The Physicochemical, Microbiological, and Structural Changes in Beef Are Dependent on the Ultrasound System, Time, and One-Side Exposition

The effect of high-intensity ultrasound (HIU) system (bath, 37 kHz and 90 W/cm2; or probe, 24 kHz and 400 W) and application time (25 or 50 min, one-side exposition) on the properties of bovine Longissimus lumborum after 7 d of storage at 4 °C was studied. The bath system significantly increased the lightness of the muscle, while other color parameters (a*, b*, hue, and chroma) were not different from the control. The water holding capacity and shear force decreased significantly (3.1–5% and 0.59–0.72 kgf, respectively) in sonicated meat independently of the system, favoring the tenderization of the muscle after storage. Microstructural changes observed in the HIU-exposed surface provided evidence of a higher area of interfibrillar spaces (1813 vs. 705 µm2 in the control), producing tenderization of the muscle, compared with the control. HIU significantly increased counts of total aerobic and coliform bacteria, especially after 50 min of ultrasonication. HIU also increased lactic acid bacterial counts in the bath system. Single-sided muscle exposition to ultrasound may produce sufficient significant changes in muscle properties, which could decrease long treatment times that would be needed for the exposition of both sides. HIU in bath systems increases tenderness by modifying meat ultrastructure, with no significant changes in physicochemical parameters. Nevertheless, microbiological quality may need to be considered during the process due to a slight increase in bacterial counts.

The Quality Changes and Proteomic Analysis of Cattle Muscle Postmortem during Rigor Mortis

Rigor mortis occurs in a relatively early postmortem period and is a complex biochemical process in the conversion of muscle to meat. Understanding the quality changes and biomarkers during rigor mortis can provide a theoretical basis for maintaining and improving meat quality. Herein, a tandem mass tag proteomic method is used to investigate the effects of differentially expressed proteins on the meat quality of cattle Longissimus lumborum muscle postmortem (0, 6, and 24 h). The pH, total sulfhydryl content and sarcomere length decrease significantly during storage. In contrast, meat color values (L*, a*, and b*) and the myofibril fragmentation index increase significantly. Altogether, 147 differentially expressed proteins are identified, most being categorized as metabolic enzymes, mitochondrial proteins, necroptosis and ferroptosis proteins and structural proteins. The results also reveal additional proteins that are potentially involved in rigor mortis, such as cardiac phospholamban, acetyl-coenzyme A acyltransferase, and ankyrin repeat domain 2. The current results provide proteomic insights into the changes in meat quality during rigor mortis.

Tandem Mass Tag Labeling-Based Analysis to Characterize Muscle-Specific Proteome Changes during Postmortem Aging of Bison Longissimus Lumborum and Psoas Major Muscles

The objective of the study was to examine the variations in sarcoplasmic proteomes of bison longissimus lumborum (LL) and psoas major (PM) muscles during postmortem aging utilizing tandem mass tag (TMT) isobaric labeling coupled with liquid chromatography mass-spectrometry (LC-MS/MS) for the categorization of muscles with muscle-specific inherent color stability. A total of 576 proteins were identified (P < 0.05) in both bison LL and PM muscles, where 97 proteins were identified as differentially abundant (fold change > 1.5, P < 0.05) from the three comparisons between muscles during postmortem aging periods (PM vs LL at 2 d, 7 d and 14 d). Among those proteins, the most important protein groups based on functions are related to electron transport chain (ETC) or oxidative phosphorylation, tricarboxylic acid cycle (TCA), ATP transport, carbohydrate metabolism, fatty acid oxidation, chaperones, oxygen transport, muscle contraction, calcium signaling, and protein synthesis. In PM, most of the proteins from ETC, TCA cycle, fatty acid oxidation, ATP and oxygen transport, and muscle contraction were more abundant or exhibited increased expression during aging compared to LL. On the other hand, the proteins involved in carbohydrate metabolism, chaperone function and protein synthesis mostly exhibited decreased expression in PM muscle relative to LL. These results clearly demonstrate that the proteins associated with oxidative metabolism showed increased expression in PM muscles. This indicates that oxidative damage or subsequent color deterioration resulted in bison PM muscles being attacked by the reactive oxygen species produced during those metabolic process. In contrast, proteins involved in glycolysis and chaperone activity exhibited a decrease in expression in bison PM muscles, resulting decline in color stability compared with LL. Because glycolytic enzymes and chaperones maintain oxidative and/or color stability by producing reducing equivalents in glycolytic pathway and with the protein folding ability of chaperones, respectively in LL muscles.

