Consumer perception, facts and possibilities to improve acceptability of health and sensory characteristics of pork

Screening for Genes Related to Meat Production Traits in Duroc × Bama Xiang Crossbred Pigs by Whole Transcriptome Sequencing

The meat production traits of pigs are influenced by the expression regulation of multiple gene types, including mRNAs, miRNAs, and lncRNAs. To study the differences in meat production traits at the transcriptional level among individuals with different growth rates, the longissimus dorsi samples from eight Duroc × Bama Xiang F2 crossbred pigs with a fast growth rate (high gTroup) or a slow growth rate (low group) were selected to perform whole transcriptome sequencing and ceRNA regulatory network construction. This study first analyzed the differences in physiological and biochemical indicators, muscle histological characteristics, and muscle fiber types. A total of 248 mRNAs, 25 miRNAs, and 432 lncRNAs were identified as differentially expressed by whole transcriptome sequencing. Key genes that may influence meat production traits include MTMR14, PPP1R3A, PYGM, PGAM2, MYH1, and MYH7. The ceRNA regulatory network map showed that ENSSSCG00000042061-ssc-mir-208b-MYH7, ENSSSCG00000042223-ssc-mir-146a-MTMR14, ENSSSCG00000045539-ssc-mir-9-3-MYH1, and ENSSSCG00000047852-ssc-mir-103-1-PPP1R3A may be the key factors affecting meat production traits through their regulatory relationships. This study provides valuable insights into the molecular mechanisms underlying porcine muscle development and can aid in improving meat production traits.

Cold exposure affects glucose metabolism, lipid droplet deposition and mitophagy in skeletal muscle of newborn goats

Cold exposure is a common stressor for newborn goats. Skeletal muscle plays an important role in maintaining whole-body homeostasis of glucose and lipid metabolism. However, the molecular mechanisms underlying regulation of skeletal muscle of newborn goats by cold exposure remains unclear. In this study, we found a significant increase (P < 0.01) in serum glucagon levels after 24 h of cold exposure (COLD, 6°C), while glucose and insulin concentrations were significantly decreased (P < 0.01) compared to room temperature (RT, 25°C). Additionally, we found that cold exposure reduced glycogen content (P < 0.01) in skeletal muscle. Pathway enrichment analysis revealed that cold exposure activated skeletal muscle glucose metabolism pathways (including insulin resistance and the insulin signaling pathway) and mitophagy-related pathways. Cold exposure up-regulated the expression of genes involved in fatty acid and triglyceride synthesis, promoting skeletal muscle lipid deposition. Notably, cold exposure induced mitophagy in skeletal muscle.

Identification of potential obese-specific biomarkers and pathways associated with abdominal subcutaneous fat deposition in pig using a comprehensive bioinformatics strategy

Abdominal subcutaneous fat deposition (ASFD) is not only related to meat quality in the pig industry but also to human health in medicine. It is of great value to elucidate the potential molecular mechanisms of ASFD. The present study aims to identify obese-specific biomarkers and key pathways correlated with ASFD in pigs. The ASF-related mRNA expression dataset GSE136754 was retrieved from the Gene Expression Omnibus (GEO) database and systematically analyzed using a comprehensive bioinformatics method. A total of 565 differentially expressed genes (DEGs) were identified between three obese and three lean pigs, and these DEGs were mainly involved in the p53 signaling pathway, MAPK signaling pathway and fatty acid metabolism. A protein-protein interaction (PPI) network, consisting of 540 nodes and 1,065 edges, was constructed, and the top ten genes with the highest degree scores-ABL1, HDAC1, CDC42, HDAC2, MRPS5, MRPS10, MDM2, JUP, RPL7L1 and UQCRFS1-were identified as hub genes in the whole PPI network. Especially HDAC1, MDM2, MRPS10 and RPL7L1 were identified as potential robust obese-specific biomarkers due to their significant differences in single gene expression levels and high ROC area; this was further verified by quantitative real-time PCR (qRT-PCR) on abdominal subcutaneous fat samples from obese-type (Saba) and lean-type (Large White) pigs. Additionally, a mRNA-miRNA-lncRNA ceRNA network consisting of four potential biomarkers, 15 miRNAs and 51 lncRNAs was established, and two targeted lncRNAs with more connections, XIST and NEAT1, were identified as potentially important regulatory factors. The findings of this study may provide novel insights into the molecular mechanism involved in ASFD.

The impact of slaughter weight and sex on the carbon footprint of pig feed intake

The impact of pork production on global livestock's greenhouse gas emissions is substantial. Understanding the factors influencing these emissions is crucial in achieving a more sustainable pig husbandry. In two independent experiments, the impact of slaughter weight on the carbon footprint (CFP) of pig feed intake (CFPFI) was evaluated for growing-finishing pigs of different sexes (entire males (EM), barrows (BA), immunocastrates (IC) and gilts (GI)). In experiment 1 118 animals were raised individually in experimental conditions. In experiment 2 384 animals were housed in group (four pigs per pen), in controlled commercial farm circumstances. All animals were fed ad libitum in a three-phase feeding regime and slaughtered at different BW, ranging from 110 to 148 kg (experiment 1) and from 99 to 138 kg (experiment 2). When only the fattening period was considered, the CFPFI was expressed per kg carcass growth. When the production of piglets was also taken into account, the CFPFI was calculated per kg carcass weight. For all sexes, the heavier the pig, the higher the CFPFI per kg carcass growth (P < 0.05, experiment 1; P < 0.001, experiment 2) and per kg carcass weight (P < 0.05, experiment 1; P < 0.01, experiment 2). In addition, BA had a significantly higher CFPFI per kg carcass growth and per kg carcass weight compared to EM and IC and to EM, IC and GI in respectively experiments 1 and 2 (P < 0.001). When performing a desk study with a soy-free (i.e. reduced CFP) feed in the third phase of experiment 2, slaughter weight no longer affected the CFPFI per kg carcass growth (P = 0.133) and per kg carcass weight (P = 0.856). A higher slaughter weight thus implies a lower sustainability, unless a sufficiently low-CFP feed is provided in the finisher phase.

