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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∙100g-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. [ABSTRACT FROM AUTHOR]

Machine learning classification approaches were used to discriminate a fishy off-flavour identified in beef with health-enhanced fatty acid profiles. The random forest approach outperformed (P < 0.001; receiver operating characteristic curve: 99.8 %, sensitivity: 99.9 % and specificity: 93.7 %) the logistic regression, partial least-squares discrimination analysis and the support vector machine (linear and radial) approaches, correctly classifying 100 % and 82 % of the fishy and non-fishy meat samples, respectively. The random forest algorithm identified 20 volatile compounds responsible for the discrimination of fishy from non-fishy meat samples. Among those, seven volatile compounds (pentadecane, octadecane, γ-dodecalactone, dodecanal, (E,E)-2,4-heptadienal, 2-heptanone, and ethylbenzene) were selected as significant contributors to the fishy off-flavour fingerprint, all being related to lipid oxidation. This fishy off-flavour fingerprint could facilitate the rapid monitoring of beef with enhanced healthy fatty acids to avoid consumer dissatisfaction due to fishy off-flavour., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024. Published by Elsevier Ltd.)

This study investigated the effects of a novel steak fabrication method, involving removal of both subcutaneous and intermuscular fats between the longissimus thoracis (LT) and spinalis dorsi (SD) muscles before cooking, on beef ribeye steak palatability and calorie content. Canada AA (n = 10) and AAA (n = 10) ribeyes were fabricated into steaks either with (fat-on) or without (fat-off) subcutaneous and intermuscular fats. Fat-on steaks had shorter cooking times and lower cooking losses than fat-off steaks (P < 0.001), regardless of quality grade. There were treatment × quality grade interactions for initial (P < 0.01) and sustainable juiciness (P < 0.05) of the LT samples and initial juiciness (P < 0.05) of the SD samples, with the fat-on AA samples being more juicy than the fat-off AA samples, but the AAA treatments were not different from each other. Regardless of quality grade, fewer panelist responses indicated livery flavour (P < 0.05) for fat-on compared to fat-off LT samples. Regardless of fat-on/fat-off treatment, AA compared to AAA samples had more responses for bloody/serumy (P < 0.01) and unidentified off-flavours (P < 0.05) in LT samples. However, AAA samples had more responses for metallic off-flavour in LT (P = 0.059) and SD (P < 0.05). There were no differences in calorie content between fat-on compared to fat-off steaks (P > 0.1) regardless of quality grade and muscle type, or between AA and AAA steaks regardless of cooking with fat-on or off (P > 0.1). Maintaining the subcutaneous and intermuscular fats while cooking will improve ribeye steak palatability without increasing calorie content, especially for leaner steaks., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Reduction in muscle glycogen triggered by adverse antemortem handling events alters postmortem energy metabolism and results in a high ultimate pH and dark, firm and dry beef, often referred to as 'dark-cutting'. However, the relationship between atypical dark (AT) beef, postmortem energy metabolism and underlying tissue characteristics remains somewhat unclear. Cattle harvested in the US and Canada representing normal (pH < 5.6), AT dark (pH 5.6-5.8) and dark cutting (DC; pH > 5.8) beef were analyzed for tissue characteristics related to energy metabolism. Results show AT dark beef is more oxidative but similar to normal beef in glycolytic potential and nucleotide abundance. Mitochondria DNA content (P < 0.05, Canada; P < 0.005, US) and oxidative enzymes for DC and AT dark beef were greater (P < 0.01; Canada and US) compared to normal beef. Myoglobin tracked (P < 0.01) with color classification. These findings show both DC and AT beef are inherently more oxidative and raise the possibility that more oxidative muscle may be more prone to develop dark beef., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This study evaluated the effects of a constant current electrical stimulation (CCES) system and hormonal growth-promoting (HGP) implants on the quality and palatability of the longissimus thoracis et lumborum (LTL) from yearling-finished steers. The experiment used a total of 46 Angus cross steers, which were either non-implanted (n = 20) or implanted with trenbolone acetate and estradiol benzoate (n = 26). The CCES was applied to one side of each carcass during the slaughter process, whereas the other side remained unstimulated. Regardless of the application of HGP implants, the CCES reduced pH at 3 and 72 h post-mortem and shear force at all ageing times (P < 0.05), improved colour at 72 h post-mortem and during the retail display (P < 0.05), increased initial and overall tenderness (P < 0.01), and decreased the amount of perceived connective tissue and the proportion of trained panelists detecting spongy texture (P < 0.05) compared to meat from unstimulated carcass sides. Although CCES increased meat purge losses and reduced moisture content (P < 0.05), this did not affect meat juiciness (P > 0.10). CCES interacted with HGP to prevent increase in drip loss (P > 0.10), increase frequency of panelists detecting bloody/serumy flavour and typical texture, and reduce the proportion of panelists detecting rubbery texture in meat (P < 0.05). Regardless of stimulation treatment, meat from implanted animals had a more pronounced pH decline at 72 h post-mortem (P < 0.05) and a higher proportion of panelists finding no off-flavours (P < 0.05) or bloody/serumy flavour (P < 0.01) than non-implanted cattle. The CCES system tested in this study improved LTL quality and palatability of heavier beef carcasses., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