Post-mortem characterization of Dorper x Santa Inês lambs fed diets containing alternative foods

The objective of this study was to evaluate the post-mortem characteristics of lambs fed diets containing alternative foods. Twenty lambs, castrated Dorper x Santa Inês males, aged approximately 90 days and with mean weight of 20 kg were used. Experimental diets were composed of ground corn, soybean meal, mineral supplement, urea and Tifton-85 hay (forage). In addition to these ingredients, cottonseed, sunflower meal and castor bean cake were used as alternative foods in the proportions of 10, 8 and 8% of %DM, respectively. The experiment lasted 106 days, with 14 days for adaptation and 92 days for evaluation and data collection. At the end of the confinement period, the lambs were slaughtered, and the carcasses kept under cooling for a period of 24 hours. The measurements of pH, carcass temperature (internal and external) were measured in the Longissimus lumborum muscle, as well as the temperature and relative humidity of the cold chamber were measured. Muscle pH was altered as a function of diet and reached a value of 5.78 (lower pH) when lambs received the diet with castor bean cake. The internal carcass temperature was higher in the lambs that received the diet containing cottonseed (19.98°C), sunflower meal (19.71°C) and castor bean cake (19.87°C). The alternative foods can be used as ingredients in the formulation of diets for Dorper x Santa Inês lamb, for promoting the proper development of the post-mortem process, characteristic of good quality sheep meat.

Fatty acid profile and lipid indices of the porker meat supplemented with pro-health herbal probiotics, ascorbic acid and allicin

PurposeThe objective of this study is to assess whether pro-health herbal probiotics, ascorbic acid and allicin added to the finishing diets of hybrid pig influenced the intramuscular fat (IMF) content in longissimus lumborum (LL) muscle, the fatty acid profile and lipid quality indices, as it has an impact on human health.Design/methodology/approachAfter 80 days of equal fattening, the pigs were divided into the control group (CT, n = 30 received commercially allowed and applicable antibiotics) and the experimental group (EX, n = 30), which until 95 days of rearing were supplied with fermented herbs extract (FHE Multikraft® Austria) with probiotics Saccharomyces cerevisiae, Lactobacillus casei, Lactobacillus plantarum, L-ascorbic acid and extract of garlic (10% allicin). After slaughter, crude fat content and fatty acid profile were determined in LL muscle samples, and on that basis lipid indices were calculated.FindingsSupplementation with FHE, probiotics, L-ascorbic acid and allicin has significantly impacted the crude fat content in the meat and the percentage of fatty acids content: tricosanoic (C23:0), heptadecanoid (C17:1 n-7), eicosanic (C22:1 11cis n-9) and eicosatrienoic (C20:3 11cis n-3), in comparison to CT group. Amongst lipid quality indices, IMF in LL of pigs from EX group, the C18:2 n-6/C18:3 n-3 ratio is characterised by a significantly higher value and thus is more beneficial to the health of the consumer.Originality/valueThe authors have indicated that using FHE, probiotic supplements with ascorbic acid and allicin in commercial fattening of pigs, as an alternative for antibiotic growth promoters (AGP), improves the fatty acid profile of the meat.

Carcass and Pork Quality and Gut Environment of Pigs Fed a Diet Supplemented with the Bokashi Probiotic

The aim of this study was to determine the effect of probiotics on gut microbiota, on carcass and meat quality and on mineral contents in the longissimus lumborum (LL) muscle in pigs. The research was carried out with 120 hybrid pigs deriving from Naïma sows and P-76 boars. Pigs from the experimental group received the EM®Bokashi probiotic (Greendland Technologia EM®, Janowiec n/Wisłą, Poland) in their feed (containing Saccharomyces cerevisiae, Lactobacillus casei and Lactobacillus plantarum). The study showed that EM®Bokashi probiotic supplementation resulted in a significantly higher count of lactic acid bacteria (LAB) and yeasts in the feed, a lower number of Clostridium in the mucosa and colorectal digesta as well as a lower Enterobacteriaceae count in the colorectal digesta. The research showed that carcasses of the pigs who received the EM®Bokashi probiotic had a higher lean percentage and lower fat content than the carcasses of the control fatteners. Diet supplementation with the EM®Bokashi probiotic resulted in a lower pH and technological yield (TY) and a higher drip loss and shear force at a lower protein content in LL muscle. Moreover, the administration of the probiotic to fatteners resulted in higher yellowness (b*) and saturation (C*) and higher concentrations of Na, Mg and Se in meat.