Transcriptome analysis of norepinephrine-induced lipolysis in differentiated adipocytes of Bama pig

Sympathetic innervation of white adipose tissue (WAT) plays a key role in the regulation of lipid metabolism. Sympathetic activation promotes release of norepinephrine (NE), which binds to adrenergic receptors on adipocytes, promoting adipocyte lipolysis and enhanced oxidative metabolism. However, the mechanism by which sympathetic nerves regulate lipid metabolism in pig adipose tissue remains unclear. We used NE to simulate the process of sympathetic driving in pig adipocytes. RNA sequencing (RNA-seq) was used to determine the gene expression profile of pig adipocytes responding to NE stimulation. Our data suggests that the lipolytic signaling pathway is activated in pig adipocytes upon acute stimulation of NE, resulting in enhanced lipid metabolism and lipolysis, consistent with the phenomena found in humans and mice. Specifically, differentially expressed protein coding genes (PCGs) (SIRT4, SLC27A1) are mainly associated with functions that inhibit fatty acid oxidation and promote lipid synthesis. Similarly, we investigated the changes in regulatory transcripts such as long non-coding RNAs (lncRNAs) and transcripts of uncertain coding potential (TUCP) in response to NE and found that differentially expressed lncRNAs (lncG47338, lncG30660, lncG29516, lncG3790) and TUCP (TUCP_G38001) were co-expressed with target genes related to the promotion of fatty acid β-oxidation, lipolysis and oxidative metabolism, thus acting as regulators. These results indicate a broad suite of gene expression alterations in response to NE stimulation and promote the understanding of the molecular mechanisms by which NE regulates lipid metabolism in pigs.

Characteristics of Transcriptome and Metabolome Concerning Intramuscular Fat Content in Beijing Black Pigs

To study the characteristics of genes and metabolites related to intramuscular fat (IMF) content with less influence by breed background and individual differences, the skeletal muscle samples from 40 Beijing black pigs with either high or low IMF content were used to perform transcriptome and metabolome analyses. About 99 genes (twofold-change) were differentially expressed. Up-regulated genes in the high IMF pigs were mainly related to fat metabolism. The key genes in charge of IMF deposition are ADIPOQ, CIDEC, CYP4B1, DGAT2, LEP, OPRL1, PLIN1, SCD, and THRSP. KLHL40, TRAFD1, and HSPA6 were novel candidate genes for the IMF trait due to their high abundances. In the low IMF pigs, the differentially expressed genes involved in virus resistance were up-regulated. About 16 and 18 differential metabolites (1.5 fold-change) were obtained in the positive and negative modes, respectively. Pigs with low IMF had weaker fatty acid oxidation due to the down-regulation of various carnitines. Differentially expressed genes were more important in determining IMF deposition than differential metabolites because relatively few differential metabolites were obtained, and they were merely the products under the physiological status of diverged IMF content. This study provided valuable information for further studies on IMF deposition.

Competing endogenous RNA network construction based on long non-coding RNAs, microRNAs, and mRNAs related to fat deposition in Songliao black swine

China has a long history of pig breeding and a number of local breeds. The Songliao Black pig, bred in China in 2009, shows high variation in backfat thickness and therefore is well-suited to fat deposition research. Fat deposition is a complex trait, and the underlying regulatory factors are not fully characterized. In this study, the molecular basis of fat deposition traits was evaluated by comparisons between three individuals with extremely high-backfat thickness and three with extremely low-backfat thickness selected from 53 gilts. Subcutaneous adipose tissues of the back were collected for strand-specific library RNA sequencing (RNA-seq) and small RNA-seq. We identified 13 184 mRNAs, 2046 long non-coding (lnc)RNAs, and 494 micro (mi)RNAs by high-throughput sequencing. Furthermore, we detected 150 differentially expressed mRNAs, 66 differentially expressed lncRNAs, and eight differentially expressed miRNAs. A functional enrichment analysis indicated that these genes are involved in multiple fat metabolism-related pathways, including positive regulation of fat cell differentiation, and fat digestion and absorption. We used various algorithms (miRanda, TargetScan, and RNAhybrid) to predict targeting relationships and constructed a competing endogenous RNA network containing seven lncRNAs, three miRNAs, and six mRNAs. All these genes were differentially expressed between the extremely high and low backfat thickness groups or enriched in pathways related to fat metabolism. Our results provide insight into the regulatory mechanisms by which non-coding RNAs and their target genes influence backfat deposition in pigs. Furthermore, our newly constructed competing endogenous RNA (lncRNA-miRNA-mRNA) network provides a basis for further exploration of fat deposition traits and non-coding RNA functions.

Identification of Potential Candidate Genes From Co-Expression Module Analysis During Preadipocyte Differentiation in Landrace Pig

Preadipocyte differentiation plays an important role in lipid deposition and affects fattening efficiency in pigs. In the present study, preadipocytes isolated from the subcutaneous adipose tissue of three Landrace piglets were induced into mature adipocytes in vitro. Gene clusters associated with fat deposition were investigated using RNA sequencing data at four time points during preadipocyte differentiation. Twenty-seven co-expression modules were subsequently constructed using weighted gene co-expression network analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses revealed three modules (blue, magenta, and brown) as being the most critical during preadipocyte differentiation. Based on these data and our previous differentially expressed gene analysis, angiopoietin-like 4 (ANGPTL4) was identified as a key regulator of preadipocyte differentiation and lipid metabolism. After inhibition of ANGPTL4, the expression of adipogenesis-related genes was reduced, except for that of lipoprotein lipase (LPL), which was negatively regulated by ANGPTL4 during preadipocyte differentiation. Our findings provide a new perspective to understand the mechanism of fat deposition.

Consequences of a low protein diet on the liver and longissimus dorsi transcriptome of Duroc × Iberian crossbred pigs

Low protein diets supplied during the growing period of pigs can diminish their growth rate and increase the intramuscular fat (IMF) content which affects the sensorial and technological characteristics of the products. In the present study, the effects of a low protein diet supplied during the growing period of Duroc × Iberian crossbred pigs on several phenotypic traits and on liver and longissimus dorsi transcriptome were analysed at the beginning (EARLY) and at the end (LATE) of the growing period. Two experimental groups of 10 crossbred pigs each were fed two isocaloric diets with different protein content: control diet (C) with 16.5% protein and 0.8% lysine and low protein diet (LP) with 11% CP and 0.6% lysine. Animals fed LP diet have a slower growth than those fed C diet, but no effect of LP diet was observed on the IMF content. The transcriptomes of liver and longissimus dorsi were characterised and quantified through RNA-sequencing (RNA-seq). In liver, 134 and 480 differentially expressed annotated genes and new isoforms (DEGs) were detected between C and LP diets for EARLY and LATE animals, respectively. In muscle, 128 and 68 DEGs were detected at EARLY and LATE time-points. Functional interpretation revealed that LP diet may inhibit immune system molecules and processes in both tissues at EARLY stage. In liver, the DEGs mainly affect lipid and cholesterol metabolic processes, while in muscle, the expression changes would be involved in growth, development and meat quality. In conclusion, a low protein diet supplied during the growing period seems to slow down the growth of Duroc × Iberian crossbred pigs, but it also seems to affect multiple biological processes that could compromise the immune system of Duroc × Iberian crossbred pigs. Therefore, these results question the adequacy of this type of regime in Duroc × Iberian pigs that must be studied in greater depth before being implemented.

