Shelf life of pork from five different quality classes

Characterization of Meat Metabolites and Lipids in Shanghai Local Pig Breeds Revealed by LC-MS-Based Method

The meat of local livestock breeds often has unique qualities and flavors. In this study, three Shanghai native pig breeds (MSZ, SWT, and SHB) exhibited better meat quality traits than globalized commercial pig breeds (DLY). Subsequently, metabolomic and lipidomic differences in the longissimus dorsi (L) and gluteus (T) muscles of the Shanghai native pig breeds and DLY pig breed were compared using liquid chromatography-mass spectrometry (LC-MS). The results demonstrated that the metabolites mainly consisted of (28.16%) lipids and lipid-like molecules, and (25.87%) organic acids and their derivatives were the two most dominant groups. Hundreds of differential expression metabolites were identified in every compared group, respectively. One-way ANOVA was applied to test the significance between multiple groups. Among the 20 most abundant differential metabolites, L-carnitine was significantly different in the muscles of the four pig breeds (p-value = 7.322 × 10-11). It was significantly higher in the L and T muscles of the two indigenous black pig breeds (MSZ and SWT) than in the DLY pigs (p-value < 0.001). Similarly, lipidomic analysis revealed the PA (18:0/18:2) was significantly more abundant in the muscle of these two black breeds than that in the DLY breed (p-value < 0.001). These specific metabolites and lipids might influence the meat quality and taste properties and lead to customer preferences. Therefore, this study provided insights into the characterization of meat metabolites and lipids in Shanghai native pig breeds.

Assessing the Effects of Cold Atmospheric Plasma on the Natural Microbiota and Quality of Pork during Storage

Cold atmospheric plasma (CAP) is a novel non-thermal technology with significant potential for use in meat processing to prolong shelf life. The objective of the study was to evaluate the efficiency of CAP treatment on the natural microbiota and quality traits of pork stored for 8 days at 4 °C. CAP treatment was applied by employing piezoelectric direct discharge technology to treat pork samples for 0, 3, 6, and 9 min. Reductions of approximately 0.8-1.7 log CFU/g were observed in total viable counts (TVC) and Pseudomonas spp. levels for CAP treatments longer than 3 min, immediately after treatment. A storage study revealed that CAP-treated pork (>6 min) had significantly lower levels of TVC, Pseudomonas spp., and Enterobacteriaceae throughout storage. Regarding quality traits, CAP application for longer than 3 min significantly increased water retention and yellowness and decreased meat redness compared to untreated pork. However, other parameters such as pH, tenderness, and lightness exhibited no statistically significant differences between untreated and CAP-treated pork. Lipid oxidation levels were higher only for the 9-min treatment compared to untreated pork. Our results revealed that CAP is a promising technology that can extend the microbiological shelf life of pork during refrigeration storage.

Wild boar captured in a large corral-style trap or hunted: preliminary comparison of meat quality traits

The management and numerical control of wild boars mainly depend on hunting practices, even if other alternative strategies such as the use of traps and cages can be adopted. There is little information available on the quality of captured wild boar meat. The aim of this study was to evaluate the meat quality of wild boars captured with a large corral-style trap compared to still hunting and collective hunting methods. Longissimus dorsi samples were collected from 60 wild boars, 20 of which were obtained by trapping, 20 by still hunting, and 20 by collective hunting. The animals considered were 32 males and 28 females, weighing between 42 and 68 kg. Muscle pH has been recorded at 1, 24, and 48 hours post-mortem. Furthermore, after 24 hours, color, drip loss, cooking loss, and Warner-Bratzler shear force were also evaluated. Trapping with large enclosures such as corral-style traps, if properly managed, does not seem to adversely affect the quality traits of wild boar meat, which were found to be like those obtained by the still hunting method.

Metabolomics Analysis Provides Novel Insights into the Difference in Meat Quality between Different Pig Breeds

The Chuanzang black (CB) pig is a new crossbred between Chinese local breeds and modern breeds. Here, we investigated the growth performance, plasma indexes, carcass traits, and meat quality characteristics of conventional DLY (Duroc × Landrace × Yorkshire) crossbreed and CB pigs. The LC-MS/MS-based metabolomics of pork from DLY and CB pigs, as well as the relationship between the changes in the metabolic spectrum and meat quality, were analyzed. In this study, CB pigs presented lower final body weight, average daily gain, carcass weight, and eye muscle area than DLY pigs (p ˂ 0.05). Conversely, the ratio of feed to gain, marbling score, and meat color score of longissimus dorsi (LD) were higher in CB than DLY pigs (p ˂ 0.05). Moreover, psoas major (PM) showed a higher meat color score and a lower cooking loss in CB than DLY pigs (p ˂ 0.05). Interestingly, CB pigs showed lower myofiber diameter and area but higher myofiber density than DLY pigs (p ˂ 0.05). Furthermore, the mRNA expression levels of MyHC I, PPARδ, MEF2C, NFATC1, and AMPKα1 were higher in CB than DLY pigs (p ˂ 0.05). Importantly, a total of 753 metabolites were detected in the two tissues (e.g., psoas major and longissimus dorsi) of CB and DLY pigs, of which the difference in metabolite profiles in psoas major between crossbreeds was greater than that in longissimus dorsi. Specifically, palmitic acid, stearic acid, L-aspartic acid, corticosterone, and tetrahydrocorticosterone were the most relevant metabolites of psoas major meat quality, and tetrahydrocorticosterone, L-Palmitoylcarnitine, arachidic acid, erucic acid, and 13Z,16Z-docosadienoic acid in longissimus dorsi meat were positively correlated with meat quality. The most significantly enriched KEGG pathways in psoas major and longissimus dorsi pork were galactose metabolism and purine metabolism, respectively. These results not only indicated improved meat quality in CB pigs as compared to DLY pigs but may also assist in rational target selection for nutritional intervention or genetic breeding in the swine industry.