This study evaluated the effects of in-the-bag dry-ageing (BDA) (21 and 42 d) on meat quality, palatability, and volatile compounds of clod heart, brisket, and flat iron cuts from steers. In all cuts, BDA increased moisture losses (P < 0.05), but this did not reduce the juiciness of 21 d BDA versus wet-aged (WA) steaks. In clod heart, BDA increased overall tenderness at 21 d compared to 21 d WA (P < 0.01). Regardless of ageing period, BDA of clod heart increased beef flavour and salty taste and decreased sour-dairy and stale/cardboard flavours and concentrations of volatile compounds derived from lipid oxidation compared to WA (P < 0.05). In brisket, BDA increased salty taste and fatty aroma and reduced bloody/serumy flavour, whereas decreased beef and buttery flavours and intensified some unpleasant aromas/flavours (P < 0.05) for both ageing periods. The BDA of flat iron increased several undesirable aromas/flavours and decreased sweet taste and beef and buttery flavours (P < 0.05), regardless of ageing period. Overall, BDA for 42 d decreased meat quality and palatability and increased concentrations of volatile compounds from lipid oxidation, especially in flat iron cuts. Value could be recovered by customizing BDA periods by cut., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

This study evaluated the effects of in-the-bag dry-ageing on eating quality and volatile compounds of longissimus lumborum from cows and steers. Compared to wet-ageing, in-the-bag dry-ageing increased purge loss (P < 0.0001), cooking time (P < 0.0001), salty taste (P < 0.05) and sour-dairy flavour (P < 0.01), whereas decreased cooking loss (P < 0.0001), amount of perceptible connective tissue (P < 0.05) and livery flavour (P < 0.05) in both cow and steer meat. This dry-ageing technology also increased juiciness (P < 0.01) and brown-roasted aroma (P < 0.05) in steer meat, whereas decreased the juiciness (P < 0.01) of cow meat. Regardless of the ageing method, cow meat was tougher (P < 0.0001), less juicy (P < 0.001) and sweeter (P < 0.05) and presented higher amount of perceived connective tissue (P < 0.0001) than steer meat, whereas steer meat had higher ratings for beef (P < 0.05) and brown-roasted (P < 0.01) flavours. Volatile compounds were largely affected (P < 0.05) by animal-type, most of them being higher in cow than steer meat. In contrast, in-the-bag dry-ageing affected a few volatile compounds such as alcohols, aldehydes and ketones., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

This study evaluated visible and near-infrared spectroscopy (Vis-NIRS) to authenticate barley-finished beef using different discrimination approaches. Dietary grain source (barley, corn, or blend-50% barley/50% corn) did not affect (P > 0.05) meat quality but influenced (P < 0.05) fatty acid profiles. The longissimus thoracis (LT) from barley-fed steers had lower n-6 fatty acid content and n-6/n-3 ratio compared to LT from corn and blended grain-fed steers. Vis-NIRS coupled with partial least square discriminant analysis (PLS-DA) and support vector machine in the linear (L-SVM) kernel classified with approximately 70% overall accuracy subcutaneous fat and intact LT samples, respectively, from barley, corn, and blended-fed cattle. When only barley and corn samples were considered, fat and intact LT samples were correctly classified with overall accuracy >94% with PLS-DA and radial/L-SVM, and approximately 90% with PLS-DA and L-SVM, respectively. Ground LT samples were classified with ≤70% overall accuracy. Vis-NIRS measurements on fat and intact LT have potential to discriminate between corn and barley-fed beef., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

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., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

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., (Copyright © 2018. Published by Elsevier Ltd.)

Dark cutting beef with pH <6.0 may have glucidic potential approaching that of normal beef but has increased toughness that may also be influenced by cattle sex and carcass characteristics. Beef longissimus thoracis (LT) from normal (Canada AA; n=24), and typical (TB4; pH>5.9, n=20) and atypical (AB4; pH<5.9, n=20) dark cutting carcasses were analyzed to investigate relationships between beef quality, pH, glucidic potential and carcass characteristics. Results indicated that reduced lactate and glucidic potential were accompanied by increased pH and reduced L*, a* and b* values. Mean glucidic potential was lowest (P<0.0001) for TB4 whereas glucidic potentials for heifers and steers AB4 LT were sufficient to attain normal pH, substantiating the existence of atypical dark cutting. Warner-Bratzler shear force of AB4 remained higher (P<0.05) than that of Canada AA LT confirming AB4 as the toughest beef irrespective of sex and carcass characteristics., (Copyright © 2017. Published by Elsevier Ltd.)

