Proteomic application in predicting food quality relating to animal welfare. A review

Effects of mitochondria on postmortem meat quality: characteristic, isolation, energy metabolism, apoptosis and oxygen consumption

Meat quality holds significant importance for both consumers and meat producers. Various factors influence meat quality, and among them, mitochondria play a crucial role. Recent studies have indicated that mitochondria can sustain their functions and viability for a certain duration in postmortem muscles. Consequently, mitochondria have an impact on oxygen consumption, energy metabolism, and apoptotic processes, which in turn affect myoglobin levels, oxidative stress, meat tenderness, fat oxidation, and protein oxidation. Ultimately, these factors influence the color, tenderness, and flavor of meat. However, there is a dearth of comprehensive summaries addressing the effects of mitochondria on postmortem muscle physiology and meat quality. Therefore, this review aims to describe the characteristics of muscle mitochondria and their potential influence on muscle. Additionally, a suitable method for isolating mitochondria is presented. Lastly, the review emphasizes the regulation of oxygen consumption, energy metabolism, and apoptosis by postmortem muscle mitochondria, and provides an overview of relevant research and recent advancements. The ultimate objective of this review is to elucidate the underlying mechanisms through which mitochondria impact meat quality.

Shotgun proteomics reveals changes in the pectoralis major muscle of broilers supplemented with passion fruit seed oil under cyclic heat stress conditions

The aim of this study was to characterize the proteins differentially expressed in the pectoralis major muscle of broilers supplemented with passion fruit seed oil (PFSO) under cyclic heat stress conditions. Ninety one-day-old male chicks were housed in cages arranged in a climatic chamber, where they were kept under cyclic heat stress for eight hours a day from the beginning to the end of the experiment. The birds were divided into two experimental groups, one group supplemented with 0.9% PFSO and a control group (CON) without PFSO supplementation. At 36 days of age, 18 birds were slaughtered to collect muscle samples. From pools of breast fillet samples from each group, proteolytic cleavage of the protein extracts was performed, and later, the peptides were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The 0.9% PFSO supplementation revealed the modulation of 57 proteins in the pectoralis major muscle of broilers exposed to cyclic heat stress. Among them, four proteins were upregulated, and 46 proteins were downregulated. In addition, seven proteins were expressed only in the CON group. These results suggest that PFSO may increase heat tolerance, with a possible reduction in oxidative stress, activation of neuroprotective mechanisms, protection against apoptosis, decrease in inflammatory responses, and regulation of energy metabolism.

Improving animal welfare status and meat quality through assessment of stress biomarkers: A critical review

Stress induces various physiological and biochemical alterations in the animal body, which are used to assess the stress status of animals. Blood profiles, serum hormones, enzymes, and physiological conditions such as body temperature, heart, and breathing rate of animals are the most commonly used stress biomarkers in the livestock sector. Previous exposure, genetics, stress adaptation, intensity, duration, and rearing practices result in wide intra- and inter-animal variations in the expression of various stress biomarkers. The use of meat proteomics by adequately analyzing the expression of various muscle proteins such as heat shock proteins (HSPs), acute phase proteins (APPs), texture, and tenderness biomarkers help predict meat quality and stress in animals before slaughter. Thus, there is a need to identify non-invasive, rapid, and accurate stress biomarkers that can objectively assess stress in animals. The present manuscript critically reviews various aspects of stress biomarkers in animals and their application in mitigating preslaughter stress in meat production.