Multi-Omics Reveals the Effect of Crossbreeding on Some Precursors of Flavor and Nutritional Quality of Pork

Over the last several decades, China has continuously introduced Duroc boars and used them as breeding boars. Although this crossbreeding method has increased pork production, it has affected pork quality. Nowadays, one of the primary goals of industrial breeding and production systems is to enhance the quality of meat. This research analyzed the molecular mechanisms that control the quality of pork and may be used as a guide for future efforts to enhance meat quality. The genetic mechanisms of cross-breeding for meat quality improvement were investigated by combining transcriptome and metabolome analysis, using Chinese native Jiaxing black (JXB) pigs and crossbred Duroc × Duroc × Berkshire × JXB (DDBJ) pigs. In the longissimus Dorsi muscle, the content of inosine monophosphate, polyunsaturated fatty acid, and amino acids were considerably higher in JXB pigs in contrast with that of DDBJ pigs, whereas DDBJ pigs have remarkably greater levels of polyunsaturated fatty acids than JXB pigs. Differentially expressed genes (DEGs) and differential metabolites were identified using transcriptomic and metabolomic KEGG enrichment analyses. Differential metabolites mainly include amino acids, fatty acids, and phospholipids. In addition, several DEGs that may explain differences in meat quality between the two pig types were found, including genes associated with the metabolism of lipids (e.g., DGKA, LIPG, and LPINI), fatty acid (e.g., ELOVL5, ELOVL4, and ACAT2), and amino acid (e.g., SLC7A2, SLC7A4). Combined with the DEGS-enriched signaling pathways, the regulatory mechanisms related to amino acids, fatty acids, and phospholipids were mapped. The abundant metabolic pathways and DEGs may provide insight into the specific molecular mechanism that regulates meat quality. Optimizing the composition of fatty acids, phospholipids, amino acids, and other compounds in pork is conducive to improving meat quality. Overall, these findings will provide useful information and further groundwork for enhancing the meat quality that may be achieved via hybrid breeding.

Slight Temperature Deviation during a 56-Day Storage Period Does Not Affect the Microbiota of Fresh Vacuum-Packed Pork Loins

It is profitable to export fresh meat overseas, where it is often regarded as a premium commodity. Meeting this demand for fresh meat, however, necessitates long export times, during which uncontrolled temperature increases can affect the microbiological quality of the meat and thereby, reduce shelf life or compromise food safety. To study the impact of temperature deviations on microbial community composition and diversity, we used 16S rRNA gene sequencing for Listeria monocytogenes and Salmonella spp. detection to describe the surface microbiota of eight batches of vacuum-packed loins stored at -1.5 °C (control) for 56 days and subjected to a 2 °C or 10 °C temperature deviation for a few hours (mimicking problems regularly encountered in the industry) at day 15 or 29. The presence of pathogens was negligible. The applied temperature deviations were not associated with different microbiota. Sequencing analysis showed the presence of Yersinia, an unexpected pathogen, and relative abundance increased in the groups subjected to temperature deviations. Over time, Lactobacillales_unclassified genus became the main constituent of the microbiota of vacuum-packed pork loins. Although the microbiota of the eight batches appeared similar at the beginning of storage, differences were revealed after 56 days, suggesting unequal aging of the microbiota.

