also met the requirements for a quick screening for the backfat IV in both cold and warm intact samples ( R 2 = 0.90 and 0.87; RMSECVs = 1.66 and 1.80% total FA, respectively), which would help provide differential feed-back to pig producers and the feed industry and may provide the opportunity for breeding pigs for a desirable fat quality.

Steers were fed grass hay or red clover silage based diets containing flaxseed or sunflower seed as sources of 18:3n-3 and 18:2n-6 respectively. Hamburgers were made from triceps brachii and perirenal or subcutaneous fat. Perirenal-hamburgers contained more polyunsaturated fatty acids (PUFA), several PUFA biohydrogenation intermediates (BHI), and 18:0 (P0.05). Oxidative stability was similar across hamburgers (P0.05). Sensory differences were found due to hamburger fat source, but wereone panel unit. Within perirenal-hamburgers, feeding flaxseed increased 18:3n-3 and its BHI (P0.05), and feeding sunflower seed increased 18:2n-6 and its BHI (P0.05). Feeding flaxseed increased off-flavour intensity and oxidation in perirenal-hamburgers (P0.05). Feeding oilseeds in forage based diets while using perirenal fat to make hamburgers provides opportunities to increase PUFA and BHI with potential to impact human health, but control measures need to be explored to limit oxidation and off-flavours when feeding flaxseed.

The meat quality characteristics of adult emus transported for 6h before slaughter were determined. Forty-two emus were used in two trials, undertaken under warm and cool weather conditions, respectively. Male emus had significantly higher fat yields than females (12.43kg vs 9.5kg, P=0.002). About 38.1% of the emus had no wounds or bruises, 40.5% had bruises, while 21.4% had small wounds after transport. Meat from injured emus had significantly higher pH45. In warm weather, emus experienced significantly higher loss in body weight than that under cool weather. Drip loss in meat after 24h of storage was higher in emus which had greater live weight loss after transport (r=0.66, P

This study tested the ability of near infrared reflectance spectroscopy (NIRS) to predict meat chemical composition, quality traits and fatty acid (FA) composition from 63 steers fed sunflower or flaxseed in combination with high forage diets. NIRS calibrations, tested by cross-validation, were successful for predicting crude protein, moisture and fat content with coefficients of determination (R2) (RMSECV, g · 100 g− 1 wet matter) of 0.85 (0.48), 0.90 (0.60) and 0.86 (1.08), respectively, but were not reliable for meat quality attributes. This technology accurately predicted saturated, monounsaturated and branched FA and conjugated linoleic acid content (R2: 0.83–0.97; RMSECV: 0.04–1.15 mg · g− 1 tissue) and might be suitable for screening purposes in meat based on the content of FAs beneficial to human health such as rumenic and vaccenic acids. Further research applying NIRS to estimate meat quality attributes will require the use on-line of a fibre-optic probe on intact samples.

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P0.05), significantly reduced meat off-flavor intensity (P0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n-6 fatty acids (FA, P0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P0.05). A significant forage × oilseed type interaction (P0.05) was found for n-3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P0.05) and significantly influenced intramuscular FA composition (P0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.

9 páginas, 4 figuras, 3 tablas., This study examined the ability of near infrared reflectance spectroscopy (NIRS) to estimate the concentration of polyunsaturated fatty acids and their biohydrogenation products in the subcutaneous fat of beef cows fed flaxseed. Subcutaneous fat samples at the 12th rib of 62 cows were stored at 80 degrees C, thawed, scanned over a NIR spectral range from 400 to 2498 nm at 31 degrees C and 2 degrees C, and subsequently analysed for fatty acid composition. Best NIRS calibrations were with samples at 31 degrees C, showing high predictability for most of the n-3 (R(2): 0.81-0.86; RMSECV: 0.11-1.56 mg g(-1) fat) and linolenic acid biohydrogenation products such as conjugated linolenic acids, conjugated linoleic acids (CLA), non-CLA dienes and trans-monounsaturated fatty adds with R(2) (RMSECV mg g(-1) fat) of 0.85-0.85 (0.16-037), 0.84-0.90 (0.21-2.58), 0.90 (5.49) and 0.84-0.90 (4.24-8.83). respectively. NIRS could discriminate 100% of subcutaneous fat samples from beef cows fed diets with and without flaxseed., Spanish National Research Council (CSIC).

Eye of round primal cuts of beef were injected with brines containing a dye and Listeria innocua. The amounts of brine in portions of meat were determined from the concentrations of dye in the tissues, and the numbers of L. innocua in the tissues were determined from the numbers of colonies recovered on hydrophobic grid membrane filters incubated on a selective agar. Portions of meat from primals injected with brine after extensive mechanical tenderizing yielded L. innocua at numbers that would be expected from the amounts of brine in the meat. However, portions of meat from primals injected with brine without or before mechanical tenderizing yielded only about 10% of the expected numbers of L. innocua. The numbers of L. innocua recovered from injected meat that was not tenderized, relative to the amount of brine retained by the meat, declined with decreasing brine pressure and increasing strokes per minute of the needle head. When brine was injected at about 5% with low brine pressure and high head speed, the numbers of L. innocua retained in the meat were

A total of 384 pigs (192 barrows and 192 gilts) was utilized to evaluate the effects of gender on the flavour and texture profiles of cured and uncured pork cuts. Observed differences in all cuts indicated the incidence, intensity, and/or order of appearance of flavour character notes were more appropriate, in samples from barrows than in samples from gilts; differences observed in all cuts also indicated textural properties were more appropriate, in samples from barrows than in samples from gilts. However, the magnitude of such differences in all cuts, was insufficient to influence flavour and texture amplitude ratings. Consequently, even though cuts from barrows are marginally superior to cuts from gilts in both flavour and texture, this superiority is unlikely to be of practical importance. The effects of ractopamine treatment and protein level (Jeremiah et al., 1994a) and ractopamine treatment and protein source (Jeremiah et al., 1994b) have been previously covered.

Equal numbers of barrows (64) and gilts (64) were randomly allocated to two separate diets containing 17·6 and 19·6% crude protein. Subsequently within each gender/diet treatment group, pigs were equally and randomly assigned to two ractopamine treatment groups (i.e. 0 or 20 ppm ractopamine), resulting in 16 pigs per gender/diet/ractopamine subgroup. The feeding trial lasted an average of 41 days, and the pigs went on trial at an average weight of 64·5 kg and were slaughtered at an average weight of 98·2 kg. Five barrows and five gilts were subsampled at random from each gender/diet/ractopamine subgroup for palatability evaluations. Comprehensive palatability evaluations were conducted on both cured and uncured pork cuts. Results revealed no meaningful differences in flavour, texture, or cooking properties attributable to dietary protein level (17·6 vs 19·6% crude protein) or to ractopamine. Thus, within the context of conditions employed in the present study, ractopamine can be administered with different dietary crude protein levels to improve production efficiency and carcass composition, without influencing palatability and cooking properties or consumer acceptance. Gender effects have been reported elsewhere (Jeremiah et al., 1994).