Effect of dietary Eucommia ulmoides oliver polysaccharide on immune function and meat quality of Songliao Black Pigs.

Eucommia ulmoides is a traditional Chinese herbal medicine, with pharmacological effects such as lowering blood pressure and enhancing immune function. The effects of dietary Eucommia ulmoides polysaccharide (EUP) on immune function and meat quality were studied in Songliao Black Pigs. Blood lymphocyte counts and percentage, concentrations of serum total protein and of albumin increased, whereas those of urea nitrogen and triglyceride decreased. White blood cell and lymphocyte counts, and serum IgA, IgE, IgG2 a and IFN-γ increased. Average daily weight gain, slaughter weight, lean meat rate and cooked meat rate increased, whereas pH24, feed-weight ratio, fat rate, yellowness (b#) and centrifugal dehydration rate decreased. Transcriptome sequencing of longissimus dorsi muscle detected 32 differentially expressed genes (DEGs), of which 26 were up-regulated and 6 down-regulated. A total of 19 genes were differentially expressed in the four groups, 18 of which were up-regulated. The DEGs included ADAMTS4, PER1, STAC, SERPINE1, FASN, THRSP, SP7 and KRT80 and the protein interaction network showed 20 up-regulated nodes, three down-regulated nodes and 14 DEGs. GO functional annotation and enrichment analysis showed that 34 items were significantly enriched, including transferase activity, actin binding, acetyl coenzyme A, acyl coenzyme A metabolism, adipose tissue development and acyl glycerol homeostasis. KEGG pathway analysis showed that the AMPK and PPAR signaling pathways were enriched. Dietary Eucommia polysaccharide enhanced immune function in Songliao Black Pigs, improved growth and carcass performance, increased the expression of genes related to meat quality traits and improved meat quality.

Polystyrene microplastics exposure reduces meat quality and disturbs skeletal muscle angiogenesis via thrombospondin 1.

Microplastics (MPs) pose a significant threat to livestock health. Yet, the roles of polystyrene MPs (PS-MPs) on meat quality and skeletal muscle development in pigs have not been fully determined. To investigate the effect of PS-MPs on skeletal muscle, piglets were given diets supplementation with 0 mg/kg (CON group), 75 mg/kg (75 mg/kg PS-MPs group), and 150 mg/kg PS-MPs (150 mg/kg PS-MPs group), respectively. The results indicated that the average daily gain (ADG) of piglets in the 150 mg/kg PS-MPs group was significantly lower than that in the CON group. No significant differences were observed in the final body weight and ADG between the CON group and the 75 mg/kg PS-MPs group. Piglets in the 150 mg/kg PS-MPs group exhibited decreased meat redness index and type I muscle fiber density. Metabolomic analysis revealed that the contents of meat flavor compounds carnosine, beta-alanine, palmitic acid, and niacinamide in muscle were lower in the 150 mg/kg PS-MPs group than in the CON group. Additionally, piglets subjected to 150 mg/kg PS-MPs exhibited impaired muscle angiogenesis. Further analysis indicated that PS-MPs exposure up-regulated thrombospondin 1 (THBS1) expression by inhibiting THBS1 mRNA and protein degradation, thereby disrupting skeletal muscle angiogenesis. These findings indicate that PS-MPs exposure adversely affects meat quality and hinders skeletal muscle angiogenesis in pigs, providing deeper insights into the detrimental effects of PS-MPs on meat quality and skeletal muscle development.

A new histopathology scoring protocol reveals myopathy features in PSE-like pork.