Filling gaps in animal welfare assessment through metabolomics

Sustainability has become a central issue in Italian livestock systems driving food business operators to adopt high standards of production concerning animal husbandry conditions. Meat sector is largely involved in this ecological transition with the introduction of new label claims concerning the defense of animal welfare (AW). These new guarantees referred to AW provision require new tools for the purpose of authenticity and traceability to assure meat supply chain integrity. Over the years, European Union (EU) Regulations, national, and international initiatives proposed provisions and guidelines for assuring AW introducing requirements to be complied with and providing tools based on scoring systems for a proper animal status assessment. However, the comprehensive and objective assessment of the AW status remains challenging. In this regard, phenotypic insights at molecular level may be investigated by metabolomics, one of the most recent high-throughput omics techniques. Recent advances in analytical and bioinformatic technologies have led to the identification of relevant biomarkers involved in complex clinical phenotypes of diverse biological systems suggesting that metabolomics is a key tool for biomarker discovery. In the present review, the Five Domains model has been employed as a vademecum describing AW. Starting from the individual Domains-nutrition (I), environment (II), health (III), behavior (IV), and mental state (V)-applications and advances of metabolomics related to AW setting aimed at investigating phenotypic outcomes on molecular scale and elucidating the biological routes most perturbed from external solicitations, are reviewed. Strengths and weaknesses of the current state-of-art are highlighted, and new frontiers to be explored for AW assessment throughout the metabolomics approach are argued. Moreover, a detailed description of metabolomics workflow is provided to understand dos and don'ts at experimental level to pursue effective results. Combining the demand for new assessment tools and meat market trends, a new cross-strategy is proposed as the promising combo for the future of AW assessment.

Fatty acid profile, oxidative stability of lipids and sensory attributes of water restricted Xhosa goat meat supplemented with vitamin C

Context Water scarcity often accompanied by limited water intake (WI) in livestock may result in pre-slaughter stress, thereby affecting meat quality parameters. Aims This study was conducted to determine the effect of vitamin C (VC) supplementations on fatty acid (FA), lipids oxidation and sensory attributes of Longissimus lumborum muscles of Xhosa goats subjected to different watering regimen. Methods In total, 42 goats were randomly assigned into seven treatments: without water restriction, WR (W0, control); WR of 70% of ad libitum WI (W70); WR of 50% ad libitum WI (W50); WR of 70% of ad libitum WI+3gVC daily (W70+); WR of 50% of ad libitum WI intake+3gVC daily (W50+); WR of 70% of ad libitum WI+3gVC and extra 5gVC given every 8 days (W70++); WR of 50% of ad libitum WI+3gVC and extra 5gVC given every 8 days (W50++). The goats were fed for 75 days and killed following standard procedures. Bodyweight changes, thaw loss, ultimate pH (pHu), thiobarbituric acid reactive substance (TBARS), moisture and fat content, sensory attributes and FA profile of the meat were evaluated. Key results Results indicated that the decreased final weight in the untreated groups (W70 and W50) was reduced (P>0.05) in the treated groups (W70+, W50+, W70++, W50++). The treatment effect was not significant (P>0.05) on pHu, thaw loss and TBARS values. The moisture and fat content in the water-restricted groups were lower (P<0.05) than in W0. The meat sensory appearance was affected (P<0.05) by WR. Regardless of VC concentration, vaccenic and docosahexaenoic acid increased (P<0.05), while linolenic acid decreased as the WR levels increased. Conclusions WR of 70% and 50% of ad libitum WI, with or without VC, did not negatively affect the meat’s lipid oxidation and FA profile. Implications Limited WI reduces body weight. However, a daily dose of VC could help reduce body weight loss during water scarcity.

How Epigenetics Can Enhance Pig Welfare?

Epigenetics works as an interface between the individual and its environment to provide phenotypic plasticity to increase individual adaptation capabilities. Recently, a wide variety of epi-genetic findings have indicated evidence for its application in the development of putative epi-biomarkers of stress in farm animals. The purpose of this study was to evaluate previously reported stress epi-biomarkers in swine and encourage researchers to investigate potential paths for the development of a robust molecular tool for animal welfare certification. In this literature review, we report on the scientific concerns in the swine production chain, the management carried out on the farms, and the potential implications of these practices for the animals' welfare and their epigenome. To assess reported epi-biomarkers, we identified, from previous studies, potentially stress-related genes surrounding epi-biomarkers. With those genes, we carried out a functional enrichment analysis of differentially methylated regions (DMRs) of the DNA of swine subjected to different stress-related conditions (e.g., heat stress, intrauterine insult, and sanitary challenges). We identified potential epi-biomarkers for target analysis, which could be added to the current guidelines and certification schemes to guarantee and certify animal welfare on farms. We believe that this technology may have the power to increase consumers' trust in animal welfare.

