Predicting pork carcass and primal lean content from electromagnetic scans

Fifty-four whole, pre-rigor, eviscerated carcasses (74.1±kg) were selected over a 5-week period to represent carcasses marketed to a Northwest Iowa packing plant during the fall season. Carcasses (spanning 40.7-65.2% carcass lean) were electromagnetically (EM) scanned before entering the chiller. Carcass right sides were fabricated and weights were recorded for each jowl, ham, loin, Boston butt, picnic shoulder, neckbone, sparerib, and belly. Each component was skinned and dissected into external fat, internal (seam) fat, bone, and lean with corresponding weights recorded. Regression equations were derived from points and areas taken from the EM scan curve. The best 5-variable equations were developed for total carcass lean (R(2)=0.9502; RMSE=1.31 kg), percentage carcass lean (R(2)=0.8789; RMSE=1.88%), ham lean (R(2)=0.8475; RMSE=0.755 kg), loin lean (R(2)=.8511; RMSE=0.781 kg), Boston butt lean (R(2)=.7251; RMSE=0.505 kg), picnic lean (R(2)=0.7387; RMSE=0.464 kg), and commodity, component carcass value (R(2)=0.9458; RMSE=$3.24).     

Ultrasonic scanning measurements of the longissimus thoracis et lumborum muscle to predict carcass muscle content in sheep

Nineteen Omani sheep (average 26 kg body weight) were scanned over the 6th rib, 12th rib and the second-last lumbar vertebra, to determine the maximum depth (B), circumference, area of the cross-section and volume of the longissimus thoracis et lumborum (LD) muscle. The volume of the muscle was estimated by multiplying the average area of its cross-section obtained at the three sites by its length. After slaughter, the LD muscle was dissected out, frozen, and its maximum depth, circumference, length, weight and volume were determined. Correlation and regression analyses were carried out to evaluate relationships between scanning and real measurements and between scanning measurements and carcass total muscle content. Generally there were positive correlations (r = 0.43-0.66) between the LD scanning measurements made at the 12th rib and the corresponding measurements made on the dissected muscle. The volume of the LD muscle estimated from scanning was positively correlated (r = 0.59) with its real volume which was correlated with its weight (r = 0.51) and consequently with the total carcass muscle content (r = 0.69). Ultrasonic scanning can be used to predict the circumference and volume of the LD muscle. These may be used for prediction of total carcass muscle content in sheep in addition to traditional measurements of the muscle (the maximum depth B) and area.     

Effects of dietary humate supplementation to broilers on performance,slaughter, carcass and meat colour

BACKGROUND: This experiment was designed to examine the effect of dietary humate supplementation primarily on pH and colour parameters of carcasses, breast fillets and drumsticks and, secondarily on performance and carcass characteristics in broilers. RESULTS: A total of 240 male broiler chicks (Ross‐308) were randomly allocated to four dietary treatments varying in supplemental humate level (0, 0.1, 0.2 and 0.3% for H₀, H₁, H₂ and H₃). Dietary humate supplementation did not affect performance traits and slaughter, hot carcass weights and yields. Carcass‐related variables (pH, L*, a*, b*, H* and C*) were responsive to the dietary treatments. The L*, a*, b*, and C* values for drumstick muscles were higher than those for breast muscles. Except for the L* value, meat colour parameters changed due to packaging. The a* value was higher and b* value was lower for vacuum packaged breast and drumsticks than for those aerobic packaged. Storage period affected colour parameters; while L*, b*, H* and C* values were higher for drumstick skin than for drumstick meat; the a* value was greater in drumstick meat than in skin. CONCLUSION: pH and colour parameters of carcasses, breast fillets and drumsticks of broilers were improved by dietary humate supplementation. However, responses of broiler performance and slaughter and carcass characteristics were minimal. Copyright © 2008 Society of Chemical Industry     

小麦粉中过氧化苯甲酰含量的简易判断方法

提出了快速测定小麦粉中过氧化苯甲酰的方法,根据小麦粉提取液色泽的深浅与其过氧化苯甲酰含量之间的相关性规律,通过肉眼观察提取液色泽的深浅即可快速判断小麦粉中过氧化苯甲酰的大致含量。     

Application of differential scanning calorimetry to estimate quality and nutritional properties of food products

Over the past years, both food researchers and food industry have shown an increased interest in finding techniques that can estimate modifications in quality, nutritional, and thermophysical properties of food products during processing and/or storage. For instance, differential scanning calorimetry (DSC) has attracted the interest of scientific community because only a small amount of sample is needed for analysis. Moreover, it does not require any specific sample preparation, and is a repeatable and reliable method. In addition, DSC methodology needs a short time for experiments compared with other techniques used for the same purpose. At this stage of investigation, there is a need to evaluate the commonly accepted and new emerging DSC applications to establish the optimum conditions of emerging processing. This paper reviews the current and new insights of DSC technique for the estimation of quality, nutritional, and thermophysical properties of food products during conventional and emerging processing and/or subsequent storage. The estimation of different properties in several food matrices after processing and/or storage is also discussed.     