Wild Boar Meat as a Sustainable Substitute for Pork: A Mixed Methods Approach

Sensory analysis is unusual in sustainability research, although it can offer a neoteric aspect of nature and wild animals’ perception. The study’s objective was to identify consumers’ attitudes towards plant and animal products from wild and conventional foods and put these findings into a broader social context. A blind sensory evaluation with 80 semi-trained assessors was used, segmented by gender, age, education, income, place of origin, family status, number of children, and willingness to pay. Wild boar (Sus scrofa) was chosen as an example of an overpopulated animal species occurring in the wild, which could be considered a partial substitute for pork. Statistical testing in these blind evaluations proved that wild boar meat is not considered less tasty. Therefore, wild boar meat could represent a partial substitute, complementing pork, on which consumers are willing to spend the same amount of money. Despite the mostly indifferent sensory evaluation, focus group responses showed considerable barriers to wild food. This paper concludes that possible educational and popularizing procedures are presented, including forest pedagogy, eliminating consumers’ prejudices. A mixed-methods approach within quantitative and qualitative methodology was chosen.

The Effect of Sustainability-Related Information on the Sensory Evaluation and Purchase Behavior towards Salami Products

Consumer's interest in sustainable livestock farming methods has grown in response to concerns for the environment and animal welfare. The purpose of this study is to examine the different influences of sustainability product information on sensory characteristics and purchase behaviors. To accomplish this aim, the study used salami, which is an Italian-style sausage processed by fermentation and drying. Three different types of information were provided: salami made from the pork of an antibiotic-free pig (SMAFP), of an animal welfare pig (SMAWP), and of a grazing pig (SMGP). This study was conducted as an off-line experiment with Korean participants (n=140). As a result, there were sensory differences according to the sustainability information. For the SMAFP, it had a significant difference in, sourness (p<0.05). With the SMAWP, there was a difference in gumminess (p<0.10), and the SMGP had significant differences in sourness (p<0.01), sweetness (p<0.01), andmoisture (p<0.05). Moreover, the purchase intention and willingness to pay were significantly higher when the sustainability information was given. Especially, among the three types of salamis, participants were willing to pay the most for the SMAWP. This is one of the first consumer studies to investigate sensory evaluation and purchase behavior for various types of sustainable livestock production. These results contribute by helping sustainable meat producers and marketers become aware of the kind of sustainable information to which consumers are sensitive.

Comparative Transcriptome Analyses of Longissimus thoracis Between Pig Breeds Differing in Muscle Characteristics

The two breeds, Mashen (MS; a northern China breed) and Large White (LW; a western lean breed) pigs, show important phenotypic differences in growth, adaptability, intramuscular fat (IMF) content, and energy metabolism since early developmental stage. The main aim of this study was the evaluation of longissimus thoracis muscle transcriptome profile of both genetic types to identify genes, pathways responsible for their differentiated phenotype. Longissimus thoracis of MS and LW pigs were sampled at 0 day (early stage), 90 days (middle stage), and 180 days (later stage) after birth. A total of 3,487 differentially expressed genes (DEGs) were identified at the three time points. Sample clustering analysis revealed the slower growth rate of MS than LW pigs. Gene expression pattern analysis revealed that multicellular organism growth genes (GHSR, EZR, FOXS1, DRD2, SH3PXD2B, CSF1, and TSHR) were involved in the fast growth rate of LW pigs at early stage. Furthermore, DEGs (ACACA, ACSF3, OXSM, CBR4, and HSD17B8) functionally related to fatty acid synthesis revealed that IMF accumulation occurred around 90 and up to 180 days. These DEGs provided valuable resource to study the phenotypic difference in longissimus thoracis muscle between MS and LW pigs.

Effect of MSTN Mutation on Growth and Carcass Performance in Duroc x Meishan Hybrid Population

Simple Summary

Myostatin (MSTN) is a transcriptional growth factor that inhibits the development and growth of skeletal muscle. The MSTN-deficient animals display an increase in skeletal muscle mass known as double-muscling. Therefore, MSTN becomes an important target for improving lean meat production in livestock husbandry. There are many local pig breeds in China, but because of the slow growth, poor feed conversion, and low lean meat percentage and other unsatisfactory qualities, pure local breeds are rarely used on commercial farms. The objective of this study is to evaluate the effects of MSTN single allele mutation on carcass composition in Meishan crossbred pigs and demonstrate a way to increase lean meat yield while maintaining prolificacy and good meat quality of local pig crossbreeds. This has significant implications for the widespread use and conservation of local pig breeds in China.

Abstract

The Meishan pig is a traditional Chinese native breed, known for its excellent reproduction performance that is widely used in commercial pig production through two-way or three-way crossbreeding systems. However, the lean meat yield of Meishan crossbred pigs is still very low and cannot meet the market demand. To evaluate the lean meat yield of Meishan crossbred pigs, six wild-type Meishan sows were artificially inseminated by using the MSTN^+/− Duroc boar semen in this experiment. Some reproductive performance-related traits of Meishan sows were recorded to ensure that semen from MSTN knockout Duroc boar did not affect offspring production, including total births, live births, sex, and litter weight. In total, 73 piglets were obtained and 63 were alive. Male to female ratio was close to 1: 1. because of factors such as disease, only 43 pigs were utilized, including 28 MSTN mutant pigs (MSTN^+/−) and 15 MSTN homozygous pigs (MSTN^+/+). We compared the growth performance and carcass performance of these full or half-sib populations and found that there were no differences between MSTN^+/− and MSTN^+/+ genotypes for live animal measures including average daily gain (ADG), body dimensions, or ultrasonic measurement of fat thickness when pigs were harvested after 120 days of feeding. Conversely, the MSTN^+/− pigs had higher dressing percentage and lean meat percentage, lower level of carcass fat, larger longissimus muscle area, less percentage of skin and skeleton, thinner average backfat thickness, and lower intramuscular fat (IMF) content than MSTN^+/+ pigs. In conclusion, the production of MSTN^+/− mutant progeny from Meishan females resulted in improved carcass composition, providing a feasible solution to improve the lean meat yield of Chinese local fat-type pig breeds.

Performance and carcass, loin and ham quality in crossbreds from three terminal sire lines

This study was designed to compare performance, carcass and meat quality of crossbred of a hybrid sow x three sire lines, i.e. stress positive Belgian Piétrain (BP), stress negative French Piétrain (FP) and Canadian Duroc (CD). BP offspring had a significantly higher carcass yield (p < .001) and lean meat content (p < .001) in comparison with FP, which was higher than CD. BP offspring had significantly lower pH (p < .05), water-holding capacity (WHC) (p < .001) and intramuscular fat (IMF) (p < .001) content in the loin compared to FP and CD, but these meat quality parameters, with the exception of pH, were superior for CD as compared to FP. In accordance with loin quality, pH_i, pH_u, WHC and IMF of BP were significantly lower (p < .05) compared to CD in the fresh and cooked ham. Most often, FP offspring could not be differentiated from the other offspring, with the exception of cooking loss of the cooked ham. Trained and consumer taste panels resulted in no significant differences (p > .1) in sensory attributes, however, consumers preffered CD based on ranking.

