Pork Quality Attributes Research Articles

Consumers’ purchasing behaviour and quality preferences for pork sold in the informal street markets of the Cape Metropole, South Africa

ABSTRACT This study evaluated the factors influencing the purchasing behaviour and pork quality preferences of 211 consumers in the Cape Metropole District, South Africa. Two-thirds of the participants bought cooked pork from the informal street markets because of affordability (36%), convenience (34%), and price (41%). Most consumers preferred grilled (87%), well done (68%) and bone-in (57%) meat of moderate lean thickness (48%). Cut type (33% of consumers) and taste (52%) were the most important pork quality indicators. Prior to purchasing pork, 70% of consumers performed a safety assessment, mostly based on pork appearance (40%). Two-thirds of consumers indicated their willingness to pay more for safe pork. Marginal effects from logistic regression showed that the likelihood of consumers to assess pork safety was positively influenced (P ≤ 0.05) by gender and education level, while the source of income, income class, and education level positively influenced (P ≤ 0.05) consumers' willingness to pay more for safe pork. Findings suggest that policy and development interventions by the government and municipalities to match quality attributes of pork to the preferences of consumers in the informal urban street markets should target specific sub-groups of the population, particularly females, low-income earners and the less educated.

Evaluation of Pork Quality and Carcass Attributes in Growing Pigs Fed Processed Avocado (Persea americana) Seed Meal

With the escalating prices of conventional feed ingredients, there is an urgent requirement to investigate sustainable alternatives that have the potential to improve performance, carcass yield, and meat quality. Twenty-four growing pigs (mixed sexes) were utilized to assess the carcass and sensory attributes of pork derived from pigs fed a diet incorporating processed Avocado (Persea americana) seed meal. The pigs were divided into four groups of six, and further replicated thrice with two pigs each, following a completely randomized design. The feeding trial spanned 70 days, during which the pigs were randomly allocated to one of the four dietary treatments containing 0 %, 2.5 %, 5 %, and 7.5 %, and designated as T1, T2, T3, and T4 respectively. At the end of the study, eight pigs (two per treatment) were randomly selected for carcass assessment. The results revealed a noteworthy increase in carcass yield with significant differences (p<0.05) between pigs in treatment 3, followed by treatments 2 and 4, which did not exhibit significant differences (p>0.05), whereas pigs in treatment 1 displayed the lowest carcass yield. Significant differences (p<0.05) were observed in primal cuts (except for the chump chop), with treatment 3 yielding the highest values, followed by treatments 2, 1, and 4, respectively. Organ weights showed no significant differences (p>0.05), suggesting that the inclusion of Avocado seed meal did not adversely affect the organs. There was a decrease in abdominal fat with increasing levels of Avocado seed meal, while the meat-to-bone ratio increased in treatment 3, followed by treatment 2, with treatment 1 exhibiting the least increase. The sensory evaluation revealed notable differences (p<0.05) in all assessed parameters, except for colour. Treatment 3 displayed significantly higher values across all parameters. Overall acceptability scores positioned treatment 3 as the highest, followed by treatment 2, while treatments 4 and 1 received the lowest scores. In conclusion, incorporating processed avocado seed meal at a 5% dietary inclusion level improved both the carcass attributes and sensory quality of pork.

Effects of slaughter weight on carcass characteristics, meat quality, and metabolomics profiling in the longissimus dorsi muscle of Tianfu finishing pigs.

In order to investigate the effect of slaughter weight (SW) on carcass characteristics and meat quality, we measured the carcass characteristics, meat quality, and amino acid metabolomics characteristics of longissimus dorsi (LD) muscle from Tianfu finishing (TF) pigs. Based on SW, 13 pigs were divided into three groups (100-kg group, 125-kg group, and 150-kg group with 3, 5, 5 pigs in each group, respectively). Raising SW to 125 kg or 150 kg increased average backfat thickness (P < 0.01) and intramuscular fat content (P < 0.01), and decreased shear force (P < 0.01). A total of 231 amino acid metabolome from three amino acid classes identified with metabolomics were analyzed, and 93 differentially expressed metabolites (DEMs) were identified (69 up-regulated DEMs and 24 down-regulated DEMs). The DEMs, including urea, 3-iodo-L-tyrosine, N-glycyl-L-leucine, and N, N-dimethylglycine with amino acid metabolism, were significantly induced (P < 0.01). KEGG pathway analysis showed that these DEMs were significantly enriched (P < 0.01) in 135 metabolism pathways, including pathways related to amino acid metabolism, such as arginine and proline metabolism, glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism, tryptophan metabolism, and beta-alanine metabolism. Our research findings provided new insights into the impact of SW on amino acid distribution and theoretical support for genetic breeding of meat quality of TF pigs. However, raising SW to 125 kg, or more, decreased the carcass leanness of live TF pigs and had no benefits to pork quality attributes.