Effect of intestinal content contamination on broiler carcass Campylobacter counts

Intestinal contents may contaminate broiler carcasses during processing. The objective of this study was to determine what effect various levels of intestinal contents had on the numbers of Campylobacter detected in broiler carcass rinse samples. Eviscerated broiler carcasses were collected from the shackle line in a commercial processing plant immediately after passing through an inside/outside washer. Broiler carcasses were cut longitudinally into contralateral halves using a sanitized saw. Cecal contents from the same flock were collected, pooled, homogenized, and used to contaminate carcass halves. Paired carcass halves were divided into groups of eight each, and then cecal contents (2, 5, 10, 50, or 100 mg) were placed onto one randomly selected half of each carcass, while the corresponding half of the same broiler carcass received no cecal contents. Campylobacter counts from carcass halves with cecal contamination were compared to the uncontaminated halves of the same carcasses using a paired t test. Carcass halves with 5 mg or more of surface cecal contamination had significantly higher numbers of Campylobacter than those without (P < 0.01). Carcass halves contaminated with only 5 mg of cecal contents had an average of 3.3 log CFU Campylobacter per ml of rinse, while corresponding uncontaminated carcass halves had 2.6 log CFU Campylobacter per ml of rinse. These data indicate that even small (5 mg) amounts of cecal contents can cause a significant increase in the numbers of Campylobacter on eviscerated broiler carcasses. Therefore, it is important to keep such contamination to a minimum during processing.     

Development of backfat and individual fat layers in the pig and its relationship with carcass lean

The development of backfat (total and individual layers) was monitored in 140 Yorkshire pigs (71 castrates and 69 gilts) during a growing period extending from 14·5 kg to 137·0 kg live weight using a serial slaughter procedure. The allometric coefficient (b) for fat thickness was calculated at several locations extending from the shoulder to the M. gluteus medius at the mid-line and lateral to the mid-line. The relationships between backfat (total and individual layers) and the yield of trimmed boneless meat were also obtained from 80 carcasses.

Total backfat was the thickest at the shoulder, decreased gradually to the last rib, increased at the maximum loin, decreased to the middle of the M. gluteus medius and then increased posterior to the M. gluteus medius. The development of total backfat relative to weight at slaughter was generally slowest at the shoulder (b = 0·555−0·767), most rapid in the region extending from the 5/6 last rib to the last rib b = 0·729−0·810) and intermediate at the loin and in the region of the M. gluteus medius (b = 0·609−0·834). The development of the middle fat layer (b = 0·609−1·107) was more rapid than that of the outer layer (b = 0·500−0·817), the inner layer being intermediate (b = 0·515−0·966). Consistent with the rate of development observed for the individual fat layers, at light weights, the outer layer was usually more predominant, particularly at positions above the M. longissimus, whereas, at heavier weights, the middle layer became predominant.

It was observed that backfat (total or individual layers) measurements, which were the most precise predictors of yield of trimmed boneless meat, that is, measurements from the 5/6 last rib to the last rib (RSE = 4·6−3·1), also had the most rapid rate of development. Furthermore, the middle layer of backfat which exhibited the fastest rate of development of all three individual layers (b = 0·609−1·107), also contributed the most to the observed precision (RSE = 4·6−3·1).     

A research note on predicting the carcass yield of Korean native cattle (Hanwoo)

This study developed a new equation to predict the carcass yield of Hanwoo cattle, as well as re-evaluating a previous prediction equation. Experimental animals comprised 79 cows, 79 steers, and 79 bulls. A stepwise model selection was performed to determine the most practical carcass traits for predicting the yield. Cold carcass weight (CW), backfat thickness (BFT), and ribeye area (REA) accounted for 52% variation in yield, and these were determined as the final parameters. When the kidney, pelvic, and heart fat were included in the model, this increased the percentage variation explained (R(2)) by 4%. To compare the newly developed equation (Yield=64.65-0.0198×CW-5.2264×BFT+0.1339×REA) and the previously used one, carcass yields of 377,048 industrial animals (145,695 cows, 225,926 bulls, and 5427 steers) were assessed. For the newly developed equation, the mean difference between experimental animals industrial animals differed only by 1.99-2.68% for all sex groups. In the case of the previous prediction equation, the mean difference ranged from 6.06% for bulls to 11.05% for steers. The results demonstrated that the prediction equation should use a mixture of sex and market weight groups. The results also support our decision to use the newly developed model in predicting the yield of Hanwoo.     

