Review: Pork quality attributes from farm to fork. Part II. Processed pork products

A Preliminary Evaluation of Sex and Dietary Field Pea Effects on Sensory Characteristics of Dry-Cured Loins

Two of the main issues related to cured meat products are castration to avoid boar taint and the hefty reliance on soybean meal to feed pigs. However, data on the effects of immunocastration in pigs and alternative crop protein feeds on the sensory traits and consumers' acceptance of dry-cured loin are still limited. A preliminary study was conducted on the effect of sex type (surgical castrated male pigs and immunocastrated male and female pigs, at approximately 140 kg in weight and 7 months of age) and animal diet (pea vs. soya) on dry-cured loins. The study involved a sensory evaluation of six treatments, with a 3 × 2 factorial design, conducted by trained panellists and untrained consumers in Spain (n = 126) and Portugal (n = 80). The consumers were also checked for their skatole sensitivity using a pure substance. The results showed that the pea-based diet was significantly different (p < 0.001) from the soy-based diet, as determined by a trained panel of surgically castrated male pigs, although the immunocastration treatments were not split. Dry-cured loin from immunocastrated male pigs fed with peas was considered tenderer and juicier (p < 0.05) than those fed soya-based diets. The untrained consumer panel scored higher on the sensory traits (flavour, juiciness, and overall liking) from the loin samples of surgically castrated male pigs fed a pea diet. All consumers scored similarly in boar taint detection. This study demonstrates the applicability of the pea-based diet for the feeding of pigs destined for cured meat and highlights immunocastration as a tool that does not compromise the skatole detection score.

Apoptosis and autophagy of muscle cell during pork postmortem aging

OBJECTIVE

Pork is an important source of animal protein in many countries. Subtle physiochemical changes occur during pork postmortem aging. The changes of apoptosis and autophagy in pork at 6 h to 72 h after slaughter were studied to provide evidence for pork quality.

METHODS

In this article, morphological changes of postmortem pork was observed through Hematoxylin-eosin staining, apoptotic nuclei were observed by TdT-mediated dUTP nick end labeling assay, protein related to apoptosis and autophagy expressions were tested by western blot and LC3 level were expressed according to immunofluorescence assay.

RESULTS

In this study, we found the occurrence of apoptosis in postmortem pork, and the process was characterized by nucleus condensation and fragmentation, formation of apoptotic bodies, increase in apoptosis-related Bax/Bcl-2 levels, and activation of caspases. Autophagy reached its peak between 24 and 48 h after slaughter, accompanied by the formation of autophagosomes on the cell membrane and expression of autophagy-related proteins beclin-1, P62, LC3-I, LC3-II, and ATG5.

CONCLUSION

Obvious apoptosis was observed at 12 h and autophagy reached its peak at 48 h. The present work provides the evidence for the occurrence of apoptosis and autophagy during postmortem aging of pork. In conclusion, the apoptosis and autophagy of muscle cells discovered in this study have important implications for pork in the meat industry.

Fatty Acid Profile and Lipid Quality Indexes of the Meat and Backfat from Porkers Supplemented with EM Bokashi Probiotic

The study aimed to assess the effect of supplementation of pig diet with the Bokashi probiotic on the fatty acid profile of longissimus lumborum (LL) muscles and backfat. The research involved 120 hybrid pigs deriving from Naïma sows and P-76 boars. The experimental group's pigs received probiotics in their feed (containing Saccharomyces cerevisiae, Lactobacillus casei, and Lactobacillus plantarum). To analyze the fatty acid profile in intramuscular fat (IMF) of LL and backfat, 24 pig carcasses from the control group and 26 from the probiotic-supplemented group were randomly selected. Probiotic supplementation increased the Atherogenic Index, reduced the proportion of C20:4, and increased C12:0 and C18:2 n-6 in IMF LL, without affecting ΣSFA, ΣMUFA, and ΣPUFA. In backfat, probiotic supplementation decreased C18:1 and C18:2 n-6 proportion and increased C18:3 n-3, C20:3 n-6, and C20:4 n-6. These changes resulted in significantly higher ΣMUFA, ΣPUFA, PUFA Σn-3/Σn-6, and lower Saturation Index (SI). From a consumer health and technological point of view, probiotic supplementation improved the lipid profile of backfat to a greater extent than LL muscle. Bokashi, at a dose of 3 g/kg of feed in the last stage of pig production, had no significant effect on the fatty acid profile of the meat.