Characterization of Growth Performance, Pork Quality, and Body Composition in Mangalica Pigs.

European heritage breeds, such as the Blonde (B), Red (R), and Swallow-bellied (SB) Mangalica pig, display an extreme propensity to fatten and are reputed to produce superior quality pork. This suggests that Mangalica pork should command a higher price, and the Mangalica is a candidate breed to target niche markets within the United States. Our objectives were to test this hypothesis by (1) directly comparing growth performance and carcass merit of purebred Yorkshire (Y), B, R, and SB Mangalica pigs to identify the best breed for adoption, and (2) comparing indices of pork quality in purebred R, Y, and crossbred (R × Y) pigs to determine if crossbreeding represented a viable alternative to the adoption of purebred Mangalica. Daily feed intake, average daily gain (ADG), and feed efficiency were highest in Y and lowest in SB pigs with B and R ranked intermediately (p < 0.001). Backfat thickness was greatest in B and lowest in Y with R and SB ranked intermediately (p < 0.001). Marbling score was greatest in R pigs and lowest in Y pigs with B and SB ranked intermediately (p < 0.01). In contrast, loin eye area (LEA) was greatest in Y pigs compared to B, R, and SB (p < 0.001). Indices of meat quality were then compared in R, R × Y, and Y pigs. Backfat thickness and marbling scores were greater in R than R × Y and Y pigs (p < 0.001) while LEA was greater in Y than R × Y and R pigs (p < 0.001). Loin and ham ultimate pH, color, and firmness scores were significantly greater in R than R × Y or Y pigs (p < 0.05). Meanwhile, cook loss was significantly less in R than Y pigs (p < 0.007) while Warner-Bratzler Shear Force (WBS) was not different in chops between groups (p < 0.11). These data indicate that though Mangalica exhibit poorer growth performance, Mangalica pork exhibits superior pork quality attributes, suggesting that higher price points for Mangalica pork in niche markets are justified.

Characterizing the sarcoplasmic proteome of aged pork chops classified by purge loss.

Unpredictable variation in quality, including fresh pork water-holding capacity, remains challenging to pork processors and customers. Defining the diverse factors that influence fresh pork water-holding capacity is necessary to make progress in refining pork quality prediction methods. The objective was to utilize liquid chromatography and mass spectrometry coupled with tandem mass tag (TMT) multiplexing to evaluate the sarcoplasmic proteome of aged pork loins classified by purge loss. Fresh commercial pork loins were collected, aged 12 or 14 d postmortem, and pork quality and sensory attributes were evaluated. Chops were classified into Low (N = 27, average purge = 0.33%), Intermediate (N = 27, average purge = 0.72%), or High (N = 27, average purge = 1.19%) chop purge groups. Proteins soluble in a low-ionic strength buffer were extracted, digested with trypsin, labeled with 11-plex isobaric TMT reagents, and detected using a Q-Exactive Mass Spectrometer. Between the Low and High purge groups, 40 proteins were differentially (P < 0.05) abundant. The Low purge group had a greater abundance of proteins classified as structural and contractile, sarcoplasmic reticulum and calcium regulating, chaperone, and citric acid cycle enzymes than the High purge group. The presence of myofibrillar proteins in the aged sarcoplasmic proteome is likely due to postmortem degradation. These observations support our hypothesis that pork chops with low purge have a greater abundance of structural proteins in the soluble protein fraction. Together, these and other proteins in the aged sarcoplasmic proteome may be biomarkers of pork water-holding capacity. Additional research should establish the utility of these proteins as biomarkers early postmortem and over subsequent aging periods.