Variation among beef breeds in carcass retail value at constant carcass saleable meat content and percentage of higher priced cuts

Data from the single slaughter point trials of the Meat and Livestock Commission's (MLC) beef breed evaluation programme were used to examine the importance of retail value (RV) calculation in breed evaluation trials.

The analysis involved a total of 2010 carcasses comprising four production system groups. Sire breeds included Aberdeen-Angus, British Friesian, Charolais, Devon, Hereford, Galloway, Limousin, Lincoln Red, Luing, Simmental, South Devon, Sussex and Welsh Black.

RV was computed as the sum of the values of trimmed deboned primal joints expressed as pence per kilogram of carcass weight. 1981 prices from MLC's Retail Prices Survey for England and Wales were used.

A model was fitted to the RV data for each of the production system groups with effects for sire breed, year and sire breed × year interaction, and with regression on saleable meat percentage in carcass (SM). The largest difference recorded between sire breeds was 2·1 pence/kg (0·85% of overall mean RV). The pooled within-system residual standard deviation after fitting the model was 1·4 pence/kg. When regression on the percentage of total saleable meat in the higher priced cuts (SMD) was added to the model, the corresponding range and residual standard deviation were reduced to 1·0 and 0·8 pence/kg, respectively. In the circumstances, the calculation of RV would, therefore, make only a minor refinement to the results.     

Development of a novel method for isolating and detecting Cryptosporidium parvum from lean and fat beef carcass surfaces

This paper describes the first reported method for the recovery and detection of Cryptosporidium parvum oocysts from beef carcasses. C. parvum oocysts were mobilized from beef surfaces into phosphate buffer saline-Tween 80, and subsequently recovered from this suspending medium by membrane filtration. Oocysts were removed from the membrane, concentrated by centrifugation, labelling with an FITC conjugated monoclonal antibody and enumerated using fluorescence microscopy. The study compared ‘pulsification’, a novel method, with ‘stomaching’ an established method, as processes for resuspending the target microorganisms from beef. Both yielded similar levels of recovery of oocysts, but pulsification produced less suspended sample debris, allowing easier oocyst detection.Membrane filter pore size (0.45, 1.0 or 3.0 μm) did not significantly affect the number of oocysts detected (P>0.05). Centrifugation at 2500g for 15 min using a swing out no brake (SONB) during deceleration rotor gave higher recoveries than a fixed angle with braking (FAB) rotor during centrifugation (P<0.05). Using inocula containing 2000 oocyst cm⁻², the optimized method (pulsification, filtration, SONB centrifugation and FITC labelling) allowed recovery and detection of 85.4% of inoculated oocysts from fat beef tissue and 128.4% from lean beef tissue. The developed method will be of value in establishing the incidence of C. parvum on beef and in future research on this parasite.     

Expert system based on computer vision to estimate the content of impurities in olive oil samples

The determination of the content of impurities is a very frequent analysis performed on virgin olive oil samples, but the official method is quite work-intensive, and it would be convenient to have an alternative approximate method to evaluate the performance of the impurity removal process. In this work we develop a system based on computer vision and pattern recognition to classify the content of impurities of the olive oil samples in three sets, indicative of the goodness of the separation process of olive oil after its extraction from the paste. Starting from the histograms of the channels of the Red–Green–Blue (RGB), CIELAB and Hue-Saturation-Value (HSV) color spaces, we construct an initial input parameter vector and perform a feature extraction previous to the classification. Several linear and non-linear feature extraction techniques were evaluated, and the classifiers used were Support Vector Machines (SVMs) and Artificial Neural Networks (ANNs). The best classification rate achieved was 87.66%, obtained using Kernel Principal Components Analysis (KPCA) and a grade-3-polynomial kernel SVM. The best result using ANNs was 82.38%, yielded by the use of Principal Component Analysis (PCA) with the Perceptron.     