The objective of the present experiment was to determine if carcass quality and fatty acid profiles of longissimus thoracis (LT) and hamburger would be affected by feeding steers extruded flaxseed on its own followed by hay (non-TMR) compared to when hay and extruded flaxseed were fed together (TMR). Forty-eight steers in six pens were assigned to TMR or non-TMR for an average of 242days. Dry matter intake was lower for non-TMR versus TMR steers (10.56 vs. 11.42kg/d; P=0.02), but final live weight (610±0.50kg) and average daily gain (1.18±0.02kg/d) did not differ. Compared to TMR, feeding non-TMR enriched LT and hamburger with α-linolenic acid (ALA; 18:3n-3) by 14%, vaccenic acid (VA; t11-18:1) by 44%, rumenic acid (RA; c9,t11-18:2) by 40%, and conjugated linolenic acid (CLnA) by 58%. Overall, feeding extruded flaxseed separately from hay in a non-TMR was more effective at enhancing deposition of ALA, VA, RA and CLnA in beef., (Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.)

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., (Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.)

The accuracy of dual energy X-ray absorptiometry (DXA) in assessing carcass composition from pigs with diverse characteristics was examined in the present study. A total of 648 pigs from three different sire breeds, two sexes, two slaughter weights and three different diets were employed. DXA estimations were used to predict the dissected/chemical yield for lean and fat of carcass sides and primal cuts. The accuracy of the predictions was assessed based on coefficient of determination (R(2)) and residual standard deviation (RSD). The linear relationships for dissected fat and lean for all the primal cuts and carcass sides were high (R(2)>0.94, P<0.01), with low RSD (<1.9%). Relationships between DXA and chemical fat and lean of pork bellies were also high (R(2)>0.94, P<0.01), with RSD <2.9%. These linear relationships remained high over the full range of variation in the pig population, except for sire breed, where the coefficient of determination decreased when carcasses were classified based on this variable., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This study tested the ability of visible and near infrared spectroscopy (Vis-NIRS) to discriminate enhanced quality pork. Vis-NIR spectra were collected on intact chops from 148 pork carcasses using a portable LabSpec®4 spectrometer (350-2500 nm). Partial least squares discriminant analyses based on Vis-NIR spectra correctly classified 94, 95 and 100% of the 2d, and 95, 98 and 100% of the 14 d aged pork samples within Lacombe, Duroc and Iberian pig breeds, respectively. Moreover, Vis-NIRS correctly classified 97 and 99% of the moisture enhanced (ME) and Non-ME pork samples aged for 2d, and 94 and 95% of those aged for 14 d, as well as 94 and 97% of the 2 and 14 d aged pork samples, respectively. Conversely, Vis-NIRS technology could not differentiate pork samples based on pre-slaughter diet or post-slaughter carcass chilling process. Vis-NIRS can segregate enhanced quality pork according to production factors and post-mortem strategies such as pig breed, moisture enhancing and ageing period., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Increased meat toughness with animal age has been attributed to mature trivalent collagen cross-link formation. Intramuscular trivalent collagen cross-link content may be decreased by reducing animal age at slaughter and/or inducing muscle re-modeling with growth promotants. This hypothesis was tested in m. gluteus medius (GM) and m. semitendinosus (ST) from 112 beef steers finished at either 12 to 13 (rapid growth) or 18 to 20 (slow growth) months of age. Hereford-Aberdeen Angus (HAA) or Charolais-Red Angus (CRA) steers were randomly assigned to receive implants (IMP), ractopamine (RAC), both IMP and RAC, or none (control). RAC decreased pyridinoline (mol/mol collagen) and IMP increased Ehrlich chromogen (EC) (mol/mol collagen) in the GM. In the ST, RAC increased EC (mol/mol collagen) but decreased EC (nmol/g raw muscle) in slow growing CRA steers. Also, IMP increased ST pyridinoline (nmol/g raw muscle) of slow-growing HAA steers. Results indicated alteration of perimysium collagen cross-links content in muscle in response to growth promotants., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

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 (P<0.05). Oxidative stability was similar across hamburgers (P>0.05). Sensory differences were found due to hamburger fat source, but were < one panel unit. Within perirenal-hamburgers, feeding flaxseed increased 18:3n-3 and its BHI (P<0.05), and feeding sunflower seed increased 18:2n-6 and its BHI (P<0.05). Feeding flaxseed increased off-flavour intensity and oxidation in perirenal-hamburgers (P<0.05). 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., (Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.)