Integrative metabolomic and transcriptomic analysis reveals difference in glucose and lipid metabolism in the longissimus muscle of Luchuan and Duroc pigs

Luchuan pig, an obese indigenous Chinese porcine breed, has a desirable meat quality and reproductive capacity. Duroc, a traditional western breed, shows a faster growth rate, high feed efficiency and high lean meat rate. Given the unique features these two porcine breeds have, it is of interest to investigate the underlying molecular mechanisms behind their distinctive nature. In this study, the metabolic and transcriptomic profiles of longissimus dorsi muscle from Duroc and Luchuan pigs were compared. A total of 609 metabolites were identified, 77 of which were significantly decreased in Luchuan compared to Duroc, and 71 of which were significantly elevated. Most differentially accumulated metabolites (DAMs) upregulated in Luchuan were glycerophospholipids, fatty acids, oxidized lipids, alcohols, and amines, while metabolites downregulated in Luchuan were mostly amino acids, organic acids and nucleic acids, bile acids and hormones. From our RNA-sequencing (RNA-seq) data we identified a total of 3638 differentially expressed genes (DEGs), 1802 upregulated and 1836 downregulated in Luchuan skeletal muscle compared to Duroc. Combined multivariate and pathway enrichment analyses of metabolome and transcriptome results revealed that many of the DEGs and DAMs are associated with critical energy metabolic pathways, especially those related to glucose and lipid metabolism. We examined the expression of important DEGs in two pathways, AMP-activated protein kinase (AMPK) signaling pathway and fructose and mannose metabolism, using Real-Time Quantitative Reverse Transcription PCR (qRT-PCR). Genes related to glucose uptake, glycolysis, glycogen synthesis, fatty acid synthesis (PFKFB1, PFKFB4, MPI, TPI1, GYS1, SLC2A4, FASN, IRS1, ULK1) are more activated in Luchuan, while genes related to fatty acid oxidation, cholesterol synthesis (CPT1A, HMGCR, FOXO3) are more suppressed. Energy utilization can be a decisive factor to the distinctive metabolic, physiological and nutritional characteristics in skeletal muscle of the two breeds we studied. Our research may facilitate future porcine breeding projects and can be used to reveal the potential molecular basis of differences in complex traits between various breeds.

The relationship between pH of pH-model beef and impedance measured using touch-type electrodes

Meat pH affects its color, texture, and water-holding capacity; however, a method for nondestructively distinguishing high-pH from normal-pH meat is unknown. We investigated the method of preparing an extensive pH-model of beef immersed in different pH buffers and the relationship between pH of the pH-model beef and impedance, measured using touch-type electrodes. The results showed that a model beef of pH 4.91-6.39 could be obtained when a beef steak (pH 5.68) was immersed in a solution of pH 4.0-7.0. In addition, we found a significant negative correlation between immersion pH and drip loss, and between immersion pH and impedance measured at 50 kHz (P < 0.01). These results provide an estimation equation (y = -16.5x + 195.3) that can be used to nondestructively determine the pH (x) of pH-model beef by measuring its impedance (y) using touch-type electrodes at 50 kHz (P < 0.01). Hence, the study shows the possibility of nondestructively estimating the pH of pH model beef by measuring impedance using touch-type electrodes.

Prevalence of gross lesions and handling practices in pigs and their association with pork quality, Kiambu, Kenya

Pre-slaughter handling of pigs has been documented to affect the quality of meat though no studies have investigated this relationship in the Kenyan context. This study aimed to determine the prevalence of gross lesions and practices related to sub-optimal welfare in pigs presented for slaughter while analyzing the relationship between occurrence of these lesions and meat quality. A cross-sectional study was conducted at a medium scale, non-integrated pig abattoir supplying to the Nairobi market, with a capacity to slaughter approximately 40 pigs a day. Data on welfare-associated lesions and handling practices were obtained from 529 pig carcasses and traders respectively. 387 pork samples were collected, and their quality evaluated by measuring their pH, meat color and drip loss. These three parameters were used to classify pork into four recognized categories namely: Red, Firm, Non-exudative (RFN), Pale Soft Exudative (PSE), Dark Firm Dry (DFD) and Red Soft Exudative (RSE). Almost all pigs were inefficiently stunned as evidenced by the presence of consciousness post-stunning. The majority of pigs (82.97%) having one or more welfare-associated gross lesions. Other animal welfare malpractices observed were high loading density and inadequate rest periods between transport and slaughter. A quarter of the pork samples were of sub-optimal quality including: RSE (11.36%), PSE (2.58%) and DFD (2.58%). Multinomial logistic regression revealed that pork originating from pigs transported at a high loading density had increased odds of being classified as DFD (OR 13.41, 95% CI 2.59-69.46). The findings indicate the need to educate stakeholders in the pork value chains on improved pig handling before and during slaughter to enhance pig welfare pre-slaughter and pork quality post-slaughter. Animal welfare legislation enforcement and implementation was observed to be insufficient. There is a need to educate key stakeholders on its importance of being put into practice both from economic and welfare perspectives.