Combining pig genetic and feeding strategies improves the sensory, nutritional and technological quality of pork in the context of relocation of feed resources

Genetic and feeding factors were combined to improve various quality attributes of pork. Thirty Duroc (D) and thirty Pietrain NN (P) female crossbreeds received a control (C) or an R diet including extruded faba bean and linseed, from 30 to 115 kg. Growth, feed efficiency and slaughter weight were higher for P vs. D pigs and for R vs. C pigs. D pigs had fatter carcasses than P, whereas feeding did not affect carcass fatness. Compared with P, loin meat from D pigs had lower drip, higher ultimate pH and lipid content, and higher marbling, tenderness and juiciness scores (P < 0.05). R feeding did not modify sensory traits but improved pork nutritional value by markedly reducing n-6:n-3 and saturated:n-3 fatty acid ratios (P < 0.001). Combining D genotype and R diet is a favorable strategy for sensory, nutritional, technological properties and societal image of pork through relocation of feed resources, but requires a better market valorization to be implemented.

PORK QUALITY AND GENETIC ASSOCIATION STUDY OF PORCINE LEPTIN AND CATHEPSIN F GENE POLYMORPHISMS

This study aims to assess the quality of raw pork intended for further processing, and also to analyse associations of genotypes, determined by single-nucleotide polymorphisms (SNPs) in leptin (LEP g.2845 A &gt; T) and cathepsin (CTSF g.22 C ≤ G ) genes, with meat and fat quality traits.&#x0D; Meat and fat products as raw materials for further processing, produced from pigs of French origin bred on the pig farm “Artsyz Meat Company Ltd” located in Artsyz district of Odesa region, are considered as the object of this study. The total number of pigs used to perform DNA analysis is 350 heads. DNA tests and physicochemical analyses of meat and fat products were conducted at the research laboratory of the Institute of Pig Breeding and Agricultural Production of the National Academy of Agrarian Sciences of Ukraine in Poltava. Genomic DNA was extracted from pig bristle using the Chelex 100 ion exchange resin. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping. Fattening pigs were assessed for leptin (LEP g.2845) and cathepsin F (CTSF g.22) genes. Upon the young stock’s reaching the target live weight of 100 kg, 60 pigs in each group genotyped for the target genes were slaughtered using conventional methods. The results of genetic tests and association studies performed have shown that leptin and cathepsin F gene polymorphisms produce an effect on particular pork and backfat quality attributes.&#x0D; Statistically significant associations of the genetic marker LEP SNP g.2845 A &gt; T with the investigated quality attributes of meat and fat products, in particular water-holding capacity, meat tenderness, intramuscular fat content, backfat moisture content and melting point, have been detected. Meanwhile, the genetic marker CTSF SNP g.22 C ≤ G is found to be associated with such pork quality attributes as water-holding capacity, tenderness, weight loss during thermal processing (cooking loss), intramuscular fat content, calcium and phosphorus levels, and energy value.

Quantification of the Effects of Electrical and CO2 Stunning on Selected Quality Attributes of Fresh Pork: A Meta-Analysis.

Simple SummaryStunning is an important and statutory pre-slaughter process that aims to induce a state of unconsciousness and insensibility to pain just before sticking and bleeding out. In Europe, two main stunning methods that are applied at pig slaughter are electrical (ES) and gas stunning with high-concentration carbon dioxide (CO2). Stunning is not only crucial in terms of the welfare of pigs at slaughter, but it may also have effects on meat quality. Various studies have compared these two methods with respect to meat-quality traits. In several studies, stunning with CO2 has been shown to improve meat quality in comparison with ES; however, other research indicated that ES enhanced the meat quality as opposed to CO2 or had no significant effect. The current study analysed the combined results of independent research and experiments to achieve quantitative evidence of the effects of two stunning methods, electrical and gas with a high concentration of carbon dioxide, on selected quality attributes of fresh pork. The results of the meta-analysis revealed that relative to CO2 stunning, overall, ES pigs had a lower pH1, higher drip loss (DL) and lightness (L*). However, the greater alterations in these traits were achieved with the application of the head-to-back (HB) electrical-stunning method and conventional chilling (Conv.) of the carcasses. The results of the meta-analysis provide evidence that differences between these two stunning methods in DL and L* may be diminished by the application of the head-only (HO) or head-to-body (HBO) method, followed by the fast chilling of the carcasses.Stunning is a statutory pre-slaughter process that may affect the quality of pork. The objective of this study was quantification of the effects of stunning (ES vs. CO2 stunning) on selected quality attributes of pork, using a meta-analytical approach. Data from 18 publications with 46 individual experiments were combined using a random-effect model to estimate the effect size of stunning on the initial and ultimate pH (pH1, pHu); drip loss (DL); colour (lightness—L*, redness—a*, yellowness—b*); and tenderness (expressed as Warner–Bratzler shear force, WBSF) of pork. In overall, loins from ES showed significantly lower pH1 (by 0.08 units); greater DL (by 0.68 p.p.); higher L* (by 1.29 units); and a* (by 0.80 units) as they compared to those from CO2 stunning. In subgroups, a greater-than-overall negative change in pH1, pHu, DL, L* and a* was detected with the application of the head-to-back (HB) stunning method. Additionally, alterations in DL and L* may be magnified with the application of conventional chilling (Conv.) to ES pigs. There was no effect of stunning on WBSF but, due to a low number of research in the database, the reliability of these results may be misleading. These results provide evidence that the differences between these two stunning methods in DL and L* may be diminished by the application of the head-only (HO) or head-to-body (HBO) method, followed by the fast chilling of carcasses.

