Intact Loin Research Articles

In-Line Estimation of Fat Marbling in Whole Beef Striploins (Longissimus lumborum) by NIR Hyperspectral Imaging. A Closer Look at the Role of Myoglobin.

Fat marbling, the amount, and distribution of intramuscular fat, is an important quality trait for beef loin (Longissimus lumborum) and is closely connected to sensory properties such as tenderness, juiciness, and flavor. For meat producers, it would be of value to grade and sort whole loins according to marbling on the production line. The main goal of this study was to evaluate high-speed NIR hyperspectral imaging in interaction mode (760–1047 nm) for in-line measurement of sensory assessed marbling in both intact loins and loin slices. The NIR system was calibrated based on 28 whole striploins and 412 slices. Marbling scores were assessed for all slices on a scale from 1 to 9 by a trained sensory panel. The calibrated NIR system was tested for in-line measurements on 30 loins and 60 slices at a commercial meat producer. Satisfactory accuracy for prediction of marbling was obtained by partial least squares regression for both slices and whole loins (R2 = 0.81 & 0.82, RMSEP = 0.95 & 0.88, respectively). The concentration of myoglobin in the meat and its state of oxygenation has a strong impact on the NIR spectra and can give deviations in the estimated marbling scores. This must be carefully considered in industrial implementation.

Use of NIRS for the assessment of meat quality traits in open-air free-range Iberian pigs

Near infrared spectroscopy (NIRS) can be useful in order to determine meat quality traits as a rapid and non-destructive technique. The aim of the present study is to assess the accuracy of NIRS technique to determine meat quality traits on Longissimus thoracis et lumborum muscle of open-air free-range Iberian pig (n = 287) both in intact and minced samples. Traits were measured by instrumental-chemical techniques: colour (L*, a* and b*), myoglobin content, centrifuge force water loss and texture: shear force and texture profile analysis (TPA: hardness, cohesiveness, springiness, chewiness). Calibration models between instrumental-chemical measures and NIRS spectral data were developed employing partial least square regressions (PLS). The samples were split in two random datasets (80 % in training set, 20 % in external validation set). An internal full cross-validation method was applied. Results were evaluated in terms of coefficient of determination (R2), root-mean-square error (RMSE), residual prediction deviation (RPD) and range error ratio (RER). Full spectral range was used to develop mathematical equations. As regard external validation procedure, the highest coefficients of determination (R2p) in intact loin samples were achieved for hardness, redness (a*) and yellowness (b*) (0.7<R2p<0.8), while for minced samples lightness (L*), myoglobin content and texture parameters obtained always R2p>0.7. The models developed suggest the ability of NIRS for quantitative prediction of shear force and for a rough classification of colour parameters L*, a*, b* in minced samples as well as hardness in intact samples.

100 Young Scholar Presentation: Effects of sex, sire line, and packaging method on the relationships among early postmortem loin quality and aged loin and pork chop quality characteristics

Abstract A challenge in the pork industry is that packers assess pork loin quality at ~1d postmortem, while consumers assess quality after a period of postmortem aging. Rapid line speed necessitates rapid noninvasive assessment of quality by packers as indicators of aged (~14d) quality. However, it is unclear if this assessment is representative of quality observed by consumers at purchase. It is also unclear if correlations differ between barrows and gilts, sire lines, or packaging methods. Therefore, several studies were conducted to address these questions. Harsh et al. (doi.org/10.1093/jas/sky183) used meta-analyses techniques to establish correlations between early and aged pork loin quality. Data sets encompassed ~3,957 loins. Early instrumental and visual color were moderately correlated ( ≥ 0.38) with aged instrumental and visual color. No early quality parameters were correlated ( ≤ 0.36) with instrumental or sensory tenderness. With correlations between early and aged quality established, differences between factors of interest were tested. Correlations were compared using a Fisher’s z test. First, barrows and gilts were compared using a single sire line and raised in commercial conditions. Correlations between early and aged quality did not differ (P &gt; 0.05) between barrows and gilts. Correlations between Pietrian- and Duroc-sired pigs were compared to determine correlation difference between sire lines using pigs from two different production focuses (meat quality vs. lean growth). Correlations between early ventral L* and aged chop L*, and early visual color and aged ventral L* differed (P ≤ 0.03) between Pietrain- and Duroc-sired pigs. However, the majority of correlations did not differ (P &gt; 0.05) between sire lines. Correlations between packaging methods were compared by assigning boneless pork loins to one of two packaging methods, intact loins or case-ready chops. The correlations between early and aged quality traits did not differ (P &gt; 0.05) between packaging methods. Overall, packers can use the same early quality characteristics to select for aged quality, regardless of sex, sire line or packaging method.

