A new manual method for pork belly firmness measurement.

A new objective and standardized method for early determination of firmness of the intact pork belly in a research environment is described, and compared to the existing bar-bend method. The belly characteristics that contribute to the outcome of each method, and the relationship between the two methods are identified. •Original method requires a ribbed pork belly, and several minutes relaxation time.•New method provides an immediate measurement on an intact belly.•Advantages include early, rather than late, application in the fabrication process; rapid measurement; standardization; measurements minimally affected by animal length or belly length.

Evaluating the effect of temperature and multiple bends on an automated pork belly firmness conveyor belt classification system.

Skin-on, and bone-in bellies (n = 94) were cut into Canadian specifications and assessed on an automated conveyor belt system based on different levels of firmness. Temperature settings at 4 °C, 2 °C, and - 1.5 °C had significant effect (P < 0.05) on the bending angle, after 24 cm of the belly had passed the nosebar. The stepwise regression relationship had R2 âˆ¼ 0.18-0.67 between iodine value and bending angle at all temperatures. Bending bellies multiple times changed firmness classification of bellies at 4 and 2 °C, but bend number did not influence firmness classification at -1.5 °C. The automated conveyer belt system presented the potential to classify pork bellies based on firmness for industrial applications.

Developing an alternative classification method for predicting ham composition using linear measurements from the cross-sectional ham surface.

Digital image analysis based on the ham cross-sectional face was used to measure two lean muscle and three subcutaneous fat locations from 248 bone-in hams. Linear measurements of the two selected fat locations were used to predict dual-energy X-ray (DXA) fat or lean percentages with prediction accuracies (R2) of 0.7 in a stepwise regression eq. A classification system was built based on the prediction equations, and the linear measurements aimed to classify extremes at the threshold of the 10th percentile of DXA fat percentage (> 32.0%) and lean percentage (< 60.2%). When using either DXA fat or lean percentage, lean ham prediction accuracy dropped by 18%, but fat ham prediction accuracy increased by 60% when the threshold was changed from the 10th percentile to the 30th percentile. This classification approach has the potential to be converted into a manual tool with several useful applications for commercial pork processors.

Understanding the effects of chilling on color and quality characteristics of bovine longissimus thoracis.

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.

Extent of dark-cutting in beef carcasses graded Canada B4.

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.

An approach for objective and automated identification of pork belly firmness.

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 (ø = 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.

Efficacy of multi-stage sous-vide cooking on tenderness of low value beef muscles.

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 B & L 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).

Distributions of brine and bacteria in beef primal cuts injected with brine without, or before or after mechanical tenderizing.

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 <1% of the expected numbers. When injected meat was examined microscopically, L. innocua were observed only between the muscle fibres in meat that was not tenderized before injection, but between fibres and in lacunae in tissue damaged by mechanical tenderizing before injection. The distributions of brine and bacteria in injected primals apparently did not alter substantially during storage in vacuum packs, at 2°C, for 2 weeks.

Potential of near infrared (NIR) spectroscopy and dual energy X-ray absorptiometry (DXA) in predicting pork belly softness.

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.

Effect of thawing rate on distribution of an injected salt and phosphate brine in beef.

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.

Compositional and dimensional factors influencing pork belly firmness.

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.

Effects of diets supplemented with sunflower or flax seeds on quality and fatty acid profile of hamburgers made with perirenal or subcutaneous fat.

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.

Meat quality variation in the robotic sorting of pork loins.

A robot was used to make fiber-optic reflectance measurements from 400 to 700 nm in 10-nm increments at six sites, 10 cm apart, along the length of 48 pork loins. Meat quality was assessed in the longissimus dorsi near the thoracolumbar junction using 1) a bag-drip method for fluid loss, 2) a subjective evaluation of wetness, 3) a colorimeter measurement of paleness (CIE L), and 4) a subjective evaluation for Japanese pork color scores (JPCS). Sorting of the loins in the commercial plant from which they originated was correlated (P < .01) with fluid loss (r=.57), with wetness scores (r=-.57), with CIE L* (r=.71), and with JPCS (r=-.64). Laboratory measurements of pH at the site of meat quality assessment were correlated (P < .01) with fluid loss (r=-.61), with wetness scores (r=.65), with CIE L* (r=-.74), and with JPCS (r=.77). Average spectra obtained robotically were correlated (P < .01) with fluid loss (r=.56 at 670 nm, and R=.76 adding 560 and 540 nm), with wetness score (r=-.65 at 480 nm, and R=.75 adding 530 and 570 nm), with CIE L* (r=.76 at 480 nm, and R=.82 adding 690 and 520 nm), and with JPCS (r=-.70). In sorting loins that were all categorized as normal at the plant, mean reflectance data collected robotically were correlated with fluid loss, r=.42 (P > .05) at 700 nm and R=.58 (P > .05) adding 430 nm; with wetness score, r=.25 (P > .05); with CIE L*, r=.58 (P < .025) at 700 nm; and with JPCS, r=-.71 (P < .01) at 700 nm. Thus, as well as detecting obvious PSE loins, the robotic probe also had a limited capability to sort loins all categorized as normal at the plant.

