Publications by authors named "Purslow P"

An associate editor of the journal has experienced an increase in the number of received reviews where the comments to either the authors or to the editor do not align with the reviewer's recommendation to accept, revise or reject. In particular, some recommendations for outright rejection of a submission have been accompanied by criticisms that clearly could have been solved by revision of the manuscript. The purpose of this letter is to provide some guidance to reviewers on the specific issue of deciding between a recommendation to revise versus reject.

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The color of fresh pork is a crucial quality attribute that significantly influences consumer perception and purchase decisions. This review first explores consumer expectations and discrimination regarding pork color, as well as an overview of the underlying factors that, from farm-to-fork, contribute to its variation. Understanding the husbandry factors, peri- and post-mortem factors and consumer preferences is essential for the pork industry to meet market demands effectively.

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Meat tenderness is an important quality trait critical to consumer acceptance, and determines satisfaction, repeat purchase and willingness-to-pay premium prices. Recent advances in tenderness research from a variety of perspectives are presented. Our understanding of molecular factors influencing tenderization are discussed in relation to glycolysis, calcium release, protease activation, apoptosis and heat shock proteins, the use of proteomic analysis for monitoring changes, proteomic biomarkers and oxidative/nitrosative stress.

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The effects of ultrasound (0, 300 and 600 W for 20 min at the frequency of 20 kHz) followed by postmortem aging (0, 4 and 8 d aging time) on beef quality were evaluated. Ultrasound treatment, aging time and their interaction all significantly affected the pH and tenderness of beef (p < 0.05).

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Comprehensive characterization of the post-mortem muscle proteome defines a fundamental goal in meat proteomics. During the last decade, proteomics tools have been applied in the field of foodomics to help decipher factors underpinning meat quality variations and to enlighten us, through data-driven methods, on the underlying mechanisms leading to meat quality defects such as dark-cutting meat known also as dark, firm and dry (DFD) meat. In cattle, several proteomics studies have focused on the extent to which changes in the post-mortem muscle proteome relate to dark-cutting beef development.

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Following a century of major discoveries on the mechanisms determining meat colour and tenderness using traditional scientific methods, further research into complex and interactive factors contributing to variations in meat quality is increasingly being based on data-driven "omics" approaches such as proteomics. Using two recent meta-analyses of proteomics studies on beef colour and tenderness, this review examines how knowledge of the mechanisms and factors underlying variations in these meat qualities can be both confirmed and extended by data-driven approaches. While proteomics seems to overlook some sources of variations in beef toughness, it highlights the role of post-mortem energy metabolism in setting the conditions for development of meat colour and tenderness, and also points to the complex interplay of energy metabolism, calcium regulation and mitochondrial metabolism.

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Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color.

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Over the last two decades, proteomics have been employed to decipher the underlying factors contributing to variation in the quality of muscle foods, including beef tenderness. One such approach is the application of high-throughput protein analytical platforms in the identification of meat quality biomarkers. To broaden our understanding about the biological mechanisms underpinning meat tenderization across a large number of studies, an integromics study was performed to review the current status of protein biomarker discovery targeting beef tenderness.

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Extracellular matrix (ECM) structures within skeletal muscle play an important, but under-appreciated, role in muscle development, function and adaptation. Each individual muscle is surrounded by epimysial connective tissue and within the muscle there are two distinct extracellular matrix (ECM) structures, the perimysium and endomysium. Together, these three ECM structures make up the intramuscular connective tissue (IMCT).

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This review focuses on the mechanisms responsible for some the achromatic aspects of meat colour (paleness or darkness) due to light scatter from structures within the tissue. Recent investigations have highlighted the role of three key mechanisms contributing to variations in the lightness of meat: (1) Variations in the myofilament lattice spacing, and the resultant changes in myofibril diameter and muscle fibre diameter. A 20% increase in lightness (L* value) between muscles with ultimate pH of 6.

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Article Synopsis
  • * Results show that cooking meat at 60°C for up to 24 hours decreases the strength of perimysium, indicating that it becomes less tough over time, but not as significantly as overall meat toughness measures.
  • * Additional findings suggest that the collagen in the perimysium has differing levels of resistance to heat, with some portions being easily denatured and others being more resilient, as evidenced by changes in digestion susceptibility and energy requirements for denaturation.
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Beef colour is essential to consumer acceptability with dark muscle colours being problematic. Dark meat has less light scattering but the mechanisms are unknown. We hypothesise that three mechanisms are responsible for decreased light scattering in dark meat, namely (i) larger lateral separation of myofilaments, (ii) decreased optical protein density in the I-band and (iii) decreased denaturation of sarcoplasmic proteins.

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Connective tissues such as tendon, ligament and skin are biological fibre composites comprising collagen fibrils reinforcing the weak proteoglycan-rich ground substance in extracellular matrix (ECM). One of the hallmarks of ageing of connective tissues is the progressive and irreversible change in the tissue mechanical properties; this is often attributed to the underlying changes to the collagen fibril structure. This dataset represents a comprehensive screen of the mechanical properties and collagen fibril structure of tendon from the tails of young to old (i.

