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The use of total volatile basic nitrogen (TVB‐N) as a quality parameter for fish is rapidly growing to include other types of meat. Investigations of meat quality have recently focused on TVB‐N as an index of freshness, but little is known on the biochemical pathways involved in its generation. Furthermore, TVB‐N and methylated amines have been reported to exert deterimental health effects, but the relationship between these compounds and human health has not been critically reviewed. Here, literature on the formative pathways of TVB‐N has been reviewed in depth. The association of methylated amines and human health has been critically evaluated. Interventions to mitigate the effects of TVB‐N on human health are discussed. TVB‐N levels in meat can be influenced by the diet of an animal, which calls for careful consideration when using TVB‐N thresholds for regulatory purposes. Bacterial contamination and temperature abuse contribute to significant levels of post‐mortem TVB‐N increases. Therefore, controlling spoilage factors through a good level of hygiene during processing and preservation techniques may contribute to a substantial reduction of TVB‐N. Trimethylamine (TMA) constitutes a significant part of TVB‐N. TMA and trimethylamine oxide (TMA‐N‐O) have been related to the pathogenesis of noncommunicable diseases, including atherosclerosis, cancers, and diabetes. Proposed methods for mitigation of TMA and TMA‐N‐O accumulation are discussed, which include a reduction in their daily dietary intake, control of internal production pathways by targeting gut microbiota, and inhibition of flavin monooxygenase 3 enzymes. The levels of TMA and TMA‐N‐O have significant health effects, and this should, therefore, be considered when evaluating meat quality and acceptability. Agreed international values for TVB‐N and TMA in meat products are required. The role of feed, gut microbiota, and translocation of methylated amines to muscles in farmed animals requires further investigation. [ABSTRACT FROM AUTHOR]

The diet of cattle has been shown to alter both subcutaneous fat and muscle fatty acid composition, and these differences cause a change in the Raman spectra of the fat due to the different chemical bonds associated with these biochemical changes. Because biochemical changes only lead to subtle changes in the Raman spectra, statistical methods based upon chemometric modelling are necessary to extract indicative information on the type of feed consumed. This investigation undertook a feasibility study using a limited sample set derived from two producers in one location to ascertain the potential for Raman spectroscopy to accurately discriminate grain‐fed cattle from grass‐fed cattle and investigated the usefulness of principal component analysis (PCA) and partial least squares discriminate analysis (PLS‐DA) to best discriminate between feeding groups using the information from the Raman spectra. The first two principal components accounted for 83% of the variation in the spectra and demonstrated discrimination of samples by feed type. PLS‐DA resulted in a model that was able to accurately predict grain‐ and grass‐fed carcases with a misclassification rate of 3.5%. Changes in beef cattle diets lead to subtle changes in subcutaneous fat; using Raman spectroscopy with chemometric modelling, these changes can be identified and used to identify the production system of beef products. This study successfully uses Raman spectroscopy as an automated, nondestructive and rapid technique in the range of 600–2000 cm−1 in combination with pattern recognition of unsupervised (PCA) and supervised (PLS‐DA) techniques to classify the production system of cattle between grain and grass fed. [ABSTRACT FROM AUTHOR]

In this study, the relationship between sensory evaluation and several objective metrics of beef tenderness was tested. Objective metrics included shear force, sarcomere length, collagen content, myofibrillar, and sarcoplasmic protein solubility and particle size analysis. These results were compared to consumer panel scores of tenderness for the same aged beef striploin (longissimus lumborum muscle) samples. There was found to be a significant relationship between sarcomere length, shear force, and particle size with tenderness scores. Collagen content and protein solubilities were not associated to tenderness scores (p > 0.05). Sarcomere length contributions for explaining tenderness variation were overlapped by the contributions of shear force (collinearity). Independent models demonstrated that the lower 95% confidence interval of the fitted regression line exceeded 50% acceptance of tenderness when shear force values <42.6 N and when particle size values <198 μm. We can recommend these as thresholds for consumer acceptance of beef tenderness, although considerations of sample type, analytical methodology, and consumer demographics should be made prior to their adoption. This provision was based on the variation in tenderness scores evident between individual panelists and experimental striploins. [ABSTRACT FROM AUTHOR]