Pale, Soft, and Exudative (PSE)-like pork defects are associated with fiber destruction and pale discoloration and have become a severe economic burden for the European meat sector. However, robust detection of PSE-like pork and its diverse features is challenging and makes studies into defect causation difficult. Implementation of histological examination may improve our knowledge about less-known features linked to PSE-like defects. Here we evaluate if a new histological protocol can reveal how myopathy in ham may be associated with visual and traditional physicochemical anomalies of PSE-like pork. We first created a list of pathological features, quantified them, and integrated them into a myodegeneration scoring scheme (MYO) for semimembranosus muscle sections. We then explored potential associations between overall MYO scoring and individual histology features with visual PSE-like defect scoring (DES) and with individual meat quality variables [pHu, color: L*, a*, b* (CIELAB), bioimpedance, and near-infrared spectroscopy (NIR)]. As the primary finding of this study, we show a significant association between overall myopathy (MYO) scoring and PSE-like defect (DES) scores. We also found associations of specific myopathy features with DES scores, and of overall MYO scoring with specific quality variables. In all, our data suggest links between signs of acute myodegeneration and PSE-like defects. Our data, hence, supports the implementation of semi-quantitative histopathological approaches for diagnosing PSE-like pork features and may help identify the underlying mechanisms behind these defects.

Feeding strategy in organic pig farming as a lever to improve various quality dimensions of pork.

Since 2022, European specifications for organic pig farming have evolved to distribute 100 % organic feed and to reinforce the link to the soil with feed resources that should primarily be obtained from the farm or the same region. Feeding strategy acts as a lever to improve various quality dimensions of organic (as well as conventional) pork, including intrinsic dimensions (carcass composition, nutritional, organoleptic, technological, sanitary qualities) and extrinsic dimensions related to animal farming (image). Diet may also influence the risk of undesirable odours or flavours that may be found in pork from non-castrated male pigs. This study aimed at evaluating the effects of a specific feeding strategy on several quality dimensions of organic meat from non-castrated male pigs. The experiment was conducted with 77 organic non-castrated male pigs (Piétrain NN × Large White) reared according to organic specifications and distributed in two batches. Within litters, male littermates were allocated at around 33 kg of live weight to either a Control group which received a Control feed (C) corresponding to the organic specifications or in a Bio+ group which received an organic test feed based mainly on French raw materials and which contained more fibres (faba bean and access to forages) and omega-3 fatty acids (linseed, camelina). All pigs were reared in the same building on deep straw bedding (1.3 m2/pig) with free outdoor access (1.0 m2/pig) using one pen per experimental group. Pigs were fed ad libitum until slaughter at about 125 kg live weight. Average daily gain, carcass weight and lean meat content did not differ significantly between C and Bio+ pigs. Compared to C, Bio+ pigs had higher (P < 0.05) ultimate pH in the loin (Longissimus muscle) and ham (Gluteus medius, and Semimembranosus) muscles, associated with a lower Longissimus muscle glycolytic potential (P < 0.001). Loin and ham meat from Bio+ vs. C pigs was lighter (P < 0.05) and had a more intense red colour (P < 0.10). The Bio+ strategy led to a lower Longissimus muscle n-6:n-3 fatty acid ratio (P < 0.001), indicating an improvement in pork nutritional value. Backfat skatole concentration was lower in Bio+ than in C pigs whereas backfat androstenone was higher in Bio+ than in C pigs (P < 0.05). Altogether, we demonstrated that the Bio+ strategy had positive impacts on several qualities of organic pork from non-castrated male pigs.

Metabolic and microbial mechanisms related to the effects of dietary wheat levels on intramuscular fat content in finishing pigs.

The current study aimed to investigate the metabolic and microbial mechanisms behind the effects of dietary wheat levels on intramuscular fat (IMF) content in the psoas major muscle (PM) of finishing pigs. Thirty-six barrows were arbitrarily assigned to two groups and fed with diets containing 25% or 55% wheat. Enhancing dietary wheat levels led to low energy states, resulting in reduced IMF content. This coincided with reduced serum glucose and low-density lipoprotein cholesterol levels. The AMP-activated protein kinase α2/sirtuin 1/peroxisome proliferator-activated receptor-γ coactivator 1α pathway may be activated by high-wheat diets, causing downregulation of adipogenesis and lipogenesis genes, and upregulation of lipolysis and gluconeogenesis genes. High-wheat diets decreased relative abundance of Lactobacillus and Coprococcus, whereas increased SMB53 proportion, subsequently decreasing colonic propionate content. Microbial glycolysis/gluconeogenesis, d-glutamine and D-glutamate metabolism, flagellar assembly, and caprolactam degradation were linked to IMF content. Metabolomic analysis indicated that enhancing dietary wheat levels promoted the protein digestion and absorption and affected amino acids and lipid metabolism. Enhancing dietary wheat levels reduced serum glucose and colonic propionate content, coupled with strengthened amino acid metabolism, contributing to the low energy states. Furthermore, alterations in microbial composition and propionate resulted from high-wheat diets were associated with primary bile acid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and biosynthesis of unsaturated fatty acids, as well as IMF content. Colonic microbiota played a role in reducing IMF content through modulating the propionate-mediated peroxisome proliferators-activated receptor signaling pathway. In conclusion, body energy and gut microbiota balance collectively influenced lipid metabolism.