The effect of straw based housing on selected quality attributes of pork – a meta-analysis.

&lt;b&gt;The aim of the research was to estimate the effect of straw-based housing on selected quality attributes of pork, using a meta-analytical approach. Meta-analysis is statistical procedure that combines the results of individual, independent studies into one common treatment effect, called the effect size. Data were extracted from 17 independent studies (20 experiments) and analysed using a random-effect model to estimate the effect of straw-based housing on the pH (initial pH at 45 min post mortem and ultimate pH), drip loss, colour (L*, a*, b*) and Warner-Bratzler shear force of pork loins. The meta-analysis of the available results showed that pigs from straw-based systems may produce pork with a faster early post-mortem pH decline (pH45), higher drip loss, and greater lightness than those reared under barren conditions with concrete (slatted) floors. A subgroup analysis showed that greater space allowance for straw-housed pigs had a greater negative effect on initial pH (pH45), drip loss, and lightness than straw housing with normal/minimal floor space requirements.

Alternative Protein Sources vs. GM Soybean Meal as Feedstuff for Pigs-Meat Quality and Health-Promoting Indicators.

Simple SummaryIn its slogan “International year of pulses” coined for 2016, the WHO has indicated trends in activities for future generations, these being “Nutritious seeds for a sustainable future”. Alternative sources of vegetable protein can be used in the conditions of sustainable development to produce high-quality animal products, including pork. One of the goals of the European Green Deal is to produce protein feedstuff in Europe and become independent from imported American soybeans. This study aimed to partially replace genetically-modified soybean meal (SBM GM) with alternative protein sources (pea seeds and rapeseeds meal—RSM) in feed mixtures for growing-finishing pigs and to determine its impact on meat quality and health-promoting indices. The SBM GM was the only protein source in feed mixtures for control pigs. In feed mixtures for experimental animals, it was replaced with increasing doses of pea seeds, i.e., 5.0, 10.0, 15.0, and 17.5% in groups E1, E2, E3, and E4, respectively. The doses were the same in both fattening stages. The feed mixtures were iso-energetic and iso-protein. After completed fattening, meat was determined for quality attributes, fatty acid profile, and values of health-promoting indices beneficial from the dietetic perspective. Values of the analyzed quality attributes of pork justify using alternative protein sources as partial SBM GM replacers in the feeding of growing pigs.This study aimed to explain the possibility of partial replacement of genetically-modified soybean meal (SBM GM) with pea seeds and rapeseed meal (RSM) in complete feed mixtures for growing-finishing pigs and to determine its impact on meat quality and health-promoting indices. The pigs (n = 50) were randomly divided into five groups, 10 animals each (gilts and barrows, 1:1, 3-breed: ♀ (landrace × yorkshire) × ♂ duroc), including the control group (C) and four experimental groups (E1, E2, E3, E4), and fed complete feed mixtures. The SBM GM was the only protein source in feed mixtures for control pigs. In feed mixtures for E1–E4 groups, it was partially replaced with pea seed doses of 5.0%, 10.0%, 15.0%, and 17.5% in groups E1, E2, E3, and E4, respectively. The feed mixtures were iso-energetic and iso-protein. After completed fattening, the animals were slaughtered. M. longissimus lumborum was sampled for analyses of the chemical and physical traits. The fatty acid profile determined in intramuscular fat (IMF) was used to compute the values of the health-promoting indices. The chemical and physical characteristics of meat were comparable in all groups. The study showed a dietetically-beneficial decrease in the values of atherogenicity index (AI), thrombogenicity index (TI), and saturation (S/P) in the meat of the experimental pigs vs. control group. The values of most of the analyzed quality attributes of pork justify using alternative protein sources as partial SBM GM replacers in diets for growing-finishing pigs in sustainable animal production.