The Impact of Premortality Stress on Some Quality Parameters of Roe Deer, Wild Boar, and Red Deer Meat

The specifics of meat production from free-ranging animals include the killing of animals in the wild with firearms. This type of uncontrolled killing sometimes leads to the phenomenon that the game does not die immediately but after a certain time from the shot to death, which may ultimately affect the quality of the meat. During one hunting year on free-ranging red deer (Cervus elaphus) (RD), roe deer (Capreolus capreolus) (RoD), and wild boar (Sus scrofa) (WB), the effect of time from shot to death on final pH, water-holding capacity (WHC), water content, and colour (L*, a*, b*) was investigated. All analyses were performed on Musculus biceps femoris (BF). After shooting, the animals were divided into two categories (A = time from shot to death ≤ 1 min; B = time from shot to death > 1 min). In RD, group B had significantly lower (p < 0.05) water content. In RoD, group B had significantly lower (p < 0.05) values of L* and b*. In WB, group B had significantly lower (p < 0.05) L* value and significantly higher (p < 0.05) pH value. The study proves that in BF of the three studied game species, the time extension from shot to death significantly affects the final water content values in RD, L* and b* in RoD and pH and L * in WB.

Effect of oregano oil and cranberry pulp supplementation in finishing pigs on the physicochemical quality of fresh loin during storage

Oregano oil and cranberry pulp supplements were added to the diets of finishing pigs to determine their effects on the meat quality of fresh loins during storage. Two and three levels of oregano oil (250 and 500 mg·kg−1) and cranberry pulp (5, 10, and 20 g·kg−1) were tested, according to a factorial experimental design. The loin meat was vacuum packed and analyzed at 0 (after the 24 h chilling period post slaughter), 23, 45, and 60 d of storage. Samples were repackaged under aerobic conditions after 0 or 23 d and analyzed after 4, 8, and 12 d. Oregano and cranberry supplements did not affect lipid oxidation (microgram of malondialdehyde equivalent per kilogram of meat) during anaerobic or aerobic storage. On day 0, the fatty acid profile of the loin samples demonstrated that the addition of cranberries at a dose of 10 g·kg−1 was associated with a lower percentage of saturated fatty acids (P = 0.04; 42.97% vs. 40.99%) and a trend for a higher percentage of monounsaturated fatty acids (P = 0.06; 47.26% vs. 46.09%). Considering the result obtained, feeding pigs with oregano and cranberry supplements had a limited effect on meat quality parameters measured during storage.

Effect of immersion in low‐pH solution on physicochemical properties of high‐pH venison

The color of venison observed at a high-pH is not preferred by consumers. However, the physicochemical properties of venison soaked in a low-pH solution to lower its high-pH are unknown. We investigated the effect of immersion in a low-pH solution on the physicochemical properties of a high-pH venison. The pH of M. longissimus thoracis from seven female wild deer (Cervus nippon) was measured and divided into normal-pH venison and high-pH venison groups. The a* and b* values for high-pH venison were lower than those for normal-pH venison before storage. There was no significant difference in the pH between high-pH venison immersed in a pH 4 solution and normal-pH venison stored. The drip loss of immersed high-pH venison was significantly lower than that of normal-pH venison and high-pH venison. Cooking loss and total loss were the lowest for normal-pH venison and the highest for immersed high-pH venison. The maximum load between normal-pH venison, high-pH venison, and immersed high-pH venison did not differ significantly. Our work showed that meat color became favorable by immersing high-pH venison in a solution of pH 4, followed by heating.

Prediction and Experimental Verification of a Hierarchical Transcription Factor Regulatory Network of Porcine Myoglobin (Mb)

Myoglobin is a key chemical component that determines meat's color and affects consumers' purchase intentions. In this work, we firstly identified the promoter sequence of the Mb gene from the primary assembly of high-throughput genome sequencing in pigs, and predicted its potential transcription factors by LASAGNA. Through the data mining of the mRNA expression profile of longissimus dorsi muscle of different pig breeds, we constructed a hierarchical interplay network of Mb-TFs (Myoglobin-Transcription Factors), consisting of 16 adaptive transcription factors and 23 secondary transcription factors. The verification of gene expression in longissimus dorsi muscle showed that the Mb mRNA and encoded protein were significantly (p < 0.05) more abundant in Bama pigs than Yorkshire pigs. The qRT-PCR (Real-Time Quantitative Reverse Transcription PCR) validation on genes of the Mb-TFs network showed that FOS, STAT3, STAT1, NEFL21, NFE2L2 and MAFB were significant positive regulatory core transcription factors of Mb-TFs network in Bama pigs, whereas ATF3 was the secondary transcription factor most responsible for the activation of the above transcription factors. Our study provides a new strategy to unravel the mechanism of pork color formation, based on public transcriptome and genome data analysis.