Preparation and characterization of fennel (Foeniculum vulgare miller) essential oil/hydroxypropyl-ß-cyclodextrin inclusion complex and its application for chilled pork preservation.

Fennel essential oil (FEO) a natural spice that has versatile biological activities. However, the direct use of FEO is limited due to its water insolubility and poor stability. Chilled pork is prone to spoilage during storage. To solve these problems, this study aimed to prepare an inclusion complex (IC) of FEO with hydroxypropyl-ß-cyclodextrin via co-precipitation and apply it to the preservation of chilled pork. Results indicated that the optimal parameters were encapsulating temperature 37 °C, wall-core ratio 14:1 g/mL, stirring speed 600 r/min, and encapsulating time 240 min, obtaining an encapsulation efficiency of 83.75%. The results of scanning electron microscopy, Fourier transform infra-red spectroscopy, and nuclear magnetic resonance demonstrated the successful preparation of IC. The release of FEO from IC was controllable through adjusting the different temperatures and relative humidities. Furthermore, IC effectively delayed the spoilage of chilled pork and extended its shelf life by 6 days at 4 °C.

Natural aromatic extract of black tea improved the water retention of pork meat batter.

The effect of varying proportions (w/w) of natural aromatic extract of black tea (NAEBT) with pre-emulsification on the water-holding capacity (WHC) of pork meat batter was investigated. The addition of NAEBT significantly reduced the cooking loss (CL) of pork meat batter from 23.95 % to 18.30 % (P < 0.05). Furthermore, NAEBT with pre-emulsification significantly improved the color stability and increased the springiness (P < 0.05). The results of TBARS and carbonyls indicated that NAEBT with pre-emulsification significantly alleviated oxidative damage to proteins (P < 0.05), resulting in an increased level of ß-sheet (P < 0.05), as confirmed by FT-IR analysis. As a result, the water mobility of pork meat batter was restricted (P < 0.05), resulting in an increase in the energy storage modulus (P < 0.05) and a decrease in the pore size. In summary, the WHC of pork meat batter was improved by the antioxidant effect of the NAEBT.

Effects of slaughter weight and backfat depth on trimming, curing, and deboning losses and quality traits of Italian dry-cured ham.

This study aimed at assessing the effects of two infra-vitam traits, specifically the slaughter weight (SW) and the ultrasound backfat depth (BCKF) on several post-mortem and quality traits of typical Prosciutto Veneto protected designation of origin (PDO) dry-cured ham. The trial was conducted on a population of 423 pigs fed using different strategies to generate a high variation in SW (175 ± 15.5 kg) and BCKF (23.16 ± 4.14 mm). All the left thighs were weighed at slaughter and the ham factory during the different processing phases. The fat cover depth of green trimmed hams was measured. Data were analyzed with a linear model including SW classified in tertiles, BCKF as a covariate, SW × BCKF interaction, sex, batch, and pen nested within batch. Our results highlighted that, for each 10 kg increase in SW, trimmed and seasoned ham weights increased by 0.76 and 0.54 kg, respectively. The increase in SW significantly reduced relative curing and deboning losses but did not affect ham fat cover depth and trimming losses. A rise in BCKF increased the ham fat cover depth and trimming losses and decreased the curing and deboning losses. Increases in SW and BCKF improved quality traits of the seasoned ham including fat cover depth, visible marbling, inner lean firmness, and fat color. These findings confirm the feasibility of increasing SW and BCKF, which will result in a reduction in the relative losses associated with the dry-curing process while improving the quality of the seasoned ham.