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Beef meat colour is impacted by both myoglobin status and the light scattering properties of the muscle, and the specific causative scattering elements of the latter are still unknown. We hypothesize that stretching muscles during rigor will generate a structure which favours light scattering, by increasing the length of the I-band (longer sarcomeres) and that a high rigor temperature will cause protein reconfiguration, changing the muscle structure and promoting light scattering. Muscle fibre fragments were isolated from four beef M.

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Variations in the quantity and thermal stability of collagen in intramuscular connective tissue (IMCT) play a role in variations in cooked meat tenderness. This review is focussed on sources of variability, especially in the perimysial IMCT, and challenges some of the accepted ideas about its denaturation behaviour, its contribution to cooking shrinkage at high temperatures and the concept of IMCT as an immutable "background toughness". IMCT dominates the shear strength of raw and lightly cooked muscle, but at cooking temperatures of 70-80° its contribution is smaller than the myofibrillar component.

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The thermal denaturation of collagen the perimysium of intramuscular connective tissue isolated from bovine Semitendinosus (ST) and Perctoralis profundus (PP) muscles was investigated using a range of heating rates in differential scanning calorimetry (DSC) and analyzed by application of the Kissinger-Akahira-Sunose (KAS) and Lumry-Eyring models. Thermograms showed a broadening of endotherms and a shift towards higher temperatures as the thermal scanning rate increased. These features are consistent with the two-step process of a reversible transition between native and unfolded collagen molecules followed by an irreversible transition between unfolded and denatured states.

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Differences in the thermal shrinkage and collagen solubility between bovine Semitendinosus (ST) and Pectoralis profundus (PP) muscles and their interactions with ageing were evaluated by studying collagen solubility, hydrothermal isometric tension and thermal denaturation properties of intramuscular connective tissue after 5-20days post-mortem storage at 4°C. Collagen solubility was higher in ST than in PP muscle at 5-13days, but the differences between the two muscles decreased at longer ageing times. A small decrease in the peak denaturation temperature of perimysium occurred with increasing ageing times in both muscles.

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Most studies have focused on myoglobin regarding meat colour development, with little focus on the contribution of muscle structure and light scattering. Our aim was to investigate the pH-dependent changes in muscle structure, on the light scattering properties of the meat. Beef longissimus thoracis muscles were segregated into light, medium or dark colour groups (n=18).

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Ivermectin (IVM) is broad-spectrum compound active against endo and ecto-parasites of clinical relevance in veterinary and human medicine. It is commercially available to use in livestock animals as injectable formulations containing 1% IVM and also as a concentrated (3.15%) long-acting (LA) preparation.

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Meat loses fluid during cooking, resulting in textural changes and loss in cook yield. To understand the structural basis of cooking losses, this work used 10 bovine semitendinosus muscles and two ageing periods (1 vs 14days) to examine micro- and macro-level dimensional changes in muscle during heating. Muscle blocks, muscle fibre fragments and myofibrils all showed similar maximum shrinkage in cross sectional area (20-24%) but maximum length shrinkage was less in myofibrils (15%) than muscle blocks and fibre fragments (25%).

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Oat β-glucan consumption is linked to reduced risk factors associated with diabetes and obesity by lowering glycemic response and serum level of low-density lipoproteins. The purpose of this study was to identify the mechanism of action of oat β-glucan at the interface between the gut wall and the lumen responsible for attenuating glucose levels. We proposed that viscous oat β-glucan acts as a physical barrier to glucose uptake in normally absorptive gut epithelial cells IEC-6 by affecting the expression of intestinal glucose transporters.

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Matrix metalloproteinases (MMPs) are a group of enzymes that degrade extracellular matrix components but are also important signaling molecules that regulate many biological processes including muscle, adipose and connective tissue development. Most recently it has been discovered that MMPs act as intracellular signaling molecules inducing gene expression and altering related proteins in the nucleus. Several single nucleotide polymorphisms of MMPs and their inhibitors are known to exist and most of the research on MMPs to date has focused on their activity in relation to human health and disease.

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A recent article in this journal documents enhanced sensory qualities of pork cooked to low temperatures. The aim of this letter is to point out that the incidence of Trichinella spiralis in many countries and the more widespread incidence of Toxoplasma gondii present a concern for the adoption of low temperature cooking of pork unless extended cooking times are used.

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The heat-solubility of intramuscular collagen is usually conducted in 1/4 Ringer's solution at pH7.4, despite this ionic strength and pH being inappropriate for post-rigor meat. The current work studied the percentage of soluble collagen and hydrothermal isometric tension characteristics of perimysial strips on bovine semitendinosus muscles in either 1/4 Ringer's solution, distilled water, PBS, or a solution of the same salt concentration as 1/4 Ringer's but at pH5.

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