A body map of super-enhancers and their function in pig

Introduction

Super-enhancers (SEs) are clusters of enhancers that act synergistically to drive the high-level expression of genes involved in cell identity and function. Although SEs have been extensively investigated in humans and mice, they have not been well characterized in pigs.

Methods

Here, we identified 42,380 SEs in 14 pig tissues using chromatin immunoprecipitation sequencing, and statistics of its overall situation, studied the composition and characteristics of SE, and explored the influence of SEs characteristics on gene expression.

Results

We observed that approximately 40% of normal enhancers (NEs) form SEs. Compared to NEs, we found that SEs were more likely to be enriched with an activated enhancer and show activated functions. Interestingly, SEs showed X chromosome depletion and short interspersed nuclear element enrichment, implying that SEs play an important role in sex traits and repeat evolution. Additionally, SE-associated genes exhibited higher expression levels and stronger conservation than NE-associated genes. However, genes with the largest SEs had higher expression levels than those with the smallest SEs, indicating that SE size may influence gene expression. Moreover, we observed a negative correlation between SE gene distance and gene expression, indicating that the proximity of SEs can affect gene activity. Gene ontology enrichment and motif analysis revealed that SEs have strong tissue-specific activity. For example, the CORO2B gene with a brain-specific SE shows strong brain-specific expression, and the phenylalanine hydroxylase gene with liver-specific SEs shows strong liver-specific expression.

Discussion

In this study, we illustrated a body map of SEs and explored their functions in pigs, providing information on the composition and tissue-specific patterns of SEs. This study can serve as a valuable resource of gene regulatory and comparative analyses to the scientific community and provides a theoretical reference for genetic control mechanisms of important traits in pigs.

Animal Health and Productivity of Organic Greek Pig Farms: The Current Situation and Prospects for Sustainability

A review of organic pig production in Greece was carried out. The aim was to present updated information on the production, development and health status of organic pig farming in Greece and potential prospects for sustainability and future development. The indigenous Greek Black Pig is the main breed reared in Greek organic pig farms. All the reasons why Greek Black Pig breeding is ideal for organic farming are mentioned. Furthermore, respiratory and parasitic infections are the most common health problems, while high piglet mortality rates are the main welfare issue in Greek organic pig farming. Concerns about how farmers and authorities should utilize the demands of modern consumers are discussed.

Long-term consumption of fermented pork fat-based diets differing in calorie, fat content, and fatty acid levels mediates oxidative stress, inflammation, redox imbalance, germ cell apoptosis, disruption of steroidogenesis, and testicular dysfunction in Wistar rats