Difference comparison of characteristic aroma compounds between braised pork cooked by traditional open-fire and induction cooker and the potential formation cause under electromagnetic cooking.

The characteristic aroma compounds of braised pork were identified through molecular sensory science and PLSR analysis, and the difference between two cooking methods, traditional open-fire (BPF) and induction cooker (BPC), was compared. Seventeen aroma compounds with odor activity values (OAVs) > 1 were identified in both samples. BPF revealed higher OAVs for most of the aroma compounds compared to BPC, and the higher aroma quality. Aroma recombination and omission experiments confirmed that twelve aroma compounds significantly contributed to the characteristic aroma of braised pork, and eight compounds such as hexanal, (E)-2-octenal, and methanethiol were further confirmed as important contributors by PLSR analysis. Furthermore, PLSR analysis clarified the role of aldehydes such as hexanal, (E)-2-octenal, and (E,E)-2,4-decadienal in contributing to fatty attribute, whereas methanethiol was responsible for the meaty aroma. These characteristic aroma compounds mainly derived from lean meat due to its high content of phospholipids, and the exogenous seasonings contributed to the balanced characteristic aroma profile of braised pork by altering the distribution of these characteristic aroma compounds. Variations in heating parameters affected the formation of lipid oxidation and Strecker degradation products, which might explain aroma discrepancy between braised pork cooked by two methods with different heat transfer efficiencies.

Insights into the identification of bitter peptides from Jinhua ham and its taste mechanism by molecular docking and transcriptomics analysis.

In order to identify the peptides responsible for bitter defects and to understand the mechanism of bitterness in dry-cured ham, the peptides were identified by LC-MS/MS, and the interaction between bitter peptides and receptor proteins were evaluated by molecular docking and molecular dynamics simulation; the signal transduction mechanism of bitter peptides was investigated using the model of HEK-293T cells by calcium imaging and transcriptomics analysis. The results of LC-MS/MS showed that 11 peptides were identified from the high bitterness fraction of defective ham; peptides PKAPPAK, VTDTTR and YIIEK derived from titin showed the highest bitterness values compared with other peptides. The results of molecular docking showed that lower CDOCKER energy was observed in the interaction between these peptides and hT2R16 in comparison with these receptors of hT2R1, hT2R4, hT2R5, hT2R8 and hT2R14, and the interaction of hT2R16 and peptides was stabilized by hydrophobic interaction and hydrogen bond. The average RMSF values of VTDTTR were higher than that of YIIEK and PKAPPAK, while EC50 values of VTDTTR were lower compared with PKAPPAK and YIIEK. Transcriptomics analysis showed that 529 differentially expressed genes were identified in HEK-293T cells during the stimulating by VTDTTR and were mainly enriched into neuroactive ligand-receptor interaction, MAPK pathway, cAMP pathway and calcium signaling pathway, which were mainly responsible for the bitter signal transduction of VTDTTR. These results could provide evidence for understanding the bitter defects of dry-cured ham and the taste mechanism of bitter peptide.

Revealing the intrinsic relationship between microbial communities and physicochemical properties during ripening of Xuanwei ham.

To clarify the relationship between microorganisms and physicochemical indicators of Xuanwei ham. Six ham samples for the first, second and third year were selected, respectively. The changes of physicochemical properties, the free fatty acids and microbial communities of Xuanwei ham were investigated by GC-MS and high-throughput sequencing technology. Results showed that scores of colour, overall acceptability, texture, taste and aroma were the highest in the third year sample. With increasing ripening time, moisture content, water activity (Aw), lightness (L*), springiness, and resilience decreased continuously, and yellowness (b*) was the highest in the second year sample. 31 free fatty acids were detected, and unsaturated fatty acids such as palmitoleic acid, oleic acid, and linoleic acid were the major fatty acids. The content of palmitoleic acid, oleic acid and eicosenoic acid increased significantly during processing. At the phylum level, the dominant bacteria were Proteobacteria and Firmicutes, and fungi were Ascomycota. At the genus level, the dominant bacteria were Staphylococcus and Psychrobacter, and fungi were Aspergillus. Correlation analysis showed that water content and Aw were closely related to microorganisms, and most unsaturated fatty acids were significantly correlated with microorganisms. These findings showed that microorganisms played an important role in the quality of Xuanwei ham, and provided a scientific basis for the quality control of Xuanwei ham.