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<6.0 (AT, atypical). LT from CL carcasses had the lowest mean lactate level, lowest glucidic potential and highest mean pH value. LT muscle from CL and AT carcasses was dark and had decreased purge, drip loss and cooking loss. Warner-Bratzler shear force values and sensory panel results showed that AT beef was toughest (P<0.0001), substantiating economic penalty. Causal mechanisms for AT carcasses may be inconsistent with traditional DFD theory because of close to normal final muscle pH., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

This study compared carcass, meat quality and fatty acid profiles of longissimus thoracis (LT) from feedlot cattle fed barley grain with or without oilseed (OS). Six diets containing no oilseed (No-OS), 10% ground flaxseed (FS), 10% high oleate sunflower seeds (SS) with or without 30% triticale dried distiller's grain (DDGS) were prepared. Feeding DDGS increased chroma at 24 and 144 h post mortem. Feeding FS increased weight% of LT PUFA (P<0.05) compared to No-OS or SS. An OS by DDGS interaction occurred for 18:3n-3 (P<0.05) where FS increased weight% of 18:3n-3 (P<0.05), a response accentuated (P<0.05) by DDGS. Feeding DDGS increased weight% of LT 18:2n-6 (P<0.05), but neither OS nor DDGS affected conjugated linoleic acid (CLA, t7,c9 &c9,t11-18:2). Feeding FS increased weight% of n-3 FA, and both FS and SS increased t10-18:1 with no effect on CLA or t11-18:1. Combination feeding of DDGS and FS further increased weight% of n-3 FA and tempered increases in t10-18:1 with no effect on CLA or t11-18:1. The findings suggest a new strategy to increase beef omega-3 fatty acids efficiently through inclusion of a combination of DDGS and FS in feedlot diet., (Copyright © 2014. Published by Elsevier Ltd.)

The effects of tissue antioxidant levels on formation of heterocyclic amines (HAs) and their mutagenicity in grilled lean beef were studied. Meat from 54 feedlot steers fed different levels of vitamin E (340, 690, 1040 and 1740 IU/animal/day) for 120-days was used to provide beef with different levels of antioxidants (α-tocopherol). Prevalent HAs were then analyzed by HPLC using UV/Fluorescence detection. Five major HAs were found: 2-amino-3,8-dimethyl-imidazo(4,5-F)Quinoxaline (MeIQx), 2-amino-3,4,7,8-tetramethyl-imidazo(4,5-F)Quinoxaline (TriMeIQx), ß-Carboline-9H-Pyrido[3,4-b]indole (Norharmane), 1-Methyl-9H-pyrido[3,4-b]indole (Harmane) and 2-amino-1-methyl-6-phenylimidaza(4,5-B)pyridine (PhIP). Total content of HAs in grilled lean beef ranged from 9.57 ng/g to 11.59 ng/g. There was, however, a trend (P=0.097) found for reduced mutagenicity with increasing tissue levels of α-tocopherol. The increasing dietary vitamin E significantly increased the α-tocopherol level in lean beef (P<0.001), but it had no significant (P>0.05) inhibitory effects on the content of individual and total HAs., (© 2013. Published by Elsevier Ltd. All rights reserved.)

The potential to increase n-3 fatty acid (FA) intake via flaxseed fed pork is underestimated when restricted to pure longissimus muscle, whereas a combination of muscle and adipose tissue is typically consumed. Presently, the FA content of pigs fed 0%, 5% and 10% dietary flaxseed for 11 weeks was measured in loin, picnic and butt primals (lean muscle with epimysium (L), L plus seam fat (LS), and LS plus 5 mm backfat (LSS)). The n-3 FA content necessary for an enrichment claim in Canada (300 mg/100 g serving) was exceeded in L from all primals when feeding 5% flaxseed, being 4 fold that of controls (P<0.001), with further enrichment from inclusion of associated adipose tissues (P<0.001). Increasing flaxseed feeding levels in combination with adipose tissue inclusion amplified total long chain n-3 FA (P<0.05), particularly 20:5n-3 and 22:5n-3. Flaxseed-fed n-3 FA enriched pork can contribute substantially to daily long chain n-3 FA intakes, particularly for societies with typically low seafood consumption., (© 2013.)

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 (P<0.05), significantly reduced meat off-flavor intensity (P<0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n-6 fatty acids (FA, P<0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P<0.05). A significant forage × oilseed type interaction (P<0.05) 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 (P<0.05) and significantly influenced intramuscular FA composition (P<0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed., (Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.)