Hierarchical clustering as a tool to develop a classification scheme for rabbit meat quality

<p>This study aimed to characterise the quality of meat from commercially-raised rabbits. Animals came from five different producers and were  laughtered in three different plants under provincial or federal inspection jurisdiction. Animal behaviour evaluated by scan sampling prior to feed withdrawal (FW) and transport, as well as blood lactate concentration at exsanguination, did not raise concerns with respect to stress. Stomach pH was higher (<em>P</em>=0.047) when the FW time was short (≤13.5 h), at a mean value of 2.23. All pH values measured 1 h post-mortem from the Biceps femoris (BF) and almost all (97.6%) from the Longissimus lumborum (LL) were higher than 6. Values for ultimate pH measured 24 h postmortem(pH_u) ranged from 5.80 to 6.83 and from 5.70 to 6.70 for BF and LL muscles, respectively. The maximum meat drip loss recorded was 2.6%, while cooking loss reached 30%. Meat lightness (L*) and colour intensity (C*) for the long FW times (≥23 h) were no different from those with short and intermediate (15.5 to 17.3 h) FW times. However, these colour parameters were higher for the short FW time class compared to the intermediate FW time class (<em>P</em>&lt;0.02). A hierarchical cluster analysis based on pH_u, cooking loss and lightness (L*) from 200 rabbit loins was performed. Of the four clusters created, clusters 1 and 2 had the best and second-best meat quality, respectively. Clusters 3 and 4 had the lowest meat quality and presented DFD-like (dark, firm and dry) characteristics. Meat did not exhibit PSE-like (pale, soft, exudative) characteristics, even for the slaughter lot with the minimum mean pH_u. Of the eight slaughter lots evaluated, more than 50% of the meat from three of them fell into clusters 3 and 4; all three were in the intermediate FW time class. Overall, the quality of rabbit meat analysed was acceptable for commercial use, but rather variable. This suggests that there are factors within the value chain that are not yet fully controlled and require further investigation.</p>

The influence of age and gender on the quality of raw and roasted wild boars (Sus scrofa) meat

The aim of this study was to determine the influence of age and gender on the chemical composition, colour, texture and sensory attributes of wild boars meat (Sus scrofa, n = 48). The animals were analysed in 6 groups (n = 8), differed in age (piglets below 1 year, yearlings 1-2 years, and adults over 2 years) and gender (male and female). Protein content in raw meat was affected by age, whereas in roasted meat by animals gender. Colour parameters, excluding lightness, were affected by animals age and values of a*, b* and C increased along the animal age. Roasted meat from piglets showed the lowest hardness and chewiness in TPA test, however shear force was similar for piglets and yearling, yet lower than adults. Age affected sensory quality of roasted meat and meat from yearlings was scored higher than from adults. The results of the study clearly indicate the predominant influence of wild boar age over gender on the meat quality.

The effects of feeding finishing pigs of two genders with a high fiber and high fat diet on muscle glycolytic potential at slaughter and meat quality

A total of 160 pigs, in groups of 8 pigs of mixed genders, were fed four finishing feeding strategies with the aim to reduce muscle glycolytic potential and improve meat quality. Pigs were fed a control diet (C; fat = 5.0%, ADF = 3.0%, NDF = 8.8%), a high-fat and high-fiber diet (HFF; fat = 11.2%, ADF = 9.1%, NDF = 19.5%), a blend of 50-50% C and HFF diets (fat = 8.2%, ADF = 6.7%, NDF = 14.2%) or the C diet and transferred to the HFF diet after a diet transition. Dietary treatments alone or in interaction with gender had no effect on pig growth performance, carcass quality traits, Longissimus and Semimembranosus muscle glycolytic potential and meat quality (P > 0.10). The inefficiency of the dietary treatments applied in this study may be due to the low ratio between fat and digestible carbohydrate in the diets combined with the mild pre-slaughter stress conditions pigs were exposed to.

Incidence of pale, soft and exudative (PSE) pork meat in reason of extrinsic stress factors

The incidence of PSE (pale, soft and exudative) pork meat is directly influenced by pre-slaughter handling of animals, compromising meat quality and resulting in economic losses for industry. Considering management, the main extrinsic stress factors are: the pre-slaughter rest time in lairage, the total fasting time and at farm and the transport time. To evaluate the effects of these factors on PSE meat incidence, pH of 1038 carcasses was measured at 45 minutes post mortem (pH45) in a pig slaughterhouse in Paraná, Brazil. Carcasses with pH45≤5.8 were classified as PSE, and those with pH45>5.8 as normal. In order to verify if the factors influence PSE meat appearance, it was divided into categories according to it duration, and according to the number of animals evaluated in each category, the PSE meat frequency was estimated, and which time intervals obtained the lower incidence of the change. The total incidence of PSE carcasses was 19.17%. The periods of rest in lairage, total fasting, fasting at farm and transport that minimized the occurrence of PSE meat were from 04h01 to seven hours, from 14h01 to 17h00, from 03h01 to five hours, and from 02h01 to three hours, respectively.