Investigating the mechanistic impact of pork soft tissue preparation techniques on the classification precision of laser-induced breakdown spectroscopy.

The investigation of the mechanism underlying the impact of biological soft tissue sample preparation methods on laser-induced breakdown spectroscopy (LIBS) signals can enhance the stability of LIBS signals. Our study focused on four specific preparation methods applied to pork samples: rapid freezing, fresh slicing, drying, and pressing. The influence of various preparation techniques on the signal-to-noise ratio and fluctuation of Ca, Na, Mg, and CN bands within the sample spectra was assessed. The signal-to-noise ratios for samples that were dried and pressed notably improved. And the pressing method effectively mitigated the uneven distribution of pork tissue components, displaying superior spectral line stability. To explain this phenomenon, we used the Saha-Boltzmann diagram to estimate the plasma temperature. Remarkably, there was a significant reduction in plasma temperature fluctuations across four pressed samples, with a standard deviation of 108.53. Furthermore, we undertook a classification analysis employing support vector machine models to corroborate the generalization efficacy of the sample preparation technique. Dried and pressed samples demonstrated notably higher classification accuracy, precision, and recall (all >93%) compared to frozen and fresh samples, where these metrics remained below 86%. The performance of the SVM model was ultimately evaluated using Receiver Operating Characteristic (ROC) curves and the Area Under the Curve (AUC). The AUC for the frozen, fresh, dried, and pressed samples was 0.854, 0.907, 0.989, and 0.996, respectively. The findings revealed that the pressing method exhibited superior performance, followed by drying, fresh slicing, and freezing, in descending order of effectiveness.

Effect of ultrasound-assisted L-lysine treatment on pork meat quality and myofibrillar protein properties during postmortem aging.

This paper aimed to investigate the effects of ultrasound-assisted L-lysine treatment on meat quality and myofibrillar proteins (MPs) properties of pork longissimus dorsi during postmortem aging. The results revealed that the L-lysine (Lys) and/or ultrasound treatment significantly increased (p < 0.05) the water-holding capacity and tenderness of the pork during postmortem aging, while the ultrasound-assisted Lys treatment had the lowest cooking loss, pressurization loss, Warner-Bratzler shear force, and hardness. In addition, L-lysine and/or ultrasound treatment increased (p < 0.05) pH value, T21, and myofibrillar fragmentation index, while the ultrasound-assisted Lys treatment had the highest value. Meanwhile, the protein solubility was increased with Lys and/or ultrasound treatment during postmortem aging, and ultrasound-assisted Lys treatment had the highest solubility, reaching 88.19%, 92.98%, and 91.73% at 0, 1, and 3 days, respectively. The result of protein conformational characteristics showed that Lys and/or ultrasound treatment caused the unfolding of the α-helix structure, resulting in the exposure of more hydrophobic amino acids and buried sulfhydryl groups, ultimately enhancing MPs solubility. In summary, ultrasound-assisted Lys treatment altered the structure of MPs, resulting in the enhancement of the water-holding capacity and tenderness of the pork. PRACTICAL APPLICATION: This study showed that ultrasound-assisted L-lysine (Lys) treatment could enhance the water-holding capacity and tenderness of pork during postmortem aging. The results might provide a reference for the application of ultrasound-assisted Lys treatment on the improvement of pork meat quality. To facilitate practical applications in production, the development of medium and large-sized ultrasound equipment for conducting small-scale and pilot experiments is crucial for future research.

In vitro digestion mimicking conditions in adults and elderly reveals digestive characteristics of pork from different cooking ways.