The Effect of Grazing Level and Ageing Time on the Physicochemical and Sensory Characteristics of Beef Meat in Organic and Conventional Production

This study investigated the influence of the production system (conventional vs. organic), the grass consumption level and the ageing period (7 and 14 days) on beef quality. Three groups of samples from Limousin × Avileña calves were analysed: F100, formed by animals fed 100% on forage; F74, formed by animals fed on an average amount of forage of 74%; and F35, formed by animals fed on straw fodder (35%) and concentrate (65%). The results showed that the higher the grass content, the lower the fat oxidation and the higher the n-3 content, but also the higher the SFA level, the initial Warner-Bratzler shear force (WBSF), and the more residue it leaves on chewing. As for the effect of production system, organic samples showed higher intramuscular fat content and lower moisture and MUFA content. These samples were darker and showed lower values for flavour quality. Among the organic samples, F100 had higher n-3 and CLA content and higher values for colour, hardness, odour and flavour quality. Increased ageing time may improve the sensory characteristics of the meat, especially in the case of the F100 samples. The results pointed out that F100 samples aged at least 14 days showed the best physico-chemical, nutritional and sensory characteristics.

Application of Proteomic Technologies to Assess the Quality of Raw Pork and Pork Products: An Overview from Farm-To-Fork

The quality assurance of pork meat and products includes the study of factors prior to slaughter such as handling practices, diet and castration, and others during the post-mortem period such as aging, storage, and cooking. The development over the last two decades of high-throughput techniques such as proteomics offer great opportunities to examine the molecular mechanisms and study a priori the proteins in the living pigs and main post-mortem changes and post-translational modifications during the conversion of the muscle into the meat. When the most traditional crossbreeding and rearing strategies to improve pork quality were assessed, the main findings indicate that metabolic pathways early post-mortem were affected. Among the factors, it is well documented that pre-slaughter stress provokes substantial changes in the pork proteome that led to defective meat, and consequently, novel protein biomarkers should be identified and validated. Additionally, modifications in pork proteins had a strong effect on the sensory attributes due to the impact of processing, either physical or chemical. Maillard compounds and protein oxidation should be monitored in order to control proteolysis and volatile compounds. Beyond this, the search of bioactive peptides is becoming a paramount goal of the food and nutraceutical industry. In this regard, peptidomics is a major tool to identify and quantify these peptides with beneficial effects for human health.

Muscle Fiber Properties in Cattle and Their Relationships with Meat Qualities: An Overview

The control of meat quality traits constitutes an important target for any farm animal production, including cattle. Therefore, better understanding of the biochemical properties that drive muscle development and final outcomes constitutes one of the main challenging topics of animal production and meat science. Accordingly, this review has focused on skeletal muscle fibers in cattle and their relationships with beef qualities. It aimed to describe the chemical and structural properties of muscle fibers as well as a comprehensive review of their contractile and metabolic characteristics during the life of the animal. The existing methods for the classification of muscle fibers were reviewed, compared, and discussed. Then, the different stages of myogenesis in cattle were defined. The main factors regulating fetal and postnatal growth and the plasticity of muscle fibers were evidenced, especially the role of myostatin growth factor and the impact of nutritional factors. This review highlights that the knowledge about muscle fibers is paramount for a better understanding of how to control the muscle properties throughout the life of the animal for better management of the final eating qualities of beef. Accordingly, the associations between bovine muscle fibers and different meat eating qualities such as tenderness, pH decline, and color traits were further presented.