Drivers of Consumer Liking for Beef, Pork, and Lamb: A Review

Tenderness, juiciness, and flavor have been associated with consumer acceptance of beef, lamb, and pork. Drivers of consumer liking are interrelated across these species, but there are differences in consumer preferences. Animal age, animal diet, and subsequent marbling impact consumer liking across species. For beef, consumer research prior to the 1990s showed that tenderness was the main driver of liking. Consumer tenderness and juiciness liking are highly correlated. More recent research has shown that as overall tenderness improved and tenderness variation decreased, flavor has become a more important driver of beef consumer liking. Flavor is affected by consumer preparation methods, familiarity with different flavor presentations, and animal production systems. Animal diet impacts consumer perception of beef tenderness and flavor, especially when comparing forage-fed versus grain-fed beef. Flavor preferences vary across countries more so than preferences for beef based on consumer tenderness preferences and are most likely influenced by the consumption of locally produced beef and the flavor-derived type of beef traditionally consumed. Drivers of pork consumer liking have been shown to be affected by pH, color, water holding capacity, animal diet, and the presence of boar taint compounds. While tenderness and juiciness continue to be drivers of consumer liking for pork, flavor, as impacted by animal diet and the presence of boar taint compounds, continues to be a driver for consumer liking. For lamb, the flavor, as affected by diet, and animal age continue to be the main drivers of consumer liking. Lamb consumers vary across countries based on the level of consumption and preferences for flavor based on cultural effects and production practices.

Association between single nucleotide polymorphisms in GPAT1 locus and pork quality in pigs

GPAT1 gene is considered to be a genetic marker for intramuscular fat content. The GPAT enzymes catalyze the first step in triacylglycerol synthesis. In the present study, the search for polymorphisms within the pig GPAT1 gene locus as well as association analyses between SNPs and meat quality traits were performed. The association analysis demonstrated that g.133513422C > T polymorphism affected IMF content in LL, SEMI post-mortem pH and shear force of cooked LL (p ≤ .05). While the association of g.133476803 T > C polymorphism was shown concerning IMF content, meat color (L*), shear force and energy of raw meat as well as some meat texture parameters (hardness, springiness, chewiness) (p ≤ .05). The g.133476733C > T SNP was significantly associated with LL 24 h post-mortem pH, raw meat toughness and TPA hardness and chewiness (p ≤ .05). The obtained results are promising but to confirm if the GPAT1 gene can be considered to be a genetic marker for improving the quality of pork, further research is required.

Effect of visual marbling levels in pork loins on meat quality and Thai consumer acceptance and purchase intent

OBJECTIVE

We investigated visual marbling level (VML) influence on pork loin physicochemical traits, consumer palatability responses, VML liking, purchase intent, and their relationships.

METHODS

For each of five slaughtering dates, at 24-h postmortem, nine paired Duroc castrated male boneless Longissimus dorsi (LD) muscles were categorized into low (LM, score 1-2, n=3), medium (MM, score 3-4, n=3), and high (HM, score 5-6, n=3) VML. Meat physicochemical quality traits and consumer responses (n=389) on palatability and VML liking, and purchase intent were evaluated. The experiment was in RCBD. ANOVA, Duncan's multiple mean comparisons, and correlation coefficients were determined.

RESULTS

VML correspond to crude fat (r=0.91, p&lt;0.01), but both were reversely related to moisture content (r=-0.75 and -0.91, p&lt;0.01, respectively). As VML increased, ash (p&lt;0.05) and protein (p=0.072) decreased, pH and b* increased (p&lt;0.05), but drip, cooking (p&lt;0.05) and thawing (p=0.088) losses decreased. Among treatments, muscle fiber diameter, sarcomere length, total and insoluble collagen contents, L*, and a* did not differ (p&gt;0.05). Compared to the others, HM had lower collagen solubility percentage (p&lt;0.05), but similar (p&gt;0.05) Warner-Bratzler Shear Force (WBSF). No differences (p&gt;0.05) were found in juiciness, overall flavor, oiliness, and overall acceptability, but HM was more tender (p&lt;0.05) than the others. Based on VML, consumers preferred MM to HM (p&lt;0.05), while LM was similar to MM and HM (p&gt;0.05). Corresponding to VML preference (r=0.45, p&lt;0.01), consumers (83%) would (p&lt;0.01) definitely and probably buy MM, over LM (74%), and HM (68%), respectively.

CONCLUSION

Increasing VML in pork LD altered its chemical composition, slightly increased pH, and improved WHC, thereby improving its tenderness acceptability. Marbling might reduce chewing resistance, as lower collagen solubility in HM did not impact tenderness acceptability and WBSF. While HM was rated as most tender, consumers visually preferred and would purchase MM.

Transcriptome Analysis of Landrace Pig Subcutaneous Preadipocytes during Adipogenic Differentiation

Fat deposition in pigs, which significantly contributes to meat quality, fattening efficiency, reproductive performance, and immunity, is critically affected by preadipocyte adipogenic differentiation. We elucidated adipogenesis in pigs using transcriptome analysis. Preadipocytes from subcutaneous adipose tissue (SAT) of Landrace piglets were differentiated into adipocytes in vitro. RNA sequencing (RNA-seq) used to screen differentially expressed genes (DEGs) during preadipocyte differentiation up to day 8 revealed 15,918 known and 586 novel genes. We detected 21, 144, and 394 DEGs, respectively, including 16 genes differentially expressed at days 2, 4 and 8 compared to day 0. Th number of DEGs increased time-dependently. Lipid metabolism, cell differentiation and proliferation, peroxisome proliferator-activated receptor (PPAR), wingless-type MMTV integration site (Wnt), tumor necrosis factor (TNF) signaling, and steroid biosynthesis were significant at days 2, 4, and 8 compared to day 0 (adjusted p < 0.05). Short time-series expression miner (STEM) analysis obtained 26 clusters of differential gene expression patterns, and nine were significant (p < 0.05). Functional analysis showed many significantly enriched lipid deposition- and cellular process-related biological processes and pathways in profiles 9, 21, 22, and 24. Glycerolipid and fatty-acid metabolism, PPAR signaling, fatty-acid degradation, phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), and TNF signaling were observed during preadipocyte differentiation in vitro. These findings will facilitate the comprehension of preadipocyte differentiation and fat deposition in pigs.