This study aimed to investigate the impact of three cooking ways (sous vide (SV), frying (FR) and roasting (RO)) on pork protein digestion characteristics under conditions simulating healthy adult (control, C) and elderly individuals with achlorhydria (EA). Changes in degree of hydrolysis (DH), SDS-PAGE profiles, zeta potential, particle size and secondary structure during digestion were evaluated. Our results revealed the EA condition markedly affected the protein digestion process of pork with different cooking ways. The DH values of SV (25.62%), FR (21.38%) and RO (19.40%) under the EA condition were significantly lower than those of under the control condition (38.32%, 33.00% and 30.86%, respectively). Moreover, differences were also observed among three cooking ways under the EA condition. For a given cooking way, the differences between control and EA conditions gradually diminished from the gastric to the intestinal phase. Under a certain digestion condition, SV maintained the highest degree of digestion throughout the process, particularly under the EA condition. Therefore, we conclude that pork cooked by sous vide is more recommendable for the elderly considering protein digestibility.

Two Debaryomyces hansenii strains as starter cultures for improving the nutritional and sensory quality of dry-cured pork belly.

Dry-cured meat products are gaining attention owing to their distinctive sensory characteristics and health benefits. In this study, two Debaryomyces hansenii strains were investigated for their potential as starter cultures for dry-cured pork belly products. After preliminary screening, these D. hansenii strains, namely, S20 and S26, both exhibiting with excellent aroma-producing capacity in a dry-cured meat model, were selected as single-strain starter cultures. For comparison, a non-inoculated control was also evaluated. In S20- and S26-inoculated pork belly, yeast dominated the microbiota and improved microbiological safety by suppressing Enterobacteriaceae growth. Compared with the non-inoculated control, the inoculated pork belly yielded higher hardness and redness (a*) values. Starter culture inoculation accelerated proteolysis in pork belly, improving the content of total free amino acids (TFFAs) and several essential free amino acids (Thr, Val, Met, Ile, Leu, and Phe) at the end of processing. Moreover, the inoculated samples exhibited higher levels of fat oxidation-derived aldehydes as well as esters, acids, alcohols and other compounds than the non-inoculated control at the end of the 95-day ripening period. Overall, these findings provide new insights into the application of D. hansenii isolated from dry-cured ham to dry-cured pork belly.

Discriminatory power of MALDI-TOF MS protein profiling analysis of pork meat and meat products.

Forty different sample preparation methods were tested to obtain the most informative MALDI-TOF MS protein profiles of pork meat. Extraction by 25% formic acid with the assistance of zirconia-silica beads followed by defatting by methanol:chloroform mixture (1:1, v/v) and deposition by using the layer-by-layer method was determined as the optimum sample preparation protocol. The discriminatory power of the method was then examined on samples of pork meat and meat products. The method was able to discriminate between selected salami based on the production method and brand and was able to monitor the ripening process in salami. However, it was not able to differentiate between different brands of pork ham or closely located parts of pork meat. In the latter case, a more comprehensive analysis using LC-MS/MS was used to assess the differences in protein abundance and their relation to the outputs of MALDI - TOF MS profiling.

A novel QTL region for pH and meat color in Duroc pigs.

One of the most important processes that occur during the transformation of muscle to meat is the pH decline as a consequence of the post-mortem metabolism of muscle tissue. Abnormal pH declines lead to pork defects such as pale, soft, and exudative meat. There is genetic variance for ultimate pH and the role of some genes on this phenotype is well established. After conducting a genome-wide association study on ultimate pH using 526 purebred Duroc pigs, we identified associated regions on Sus scrofa chromosomes (SSC) 3, 8, and 15. Functional candidate genes in these regions included PRKAG3 and PHKG1. The SSC8 region, at 71.6 Mb, was novel and, although no candidate causative gene could be identified, it may have regulatory effects. Subsequent analysis on 828 pigs from the same population confirmed the impact of the three associated regions on pH and meat color. We detected no interaction between the three regions. Further investigations are necessary to unravel the functional significance of the novel genomic region at SSC8. These variants could be used as markers in marker-assisted selection for improving meat quality.

USA millennial and non-millennial beef consumers perception of beef, pork, and chicken.