Proteomic Changes in Sarcoplasmic and Myofibrillar Proteins Associated with Color Stability of Ovine Muscle during Post-Mortem Storage

The objective of this study was to investigate the proteomic characteristics for the sarcoplasmic and myofibrillar proteomes of M. longissimus lumborum (LL) and M. psoasmajor (PM) from Small-tailed Han Sheep. During post-mortem storage periods (1, 3, and 5 days), proteome analysis was applied to elucidate sarcoplasmic and myofibrillar protein changes in skeletal muscles with different color stability. Proteomic results revealed that the identified differentially abundant proteins were glycolytic enzymes, energy metabolism enzymes, chaperone proteins, and structural proteins. Through Pearson’s correlation analysis, a few of those identified proteins (Pyruvate kinase, Adenylate kinase isoenzyme 1, Creatine kinase M-type, and Carbonic anhydrase 3) were closely correlated to representative meat color parameters. Besides, bioinformatics analysis of differentially abundant proteins revealed that the proteins mainly participated in glycolysis and energy metabolism pathways. Some of these proteins may have the potential probability to be predictors of meat discoloration during post-mortem storage. Within the insight of proteomics, these results accumulated some basic theoretical understanding of the molecular mechanisms of meat discoloration.

Carcass Composition and Quality of Meat of Pulawska and Pulawska x PLW Crossbred Pigs Fed Rations with Naked Oats

The study aimed to determine the impact of a 60% inclusion of naked oats in feed rations for Pulawska pigs and Pulawska x Polish Large White (PLW) crossbreds on the fattening performance, carcass composition, and meat quality. It was demonstrated that—independent from their diet—Pulawska pigs showed a daily weight gain about 14.5% lower (p ≤ 0.05), with about 15% higher feed conversion rate. The experimental factors showed no impact on the dressing percentage, meatiness, and backfat thickness, except that the “eye” of the loin was significantly smaller (by 4.55 cm2) in Pulawska pigs. There was no interaction effect (diet/breed) for the pigs’ performance results and carcass composition. A 60% inclusion of naked oats in the pigs’ diet did not affect the weight of primal cuts in the right-side half-carcass. Compared to Pulawska pigs, crossbreds featured a significantly lower weight of bacon and ribs (by 1.17 kg) but a higher (p ≤ 0.05) weight of fillet (by 1.0 kg) and ham with shin (by 0.43 kg). The diet had no impact on the evaluated muscles, except a reduction (by 2.3 points) in colour lightness (L) of musculus semimembranosus in fattening pigs receiving feed rations with a 60% share of oats. Both muscles in Pulawska pigs showed significantly better (p ≤ 0.05) water-holding capacity and reduced colour lightness (L) in comparison to crossbred pigs. Moreover, the longissimus lumborum muscle of Pulawska pigs had a higher chroma (C) and a lower hue (H). The contents of essential nutrients in the evaluated muscles did not depend on the pigs’ diet and breed, except that a higher by 0.3% (p ≤ 0.05) intramuscular fat content was found in the longissimus lumborum muscle of Pulawska pigs. Neither of the experimental factors showed significant impact on the total saturated fatty acids (SFA) and total unsaturated fatty acids (UFA), or on neutral or hypocholesterolemic (DFA) and hypercholesterolemic fatty acids (OFA) in the evaluated muscles. The muscles of Pulawska x PLW pigs contained more (by 1.77% FA in the longissimus lumborum and 1.16% in the semimembranosus) polyunsaturated fatty acids (PUFA) than the muscles of the Pulawska breed (p ≤ 0.05). In addition, naked oats included in the pigs’ diet increased (p ≤ 0.05) the share of PUFA in intramuscular fat. The muscles of Pulawska pigs, in comparison to the muscles of crossbreds, showed a significantly improved ratio: by 66% and 69% in the longissimus lumborum and the semimembranosus muscles, respectively. To sum up, a 60% inclusion of naked oats is recommended in the rations of both Pulawska pigs and Pulawska x PLW crossbreds, since it allows satisfactory carcass composition and meat quality to be maintained. Pulawska pigs had worse productivity ratios but showed improved meat quality traits in terms of the n-6/n-3 ratio.