There is a dearth of experimental evidence available as to whether the consumption of fermented pork fat (FPF) food has any harmful effects on metabolism and reproduction due to its excessive calories, high fat content, and fatty acid methyl ester (FAME) levels. We hypothesized that exposure to a FPF-diet with excessive calories, a high fat content, and high FAME levels alters testicular physiology and metabolism, leading to permanent damage to the testicular system and its function. Thirteen-week-old male rats (n = 20) were assigned to a high-calorie, high-fat diet (FPF-H, fat-60%, 23 kJ/g), a moderate-calorie, moderate-fat diet (FPF-M, fat-30%, 17.5 kJ/g), a low-calorie and low-fat diet (FPF-L, fat-15%, 14.21 kJ/g) compared to the standard diet (Control, fat-11%, 12.56 kJ/g) orally for 90 days. GC-MS analysis of the three FPF-diets showed high quantities of saturated fatty acids (SFAs) and polyunsaturated fatty acids-ω6 (PUFA-ω6) and low levels of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids-ω3 (PUFA-ω3) compared to the control diet. Consequently, the levels of serum FAMEs of the FPF-diet fed rats were significantly increased. In addition, a high level of n-6:n-3 PUFA towards PUFA-ω6 was observed in the serum of FPF-diet fed rats due to the high content of linoleic, γ-linolenic, and arachidonic acid. Long-term consumption of FPF-diets disturbed the anthropometrical, nutritional, physiological, and metabolic profiles. Furthermore, administration of FPF-diets generated metabolic syndrome (dyslipidemia, leptinemia, insulin resistance, obesity, hepato-renal disorder and function), increased the cardiovascular risk factors, and triggered serum and testis inflammatory markers (interleukin-1↑, interleukin-6↑, interleukin-10↓, leukotriene B4↑, prostaglandin↑, nitric oxide↑, myeloperoxidase↑, lactate dehydrogenase↑, and tumor necrosis factor-α↑). Activated testis oxidative stress (conjugated dienes↑, lipid hydroperoxides↑, malondialdehyde↑, protein carbonyl↑, and fragmented DNA↑) and depleted antioxidant reserve (catalase↓, superoxide dismutase↓, glutathione S-transferase↓, reduced glutathione↓, glutathione disulfide↑, and GSH:GSSG ratio↓) were observed in FPF-diet fed rats. Disrupted testis histoarchitecture, progressive deterioration of spermatogenesis, poor sperm quality and functional indices, significant alterations in the reproductive hormones (serum and testis testosterone↓, serum estradiol↑, serum luteinizing hormone↓, and follicle-stimulating hormone↑), were noted in rats fed with FPF diets than in the control diet. Severe steroidogenic impairment (steroidogenic acute regulatory protein, StAR↓; 3β-hydroxysteroid dehydrogenase, 3β-HSD↓; and luteinizing hormone receptor, LHR↓), deficiency in germ cells proliferation (proliferating cell nuclear antigen, PCNA↓), and abnormally enhanced testicular germ cell apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, TUNEL assay↑; B-cell lymphoma-2, BCL-2↓; Bcl-2-associated X protein, BAX↑; and BAX/BCL-2 ratio↑) were remarked in the FPF-diet administered rats in comparison with the control diet. In conclusion, the long-term feeding of an FPF-diet with excessive calories, a high fat content, and high FAME levels induced oxidative stress, inflammation, and apoptosis, resulting in metabolic syndrome and hampering male reproductive system and functions. Therefore, the adoption of FPF diets correlates with irreversible changes in testis metabolism, steroidogenesis, germ cell proliferation, and apoptosis, which are related to permanent damage to the testicular system and function later in life.

Development and Innovation in Cooked Ham Produced in Spain

The production of cooked ham has been gaining popularity in recent years in Spain. In general, the production process carried out by the companies remains traditional, and different production methods are therefore being sought to innovate and improve the quality of the product. This is either through pig crossbreeding, varying additives and ingredients, improving some stages of the production process, or providing nutritional and health claims that are useful to guiding the purchasing decision of consumers. Obviously, this series of changes must be subject to Spanish and European regulations in order to be marketed inside and outside the country.

Pearls before Swine: Plant-Derived Wastes to Produce Low-Cholesterol Meat from Farmed Pigs-A Bibliometric Analysis Combined to Meta-Analytic Studies

Due to environmental and human factors, there is a growing amount of agri-food waste worldwide. The European Commission is incentivizing a zero-waste policy by 2025, pushing to find a "second life" for at least the avoidable ones. In this review, after summarizing the nutritional values of pork and the importance of its inclusion in human diet, a phylogenetic analysis was conducted to investigate potential differences in the structure and activity of HMGCR, which is a key enzyme in cholesterol metabolism. In addition, a bibliometric analysis combined with visual and meta-analytical studies on 1047 scientific articles was conducted to understand whether the inclusion of agro-food waste could affect the growth performance of pigs and reduce cholesterol levels in pork. Although some critical issues were highlighted, the overall data suggest a modern and positive interest in the reuse of agri-food waste as swine feed. However, although interesting and promising results have been reported in several experimental trials, further investigation is needed, since animal health and meat quality are often given marginal consideration.