Characterizing Pork Quality of Carcasses with an Average Weight of 119 Kg

ObjectivesBetween 1995 and 2018, average hot carcass weight of U.S. pork carcasses increased from 82 kg to 96 kg, which is an increase of approximately 17%. At current rates, pork carcasses in the U.S. will weigh on average, 105 kg by the year 2030 and over 118 kg by 2050. Although this represents an increase in throughput efficiency due to increases in economy of scale, projecting continued increases in the future raises some concerns. Therefore, the objective was to characterize pork quality of carcasses ranging from 78 to 145 kg with a mean weight of 119 kg.Materials and MethodsCarcass composition, such as hot carcass weight (HCW), back fat depth and loin depth were measured on 666 carcasses. Additionally, loin quality measurements, such as pH, loin instrumental and visual color, and iodine value of clear plate fat were measured on approximately 90% of the total population. Ham quality, 14 d aged loin and chop quality measurements, and loin chop slice shear force (SSF) were evaluated on approximately 30% of the total population. Finally, myosin heavy chain fiber type determination was completed on approximately 50 carcasses selected from carcasses ranging from 97 to 133 kg. The slope of regression lines and coefficients of determination between hot carcass weights and quality traits were calculated using the REG procedure in SAS and considered significantly different from 0 at P ≤ 0.05.ResultsAs HCW increased loin depth (b1 = 0.2496, P &lt; 0.0001), back fat depth (b1 = 0.1374, P &lt; 0.0001), loin weight (b1 = 0.0345, P &lt; 0.0001), chop weight (b1 = 1.6626, P &lt; 0.0001), and ham weight (b1 = 0.1044, P &lt; 0.0001) increased. There was a decrease in estimated lean (b1 = –0.0751, P &lt; 0.0001) and iodine value (b1 = –0.0923, P &lt; 0.0001) as carcass weight increased, however, HCW only accounted for ≤ 24% (R2 = 0.24) of the variation in estimated lean and iodine value. Additionally, there were no significant differences in gluteus medius pH (b1 = 0.0009, P = 0.30) or instrumental lightness (b1 = 0.0301, P = 0.15), redness (b1 = –0.0036, P = 0.73) or yellowness (b1 = 0.0058, P = 0.57) of the ham as carcass weight increased. As carcass weight increased, 1 d loin instrumental yellowness (b*) increased (b1 = 0.0092 P &lt; 0.01), however HCW only explained 1% of the variation in b*. Heavier carcasses were more tender (decreased SSF of chops cooked to 71°C, (b1 = –0.0674, P &lt; 0.0001), although HCW only explained 9% of the variation in SSF. Total cook loss of chops used for SSF determination decreased as HCW increased (b1 = –0.0512, P &lt; 0.0001), and HCW explained 15% (R2 = 0.15) of the variation in total cook loss. There were no significant differences in fiber type percentage, type 1 (b1 = –0.0170, P = 0.81), 2a (b1 = –0.0786, P = 0.23), 2x (b1 = –0.0201, P = 0.80), or 2b (b1 = 0.1224, P = 0.37), or fiber type area, type 1 (b1 = –26.6331, P = 0.22), 2a (b1 = –40.7257, P = 0.07), 2x (b1 = –46.9459, P = 0.25), or 2b (b1 = –26.2537, P = 0.38) as HCW increased.ConclusionDue to the lack of variation explained by HCW (≤ 15%), pork quality traits are not expected to be compromised as HCW continues to increase. The results suggest that increasing HCW to 119 kg did not have detrimental effects on pork quality attributes.

Correlation of Computer Vision System Data with Traditional Methods of Evaluating Pork Color and Marbling on the Ventral Side on the Whole Loin and on Individual Loin Chops