Impacts of heat stress on meat quality and strategies for amelioration: a review

During the summer, high ambient temperature and humidity cause economic loss to the global livestock industry via reduced livestock productivity and increased mortality. The problem of heat stress (HS) is likely to be exacerbated by global warming and climate change. Recent research has shown that HS not only leads to physiological and metabolic perturbations in live animals but can also affect carcass and meat quality characteristics plausibly by altering the rate and extent of postmortem muscle glycolysis and resultant pH. However, these impacts of HS are not consistent across species. Higher incidence of pale soft and exudative (PSE) meat has been reported in poultry. On the contrary, higher incidence of high ultimate pH and dark firm and dry (DFD) meat or no impacts of HS have been reported in sheep and cattle. With the limited data on HS impacts on meat quality of ruminants, it is difficult to explain the exact mechanisms driving these variable impacts. However, it is hypothesized that the severity and duration of HS may lead to variable impacts due to lack of opportunity to adapdate to acute heat exposure. Longer HS exposure may allow ruminants to adapdate to heat and may not record any negative impacts on meat quality. This paper reviews the recent research on impacts of HS on meat quality characteristics and identify the key areas of further research required to better understand these negative impacts to develop strategies for amelioration. In addition, some mitigation strategies of HS have also been discussed which include both managemental and nutritional interventions.

Shelf-Life Prediction Model of Chitosan Coated Eggs at Different Storage Temperatures

In order to study the quality changes and shelf life of chitosan coated eggs during storage, the quality, gas chamber diameter, yolk coefficient and the quality change of Hough unit during storage were measured at temperature of 5, 20 and 35 ℃. The Pearson correlation between the quality indexes and the egg Hough’s unit value was analyzed, and the yolk coefficient was analyzed dynamically and the shelf life prediction model was based on the basis of the Arrhenius equation. The results showed that the quality of eggs, egg yolk coefficient, and Huff units all decreased with the extension of storage time, and the diameter of the air chambers of eggs showed an increasing trend with the extension of storage time. Moreover, the storage environment at high temperature (20 and 35 ℃) had a significant effect on the quality deterioration than the low temperature (5℃) storage environment; The correlation coefficient between egg yolk coefficient and Hough unit is the highest at all temperatures, which can be used as an important indicator for shelf life prediction; According to the changing rule of egg quality, the yolk coefficient can establish a first order kinetic model. According to the model established by the egg yolk coefficient, the coefficient R2 of the fitting curve of the predicted value and the measured value is 0.9825, and the average relative error P is 9.32% and less than 10%. The kinetic relationship between yolk coefficient and temperature is well described. At the same time, based on the dynamic model, the shelf life prediction model of chitosan-coated eggs based on yolk coefficient was determined by the dynamic model. The average relative error was 7.6%, less than 10%, which indicated that the egg shelf life prediction model based on the change of egg yolk coefficient was feasible.

The effect of age and ultimate pH value on selected quality traits of meat from wild boar

The meat from hunted wild boar juveniles (N = 18) and yearlings (N = 17) was analysed to assess the influence of age and the ultimate pH value on selected quality traits. The analysed meat of 55.56% of the juveniles and 64.71% of the yearlings was characterised with normal pH. The pH had been measured 24 and 48 h post mortem. More cases of high ultimate pH (pHu > 5.8) and high maximal pH (about 6.2) have been noted in the meat of younger animals compared with older ones. We found no effect of pHu on the colour coordinates of analysed wild boar meat. A slight effect of age was observed for the lightness (L*) coordinate. The postmortem time was the most important factor influencing meat colour [L*, yellowness (b*), and hue angle]. A high pHu was related to lower drip loss (P = 0.001), lower percentage of free water (P = 0.036), lower cooking loss (P = 0.001), and lower plasticity (P = 0.042). The meat from juveniles showed higher plasticity than meat from yearlings. Summing up, both the pHu level and the age of wild boars may affect some qualitative patterns of meat, changing the technological usability of this raw animal product.

Influence of the method of storage on the quality of venison from wild fallow deer (Dama dama)

The quality of two muscles (musculus longissimus lumborum and musculus semimembranosus) was studied in a group of 15 wild fallow deer does hunted in January. The aim of the research was to analyse the influence of the method of storage on the quality of venison. The pH value after chilled storage and after freezer storage ranged from 5.64 to 5.70, indicating high meat quality of meat. The freezer storage caused a decrease in the redness and chroma in the longissimus lumborum muscle (P < 0.0001 and P = 0.001). The frozen and thawed venison characterised with a higher percentage of free water (P = 0.001), drip loss (P = 0.033) and lower plasticity (P = 0.001) compared to the meat stored under chilled conditions. The instrumental measures of tenderness were affected by the storage. The results indicated a lower technological quality of venison after freezer storage compared to meat stored under chilled conditions.

Carcass characteristics and meat quality of purebred Pakchong 5 and crossbred pigs sired by Pakchong 5 or Duroc boar

Objective

This study investigated carcass characteristics and meat quality of purebred Pakchong 5, crossbred pigs sired by Pakchong 5, and crossbred pigs sired by Duroc.