Identification of Candidate Genes and Regulatory Factors Underlying Intramuscular Fat Content Through Longissimus Dorsi Transcriptome Analyses in Heavy Iberian Pigs

One of the most important determinants of meat quality is the intramuscular fat (IMF) content. The development of high-throughput techniques as RNA-seq allows identifying gene pathways and networks with a differential expression (DE) between groups of animals divergent for a particular trait. The Iberian pig is characterized by having an excellent meat quality and a high content of intramuscular fat. The objectives of the present study were to analyze the longissimus dorsi transcriptome of purebred Iberian pigs divergent for their IMF breeding value to identify differential expressed genes and regulatory factors affecting gene expression. RNA-seq allowed identifying ∼10,000 of the 25,878 annotated genes in the analyzed samples. In addition to this, 42.46% of the identified transcripts corresponded to newly predicted isoforms. Differential expression analyses revealed a total of 221 DE annotated genes and 116 DE new isoforms. Functional analyses identified an enrichment of overexpressed genes involved in lipid metabolism (FASN, SCD, ELOVL6, DGAT2, PLIN1, CIDEC, and ADIPOQ) in animals with a higher content of IMF and an enrichment of overexpressed genes related with myogenesis and adipogenesis (EGR1, EGR2, EGR3, JUNB, FOSB, and SEMA4D) in the animals with a lower content of IMF. In addition to this, potential regulatory elements of these DE genes were identified. Co-expression networks analyses revealed six long non-coding RNAs (lncRNAs) (ALDBSSCG0000002079, ALDBSSCG0000002093, ALDBSSCG0000003455, ALDBSSCG0000004244, ALDBSSCG0000005525, and ALDBSSCG0000006849) co-expressed with SEMA4D and FOSB genes and one (ALDBSSCG0000004790) with SCD, ELOVL6, DGAT2, PLIN1, and CIDEC. Analyses of the regulatory impact factors (RIFs) revealed 301 transcriptionally regulatory factors involved in expression differences, with five of them involved in adipogenesis (ARID5B, CREB1, VDR, ATF6, and SP1) and other three taking part of myogenesis and development of skeletal muscle (ATF3, KLF11, and MYF6). The results obtained provide relevant insights about the genetic mechanisms underlying IMF content in purebred Iberian pigs and a set of candidate genes and regulatory factors for further identification of polymorphisms susceptible of being incorporated in a selection program.

Comparative Analysis of Long Noncoding RNAs Expressed during Intramuscular Adipocytes Adipogenesis in Fat-Type and Lean-Type Pigs

The meat quality of local breed pigs is more tender and juicier than the imported varieties. The important reason is that the intramuscular fat content is high. Even through modest sequence conservation and evolution, the expression pattern and function of long noncoding RNAs (lncRNAs) seem to be conserved. In spite of that, analysis of lncRNAs associated with intramuscular fat development remains unknown to us in porcine. Here, we systematically investigated lncRNAs of intramuscular adipocytes of fat local Bamei pigs and lean Large White pigs to consider the function of lncRNAs on intramuscular fat development. We selected three piglets of both breeds separately to isolate intramuscular preadipocytes, performed RNA sequencing across four stages (0, 2, 4, and 8 d) during the intramuscular preadipocytes differentiation, and identified 1932 lncRNAs (760 novel). In addition, we have screened lnc_000414 closely related to fat synthesis. This lncRNA function as an inhibitor in the proliferation of porcine intramuscular adipocytes. These novel findings will provide new targets for improving pork quality and making pig breeding better.

Consumers' acceptability of indigenous cockerel

Commercial poultry production, although fairly well developed, continues to develop rapidly in Africa and other areas of the world. The local chickens, which may perhaps be harnessed and exploited for poverty alleviation, form part of the many local assets of underprivileged people living in the rural areas. In view of this, the study aims to investigate consumer acceptability of indigenous chicken meats using survey and sensory evaluation. The survey is comprised mainly of interviewing market women and supplying birds to them for sale in order to find answers to questions related to marketability or otherwise of the naked-neck, frizzled naked-neck, and normal-feathered cockerels. An experiment was carried out to evaluate consumers' preference of the 3 genotypes, namely NanaFf, Nanaff, and nanaff. The birds used were of the fourth generation (F4) offspring of crosses between local heterozygous naked neck (Nana) and heterozygous frizzled (Ff) males and hybrid commercial Lohmann females. Three hundred (300) cockerels that were 11 wk old crossbreds (100 of each of the 3 genotypic groups) were randomly housed in 15 open-sided, deep-litter pens with 20 cockerels in each pen in a completely randomized design for 9 wk. Burgers were prepared from the breast muscle of the carcass for sensory evaluation. The results from the survey indicated that a majority (91.7%) of the respondents admitted that they would readily accept to sell the naked-neck cockerels. Also, at almost all the sales points, the Nanaff was first to be sold out, followed by the nanaff feathered with the NanaFf being the last both before and during the major season's sales. The results from the sensory evaluation indicated that the burgers from nanaff and NanaFf birds had significantly (P < 0.05) lower acceptability levels than those from the Nanaff birds. The naked-neck gene cockerel had a positive effect on cockerel meat and marketability.

Effects of dietary hop (Humulus lupulus L.) β-acids on quality attributes, composition and oxidative stability of pork meat

BACKGROUND

The effects of dietary levels of hop β-acids on physical attributes, lipid oxidation and chemical composition of pork meat were evaluated. Thirty-two castrated male pigs obtained from a complete block design feeding experiment (6.23 ± 0.42 kg initial body weight (BW) to 20.45 ± 0.95 kg final BW) and fed diets supplemented with 0, 120, 240 or 360 mg kg^-1 hop β-acids during 35 days were slaughtered to sample longissimus dorsi muscle for meat analysis.

RESULTS

No effects (P > 0.05) of dietary hop β-acids were observed on meat physical attributes. Quadratic effects (P < 0.05) of hop β-acids were observed on lipid and protein contents and on thiobarbituric acid-reactive substance (TBARS) values of meatballs, whose equations allowed the estimation of dietary hop β-acid levels of 176, 169 and 181 mg kg^-1 to provide up to 16.20% lipid reduction, 1.95% protein accretion and 23.31% TBARS reduction respectively.

CONCLUSION

Dietary hop β-acids fed to pigs might reduce lipid, increase protein and reduce lipid oxidation without affecting physical attributes of the pork meat. © 2017 Society of Chemical Industry.

Metabonomics profiling of marinated meat in soy sauce during processing

BACKGROUND

Marinated meat in soy sauce is one of the most popular traditional cured meat products in China. Its taste quality is directly related to primary and secondary metabolites. Herein, the change of metabolite composition of marinated meat in soy sauce during processing was systematically characterised using ¹ H NMR and multivariate data analysis.