Fourier transform near-infrared spectroscopy coupled to a long fibre optic head for the quality control of IBERIAN pork loins: Intact versus minced

Conventional chemical analyses of meat products are time-consuming, expensive and destructive. The advantages of NIR spectroscopy are its speed, portability, suitability for both at-line and on-line analysis, low cost and the possibility of simultaneously measuring many different parameters in a large number of samples. The purpose of this study was to develop and validate calibrations for the prediction of moisture, protein and fat in Iberian pig pork loins using an FT-NIR instrument coupled to a 5-m fibre optic sensor head.The best equations obtained for intact loin in both modes of analysis (full and optimal spectral range) displayed Standard Error of Cross-Validation (RMSECV) of 1.06% and 1.09% and Determination Coefficient of Cross-Validation (RCV2) of 0.69 and 0.77 for fat: RMSECV of 0.87% and 0.77% and RCV2 of 0.67 and 0.73 for moisture; while for protein, the RMSECV values were 0.51% and 0.49% and the RCV2 values were 0.66 and 0.70.

186 Comparisons of Correlations Among Early and Aged Pork Quality Traits for Loin Chops Aged As Intact Loins or in Case-Ready Packages.

186 Comparisons of Correlations Among Early and Aged Pork Quality Traits for Loin Chops Aged As Intact Loins or in Case-Ready Packages.

Correlation Comparisons of Early and Aged Quality Traits of Pork Aged Either as Intact Loins or Case-Ready Chops

Approximately half of retail pork chops in the U.S. arrive at the store in case-ready packages. The other half arrives as intact-loins and are sliced when needed. Cutting chops from loins may increase moisture loss leading to lighter colored and less juicy meat. Therefore, it is possible that correlations between loin quality traits observed early postmortem (PM) and aged quality traits would differ between intact-loin aged (ILA) chops and case-ready aged (CRA) chops. Loins (288 total) were selected to fill a matrix that varied in visual color and marbling. Loins were assigned to 1 of 2 packaging treatments (n = 144): ILA or CRA. Loins assigned as ILA remained vacuum-packaged at 4°C until 12 d PM, sliced and chop surface was evaluated. Loins assigned to CRA were sliced into 28-mm thick chops at 2 d PM, packaged in individual Styrofoam trays overwrapped in polyvinyl-chloride (PVC) film, and gas flushed in bulk packages. Quality parameters of packaging treatments at early and aged time points were compared as a randomized complete block design. Pearson correlation coefficients between early and aged quality traits for packaging treatments were transformed using Fisher’s r to z transformation for independent correlation comparisons of packaging treatments. Chops from ILA were darker and redder at 12 d PM than CRA chops (P &lt; 0.0001). Lightness and redness values on ventral surface for ILA loins (r = 0.52 lightness; r = 0.63 redness) and CRA loins (r = 0.45 lightness; r = 0.61 redness) at 1 d PM were both correlated with aged lightness and redness values on aged chop face at 12 d PM and the correlations did not differ (P ≥ 0.43) for either trait. Overall, aging intact loins in vacuum-packaging improved color after 12 d of aging compared with aging chops in case-ready packaging. Despite the differences between aging methods, the correlations between early and aged loin quality didn’t differ.