The potential of spatially offset Raman spectroscopy (SORS) for distinguishing different beef cuts was investigated. Six different retail beef cuts (rump, Scotch fillet, round, chuck, tenderloin, and T‐bone) were analysed spectroscopically using SORS. This technique makes it possible to measure the Raman signal 5 mm below the surface of meat muscles, allowing non‐invasive analysis of meat samples that are not readily feasible using conventional Raman spectroscopy. This study has shown for the first time that monitoring of the changes in glycogen, fat, and protein content of muscles can be investigated directly and, most importantly, non‐invasively within various meat cuts. The spectral results reveal differences in structure‐sensitive bands from the amide I and III regions as well as from cysteine, glutamic acid, and phenylalanine vibrations. Statistical analysis confirms these observations based on strong clustering of SORS bands (this was derived from principal component analysis scores of the SORS data) measured for the different cuts. Highlights: Deep Raman spectroscopy was employed to investigate the subsurface composition of meatNon‐invasive differentiation of dissimilar meat cutsIdentification of biomarker bands for each individual meat cutsStatistical analysis clustering of each meat cut confirmed the spectroscopic results [ABSTRACT FROM AUTHOR]

Summary: The global population is becoming older, and still, this cohort considers red meat (beef and sheep meat) as an important staple in their diet. It is understood that the requirements from these red meats will vary as a person ages, often because of associated physiological changes; nutrition and health concerns; and reduced sensorial capacities. This creates an imperative to develop red meat products that appeal and satisfy the demands of elderly people. Here, we have reviewed current literature with the aim to comprehend the elderly consumer market, their demands for nutritive and quality traits, and their requirements for safe and convenient red meat (beef and sheep) products. Based on these studies, it was apparent that these specifications may be delivered using available knowledge of intrinsic and extrinsic influences on red meat if considered within the context of elderly customers, that is, to deliver upon elderly people's requirements for conventional red meat products which are inexpensive, of consistent and perceivable high quality, and quell any associated health concerns for the consumer. [ABSTRACT FROM AUTHOR]

Chilling procedures have been widely used in livestock abattoirs since the development of refrigeration systems. The major criteria when applying chilling regimes is not only complying with regulations, but economic concerns, and also meat safety and quality assurance requirements. Given recent developments, an updated review is required to guide the industry to choose the best chilling method and to inspire the development of new approaches to chilling. Thus in this paper, the quality and microbial safety of beef, lamb, pork, venison, and bison resulting from different chilling treatments has been reviewed, as well as the underlying mechanism(s) for the different impacts on meat quality traits as a result of different chilling regimes. The effect of fast chilling on the tenderness of beef and lamb is a focus, as some new findings, have recently been reported, while multistep chilling is highlighted as it incorporates the advantages of fast chilling to reduce carcass weight loss, resulting in similar quality improvements as found with slow chilling. It is, suggested, that if spray chilling can be combined with the second phase of multi‐step chilling, it will benefit the meat industry in terms of both meat quality and safety. Future studies should focus on combinations of chilling methods with new technologies, such as medium voltage electrical stimulation, muscle stretching, or ultrasound and so on, to move meat quality and safety to a new level. [ABSTRACT FROM AUTHOR]

BACKGROUND: The aim of this study was to evaluate the effect of dietary lycopene powder on meat quality and the oxidative stability of lipid and protein of longissimus thoracis (LT) in lamb. A total of 30 male lambs were randomly sampled from three feeding groups (control without lycopene supplement, 200 and 400 mg kg−1 lycopene powder respectively) after 3 months of feeding. The muscle samples were taken after slaughter and stored at 4 °C for 7 days. RESULTS: Compared with the control, the results showed that supplementation with lycopene powder gave a higher a* value (redness), and increased the levels of vitamin A and vitamin E. Increasing dietary lycopene powder resulted in a lower degree of lipid and protein oxidation, as evidenced by lower contents of thiobarbituric acid‐reactive substance and carbonyl compounds, and higher levels of sulfhydryl groups. CONCLUSION: Dietary lycopene powder is an effective antioxidant that blocks the oxidation of meat proteins and lipids, and has a positive effect on increasing lamb meat quality during storage. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This study evaluated a microwave (Mw) cooking method for determining beef toughness using the Warner–Bratzler slice shear force (WBsSF) protocol. Longissimus thoracis muscles were aged for 1, 10, 19, and 28 days at 4C. They were then either cooked on a clam‐shell grill until reaching an internal temperature of 72C, in a Mw for 100 s at maximum power (Mw100) or for 140 s at 60% of maximum power (Mw60). Cooking loss and shear force (SF) values were higher in Mw samples than in grilled ones. SF assessment by grill and Mw100 were able to discriminate tenderness by aging times in the same way as the sensory panel. The SF measured in a grilled sample had higher repeatability (R = .74) and correlation with sensory scores (r = −.79) than Mw100 (R = .61; r = −.62) and Mw60 (R = .51; r = −.53). Mw100 can be considered as an appropriate alternative for the WBsSF protocol. Practical applications: Tenderness is the most important attribute for consumers. Many studies have evaluated tenderness in meat and different protocols for cooking. This work was intended to optimize and evaluate the use of the microwave as a cooking method for shear force determination, against a standard protocol and establish the correlation to sensory tenderness. [ABSTRACT FROM AUTHOR]