RESULTS

The marinated meat in soy sauce metabonome was dominated by 26 metabolites, including amino acids, sugars, organic acids, nucleic aides and their derivatives. PC1 and PC2 explained a total of 78.6% and 16.6% of variables, respectively. Amino acids, sugars, acetate, succinate, uracil and inosine increased during marinating, while lactate, creatine, inosine-5'-monophosphate (5'-IMP) and anserine decreased (P < 0.05). After marinating, most of the metabolites decreased except for acetate and alanine (P < 0.05). There was a negative effect on the taste of marinated meat in soy sauce during the late stage of dry-ripening.

CONCLUSION

These findings indicated that the potential of NMR-based metabonomics is of importance for taste quality of marinated meat in soy sauce, which could contribute to a better understanding of the changes of taste compounds in meat products during processing. Shortening the dry-ripening period could be considered to improve the taste quality. © 2017 Society of Chemical Industry.

Knockdown of ubiquitin D inhibits adipogenesis during the differentiation of porcine intramuscular and subcutaneous preadipocytes

OBJECTIVES

Intramuscular fat (IMF) has a significant influence on porcine meat quality. Ubiquitin D (UBD) is involved in the management of diverse intracellular processes. However, its physiological functions in adipose cell differentiation and proliferation are still poorly defined.

MATERIALS AND METHODS

Intramuscular and subcutaneous preadipocytes were isolated from the longissimus dorsi and neck subcutaneous deposits of Chinese native Guanzhong Black piglets (3-5 days old), respectively. Lentivirus with short hairpin RNA (shRNA) for UBD was applied to knockdown UBD expression. We used real-time PCR and Western blot analysis to detect gene expression. Lipid droplets were dyed with Oil Red O, and cell proliferation was assessed using flow cytometry, 5-ethynyl-2'-deoxyuridine incorporation and cell counting assays.

RESULTS

Lipogenesis through the Akt/mTOR pathway was inhibited when preadipocytes were transfected with UBD shRNA. The expression of adipogenic genes and the number of lipid droplets were obviously diminished. Moreover, repression of UBD attenuated cell proliferation. UBD downregulation resulted in cell cycle arrest because of a decreased proportion of S-phase cells, and the expression of positive cell proliferation markers was significantly decreased.

CONCLUSION

These observations illustrated that knockdown of UBD partially suppressed porcine intramuscular and subcutaneous preadipocyte adipogenesis through the Akt/mTOR signalling and inhibited cell proliferation, suggesting the essential role of UBD in the differentiation of preadipocytes.

Review of Black Soldier Fly (Hermetia illucens) as Animal Feed and Human Food

Food futurists accept that sustainability-minded humanity will increasingly incorporate insects as alternative protein. The most studied and easily reared species are not necessarily the most sustainable, acceptable, or delicious. Here, we review the literature on the black soldier fly, Hermetia illucens, which is capable of efficiently converting a wide variety of organic materials, from food waste to manure, into insect biomass. They can be grown and harvested without dedicated facilities and are not pestiferous. Their larvae are 42% crude protein and 29% fat, although they are higher in saturated fats than most insects. They do not concentrate pesticides or mycotoxins. They are already grown and recommended for use as animal feed, but with regional legal restrictions on how this is done. For commercial use in human foods, larvae could potentially be milled and converted into a textured protein with a strong flavor. Their biggest advantage over other insects is their ability to convert waste into food, generating value and closing nutrient loops as they reduce pollution and costs. This general advantage is also their greatest disadvantage, for the social stigmas and legal prohibitions against eating organisms that eat waste are added to extant taboos facing insect consumption.

Effect of high pressure treatment on metabolite profile of marinated meat in soy sauce

Marinated meat in soy sauce was produced using hind leg by washing, rubbing salt, marinating with soy sauce and spices, and air dry-ripening for 15d. The effect of high pressure (HP) (150 and 300MPa for 15min) on the metabolite profiles of products was characterized using ¹H NMR and multivariate data analysis. The results showed that the metabonome was dominated by 26 metabolites, including amino acids, sugars, organic acids, nucleic aides and their derivatives. PC1 and PC2 explained a total of 75.4 and 11.9% of variables, respectively. HP treatments increased most of the metabolites, especially PC1, glutamate, sugars, nucleotides, anserine, lactate and creatine compared to the control. The increase of metabolites under HP was not dependent on pressure level except for alanine, lactate, acetate, formate, fumarate, glucose and 5'-IMP. These findings demonstrated that HP treatment at 150MPa was economical to improve the taste of marinated meat in soy sauce.

TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Intramuscular fat deposition in ruminants and pigs: A transcriptomics perspective

The genomics era has led to an explosion in the study of gene expression in production animals. Intramuscular fat (IMF) content (both high and low) and composition are major quality attributes of meat, and more than 90 transcriptomic studies of IMF deposition have been undertaken in the ruminants and pigs since 2001, with the majority since 2008. The studies have implicated many genes involved in the control of adipogenesis, lipogenesis, and deposition of IMF, but there is relatively little consistency between the different studies. However, the genes encoding the synthesis enzymes acetyl-CoA carboxylase α, fatty acid synthase, and stearoyl-CoA desaturase; the fatty acid binding protein 4; the potential signaling protein thyroid hormone responsive; and the regulators C/EBPα, PPARγ, and sterol regulatory element binding transcription factor 1 are supported by 5 or more of the 90 studies. By combining the results of all the studies, complete pathways for long-chain fatty acid (LCFA) and triacylglyceride (TAG) synthesis are identified, as are a number of genes encoding proteins probably associated with the storage of TAG and genes encoding a number of known and potential adipokines. In contrast, support for the association of lipolytic pathways with IMF percentage is less strong. Differences in experimental design-in particular, the age of the animals, the rate of IMF deposition at sampling, the past nutritional history of the animals used, and the complexities of using a tissue with mixed cell types-have contributed to the differences in results and interpretation. Biomarkers predictive of future IMF percentage, facilitating reaching optimal IMF content at slaughter, may have industry utility, but to be useful in animal biopsy and postslaughter samples, where multiple cell types are present, genes must be carefully chosen to ensure that they are informative about the expected processes. Despite these problems, candidate biomarkers for estimation of de novo intramuscular adipocyte LCFA synthesis, LCFA uptake rate by intramuscular adipocytes, and IMF deposition rate have been identified and examples of their utility have been published. However, further work is required to demonstrate how best to apply the assays for the benefit of the relevant livestock production industries.