Predicting Pork Quality Measures at the 10th Rib Using Measurements Collected from Various Locations on the Boneless Loin

ObjectivesMany U.S. pork export markets demand high quality pork with darker color and higher marbling content than domestic markets. Although, the U.S pork industry does not have a quality grade program through the USDA-Agricultural Marketing Service, application of voluntary quality grade standards may result in financial benefits to the pork industry as well as enhanced eating experiences for consumers. This study analyzed quality measurements collected at locations along the surfaces of boneless pork loins to determine the relationship between these measures and traditional pork quality measures collected at the 10th rib.Materials and MethodsMarket hogs (n = 83) from 2 genetic lines and 2 sexes were slaughtered at 113.4, 136.1, and 158.8 kg endpoints. One genetic line was selected for increased lean yield, while the other was selected for meat quality attributes. Seven litters from each line with at least 6 pigs (3 barrows and 3 gilts) were used in the study. When the pigs reached their preassigned endpoint, they were transported to the University of Georgia Meat Science and Technology Center and slaughtered under federal inspection. Following a 24-hr chill period, carcasses were ribbed between the 10th and 11th ribs, bloomed for 20 min and the following pork quality attributes were measured on 10th rib surface: Hunter L*, a*, b* (D65); Minolta L*, a*, b* (D65); and NPPC color and marbling score. Carcasses were then fabricated and the boneless loin (IMPS# 413C, trimmed to 0.64 cm of fat) was weighed. The loin was allowed to bloom, ventral side up, for at least 20 min before collection of the previously listed loin quality attributes collected at the following 5 locations anterior to posterior: blade-end and sirloin-end (cross-section), and at approximately the 7th/8th rib, 12th/13th rib, and first/second lumbar regions on the ventral surface of the loin.ResultsThese locations were evaluated since they would allow assessment of quality attributes without devaluing the loin. Pearson correlations were calculated between 10th rib color and marbling scores and all other loin measures and Max R2 regression was used to determine the best variables to predict 10th rib color and marbling scores (SAS Inst. Inc., Cary, NC). Sirloin end marbling score had the strongest correlation with 10th rib marbling score (r = 0.78; P < 0.01), followed closely by the 7th/8th rib location on the ventral surface (r = 0.77; P < 0.01). Instrumental L* values were more highly correlated to 10th rib color than subjective color scores. For regression, subjective measures collected on the ventral surface of the loin were better predictors of 10th rib marbling score (R2 = 0.61) than 10th rib color score (R2 = 0.30), with marbling score and color score collected at the 7th/8th rib region being the most valuable predictor. Inclusion of all subjective measures slightly increased the prediction accuracy for 10th rib marbling score (R2 = 0.71) and 10th rib color score (R2 = 0.35). In contrast, instrumental measures were better predictors of 10th rib color (R2 > 0.41) than 10th rib marbling score (R2 < 0.29).ConclusionThese results suggest that the U.S. pork industry could use measures on the intact loin to predict 10th rib color and marbling scores, providing the potential to sort loins into quality-based grades.

Tenderization of beef loins using a high efficiency sparker

Abstract The tenderizing effects of treating beef loins with high-pressure shockwaves from a sparker source were evaluated. Samples were sparker treated as either steaks or intact loin roasts on day 0 and Warner–Bratzler shear force (WBSF) was measured on days 0 and 7. With the sparker head 7.5-cm above the samples, non-aged steaks receiving 80 pulses at two locations had lower WBSF than controls. Aging decreased WBSF in all samples. With the sparker head set at 3.75-cm, treated samples exhibited 20–25% lower WBSF values than controls on day 0 and all of the treated samples demonstrated WBSF reductions > 10%. Samples treated as individual steaks and intact loin roasts had similar tenderness improvements. The maximum observed tenderness improvements were 37% (entire steak), 56% (medial portion of steak), and 31% (lateral portion of steak). Data from this study indicate that high-pressure shockwaves generated from a sparker source are an effective postharvest technology for tenderizing beef. Industrial relevance Improving meat tenderness is essential to enhancing the value and consumer appeal of inferior quality meat cuts. Demonstrating the ability to tenderize tough cuts of meat using sparker generated high-pressure shockwaves is an important step in providing the meat industry with an effective postharvest technology for improving product quality.