Dark cutting in beef and sheep meat has been the subject of extensive research with numerous associations established between it and various production practices. Despite these associations, dark cutting still occurs and causes significant financial losses globally in the fresh meat market. Consumers tend to reject dark meat as it is perceived to be from old or poorly-handled animals and is described as being tough, having an undesirable flavor, and having a short shelf-life. There is no universal system to categorize dark cutting carcasses and meat across countries, although various methods are used to determine the phenomenon. Classifying carcasses as dark cutters on the basis of ultimate pH or color using one muscle, such as the m. longissimus thoracis can lead to mis-description of other muscles within the same carcass and loss of income across the supply chain. The purpose of this review was to identify the factors predisposing animals to dark cutting and to provide recommendations and directions for future research. The review revealed no single production factor causing dark cutting, but that a range of factors or a combination of factors and interactions lead to its occurrence. Dark cutting is a complex condition that can be resolved through comprehensive management of animals, and management of human involvement, and clear guidelines to minimize the incidence of 'dark cutting' meat and to improve the profitability of all sectors in the supply chain are provided here. [ABSTRACT FROM AUTHOR]

This review aims to summarize the relevant published information about the effects of extensive feeding systems on the carcass and meat quality characteristics of lambs. Lambs finished in a feedlot or with supplementation under extensive systems exhibit faster growth rates, achieve target weights quicker, and produce heavier carcass weights when compared to grazing lambs. However, the literature also shows that finishing lambs on high-quality pasture can produce satisfactory growth rates without compromising carcass and meat quality traits. Lately, the consumer demand for products perceived as 'healthy' and that are produced where animal welfare is optimal under systems which do not impact negatively on the environment, has heightened the interest in lamb production under extensive systems. Lambs raised on pasture can meet many of these specifications. Also, lambs fed higher quality green pasture can produce meat with greater amounts of health-claimable omega-3 fatty acids such as eicosapentaenoic acid plus docosahexaenoic acid than feeding systems based on feedlot pellets, grain, or dry pasture/straw. It is apparent that in some previous published research, the number of animals allocated for each treatment, and the lack of replicates, makes it difficult to formulate a correct understanding of the effect of forages on lamb carcass and meat quality. Future research should concentrate on the effect of legume, improved pasture, and specialized forage finishing systems on growth rate, carcass traits, and nutritional value of meat using well-designed experiments with an adequate number of lambs and appropriate paddock replicates per treatment. [ABSTRACT FROM AUTHOR]

A number of studies have shown that dietary omega-6 and omega-3 long-chain fatty acids can be incorporated into muscle tissue of ruminants despite the biohydrogenation of dietary fatty acids in the rumen. The main focus of this review is on eicosapentaenoic (20:5 n-3) and docosahexaenoic (22:6 n-3) fatty acids because health authorities around the world consider the sum of these fatty acids as the basis of classifying a food as a source or good source of omega-3 polyunsaturated fatty acids (PUFAs). A high proportion of polyunsaturated fatty acids are hydrogenated in the rumen, leading to a higher concentration of 18:0, but some escapes the rumen to be absorbed intact by the small intestine. Feeding strategies for ruminants have been successfully applied to increase the absorption of PUFAs in the small intestine and therefore to increase the levels of PUFAs in muscle tissue. Protected fats and algae are strong candidates to improve the nutritional value of red meat in ruminants in terms of health-claimable omega-3 fatty acids. Efforts to understand the genetic basis of fatty acid metabolism have been underway. The knowledge of the main genes which control the output of omega-3 fatty acids is still lacking, but gene expression studies have helped to explain the deposition of these acids in muscle, liver, and subcutaneous fat. [ABSTRACT FROM AUTHOR]