Comparison of Meat Quality and Fatty Acid Composition of Longissimus Muscles from Purebred Pigs and Three-way Crossbred LYD Pigs

This study was conducted to find pork quality to meet the needs of consumers. Thus, the meat quality and fatty acid composition of longissimus muscles from purebred pigs (Landrace, Yorkshire, and Duroc) and three-way crossbred LYD pigs were compared and evaluated. Chemical compositions of longissimus muscles were significant (p<0.05) different among pigs. Duroc contained significant (p<0.05) higher fat contents than other pigs, whereas significant (p<0.05) higher moisture contents were observed in Landrace, Yorkshire, and LYD pigs compared to those of Duroc pigs. The values of pH_{24 h} and pH_{14 d} were the highest in Landrace pigs. Myoglobin contents of LYD pigs were higher (p<0.05) than those of purebred pigs. Regarding meat color, Duroc and Yorkshire pigs had higher redness values than Landrace and LYD pigs, while Landrace pigs had the lowest (p<0.05) color values among all pigs. There was no significant difference in shear force or water holding capacity (WHC). Duroc pigs maintained the lowest drip loss during 14 d of cold storage. In sensory evaluation, the marbling scores of Duroc pigs were higher (p<0.05) than other pigs. Regarding fatty acid compositions, total USFA, poly-, n-3, and n-6 contents were the highest (p<0.05) in LYD pigs, while total SFA contents were the highest (p<0.05) in Duroc pigs. Based on these results, purebred pigs had superior overall meat quality to crossbred pigs.

Study of cholesterol and vitamin E levels in broiler meat from different feeding regimens by TOF-SIMS

The quality of chicken meat, which is one of the most widely consumed meats in the world, has been the subject of research and studies for many years. There are several ways to improve the quality of this type of meat, including changing the concentrations of individual molecular components. Such important components of meat are inter alia, cholesterol, vitamin E, and some fatty acids such as ω-3 and ω-6. Manipulation of ingredient levels may be achieved by enriching chicken feed with elements of different types such as vegetable oils, garlic, or selenium. Thus far, various biochemical and biophysical methods have been used to study quality of different meat types, especially broiler meat. Here, the authors demonstrate the use of high-resolution time-of-flight secondary ion mass spectrometry (TOF-SIMS) mass spectrometry to assess how variations in animal nutrition affect concentrations of specific lipids in the meat, such as cholesterol and vitamin E. In the presented experiment, there were four different dietary treatments. Feed for animals in the first group was supplemented with soy oil in 50%, the second group's feed was supplemented with linseed oil in 50%, a combination of these two oils in the proportion of 44%:56% was used for the third group, and in the reference group, animals were fed with beef tallow. From each group, four individuals were selected for further analysis. Positive and negative ion mass spectra were generated from the pectoralis superficialis muscle tissue of the left carcass side of each one animal. Using TOF-SIMS with a bismuth cluster ion source (Bi3 (+)), and based on characteristic peaks for cholesterol in the positive mode and vitamin E in the negative mode, the authors have illustrated the relationship of these lipids levels to the various feeding regimens. Simultaneously, the authors characterized the varying dependences on the concentrations of measured lipids in fat and muscle fibers. The cholesterol concentration in muscle fibers was the lowest in the group fed with soybean oil and the highest in reference group IV (tallow feed). In the fatty region, the highest level of cholesterol was found in the third group. The highest concentrations of vitamin E were found in the fibers of the first group and the fat region of the second group. The obtained results show that SIMS imaging is a useful approach for assessing changes in lipid concentrations in the meat tissue from animals on different diets and provides a foundation for future research.

Activation of PPARγ2 by PPARγ1 through a functional PPRE in transdifferentiation of myoblasts to adipocytes induced by EPA

PPARγ and Wnt signaling are central positive and negative regulators of adipogenesis, respectively. Here we identified that, eicosapentaenoic acid (EPA) could effectively induce the transdifferentiation of myoblasts into adipocytes through modulation of both PPARγ expression and Wnt signaling. During the early stage of transdifferentiation, EPA activates PPARδ and PPARγ1, which in turn targets β-catenin to degradation and down-regulates Wnt/β-catenin signaling, such that the myogenic fate of myoblasts could be switched to adipogenesis. In addition, EPA up-regulates the expression of PPARγ1 by activating RXRα, then PPARγ1 binds to the functional peroxisome proliferator responsive element (PPRE) in the promoter of adipocyte-specific PPARγ2 to continuously activate the expression of PPARγ2 throughout the transdifferentiation process. Our data indicated that EPA acts as a dual-function stimulator of adipogenesis that both inhibits Wnt signaling and induces PPARγ2 expression to facilitate the transdifferentiation program, and the transcriptional activation of PPARγ2 by PPARγ1 is not only the key factor for the transdifferentiation of myoblasts to adipocytes, but also the crucial evidence for successful transdifferentiation. The present findings provided insight for the first time as to how EPA induces the transdifferentiation of myoblasts to adipocytes, but also provide new clues for strategies to prevent and treat some metabolic diseases.

Comparative transcriptomic analysis to identify differentially expressed genes in fat tissue of adult Berkshire and Jeju Native Pig using RNA-seq

Pork is a major source of animal protein for humans. The subcutaneous, intermuscular and the intramuscular fat are the factors responsible for meat quality. RNA-seq is rapidly adopted for the profiling of the transcriptomes in the studies related to gene regulation. The discovery of differentially expressed genes (DEGs) between adult animals of Jeju Native Pig (JNP) and Berkshire breeds are of particular interest for the current study. RNA-seq was used to investigate the transcriptome profiling in the fat tissue. Sequence reads were obtained from Ilumina HiSeq2000 and mapped to the pig genome using Tophat2. Total 153 DEGs were identified and 71 among the annotated genes, have BLAST matches in the non- redundant database. Metabolic, immune response and protein binding are enriched pathways in the fat tissue. In our study, biological adhesion, cellular, developmental and multicellular organismal processes in fat were up-regulated in JNP as compare to Berkshire. Multicellular organismal process, developmental process, embryonic morphogenesis and skeletal system development were the most significantly enriched terms in fat of JNP and Berkshire breeds (p = 1.17E-04, 0.044, 3.47E-04 and 4.48E-04 respectively). COL10A1, COL11A2, PDK4 and PNPLA3 genes responsible for skeletal system morphogenesis and body growth were down regulated in JNP. This study is the first statistical analysis for the detection of DEGs from RNA-seq data generated from fat tissue sample. This analysis can be used as stepping stone to understand the difference in the genetic mechanisms that might influence the identification of novel transcripts, sequence polymorphisms, isoforms and noncoding RNAs.

Longissimus dorsi transcriptome analysis of purebred and crossbred Iberian pigs differing in muscle characteristics

BACKGROUND

The two main genetic types in Iberian pig production show important phenotypic differences in growth, fattening and tissue composition since early developmental stages. The objective of this work was the evaluation of muscle transcriptome profile in piglets of both genetic types, in order to identify genes, pathways and regulatory factors responsible for their phenotypic differences. Contemporary families coming from pure Iberian pigs (IB) or from crossing with Duroc boars (DU×IB) were generated. Piglets (14 from each genetic type) were slaughtered at weaning (28 days) and longissimus dorsi was sampled for composition and gene expression studies. RNA was obtained and hybridized to Affymetrix Porcine Genechip expression arrays.