Millennials have been shown to have distinctly different behaviors; however, factors affecting their liking of beef, pork and chicken has not been fully elucidated. As millennials are current and future animal protein consumers, the question of if they have different drivers of liking for beef, pork, and chicken has not been answered. Top loin steaks cooked to 58.3 or 80 °C; and pork loin chops and chicken breasts cooked to 62.7 or 80 °C were cooked on a flat grill. Beef bottom round roasts cooked to 58.3 or 80°; and pork inside ham roasts and chicken thighs were cooked to 62.7 or 80 °C in a Crock-pot®. A descriptive flavor and texture attribute panel and a consumer central location test in four cities were used to evaluated flavor and texture attributes. Consumers were either millennials or non-millennials, and light or heavy beef-eaters. Meat descriptive flavor and texture attributes differed by cooking method, cut, and internal temperature (P < 0.05). Consumers preferred grilled meat more than meat cooked in the Crock-pot® (P > 0.05). Consumers rated grill flavor, juiciness, and tenderness (P ≥ 0.05) higher in grilled meat. Light beef-eaters, those who ate beef 2 to 4 times per month, rated overall, flavor, and species flavor lower (P < 0.05) than heavy beef-eaters, but consumers liked beef regardless of generational segment or their consumption of beef; however, millennials rated overall, overall flavor, and tenderness liking slightly lower than non-millennials. These results indicate that millennials have similar drivers of liking as non-millennials across beef, pork, and chicken protein sources.

Rapid and non-destructive microbial quality prediction of fresh pork stored under modified atmospheres by using selected-ion flow-tube mass spectrometry and machine learning.

Volatile organic compounds (VOCs) indicative of pork microbial spoilage can be quantified rapidly at trace levels using selected-ion flow-tube mass spectrometry (SIFT-MS). Packaging atmosphere is one of the factors influencing VOC production patterns during storage. On this basis, machine learning would help to process complex volatolomic data and predict pork microbial quality efficiently. This study focused on (1) investigating model generalizability based on different nested cross-validation settings, and (2) comparing the predictive power and feature importance of nine algorithms, including Artificial Neural Network (ANN), k-Nearest Neighbors, Support Vector Regression, Decision Tree, Partial Least Squares Regression, and four ensemble learning models. The datasets used contain 37 VOCs' concentrations (input) and total plate counts (TPC, output) of 350 pork samples with different storage times, including 225 pork loin samples stored under three high-O2 and three low-O2 conditions, and 125 commercially packaged products. An appropriate choice of cross-validation strategies resulted in trustworthy and relevant predictions. When trained on all possible selections of two high-O2 and two low-O2 conditions, ANNs produced satisfactory TPC predictions of unseen test scenarios (one high-O2 condition, one low-O2 condition, and the commercial products). ANN-based bagging outperformed other employed models, when TPC exceeded ca. 6 log CFU/g. VOCs including benzaldehyde, 3-methyl-1-butanol, ethanol and methyl mercaptan were identified with high feature importance. This elaborated case study illustrates great prospects of real-time detection techniques and machine learning in meat quality prediction. Further investigations on handling low VOC levels would enhance the model performance and decision making in commercial meat quality control.

Real-time monitoring of pork freshness using polyvinyl alcohol/modified agar multilayer gas-sensitive labels.

Accurate consumer perception of food packages should provide real-time feedback on any changes inside food packaging. Hence, a new multilayer gas-sensitive label (POA-12) was prepared using a layer-by-layer pouring method for simple, visual, and real-time detection of pork's freshness, while the front side was developed by immobilizing red carbon dots and fluorescein isothiocyanate in POA as indicator for volatile nitrogen, and the back side was created using bromothymol blue in POA as pH indicator. The swelling index of the multilayer gas-sensitive labels reduced from 159.19% to 148.36%, and the tensile strength increased from 25.52 MPa to 42.61 MPa. In addition, the POA-12 multilayer label showed a red-to-yellow fluorescence change as TVB-N increased from 6.84 to 31.4 and a yellow-brown-to-blue-green color change as pH increased from 5.74 to 7.24 when detecting pork samples. Thus, it provides dual-indicator monitoring that improves the accuracy and reliability of assessing the freshness of high-protein products.