Lipid oxidation of M. longissimus lumborum in fresh or vacuum packaged (aged) lamb meat stored at 3 °C for 0 or 4 weeks, respectively and displayed under refrigerated conditions for a further 4 days was assessed by measuring the concentration of malondialdehyde (MDA) in meat using the thiobarbituric acid reactive substances procedure. The effects of vitamin E, heme iron and polyunsaturated fatty acids (n-6 and n-3) on lipid oxidation were examined. Results showed a strong positive relationship between heme iron, n-6 and n-3 fatty acids and lipid oxidation when vitamin E was below 2.95 mg/kg muscle. When lipid oxidation was related to vitamin E concentration and the other three variables, respectively, any increase in heme iron or n-6 or n-3 fatty acids concentration did not influence lipid oxidation. Management of diet to elevate muscle vitamin E concentration above 3.45 mg/kg muscle is beneficial to maintain the level of lipid oxidation below 2.4 mg MDA/kg muscle in meat stored for up to 4 weeks. This demonstrates that vitamin E concentration in muscle has a greater influence on controlling lipid oxidation in muscle tissues than do heme iron or polyunsaturated fatty acids. [ABSTRACT FROM AUTHOR]

Algae high in docosahexaenoic acid (DHA) may provide a source of long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) for inclusion in the diet of lambs to improve the LCn-3PUFA status of meat. The effect of background LCn-3PUFA status on the metabolism of high DHA algae is, however, unknown. The aim of the current study was to determine whether the response to a high in DHA algae supplement fed to lambs for six weeks prior to slaughter was mediated by a maternal periconceptional diet. Forty Poll Dorset × Border Leicester × Merino weaner lambs were allocated to receive either a ration based on oat grain, lupin grain, and chopped lucerne (control) or the control ration with DHA-Gold™ algae included at 1.92 % DM (Algae) based on whether the dams of lambs had previously been fed a diet high in n-3 or n-6 around conception. LCn-3PUFA concentration was determined in plasma and red blood cells (RBC) prior to and following feeding. The concentrations of EPA and DHA in the plasma and RBC of lambs receiving the control ration were significantly ( p < 0.001) lower when lambs received the ration for 14 days compared with pre-feeding concentrations. The concentrations of EPA and DHA were also significantly ( p < 0.001) higher when lambs consumed the Algae ration compared with the control ration for 42 days. The increase in EPA and DHA was, however, significantly ( p < 0.05) lower if lamb dams had previously been fed a diet high in n-6 at conception. Assessing the previous nutrition and n-3 status of lambs may allow producers to more accurately predict the likely response to supplements high in LCn-3PUFA, particularly, DHA. [ABSTRACT FROM AUTHOR]

Oxidation of meat occurs under postmortem conditions and is inevitable. This oxidation includes the biochemical changes in meat leading to changes in color pigments and lipids. As a consequence, color deteriorates, and undesirable flavors and rancidity develop in meat thereby impacting on consumer appeal and satisfaction. Across carcasses, there is variation in the rate at which muscle undergoes chemical reactions under postmortem conditions that reflect inherent variation at the biochemical level. It is expected that this underlying biochemical variation will be reflected in living muscle through oxidative processes. The oxidative process of muscle tissues will vary according to an animal's immunity status, temperament, and ability to cope with stress, with all these affected by nutrition, genetics, management practices, and environmental conditions (hot and cold seasons). Identification of biomarkers that indicate the oxidative status levels of animals or muscle tissues in vivo could provide insight as to how the muscle will respond to the anoxic conditions that produce undesirable results in meat. This review outlines the potential use of 1 group of biomarkers, the isoprostanes, in the context of complex biochemical reactions relating to oxidative processes that take place in the biological systems of live animals ( in vivo) and subsequently in meat ( in vitro). [ABSTRACT FROM AUTHOR]

The cover image is based on the Research Article Dietary lycopene powder improves meat oxidative stability in Hu lambs by Chenchen Xu et al., DOI: 10.1002/jsfa.9282. The cover image is based on the Research Article Dietary lycopene powder improves meat oxidative stability in Hu lambs by Chenchen Xu et al., DOI: 10.1002/jsfa.9282. [ABSTRACT FROM AUTHOR]