Pork quality traits and associated muscle metabolic changes in pigs under chronic prenatal and postnatal heat stress

Chronic heat stress (HS) is a major concern affecting pig growth performance and metabolism, with potential consequences on carcass and meat quality traits. The objective of this study was to assess the influence of prenatal (PE) and growing (GE) thermal environments, and their combination, on muscle metabolism, carcass characteristics, and pork quality. From 6 to 109 d of gestation, 12 sows (1 per block) were kept under thermoneutral (TN) conditions (cyclic 18 to 24 °C; PTN) and 12 sows under chronic HS (cyclic 28 to 34 °C; PHS). Two female offspring per sow were selected based on body weight at weaning, for a total of 48 female pigs (12 blocks of 2 sisters from each PE), and one sister was placed in each GE. Gilts were housed from 82 to 140 d of age under cyclic GTN (18 to 24 °C; n = 24) or GHS (28 to 34 °C; n = 24) environments. Data were analyzed using a mixed model including PE, GE, and PE × GE interaction as main effects, and sire, sow within PE, pen within PE × GE, and slaughter day (for plasma, muscle, and meat traits) as random effects. No significant PE × GE interaction was found on any trait under study (P ≥ 0.05). Prenatal HS did not affect growth performance and carcass traits (P ≥ 0.05). Compared with GTN, GHS pigs had lower average daily feed intake, average daily gain, and hot carcass weight (P < 0.01), but similar carcass lean meat content (P ≥ 0.05). Prenatal HS had scarce effects on pork quality, with only higher a* and C* values (P < 0.05) in the Gluteus superficialis. Growing HS led to a higher pH 24 h (P < 0.05) in the Longissimus thoracis et lumborum (LTL) and ham muscles, and higher meat quality index in the ham muscles. In contrast, quality traits of the Semispinalis capitis (SC) were not affected by either PE or GE (P > 0.05). Except a tendency for a higher citrate synthase activity in the SC (P = 0.065), PHS did not affect muscle metabolism. Growing HS induced muscle-specific metabolic responses, with reduced glycolytic potential (P < 0.01) and metabolic enzyme activities (P < 0.05) in the glycolytic LTL, but not in the oxidative SC (P > 0.05). Plasma glucose content at slaughter was lower in the GHS compared with GTN pigs (P = 0.002), indicating an altered energy metabolism in pigs under GHS. Altogether, growing HS altered growth without affecting carcass traits, but improved technological quality of loin and ham. Prenatal HS, alone or combined with GHS, had limited or even no effect on carcass and pork quality.

Productive performance and in vivo body composition across the growing and finishing period and carcass traits in pigs of four sex types

This study compares performance, body and carcass composition among castrated (CM), immunocastrated (IM) and entire males (EM), and females (FE) at 30, 70, 100 and 120 kg of body weight (total of n = 92; 20-24/sex type). Overall, IM had similar growth and feed intake to CM and greater than EM and FE. At each slaughter stage, IM had a lower killing-out percentage than CM and FE, in line with their heavier liver and kidneys. Flare fat proportion and backfat thickness on the ham and at the last rib level were similar for IM, EM and FE, and these were lower than CM. In EM and FE, backfat between the 3rd and 4th last ribs was lower and carcass lean content was higher than in CM, whereas IM were intermediate and not different to the other sexes. Females showed the largest ham proportion, this cut being leaner and less fatty than in CM. Belly proportion was higher in CM than in EM.