Methods

Forty-eight pigs (average body weight of 22.25 kg) were composed of three groups as purebred Pakchong 5 (PP), Large White×Landrace pigs sired by Pakchong 5 (LWLRP), and Large White×Landrace pigs sired by Duroc (LWLRD). Each group consisted of eight gilts and eight barrows. At 109-day-raising period, pigs were slaughtered, and carcass characteristics were evaluated. Longissimus thoracis (LT) muscles from left side of carcasses were evaluated for meat quality and chemical composition. Data were analyzed using general linear model procedure, where group, sex, and their interaction were included in the model.

Results

The PP had greater carcass, total lean, and ham percentages than crossbred pigs (p< 0.05). LWLRP had thicker backfat and more carcass fat percentage than LWLRD (p<0.05). There were no differences (p>0.05) on cutting percentages from tender loin, loin, boston butt, and picnic shoulder among groups. The PP and LWLRP had larger loin eye area (LEA) than LWLRD (p<0.05). Gilts had more loin percentage and lower L* value than barrows (p<0.05). No meat color parameters (L*, a*, and b*) were affected by groups (p>0.05). PP and LWLRP had larger muscle fiber diameters than LWLRD (p<0.05). However, water holding capacity, Warner-Bratzler shear force values, and chemical composition of LT were not affected by group or sex (p>0.05).

Conclusion

Pakchong 5 purebred has good carcass and lean percentages. Compared to Duroc crossbred pigs, Pakchong 5 crossbreds have similar carcass and lean percentages, larger LEA, and slightly more carcass fat, with comparable meat quality and chemical composition. Pakchong 5 boars are more affordable for very small- to medium-scale pig producers.

Determination of Water-holding Capacity of Porcine Musculature Based on Released Water Method Using Optimal Load

The purpose of this study was to evaluate the suitability of the released water (RW) method for measuring water-holding capacity (WHC) by pressure and filter-paper absorption within two thin plastic films. One hundred fifty pork loins with considerable variations in WHC (three pork qualities: PSE, pale, soft, and exudative; RFN, reddish-pink, firm, and nonexudative; and DFD, dark, firm, and dry; 50 pork loins in each pork quality group) were used to measure drip loss (DL)% and RW % after applying different loads (1.5, 2.0, 2.5, 3.0 and 3.5 kg). Percentages of DL and RW were significantly (p<0.05) different among pork quality groups. The RW % of 2.5 kg load sample was significantly (p<0.05) higher than that of 2.0 kg or 1.5 kg load sample. However, there were no significant (p>0.05) differences in RW % among 2.5 kg, 3.0 kg, and 3.5 kg load samples for all three pork quality groups. The RW % was highly and positively correlated (r>0.95; p<0.001) with DL %. The highest correlation was observed between DL % and RW % of 2.5 kg load sample (r=0.97; p<0.001). Among all RW loads within each quality groups, the highest correlation between DL % and RW % was observed for 2.5 kg load sample (r=0.43, 0.66, and 0.46 for PSE, RFN and DFD quality groups, respectively, p<0.001). These results imply that applying 2.5 kg load is the best for determination of RW %. It is recommended as a reference method to assess DL % of pork muscles.

Effects of the Truck Suspension System on Animal Welfare, Carcass and Meat Quality Traits in Pigs

The objective of this study was to assess the effects of two types of commercial suspension (leaf-spring (LS) vs. air suspension (AS)) installed on two similar double-decked trucks on blood cortisol and lactate concentration, lairage behavior, carcass skin lesions and pork quality traits of 120 crossbred pigs. The suspension type neither influenced pig behaviour in lairage nor blood cortisol and lactate concentrations (p > 0.10). However, when compared with the AS suspension system, the use of LS increased the number of skin lesions in the back and thigh (p = 0.03 and p = 0.01, respectively) and produced thigh with lower pH_u (p < 0.001) and yellower colour (higher b* value; p = 0.03), and paler back muscles (subjective colour; p < 0.05), with a tendency to lower pH (p = 0.06). Therefore, the use air suspension system can improve carcass and meat quality traits of pigs transported to slaughter.

Drip Loss Assessment by Different Analytical Methods and Their Relationships with Pork Quality Classification

We analyzed drip loss in pork by comparing the standard bag (DL), filter-paper wetness (FPW), and EZ-DripLoss methods by weighing the meat juice container and dabbed sample after 24 h and 48 h. Samples were classified into quality categories based on pH, color, and drip loss. The relationship between DL and FPW revealed the cut-off of 5% DL as corresponding to FPW of 139 mg; 1.89% when analyzed by weighing meat juice container or dabbed sample after 24 h; and 3.18% and 3.74% for those analyzed by weighing both meat juice container and dabbed sample after 48 h, respectively. Highest correlations were observed between DL and EZ when the meat juice container was weighed after 48 h (r=0.86). The EZ-DripLoss method in which the meat juice container was weighed after 24 h was able to distinguish drip loss into meat-quality categories in accordance with the bag method. Therefore, this method is recommended for meat categorization because of its greater standardization and ease of application.