RESULTS

Loin muscle chemical composition showed significant differences between genetic types in intramuscular fat content (6.1% vs. 4.3% in IB and DUxIB animals, respectively, P = 0.009) and in saturated (P = 0.019) and monounsaturated fatty acid proportions (P = 0.044). The statistical analysis of gene expression data allowed the identification of 256 differentially expressed (DE) genes between genetic types (FDR < 0.10), 102 upregulated in IB and 154 upregulated in DU×IB. Transcript differences were validated for a subset of DE genes by qPCR. We observed alteration in biological functions related to extracellular matrix function and organization, cellular adhesion, muscle growth, lipid metabolism and proteolysis. Candidate genes with known effects on muscle growth were found among the DE genes upregulated in DU×IB. Genes related to lipid metabolism and proteolysis were found among those upregulated in IB. Regulatory factors (RF) potentially involved in the expression differences were identified by calculating the regulatory impact factors. Twenty-nine RF were found, some of them with known relationship with tissue development (MSTN, SIX4, IRX3), adipogenesis (CEBPD, PPARGC1B), or extracellular matrix processes (MAX, MXI1). Correlation among the expression of these RF and DE genes show relevant differences between genetic types.

CONCLUSION

These results provide valuable information about genetic mechanisms determining the phenotypic differences on growth and meat quality between the genetic types studied, mainly related to the development and function of the extracellular matrix and also to some metabolic processes as proteolysis and lipid metabolism. Transcription factors and regulatory mechanisms are proposed for these altered biological functions.

Fortification of pork loins with docosahexaenoic acid (DHA) and its effect on flavour

Pork is traditionally low in docosahexanoic acid (DHA, C22:6n-3) and deficient in omega-3 fats for a balanced human diet. DHA as triglycerides was commercially prepared from the microalgae Schizochytrium and injected into fresh pork loins. Treatments of a mixed brine control (CON), 3.1% sunflower oil in mixed brine (SF) and a 3.1% DHA oil in mixed brine (DHA) were injected into pork loins at 10 mL/100 g and grilled at 205°C. After cooking, the CON and SF pork loins contained 0.03 to 0.05 mg DHA/g of pork and the DHA injected loins contained approximately 1.46 mg DHA/g. This also changed the fatty acid profile of omega-6: omega-3 from, 5 to 1 in the CON pork, to a ratio of 1.7 to 1 in DHA pork. The appearance, odor, oxidation rates and sensory taste, as judged by a trained panel, determined the DHA injected meat to be, 'slightly desirable’ and gave lower 'off flavour’ scores, relative to the CON and SF injected pork. Pork can be fortified with DHA oil to 146 mg/100 g serving, which would meet half the recommended daily omega 3 fatty acid requirements for adult humans and would be desirable in taste.

Transcriptome comparison between porcine subcutaneous and intramuscular stromal vascular cells during adipogenic differentiation

Intramuscular fat (IMF) is an important trait influencing meat quality, and preadipocyte differentiation is a key factor affecting IMF deposition. Here we compared the transcriptome profiles of porcine intramuscular and subcutaneous preadipocytes during differentiation to gain insight into specific molecular and cellular events associated with intramuscular stromal vascular cell (MSVC) differentiation. RNA-Seq was used to screen for differentially expressed genes (DEGs) during the in vitro differentiation of MSVC and subcutaneous stromal vascular cell (ASVC) on days 0, 2 and 4. A total of 985 DEGs were identified during ASVC differentiation and 1469 DEGs during MSVC differentiation. Among these DEGs, 409 genes were specifically expressed during ASVC differentiation, 893 genes were specifically expressed during MSVC differentiation, and 576 DEGs were co-expressed during ASVC and MSVC differentiation. The expression profiles of DEGs during ASVC or MSVC differentiation were determined by cluster analysis based on Short Time-series Expression Miner (STEM). Four significant STEM profiles (profiles 1, 4, 5, and 14) were determined during ASVC differentiation, and four significant STEM profiles (profiles 1, 4, 11, and 14) were determined during MSVC differentiation. Gene ontology (GO) analysis indicated that DEGs related to adipocyte differentiation were identified to be significantly enriched in both adipose and muscle profile 14. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEGs in adipose profile 14 and muscle profiles 11 and 14 (STEM clustered them into one cluster) showed that the PPAR signaling pathway was significantly enriched in these profiles and four signaling pathways were specifically enriched in muscle profiles 11 and 14. Furthermore, analysis of transcription factor binding sites (TFBS) in the gene set revealed two over-represented transcription factors (NR3C4 and NR3C1), which were specifically significantly enriched in the promoter regions of genes within muscle gene expression profiles 11 and 14.

Role of intrinsic search cues in the formation of consumer preferences and choice for pork chops

This study investigates the role of drip, colour, marbling and fat cover as intrinsic search cues in the formation of pork chop preferences and individual determinants. Data are collected from a sample of 443 pork consumers in Belgium through using repeated selection of chops from randomised photobooks and questionnaires including socio-demographic, attitudinal and behavioural variables. Data analysis includes mixture regression analysis, bivariate descriptive statistics and the estimation of multivariate probit models. Consumers sampled in this study prefer pork chops without fat cover. Preference for fat cover is stronger among male, 35+ aged consumers with lower levels of awareness of the relation between food and health and who like pork for other reasons than taste and nutritional value (all p<0.05). Preference for colour is equally consistent within an individual, though fifty-fifty light-dark, with dark chops being more preferred by 35+ aged consumers (p<0.05). Preferences for marbling and drip are not consistent and not determined by joint socio-demographic, attitudinal and behavioural factors. Preferences for cue levels are not correlated, except a weak relation between preference for dark chops without drip (r=0.116). Preferences are apparently formed by deductions with the use of single cues as key information, mainly based on fat cover or colour, and random choice on marbling and drip.

HRMAS-NMR spectroscopy and multivariate analysis meat characterisation

¹H-High resolution magic angle spinning-nuclear magnetic resonance spectroscopy was employed to gain the metabolic profile of longissimus dorsi and semitendinosus muscles of four different breeds: Chianina, Holstein Friesian, Maremmana and Buffalo. Principal component analysis, partial least squares projection to latent structure - discriminant analysis and orthogonal partial least squares projection to latent structure - discriminant analysis were used to build models capable of discriminating the muscle type according to the breed. Data analysis led to an excellent classification for Buffalo and Chianina, while for Holstein Friesian the separation was lower. In the case of Maremmana the use of intelligent bucketing was necessary due to some resonances shifting allowed improvement of the discrimination ability. Finally, by using the Variable Importance in Projection values the metabolites relevant for the classification were identified.