ObjectivesPork quality is a combination of many different attributes, including color, intramuscular fat percentage (IMF), pH, drip loss, and tenderness. Currently, in the pork industry, color and marbling of the whole loins are commonly assessed subjectively by a trained evaluator according to the National Pork Board’s color and marbling standard cards. However, subjective color (SCS) and marbling (SMS) scores can be influenced by lighting and evaluator fatigue. Colorimeters are a common technology that are utilized for measurement of color in the meat industry but have their limitations as they only measure a small portion of the surface and cannot separate lean and fat tissue. Ether extract is commonly used for crude fat determination, but it requires a longer time for analysis and a sample that will be consumed by the process. Computer vision system (CVS) is a technology that has been applied in the food industry and is a non-invasive, efficient, and consistent method. Therefore, the objectives of this study were to compare pork color and marbling measured from the whole loin versus its individual chops and to compare the results from different pork quality measurement methods on the same sample.Materials and MethodsWhole pork loins (n = 1400) were obtained from 6 major pork processing plants, with SCS, SMS, Hunter L, a, and b, and CVS images being collected on the ventral side of the loin in the plant. Samples were vacuum packed, shipped, and stored at 4°C for 14 d. Then whole loins were sliced into chops and the third (A) and 10th (B) rib chops were evaluated for SCS and SMS after a 10 min bloom. After SCS and SMS evaluation, Hunter L, a, and b, and CVS images were collected. The A and B chops were vacuum packaged, shipped, trimmed, freeze dried, and then evaluated for crude fat percentage (CF%) using ether extract method. The CF% of the whole loin was estimated as the average of the A and B chops. From the CVS images, lean and fat pixels were segmented to estimate L*, a*, and b* of the lean tissue and CVS IMF.ResultsA lower L* was found for both CVS and colorimeter when evaluating the whole loin (63.06 &amp; 53.63, respectively) compared to the average of A and B chops (68.65 &amp; 58.10, respectively). However, for SCS, individual chops, on average, were darker than the whole loin (2.88 vs. 2.67, respectively). Of all color measurements, Hunter L had the highest correlation when comparing the whole loin to A and B chops (r = 0.72 and 0.72, respectively). When comparing marbling results of the whole loin to the A and B chops, a moderate correlation was found using both SMS (r = 0.67 and 0.60, respectively) and CVS IMF (r = 0.52 and 0.54, respectively). When comparing methods, CVS L* had a stronger correlation with Hunter L than SCS for the whole loin and A and B chops. (r = 0.40 vs. 0.34, 0.82 vs. 0.47, and 0.84 vs. 0.40, respectively). For IMF, SMS had a stronger correlation with CF% than CVS IMF (r = 0.48 vs. 0.34, 0.62 vs. 0.39, and 0.54 vs. 0.38, respectively).ConclusionThese results show great potential for CVS to be used in evaluating pork quality, specifically color and marbling. Additionally, it is possible to predict individual chop color and marbling based on the ventral side of the loin. Further research should be conducted to look at more technologies that can predict pork quality attributes.

Consumers' Willingness to Pay for Food with Information on Animal Welfare, Lean Meat Essence Detection, and Traceability.

Amid high-profile food scares, health concerns and threats of information imperfection and asymmetry, the Chinese pork industry faces increasing demands from consumers for assurances regarding quality and production methods in both the domestic and export markets. Using a real choice experiment (RCE), 316 consumers in Wuxi, located in China’s Jiangsu Province, were randomly surveyed to examine the impact of various factors (e.g., traceability, lean meat essence testing, animal welfare, appearance, and price) on consumers’ preference and willingness to pay (WTP) for pork products. A random parameter logit model was estimated, and the results show that having a traceable code is the second important factor after price for consumers, corresponding to a WTP of 4.76 yuan per catty, followed by a bright red appearance, a national stocking density standard of animal welfare, and detected no lean meat essence, corresponding to a WTP of more than 2 yuan per catty. In addition, there is a complementary interrelationship between a traceable code and a bright red appearance, detected no lean meat essence, and a national stocking density standard of animal welfare. The results concerning the latent class model (LCM) indicate that 56.9% of consumers are “quality-focused” consumers who are willing to pay a high price for traceable code, detected no lean meat essence, a national stocking density standard of animal welfare, and bright red appearance attributes. A further 28.1% are “price-sensitive” consumers who pay significant attention to the price, and the price that they pay for each product is meagre. The consumers with “preference combination attributes” attach greater value to interaction attributes, such as a traceable code combined with detected no lean meat essence or a bright red appearance and detected no lean meat essence combined with a national stocking density standard of animal welfare or a bright red appearance, accounting for 15% of consumers. The government should improve the traceability system, increase the intensity of lean meat essence testing, promote the welfare level of pigs, and promote public education and publicity on pork quality and safety attributes. Meanwhile, enterprises can formulate “differentiated” pork products, according to different consumer groups, and appropriately increase prices, according to production costs, in order to meet the requirements for pork quality and safety for consumers.