Effect of source of dietary fat on pig performance,carcass characteristics and carcass fat content,distribution and fatty acid composition

Seventy gilts were used to compare the effect of including 10% tallow (T), high-oleic sunflower oil (HOSF), sunflower oil (SFO), linseed oil (LO), a fat blend (FB), or an oil blend (OB) in finishing diets vs. feeding a semi-synthetic diet with no added fat (NF) on pig performance, carcass traits and carcass fatty acid (FA) composition. Carcasses from SFO-fed gilts had greater fat and lower lean compositions than carcasses from T-fed gilts. Gilts fed NF had greater loin fat than FB-fed gilts, and greater flare fat, loin intermuscular fat and fat:lean than T-fed gilts. Bellies from NF-fed gilts had lower lean and higher intermuscular fat and fat:lean than other diets except HOSF. Fat source had minor effects on animal performance, carcass characteristics and carcass fat content and distribution, whereas feeding NF resulted in carcasses and major cuts with higher fat content. Diets rich in polyunsaturated FA (PUFA) did not reduce fat deposition in separable fat depots with respect to monounsaturated FA (MUFA) and saturated FA (SFA). Carcasses from gilts fed NF had a high degree of saturation (40.6% SFA) followed by carcasses of T- and FB-fed gilts. Feeding HOSF, SFO and LO enriched diets elevated the percentages of MUFA (56.7%), n−6 (30.0%) and n−3 (16.6%) PUFA, respectively, whereas carcasses from gilts fed OB had greater percentages of n−3 FA (14.8% n−3, 0.9% EPA, 1.0% DPA, 3.1% DHA) than gilts fed FB (6.72% n−3, 0.1% EPA, 0.4% DPA, 0.1% DHA).     

猪胴体瘦肉率仪器测定值与生猪品种等级的关系研究

使用PG100瘦肉率测定仪,对四种不同品种等级的生猪屠宰后的胴体的瘦肉率进行了测定,并与精确分割试验测定的瘦肉率进行了比较。结果表明使用仪器测定的瘦肉率指标,能够较好地反映生猪品种等级的优劣,可以用于生猪屠宰过程中的智能分级。     

Effect of feeding system on the growth and carcass characteristics of Iberian pigs, and the use of ultrasound to estimate yields of joints

Forty three-castrated male Iberian pigs of the Torbiscal line with an average initial weight of 102.27kg were used. A group of 22 pigs was fed according to the traditional way in free-range conditions with acorn and grass from November to January. Another group of 21 animals was fed 3.72kg/day of a conventional feed that contained 12.53MJME/kg, 16.21% crude protein, 4.94% fat and 6.64% of crude fiber, during the same period. Measurements of backfat thickness and Longissimus dorsi muscle area at the last rib were taken by means of a real-time ultrasound device (Kretz Technick Inc., 600 V-V2.32, Sonovet, Austria) in all pigs before slaughter. After slaughter, carcass, ham and foreleg weights and backfat and muscle area measurement from the last rib chop were recorded. The average daily gain, carcass yield, fat thickness, loin area, ham weight and proportion of hams were significantly higher (P<0.05) in the pigs fed in confinement than in those fed extensively (653.36g, 77.97%, 56.46mm, 3031mm(2), 22.26kg and 14.32% vs 501.48g, 76.94%, 51.74mm, 2673mm(2), 21.52kg and 13.79%, respectively). This paper shows the prediction equations for hams, forelegs and total hams and forelegs weights and proportions with respect to slaughter weight and live ultrasound measurements in pigs fed either extensively or in confinement. The ultrasound measurements better predicted the carcass cuts absolute amounts (R(2)=0.591-0.875) than the carcass cuts proportions (R(2)=0.23-0.40). The use of real-time ultrasound should be used with caution to predict the absolute quantities of hams and forelegs from Iberian pigs since the ultrasound measurements are only moderately accurate.     

The relationship of carcass measurements to carcass composition and intramuscular fat in Spanish beef

Forty beef carcasses were classified for conformation and fatness. Besides, carcass weight, fat thickness (FT), carcass dimension, marbling by computer image analysis and ultrasound readings was recorded to complement grading. For predicting intramuscular fat (IMF) content, FT, number of intramuscular flecks and conformation increased R²-value from 0.19 to 0.64 compared to conformation alone. For visual marbling, ultrasound readings and thoracic depth (TD) increased the R²-value from 0.24 to 0.57 compared to fatness score (FS). The best variables for predicting weight of fabricated subprimals were carcass weight or compactness which is a function of carcass weight (R² between 0.94 and 0.63). Fatness score was poorer than FT for predicting yield of subprimals cuts from round (R² = 0.16 vs. 0.50) and ultrasound readings for less valuable subprimals (R² = 0.31 vs. 0.39). These results showed that other variables could be used in combination with carcass fatness or conformation to achieve a more accurate estimation of fat and carcass yield.     