Intramuscular fat content has little influence on the eating quality of fresh pork loin chops1

Fresh pork loins (n = 290) were selected from a commercial packing facility based on subjective marbling of the intact loin and 24-h pH to determine the influence of marbling on sensory attributes. The study was designed using pigs from a similar genetic background, raised in similar production facilities, and slaughtered on a single kill day to minimize the effects of genetics, management, environment, and slaughter day. Loins were vacuum-packaged, transported to the University of Illinois Meat Science Laboratory, and aged for 7 d, after which a chop was removed from the area of the tenth rib for proximate analysis. Quality measurements, including National Pork Producers Council color, marbling, and firmness, ultimate pH, Minolta L*, a*, and b*, and drip loss, were determined after aging. After the proximate composition was completed, 150 loins were selected to provide a continuous and uniform distribution of extractable lipid, ranging from 1 to 8%, and a pH range from 5.5 to 5.8. Trained sensory panel analyses (end point cooking temperatures of 62, 71, or 80 degrees C) as well as measurement of Warner-Bratzler shear force (cooked to 71 degrees C) were performed on chops from the 150 loins. Consumer evaluation was also conducted on a subset (n = 40) of these loins, which were broken down into 5 discrete levels of intramuscular lipid, with averages of 1.6, 2.5, 3.6, 4.5, and 5.7% extractable lipid. Consumers were also asked to select the chops they would most prefer from a retail display case based on the amount of marbling present. Results from the consumer portion of the study indicated that intramuscular fat content had limited effects on perceived tenderness, juiciness, pork flavor, and oiliness; some significant differences (P < 0.05) were detectable, but they were numerically small. Most consumers also selected lean chops from the retail case, with nearly 50% selecting chops with less than 1.7% extractable lipid. Warner-Bratzler shear force was negatively related (P < 0.0001) to extractable lipid, with an R(2) value of 0.10. Results from the trained panel sensory analysis indicate that the percentage of extractable lipid did not correlate strongly with perceived tenderness, juiciness, or pork flavor for this group of pork loins that was controlled for genetics, pH, management, and day of slaughter.

Mineral analysis (Fe, Zn, Ca, Na, K) of fresh Iberian pork loin by near infrared reflectance spectrometry: Determination of Fe, Na and K with a remote fibre-optic reflectance probe

Near infrared spectrometry (NIRS) was used for the determination of the mineral concentrations of the elements iron, calcium, zinc, sodium and potassium in fresh samples of ground Iberian pork loin and for the determination of Fe, Na and K using a remote fibre-optic reflectance probe by direct application of the probe on intact loin. The regression method employed was the modified partial least squares (MPLS). The calibration results using 42 samples of ground pork loin had a corrected standard error of prediction (SEPC) and a correlation coefficient (RSQ) for Fe of 0.085 and 0.842; for Zn, 0.0097 and 0.695; for Ca, 0.101 and 0.761; for Na, 0.710 and 0.639 and for K, 4.414 and 0.781, respectively. The calibration results using NIR interactance with direct application to the same loin samples of a remote fibre-optic reflectance probe allowed the determination of the concentrations of Fe, Na and K, with SEPC and RSQ values of 0.084 and 0.898 for Fe; 0.698 and 0.757 for Na, and 6.760 and 0.775 for K. The robustness of the method was confirmed by applying it to eight samples of loin (ground and intact) for external validation.

STORAGE LIFE OF PRE‐CUT, REFORMED, VACUUM PACKAGED LAMB LOINS

ABSTRACTThirty‐two lamb loins were cut into retail chops, the chops were stacked together to reform the original configuration of the primal cut and the pre‐cut, reformed loins were vacuum packaged. The 32 pre‐cut, reformed, vacuum packaged loins and 32 intact, vacuum packaged loins were transported‐stored at 0–2°C for 7, 14, 21 or 28 days. Following storage, one retail chop from each of the 64 loins was displayed under retail conditions for 4 days. Chops from pre‐cut, reformed loins stored for. 14–28 days sustained greater (P &lt; 0.05) surface discoloration and were less desirable (P &lt; 0.05) in overall appearance than chops from intact loins. Chops from pre‐cut, reformed loins stored for 21 or 28 days had a higher (P &lt; 0.05) incidence of off‐odor than chops from intact loins. If transport‐storage intervals of 14 days or longer are needed to distribute lamb loins, pre‐cutting of chops and distribution as reformed, vacuum packaged loins cannot be recommended.