Postmortem glycolysis and pork quality

After an animal is harvested for meat, the skeletal muscle initiates a myriad of biochemical pathways in an attempt to maintain energy homeostasis. Anaerobic glycolysis is responsible for the generation of ATP to help meet energy demand and for the decrease in pH by generating H+. Both the rate and the extent of the post-mortem pH decline are paramount in the context of the development of pork quality attributes, such as color, water holding capacity, and texture. Pale, soft and exudative meat and dark, firm, and dry meat are two of the major quality defects facing the pork meat industry. Because glycolysis has the potential to affect meat quality attributes either positively or negatively, evaluating its regulation post-mortem is fundamental to understanding meat quality. Therefore, the aim of this study was to evaluate factors that affect mechanism of glycolysis. Special consideration will be given to meat quality attributes and development of pork quality defects.

Real-time inspection of pork quality attributes using dual-band spectroscopy

The real-time determination of meat quality is important to both consumers and meat producers. In this study, a portable optical device was developed based on dual-band visible/near-infrared (Vis/NIR) spectroscopy to realize the real-time and simultaneous detection of multiple quality attributes of pork. A ‘response correction’ algorithm was proposed to fuse two separate spectral regions into a contiguous one that covers the entire Vis/NIR region. Then, partial least square regression (PLSR) models based on single and dual spectral regions for each attribute were developed and their results were compared. Finally, an improved competitive adaptive reweighted sampling algorithm (ICARS) was proposed to select specific wavelengths for each attribute. The optimized calibration models using these selected informative variables exhibited better performance than those with full band spectra. The results demonstrated that the developed device in tandem with the proposed algorithm could help realize the real-time detection of multiple quality attributes of meat.

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.

Evaluation of the Quality Characteristics of Premium Pork Loins

ObjectivesThe objective of this study was to determine the quality attributes of premium pork loins.Materials and MethodsPork loins (n = 30/treatment) from 5 premium (PRE A, B, C, D, and E) and 2 commodity brands (COM A and B), were purchased from food service purveyors and commercial abattoirs. Loins were fabricated at 14 or 15 d postmortem. Prior to fabrication, loins were weighed in the package to obtain an initial weight. After unpackaging, loins were dried and reweighed to determine the amount of purge lost during storage (PL). After unpackaging, L*, a* and b* values were collected on the ventral side of the loin using a Hunter Lab Miniscan spectrophotometer (Illuminant A, 2.54-cm aperture, 10° observer, Hunter Lab Associates Laboratory, Reston, VA). Each loin was evaluated for subjective color (SC) and marbling scores according to the National Pork Board Color and Marbling Standards. Loins were cut immediately posterior to the spinalis dorsi and the posterior end of the loin was used for all analyses. Loins were then fabricated into 2.54 cm chops. Chops were assigned to either: pH, instrumental (IC) and SC analysis, visual marbling (VM) and proximate analysis, Warner-Bratzler Shear force (WBSF), Slice Shear force (SSF) analysis or drip loss analysis. Chops designated for instrumental and visual color analysis were evaluated 30 min after slicing. Chops designated for WBSF and SSF were cooked on clam style grills to a peak temperature of 71°C.ResultsAll PRE brands were similar (P > 0.05) with lesser (P < 0.05) SSF values than COM A, with the exception of PRE C, which had greater (P < 0.05) SSF values than all other brands evaluated. Similar results were found for WBSF, with PRE C having greater (P < 0.05) WBSF values than all other treatments, and no difference (P > 0.05) found among the other PRE products. Commodity A was also tougher (P < 0.05) than all PRE brands, except PRE C for WBSF. For SC evaluations, the 2 COM products had a similar (P > 0.05) chop color score, however COM B, was lighter (P < 0.05) than all PRE brands. Loin SC was similar (P > 0.05) among all PRE brands, with only PRE C having a greater (P < 0.05) color score than PRE B. Commodity B had a lesser (P < 0.05) loin SC than all PRE products except PRE B and D. Also, COM B had a greater (P < 0.05) L* value and lesser (P < 0.05) a* value than all of the other brands. No difference (P > 0.05) in a* was found among the PRE brands and only PRE D and E differed (P < 0.05) for L*. Little variation was found among brands for pH, but COM B had a lesser (P < 0.05) pH than all of the other brands. Premium A and E had greater loin VM than all other brands, with no difference (P > 0.05) found among the 2 COM brands and the other 3 PRE brands. However, for chop VM, the 2 COM brands had less (P < 0.05) marbling than all PRE brands, except PRE B and C. For fat percentage, all brands had between 2 to 3% fat, with COM A having less (P < 0.05) fat than all PRE brands other than PRE B and D. Premium A, C and D had less (P < 0.05) weight lost as purge than any of the other brands.ConclusionThe differences observed within the quality traits evaluated show variation among different premium pork loin brands. This provides evidence that consumers and retailers will receive different levels of pork quality and eating satisfaction dependent on the premium brand purchased.