Effect of ractopamine and sex on growth, carcass characteristics, processing yield, and meat quality characteristics of crossbred swine.

One hundred twenty-eight 64-kg crossbred barrows and gilts were administered either 0 or 20 ppm of Ractopamine (RAC) in a pelleted corn-soybean meal diet that contained either 17.5 or 19.6% CP. Carcass quality was evaluated after slaughter at 100 kg. Dietary protein levels produced few significant effects; therefore, data were pooled for analysis. Pigs fed RAC exhibited improvement in feed efficiency (P < .01), ADG (P < .01), and number of days to slaughter (P < .01). Pigs fed RAC had 1.8 mm less fat (P < .05) and 3.4 mm more lean (P < .01) at the grading probe site. Gilts had 4.9 mm less fat than barrows at the probe site (P < .01) and also yielded an estimated 4.1% more lean (P < .01). Trimmed loins and bellies of animals fed 20 ppm of RAC were 230 g heavier (P < .05) than those of animals fed the control diet. Trimmed loins from gilts were 260 g heavier (P < .05), whereas barrows produced bellies that were 490 g heavier (P < .05) than those of gilts. The yield of processed ham was greater from both pigs fed RAC (P < .01) and barrows (P < .05). Loins of pigs fed RAC had lower cooking loss (P < .05), greater Warner-Bratzler shear value (P < .05), and higher fragmentation index value (P < .01). Although effects of sex were similar to or greater than the effects of 20 ppm of RAC, these effects were additive.

Effects of feed treatment and gender on the flavour and texture profiles of cured and uncured pork cuts. I. Ractopamine treatment and dietary protein level.

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).

The effects of feed treatment and gender on the flavour and texture profiles of cured and uncured pork cuts. III. Effects of gender.

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.

Use of near infrared spectroscopy for estimating meat chemical composition, quality traits and fatty acid content from cattle fed sunflower or flaxseed.

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 (R(2)) (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 (R(2): 0.83-0.97; RMSECV: 0.04-1.15mg·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.

The impact of ultimate pH on muscle characteristics and sensory attributes of the longissimus thoracis within the dark cutting (Canada B4) beef carcass grade.

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.

Predicting fat quality from pigs fed reduced-oil corn dried distillers grains with solubles by near infrared reflectance spectroscopy: fatty acid composition and iodine value.

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.

Inclusion of sunflower seed and wheat dried distillers' grains with solubles in a red clover silage-based diet enhances steers performance, meat quality and fatty acid profiles.

The current study compared beef production, quality and fatty acid (FA) profiles of yearling steers fed a control diet containing 70 : 30 red clover silage (RCS) : barley-based concentrate, a diet containing 11% sunflower seed (SS) substituted for barley, and diets containing SS with 15% or 30% wheat dried distillers' grain with solubles (DDGS). Additions of DDGS were balanced by reductions in RCS and SS to maintain crude fat levels in diets. A total of two pens of eight animals were fed per diet for an average period of 208 days. Relative to the control diet, feeding the SS diet increased (P<0.05) average daily gain, final live weight and proportions of total n-6 FA, non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) with the first double bond at carbon 8 or 9 from the carboxyl end, conjugated linoleic acid isomers with the first double bond from carbon 7 to 10 from the carboxyl end, t-18:1 isomers, and reduced (P<0.05) the proportions of total n-3 FA, conjugated linolenic acids, branched-chain FA, odd-chain FA and 16:0. Feeding DDGS-15 and DDGS-30 diets v. the SS diet further increased (P<0.05) average daily gains, final live weight, carcass weight, hot dressing percentage, fat thickness, rib-eye muscle area, and improved instrumental and sensory panel meat tenderness. However, in general feeding DGGS-15 or DDGS-30 diets did not change FA proportions relative to feeding the SS diet. Overall, adding SS to a RCS-based diet enhanced muscle proportions of 18:2n-6 biohydrogenation products, and further substitutions of DDGS in the diet improved beef production, and quality while maintaining proportions of potentially functional bioactive FA including vaccenic and rumenic acids.