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°C and 33°C, respectively, over a NIR spectral range from 400 to 2498nm 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., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Myofibrillar (MF-SF) and connective tissue (CT-SF) peak shear forces were interpolated from Warner-Bratzler shear force (SF) deformation curves of cooked bovine M. gluteus medius (GM) and M. semitendinosus (ST) from 112 crossbred steers in a 2×2×2 factorial experiment examining the interactions between slaughter age, growth promotants and breed cross (British versus Continental). Mixed model analyses, Pearson correlations and stepwise multiple regression identified relationships between shear forces, meat quality measurements and production treatments. Connective tissue contribution to SF increased with slaughter age and implantation in the ST and with slaughter age only in the GM. Myofibrillar contribution to SF increased with slaughter age for the ST and with Continental genetics for the GM. Variation in ST SF and MF-SF was best described by muscle weight, which increased with animal age, while GM SF and MF-SF variation was best described by cooking loss, indicating that ST and GM SF were most affected by connective and myofibrillar proteins, respectively., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The fatty acid composition of beef and pork has been stigmatized due to their relationships with several diseases from cardiovascular disease to cancer. Meat lipids are, however, one of the few components of meat that can be modified in content and composition, and can present opportunities for value added production and health promotion. Until regulations and policies are in place to define requirements for fatty acid enrichment, however, the process remains relatively academic. Once practical goals are in place for fatty acid enrichment in meat, both theory and practice need to converge for successful production of fatty acid enriched meat. The present review covers aspects of policy in Canada, and requirements for research networks to respond to theoretical and practical challenges associated with production of fatty acid enriched meat. Finally, needs for education and marketing are outlined which must be in place to truly realize a transition of meat lipids from perceived disease and waste to health and opportunity., (Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.)

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°C, thawed, scanned over a NIR spectral range from 400 to 2498 nm at 31°C and 2°C, and subsequently analysed for fatty acid composition. Best NIRS calibrations were with samples at 31°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 acids with R(2) (RMSECV, mgg(-1) fat) of 0.85-0.85 (0.16-0.37), 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., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

This study was conducted to investigate changes in fatty acid profiles of beef cows fed grass hay or barley silage based diets, with or without flaxseed supplementation. Both flaxseed and hay feeding increased levels of α-linolenic acid (LNA; 18:3n-3) in longissimus thoracis and backfat (P<0.001). A forage type by flaxseed level interaction was observed for most LNA biohydrogenation intermediates (P<0.05) that indicated feeding hay combined with flaxseed led to the greatest levels of total conjugated linolenic acid, total conjugated linoleic acid, total non-conjugated dienes and total trans-18:1. Predominant biohydrogenation intermediates included t11,c15-18:2, rumenic acid (c9,t11-18:2) and vaccenic acid (t11-18:1)., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)

A considerable amount of information has been generated on the feeding value and impact of corn dried distillers' grains with solubles (DDGS) on meat quality, whereas little is known about the effects of wheat DDGS on meat quality, and no direct comparison of these two sources of DDGS has been completed. The current study was conducted to examine the objective and subjective carcass and meat quality traits of cattle fed diets containing corn or wheat (20% or 40%) DDGS (DM basis) as compared to a standard barley-based finishing diet (control). In general, meat obtained from animals fed the barley-based control diet was slightly darker in colour (lower chroma and hue at 24 h, P<0.01) and less tender (highest proportion of tough shears at 2 d and lowest proportion of tender shears at 20 d). Meat from corn DDGS was rated as more tender and palatable than control samples (P<0.05), and 20% corn samples were rated better for beef flavour intensity (P<0.01) and desirability (P<0.05) than 40% corn DDGS samples. In contrast, meat from steers fed wheat DDGS showed intermediate characteristics between steers fed control and corn DDGS diets. Hence, feeding wheat DDGS had no negative effects, and feeding corn DDGS had some positive effects on meat quality characteristics of beef., (Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.)

The combined effect of blade tenderization (BT), moisture enhancement and enzymatic tenderization on drip loss, cook loss, Warner-Bratzler shear force (WBSF) and sensory characteristics of beef semitendinosus (ST) steaks from cattle under 30 months of age was investigated. Injection with phosphate/chloride solution improved tenderness and juiciness of ST muscles (P<0.01). No additional improvement in tenderness was observed with incorporation of a pancreatin enzyme preparation into the moisture enhancement solution (P>0.1). Injection of pancreatin alone tended to improve overall tenderness (P=0.09) and did not adversely affect other palatability attributes. Blade tenderization of ST muscles improved tenderness, as indicated by lower WBSF and increased sensory tenderness scores than for control samples, without decreasing flavour and juiciness. The results suggest that moisture enhancement and blade tenderization can be effectively utilized to reduce the variability in and improve both tenderness and palatability of ST muscles. Pancreatin was not particularly effective at the 0.02% level used., (Copyright 2009 Elsevier Ltd. All rights reserved.)