Eating quality traits of shoulder roast and stir fry cuts outperformed loin and silverside cuts sourced from entire and immunocastrated male pigs

This study investigated the effects of ageing period (2 or 7days), endpoint temperature (70 or 75°C), cut type (loin (M. longissimus thoracis et lumborum), silverside (M. biceps femoris), blade (M. triceps brachii) and chuck tender (M. supraspinatus)), cooking method (roast and stir fry (all cuts) and steak (loin only)) on eating quality attributes of pork from entire and immunocastrated male pigs. Higher intramuscular fat levels were found in all cuts from immunocastrated males compared with entire males. Of the seven cut type×cooking method combinations evaluated, shoulder cuts had the lowest fail rate (P<0.001) and loin steak and silverside cuts scored lowest (P<0.001) for tenderness, juiciness, overall liking, quality grade and re-purchase intention. Although no differences in sensory scores due to gender were observed, boar taint was identified in 10% of entire males. Minimising adverse risks in eating quality due to boar taint in males remains a key industry issue to ensure consistent delivery of high quality pork.

A systematic review and meta-analysis of tenderness metrics in control groups used in comparative nutrition experiments.

This review reports the pork quality attributes, Warner-Bratzler Shear Force, Slice Shear Force, Star Probe, pH, marbling, color (Minolta L*/L or Hunter L*/L), and sensory tenderness evaluation, in control groups used in comparative nutrition experiments over the past 20 yr. The original aim of this study was to evaluate if changes in pork quality based on the above metrics occurred over time. To address this question, it was anticipated that data may come from 3 sources with decreasing relevance: representative retail pork surveys, representative post-harvest carcass surveys, and control groups from comparative nutrition experiments. To identify the study population, a review of studies reported in Centre for Agricultural Biosciences International s (Web of Knowledge; 1994–2014) was conducted. Two national level surveys of retail pork and 146 relevant nutritional experiments studies, with 228 control groups, were identified by the search. It was not possible to conduct a meta-analysis of the retail pork surveys based on only 2 time points. For the comparative studies, a random effects meta-analysis was conducted with year as a covariate to assess the impact of time on the outcome. In the absence of modifiers, there was no evidence of meaningful change in the mean Warner-Bratzler Shear Force, pH, color, marbling, or sensory scores over the study period. There was evidence of substantial between-study heterogeneity in the characteristics of control pigs used over the years for Warner-Bratzler Shear Force and measures of color. The absence of publicly-available representative surveys of pork quality meant the changes in pork quality over time were not clear. If changes in pork quality have occurred, the data suggest that pigs used as controls in experiments may have become less representative of commercial pigs over time and the translatability of study findings from nutrition experiments might be reduced over time. Alternately, if commercial pigs have not changed, then control pigs reflect this. The study does not address if control groups in other experimental intervention studies had similar tenderness patterns as reported here for nutritional interventions. A large amount of potentially available data was excluded from the analysis due to incomplete reporting in the original study reports.

Identification of single nucleotide polymorphisms in carnosine-related genes and effects of genotypes on pork meat quality attributes

Carnosine has pH-buffering and antioxidant properties that may bring advantages in terms of meat quality attributes. This study aimed at identifying polymorphisms in carnosine-related genes (CARNS1, SLC6A6, SLC15A3, SLC15A4) that might associate with muscle carnosine content and meat quality traits in pigs (Duroc, Landrace, Yorkshire). Twenty seven SNPs were identified and association analyses performed for SLC15A3 c.*35C>T and c.*52C>T (3′ UTR region), and SLC15A4 c.658A>G (Ile220Val) and c.818G>A (Ser273Asn) SNPs. Associations were observed for SNP c.658A>G with carnosine content, color b* and L*, drip and cooking losses, pH24h and glycolytic potential values (P≤0.05). The same associations were observed for SNP c.818G>A, but they were not significant after FDR correction. Results suggest that specific SLC15A4 gene variants might increase muscle carnosine content and improve meat quality. With a minor allele frequency of 0.17 for SNP c.658A>G in Yorkshire pigs, selection in favor of the c.658A allele may be considered as a mean to improve pork quality attributes.