The practical application of 3-methylhistidine in determining the lean meat content of food products

Protein-bound 3-methylhistidine, which is present at similar concentrations in various meat species but absent from non-meat proteins, was used to estimate the lean meat content of a range of retailed meat products. The results of the application of this novel method were compared and contrasted with those using standard methods of product analysis. The presence of textured soya protein in products was determined using polyacrylamide gel electrophoresis. Formulae for the calculation of the fat-free lean meat content on the bases of (i) the 3-methylhistidine index for muscle protein and (ii) the connective tissue content, are given. The lean meat contents of products calculated on these bases were found to be of the same order as, but generally lower than, those obtained using standard methods. This was considered to be due to the presence of non-meat proteins, of added connective tissue and/or certain types of offal. These would not be included in the lean meat content, as calculated by the 3-methylhistidine index, but could be legitimately included in the meat content calculated using standard methods according to current practice. A new interpretation of 'meat' in terms of 3-methylhistidine content is given.     

Evaluation of a pilot on-line instrument for the measurement of lean content of cartoned boneless beef

A laboratory evaluation of a pilot, new instrument for the on-line (batch continuous) measurement of the per cent chemical lean content (CL) of whole cartons (nominally 27.2 kg) of boneless beef, based on an idealized design, is reported. For 24 cartons obtained from an export meatworks there was a highly linear (P < 0.001) dependence of CL on (reciprocal of) the instrument reading. The standard deviation of the predicted CL about this regression line was 2.02. For a further 20 cartons in which the cardboard was equilibrated at high RH prior to packing with the meat, the standard deviation in CL was 3.14. Predictions for CL were not significantly influenced by the order in which the meat pieces were packed into the carton, but were significantly (P< 0.001) affected by the size of the meat pieces. Best results of predicted CL were obtained with large meat pieces in cartons as supplied from the meatworks. These findings together with the fact that model predictions were not improved by a temperature term for meat (range 8.7–15.7°C) should augur well for future development of the instrument.     

Performance and carcass characteristics of growing pigs and broilers fed diets containing micronised barley,ground barley,wheat and maize

Two swine starter/grower/finisher trials utilising 216 24‐day‐old pigs and one 40‐day broiler growth trial utilising 1920 1‐day‐old chicks were conducted to determine the influence of dietary micronised dehulled barley (MDB) as a replacement for hulled barley (HB), wheat (W) and maize (M) on live performance, carcass and meat measurements, organ weights (swine), plasma urea nitrogen (PUN) level (swine) and intestinal digesta viscosity (broilers). Dehulling and micronising the barley reduced crude protein by 20%, neutral detergent fibre by 17% and amino acids by varying amounts. Replacing M or W with MDB in swine diets had no effect (P > 0.05) on any measured parameter, with the exception of decreased PUN (P = 0.03) when MDB replaced 100% of W. Broilers fed W, M or HB generally had similar live performance, carcass traits and digesta viscosity, with the exception of reduced (P < 0.05) average daily gain and average daily feed intake for HB during the first 20 days of the trial. However, broilers fed MDB had slightly reduced (P = 0.05) live performance during each phase of the trial and greatly increased (P = 0.01) digesta viscosity. Addition of a commercial enzyme product to the diets reversed the reduced performance and increased the digesta viscosity of the MDB diet, but generally had no influence in the W, M and HB diets. These results suggest that MDB can be utilised in swine diets without affecting performance, but that reduced performance may result from its use in broiler diets. © 2001 Society of Chemical Industry     

Using machine learning procedures to ascertain the influence of beef carcass profiles on carcass conformation scores

In this study, a total of 163 young-bull carcasses belonging to seven Spanish native beef cattle breeds showing substantial carcass variation were photographed in order to obtain digital assessments of carcass dimensions and profiles. This dataset was then analysed using machine learning (ML) methodologies to ascertain the influence of carcass profiles on the grade obtained using the SEUROP system. To achieve this goal, carcasses were obtained using the same standard feeding regime and classified homogeneous conditions in order to avoid non-linear behaviour in grading performance. Carcass weight affects grading to a large extent and the classification error obtained when this attribute was included in the training sets was consistently lower than when it was not. However, carcass profile information was considered non-relevant by the ML algorithm in earlier stages of the analysis. Furthermore, when carcass weight was taken into account, the ML algorithm used only easy-to-measure attributes to clone the classifiers decisions. Here we confirm the possibility of designing a more objective and easy-to-interpret system to classify the most common types of carcass in the territory of the EU using only a few single attributes that are easily obtained in an industrial environment.