To examine the effect of co-extrusion on subsequent n-3 fatty acids in pig tissues, 8 pigs (barrows and gilts) were assigned to either a control treatment or one of nine treatments arranged in a 3 x 3 factorial design with 3 levels of co-extruded flaxseed (5%, 10% and 15%) and 3 durations of feeding (4, 8 and 12 weeks). Feed conversion improved slightly (P=0.01) with increasing dietary flaxseed but feeding flax for more than 8 weeks reduced average daily gain (P=0.02). In general, the duration and level of co-extruded flaxseed feeding affected (P<0.05) most fatty acids except for 22:6n-3 (P>0.05). Increasing the duration of flax feeding led to significant quadratic effects in backfat 18:3n-3 (P<0.001) and total n-3 fatty acids (P=0.002) when feeding 5% co-extruded flaxseed. Those increases were linear (P<0.001) when feeding 10% and 15% co-extruded flaxseed. Consequently feeding higher levels of flax for shorter periods vs. lower levels for longer periods appears to be more efficient at increasing n-3 fatty acids in pig backfat, but increases appeared to be less consistent. Moreover the addition of a 50:50 mix of extruded flax/peas to pig diets provided a highly available source of 18:3n-3 yielding n-3 fatty acid enrichments in backfat comparable to studies where extracted flaxseed oil was fed. Feeding flax co-extruded with field peas can be used to optimize consistent enrichments of n-3 fatty acids in back fat and relatively small amounts of this fat could be used to manufacture pork products to meet Canadian standards for n-3 fatty acid enrichment., (Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.)

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 (5h at 12-17°C) or slowly in air (48h 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.

A novel approach to mapping Warner-Bratzler shear of whole muscles was explored. The procedure was used on the Longissimus thoracis et lumborum (LTL) and Semitendinosus (ST) from six beef cattle by first marking skeletally defined anatomical landmarks on the muscle in situ. After removal from the carcass, further divisions were made while preserving sample orientation during cooking and preparation for shearing. Shear gradients were observed in all planes of the LTL, particularly the medial-lateral. The mid-section of the ST had the lowest shears while superficial locations of the cross-section had greater values. Muscle comparison indicated the ST was more uniform than the LTL. The mapping technique was subsequently used to identify localized effects of altered carcass suspension on shear values and sarcomere length in the lumbar Longissimus from four beef cattle. This mapping method will provide guidance for further intensive investigation across the carcass musculature and under varying carcass conditions.

The relationships of chemical components to palatability attributes in 33 different muscles and muscle groups from 25 Canada AA steer carcasses were assessed. Intramuscular fat and moisture accounted for 38.4 and 23.0% of the variation in panel juiciness ratings of all 33 muscles or muscle groups. Insoluble hydroxyproline content was more closely related with palatability attributes than either total or soluble hydroxyproline content, and accounted for 16.8, 26.0, 34.8, 24.0 and 34.8% of the variation in initial and overall tenderness, amount of perceived connective tissue, flavour desirability, and overall palatability, respectively, of all muscles. Exclusion of "sheet-like" support muscles improved the amount of variation accounted for in palatability traits slightly and exclusion of "combination cuts" containing two or more muscles improved the amount of variation accounted for in palatability traits significantly. Insoluble hydroxyproline not only adversely influenced textural properties contributing to tenderness, but also adversely influenced flavour desirability. The amount perceived connective tissue provides a reliable indication of the amount of insoluble hydroxyproline, and vice versa particularly in individual muscles, where the epimysium has been removed.

One kilogram roasts from 33 muscles or muscle groups from 25 Canada AA steer carcasses were evaluated for palatability after roasting to 72 °C internal temperature in an electric convection oven preheated to 177 °C. Initial tenderness ranged from moderately tough to tender. All butt tender and tenderloin samples were tender on the first bite, but less than 10% of the rib cap (top and lower portions), deckle point, brisket, and eye of round samples were rated tender on the first bite. Overall tenderness also ranged from moderately tough to tender. All of the tenderloin, butt tender, rib-eye cap, and cross rib samples were rated tender overall, but none of the deckle point samples were rated tender overall. Perceptible connective tissue ranged from slight to moderately abundant. Juiciness ranged from slightly dry to moderately juicy. All of the tenderloin, cross rib cap, rib-eye cap, tri tip, flap meat, short rib, and skirt samples were rated juicy, but 40% or less of the shoulder, eye of round, and loss side samples were rated juicy. Beef flavor intensity ranged from slightly to moderately intense, and flavor desirability ranged from slightly undesirable to moderately desirable. All tenderloin, butt tender, striploin, rib-eye, and cross rib cap samples were rated desirable in overall palatability, but 25% or less of the rib cap (top and lower portions), shank meat, eye of round, brisket, and deckle point samples were rated desirable in overall palatability. To the extent desirability to the panel utilized is representative of consumer acceptance, only the tenderloin, butt tender, rib-eye cap, cross rib, cross rib cap, and rib-eye either met or came close to meeting the Canadian Cattlemen's Association's goal of 95% acceptance based upon palatability. Consequently, effective postmortem intervention techniques or alternative cooking methods must be developed and applied to improve the palatability of most beef muscles, if the aforementioned goal is to be achieved.