Effects of plant extracts and essential oils as feed supplements on quality and microbial traits of rabbit meat

The effects of dietary supplementation of onion, cranberry,  strawberry and essentials oils on meat quality were analysed. Five groups of 48 Grimaud female weaned rabbits received the supplemented or the control ration; the experimental unit was a cage of 6 rabbits. Each experimental diet contained 10 ppm of added active ingredients.  Rabbits were fed with the experimental diets for 4 wk before determining slaughter and carcass traits and determining the pH at 1 and 24 h post mortem (pHu) of the <em>Longissimus dorsi</em> (LD) and the <em>Biceps femoris</em> (BF) muscle, left and right, respectively. Cooking loss, drip loss and L*, a* and b* color parameters were obtained of the right<em> </em>LD and for ground meat and antioxidant status (TBARS, DNPH, Folin Ciocalteu). Only the pHu of the LD muscle for the strawberry supplemented group was significantly lower when compared to the control group (P=0.04). However, we note that for the pH of the LD, the average was less than 6 for the meat of animals who received a diet enriched in polyphenols, compared to the control group. Plant extract supplementation did not influence meat quality traits, growth performance or oxidative stability. But under aerobic and anaerobic conditions, our results indicate that diet supplementation with extracts rich in polyphenols, especially with essential oils, had a small bot sporadic positive effect in reducing bacterial microflora compared to the control group (P&lt;0.05). In conclusion, plant extracts and essential oils can be used in a rabbit diet without adverse effects on performance and meat quality traits. This effect could be optimized by investigating higher doses.

Microbial spoilage, quality and safety within the context of meat sustainability

Meat is a nutrient-dense food that provides ideal conditions for microbes to grow and defines its perishable nature. Some organisms simply spoil it while others are a threat to our health. In either case, meat must be discarded from the food chain and, being wasted and consequently an environmental burden. Worldwide, more than 20% of the meat produced is either lost or wasted. Hence, coordinated efforts from farm to table are required to improve microbial control as part of our effort towards global sustainability. Also, new antimicrobial systems and technologies arise to better fulfill consumer trends and demands, new lifestyles and markets, but for them to be used to their full extent, it is imperative to understand how they work at the molecular level. Undetected survivors, either as injured, dormant, persister or viable but non-culturable (VBNC) cells, undermine proper risk evaluation and management.

Comparison of objective measures of pork colour traits during ageing of the longissimus muscle from pigs housed organically and conventionally

Pigs raised conventionally (n = 56) and indoors organically (n = 47) from different three-way crossbred genotypes were used to assess the capacity of pork colour attributes during ageing to discriminate between two methods of rearing pigs. Instrumental colour characteristics were measured on L. thoracis muscle from day 1 to 7 of storage, and the relative contents of metmyoglobin (MMb) and oxymyoglobin (MbO2) were estimated. The yellowness and chroma indices were lower in conventional than organic pork at all sampling times except on day 3 of storage. Lightness and hue angle were lower, whereas redness index was greater, in conventional than organic pork during all days of storage. Using MMb rather than MbO2 could be useful to highlight myoglobin oxidation in pork meat because it was weakly correlated with the measured CIELab colour attributes. Despite the differences in instrumental colour attributes, discrimination between conventional and organic (not free-ranging) pig husbandry was not possible. However, 3 days of storage combined the best colour (low hue angle and high redness index) and haeminic pigment balance (low MMb and high MbO2).

Effects on microbial quality of fresh pork loin during storage from oregano oil and cranberry pulp diet supplementation in pigs

Fortier, M. P., Saucier, L. and Guay, F. 2012. Effects on microbial quality of fresh pork loin during storage from oregano oil and cranberry pulp diet supplementation in pigs. Can. J. Anim. Sci. 92: 465–471. Oregano oil and ground cranberry pulp supplements were added to the diets of finishing pigs to determine their antimicrobial effects on fresh loin during storage at 2±1°C. Two doses of oil (250 and 500 mg kg−1) and three doses of cranberry (5, 10 and 20 g kg−1) were tested according to a factorial experimental design. The control group did not receive any supplements. The meat was vacuum packed and analyzed after 0, 23, 45 and 60 d. Samples were re-packaged under aerobic conditions after 0 or 23 d and analyzed after 4, 8 and 12 d. Microbial analysis was performed periodically throughout the experiment. Initial cell counts were below detection level for total aerobic mesophilic (TAM) (<102 cfu g−1), Pseudomonas spp. (<102 cfu g−1), presumptive lactic acid bacteria (LAB) (<102 cfu g−1), and Escherichia coli and coliform counts (<101 cfu g−1). No significant difference in TAM counts was observed between all of the six different treatments and the control group except for samples packaged at day 0 under aerobic conditions after 12 d of storage where a significant effect of the supplementation was observed (P<0.03). Under anaerobic conditions, LAB were not affected and remained the predominant microflora despite antimicrobial treatments.