Thirty-three muscles or muscle groups were separated from 25 Canada AA beef carcasses. Each of these muscles and muscle groups was subsampled, and the contents of moisture, fat, soluble hydroxyproline, insoluble hydroxyproline, and total hydroxyproline were determined. In addition, a 1-kg roast from each muscle or muscle group was used to determine thaw-drip losses, cooking times, and total cooking losses. Cooking times ranged from 51.0 to 111.3 min/kg (S.E.=2.90). Thaw-drip losses ranged from 1.26 to 10.05% (S.E.=0.40). Total cooking losses ranged from 21.51 to 33.26% (S.E.=0.70). Moisture content ranged from 666.4 to 761.8 mg/g (S.E.=0.23). Fat content ranged from less than 30 to 118.7 mg/g (S.E.=0.25). The amount of total hydroxyproline on a dry, defatted basis ranged from 17.8 to 117.4 μMol/g (S.E.=2.24). Insoluble hydroxyproline ranged from 15.2 to 101.9 μMol/g, (S.E.=1.70), and soluble hydroxyproline ranged from 2.1 to 30.9 μMol/g (S.E.=0.78). Percent soluble hydroxyproline ranged from less than 10 to more than 30% (S.E.=0.79). Such wide variation in cooking and chemical properties undoubtedly has a considerable impact on the palatability attributes and consumer acceptance of beef. However, greater understanding of the chemical composition of muscle will provide a basis for the development of technologies to enhance the palatability of individual muscles and muscles groups.

Cyclical texture profile analysis (TPA) parameters measured using a star-shaped probe with two cycles of 80% penetration and Warner-Bratzler shear force (WBS) were compared as predictors of objective tenderness and subjective sensory characteristics of rib steaks from 52 beef loins. The TPA parameters of hardness, cohesiveness and chewiness were negatively correlated (P<0.05) with trained panel sensory characteristics of initial tenderness (r=-0.64, -0.41, -0.62, respectively), amount of connective tissue (r=-0.57, -0.27, -0.55, respectively), overall tenderness (r=-0.68, -0.39, -0.64, respectively) and overall palatability (r=-0.56, -0.37, -0.53, respectively). These sensory characteristics were also negatively correlated (P<0.05) with WBS (r=-0.61, -0.49, -0.60, -0.56, respectively). Stepwise regression analysis generated prediction equations that included the TPA parameters of hardness and adhesiveness, which accounted for 47, 36, 51 and 38% of the variation in initial tenderness, amount of connective tissue, overall tenderness and overall palatability, respectively. Prediction equations using WBS accounted for 37, 24, 36 and 31% of the variation in initial tenderness, amount of connective tissue, overall tenderness and overall palatability, respectively. Hence, TPA explained more of the variation in subjective sensory tenderness of the rib steaks than WBS.

The present study was conducted to investigate the palatability of bison semimembranosus muscle (SM) and the effects of injection with sodium chloride and sodium tripolyphosphate on cooking yield, colour, shear force and consumer acceptability. Twenty paired SM were obtained from 10 intact male bison (aged 24-30 months); each of these muscles was divided longitudinally into two sections. One section was injected to 110% of its original weight to contain 0.5% sodium chloride and 0.3% sodium tripolyphosphate, while the other was kept as a non-injected control. HunterLab a* (redness) and b* (yellowness) values did not differ (P>0.05) between injection treatments; however, injected steaks had lower L* values (darker) compared to controls. Control samples from bison SM were very lean and high in protein but not very tender. Marination by injection was able to significantly reduce shear force values of SM; that is, injected steaks/roasts had significantly (P<0.001) lower shear force values (63.9 N) compared to control samples (102.3 N). Cooking yields for the steaks/roasts from the injected sections were significantly (P<0.001) higher compared to those from control non-injected sections when cooked to either 71 or 77 °C. Bison samples cooked by moist-heat had significantly (P<0.001) lower cooking losses and shear force values compared to those cooked by dry-heat. As expected, steaks/roasts were more tender and had higher cooking yields when cooked to a medium level of doneness (71 °C) compared to an internal temperature of 77 °C (well done). A panel of 80 consumers preferred injected steaks cooked to 77 °C endpoint over other combinations, followed by non-injected steaks cooked to 71 °C, whereas injected steaks cooked to 71 °C and non-injected steaks cooked to 77 °C were equally but least preferred. Hence, injection seems to be protecting against moisture loss at high end-point cooking temperatures.

One hundred and twenty-eight purebred Lacombe pigs (equal number of barrows and gilts) were assigned to one of four treatments at 64 kg and fed a commercial grower-finisher diet ad libitum to which ractopamine (RAC) was incorporated (0, 10, 15 or 20 mg kg(-1)). Pigs were slaughtered at 100 kg. Histological samples were collected from the semimembranosus (SM) and the psoas major (PM) muscles from the 0 and 20 mg kg(-1) RAC groups. Meat quality and muscle composition data were collected for all pigs. A significant 3-way interaction for muscle weight involving treatment, muscle and gender (P = 0·01) indicated that for the SM, gilts appeared to respond to RAC at a lower level of incorporation (10 mg kg(-1)) than barrows. Despite these differences in response at the gross muscle level, responses were similar at the cellular level for both muscles. The proportion of red fibres did not change (P = 0·21), the proportion of intermediate fibres decreased (P = 0·01) and the proportion of white muscle fibres increased (P = 0·02) in the mg kg(-1) RAC group compared to the controls. In addition, when compared to controls, average fibre diameters in the 20 mg kg(-1) RAC group remained constant in the red fibres, and increased significantly in both the intermediate and white fibres (P = 0·01 and 0·02, respectively). Over both muscles Kramer Press values were significantly higher (P = 0·030 in the RAC-fed pigs than in the controls. Incorporation of RAC into the diet did not result in any changes to crude protein or total and soluble hydroxyproline levels. Crude fat tended to increase in the 15 mg kg(-1) RAC treatment in the SM and decreased in the 20 mg kg(-1) RAC treatment in the PM. The shift in fibre type, and the associated changes in fibre size, may contribute to the increased shear values found in RAC-fed pigs., (Copyright © 1992. Published by Elsevier Ltd.)

Seventy-one barrows of three porcine genotypes (nn, Nn and NN genotypes with respect to halothane) were electrically stunned on the right side and randomly assigned to one of three treatments during the bleeding process (prone, PR; shackled left, SL; or shackled right, SR) to investigate the influence of both shackling and stunning on ultimate meat quality. PR carcasses had less side-to-side variation in 40 min pH than either SL or SR carcasses. Shackling contributed to a decreased 40 min pH in the semimembranosus (SM) and posterior longissimus dorsi (PL). The effects of stunning appeared to be additive when combined with shackling, tending to lower pH in the mid-longissimus dorsi (ML; P <- 0·10). The 'free' side of the shackled carcass also had significantly lower 40 min pH in the ML, PL and SM locations when compared to PR sides. Genotype had no influence on shackling since there was no treatment by genotype interactions. Despite significant effects on post-mortem metabolism (indicated by the differences in 40 min pH) shackling alone had little influence on overall ultimate meat quality of the carcass. Depending on the sampling location, soluble protein and L (∗) and b (∗) values varied among treatments. Shear force and a (∗) values were similar among treatments, but PR and SL carcasses had significantly lower expressible juice and drip loss compared to SR carcasses. These results suggest that, although shackling alone has little effect on meat quality, in combination with electrical stunning, shackling can lead to a decrease in meat quality., (Copyright © 1991. Published by Elsevier Ltd.)

A study was conducted to examine the effect, in ram lambs, of chronic treadmill exercise, on meat quality. A secondary objective was to relate changes in tenderness to metabolic and chemical phonomena. Meat quality traits, including instrumental measurements of tenderness and thaw and drip losses, were recorded for two muscles from the hind limb (semimembranosus SM; vastus lateralis, VL). Chemical analyses, including total and soluble collagen, total and myofibrillar protein, and myofibrillar fragmentation were also performed. Muscles from exercised sheep were significantly more tender than muscles from their control counterparts. A larger myofibrillar protein to total collagen ratio was observed in the VL muscles from exercised sheep (P < 0·01) which probably contributed to the observed increase in tenderness. However, similar results were not observed for the SM muscle. The tendency for a slightly higher pH at similar post-mortem temperatures in meat from exercised sheep may also have contributed to the increased tenderness., (Copyright © 1990. Published by Elsevier Ltd.)

A study was conducted with Suffolk ram lambs to determine whether chronic endurance exercise would affect post-mortem changes in muscle tissue. Muscle fibre diameters, sarcomere lengths, fibre types, and pH and temperature declines were measured in five skeletal muscles (semimembranosus, SM: vastus lateralis, VL; semitendinosus, ST; psoas major, PM; gastrocnemius, G). The exercise had no significant effect on muscle size or muscle fibre diameter in any of the muscles studied. However, endurance-exercised sheep had significantly shorter sarcomeres in all five muscles than their non-exercised counterparts. The pH decline curves differed among muscles; those having the highest proportion of glycolytic fibres had the slowest rates of pH decline. The increased proportion of slow-twitch fibres in the SM, VL, ST and G associated with the exercise regime had little effect on the post-mortem pH decline. However, the ST also had a significant exercise-associated increase in the proportion of oxidative-glycolytic fibres (intermediate) and was the only muscle in which exercise influenced the rate of pH decline significantly., (Copyright © 1990. Published by Elsevier Ltd.)