Meat Science最新文献

The impact of using incorrect lighting while subjectively scoring pork colour with subjective standards (Japanese, Canadian, and Kodak grey) was explored. Lightness was more important than a good colour match between standards and meat. Subjective and image-based automated scoring with Canadian standards were correlated at 0.71–0.77 (P < 0.001) with significant differences in scale distribution (D = 0.14–0.46; P < 0.002), primarily with moderately dark meat. Automated scoring on full colour and greyscale images were strongly related (r = 0.83, P < 0.001) and showed matching score distributions when whole scores were used. Tracking automated colour categorization during blooming showed very good potential for reliable categorization after 1 min exposure to air for most meat colours, indicating that reliable automated on-line sorting of pork for colour is easily within reach.

Acacia mearnsii byproducts are naturally endowed with a plethora of diverse polyphenols that exhibit antioxidant properties indicating potential application in enhancing oxidative shelf-life of perishable foods. The current study evaluated the oxidative shelf-life of raw ground beef patties fortified with 450 μg/g of polyphenolic extracts from A. mearnsii bark (AMBE) or leaves (AMLE) compared to positive (sodium metabisulphite; SMB) and negative (no extract; CTL) controls for 9 d at 4 °C in a simulated retail display. The AMBE had higher (P ≤ 0.05) contents of proanthocyanidins, and total phenols, flavonoids and tannins, and consequently demonstrated greater (P ≤ 0.05) in vitro antioxidant activity than AMLE. The polyphenolic extracts increased (P ≤ 0.05) antioxidant activity in beef patties compared to the CTL though they were outperformed (P ≤ 0.05) by the SMB. Fortification of beef patties with the polyphenolic extracts, particularly AMBE, delayed colour deterioration and oxidation of myoglobin during retail display relative to the CTL but were less efficient than SMB (P ≤ 0.05). Beef patties fortified with the polyphenolic extracts and SMB had comparable (P > 0.05) peroxide values, TBARS and p-Anisidine values which were all lower (P ≤ 0.05) than those for the CTL patties. The order of protein thiol content in beef patties was as follows: CTL ≥ AMLE ≥ AMBE ≥ SMB (P ≤ 0.05). Findings suggest that A. mearnsii-derived polyphenolic antioxidants, particularly AMBE has great potential to extend oxidative shelf-life of raw beef patties.

Tenderness is considered a crucial attribute of postmortem meat quality, directly influencing consumers' preferences and industrial economic benefits. The degradation of myofibrillar proteins by endogenous enzymes within muscle fibers is believed to be the most effective pathway for meat tenderization. After animals are slaughtered and exsanguinated, there is a significant accumulation of reactive oxygen species (ROS), and a dramatic depletion of adenosine triphosphate (ATP) in muscle, leading to inevitable cell death. Caspases are activated in postmortem muscle cells, which disrupt the cell structure and improve meat tenderness through protein hydrolysis. In this review, we systematically summarized the three primary types of cell death studied in postmortem muscle: apoptosis, autophagy and necrosis. Furthermore, we emphasized the molecular mechanisms of apoptosis and its corresponding apoptotic pathways (mitochondrial apoptosis, death receptors, and endoplasmic reticulum stress) that affect meat tenderness during muscle conversion to meat. Additionally, factors affecting apoptosis were comprehensively discussed, such as ROS, heat shock proteins, calcium (Ca²⁺)/calpains, and Bcl-2 family proteins. Finally, this comprehensive review of existing research reveals that apoptosis is mainly mediated by the mitochondrial pathway. This ultimately leads to myofibrillar proteins degradation through caspase activation, improving meat tenderness. This review summarizes the research progress on postmortem muscle apoptosis and its molecular mechanisms in meat tenderization. We hope this will enhance understanding of postmortem meat tenderness and provide a theoretical basis for meat tenderization techniques development in the future.

Reflectance-based oxygen consumption measurement utilizes changes in oxymyoglobin levels between bloomed and vacuum-packaged meat, assuming that oxymyoglobin is converted to deoxymyoglobin. However, the interconversion of oxymyoglobin to deoxymyoglobin depends on the age of the meat and the length of display; hence, oxygen consumption calculations might yield inaccurate interpretations if deoxymyoglobin is not the final form. The objective was to evaluate the effectiveness of determining metmyoglobin levels during oxygen consumption analysis and its relationship to beef color stability. Seven psoas major (color labile) and longissimus (color stable) were displayed in retail for 6 d and evaluated for oxygen consumption on the retail (oxygen exposed) and interior (non‑oxygen exposed) surfaces. The retail surface had greater (P < 0.05) metmyoglobin formed during oxygen consumption than the interior surface on d 6 of the display. Furthermore, the psoas major muscle exhibited greater (P < 0.05) metmyoglobin content during oxygen consumption than the longissimus on the retail surface paralleling with the decline in color stability. Therefore, the study indicates that sampling location and including metmyoglobin content in oxygen consumption calculations, along with changes in oxymyoglobin, will better explain meat color stability.

The aim of this study was to assess the influence of ageing on instrumental and sensory qualities in Longissimus thoracis et lumborum (LTL) from heifers (n = 200) and cows (n = 100) of Lidia breed. The animals were slaughtered as heifers (24–48 months) or cull cows (> 48 months). For instrumental analysis, pars Thoracis aged at 7, 14 and 28 days was used; for sensory analysis, pars Lumborum aged at 14 and 28 days was evaluated. Heifers showed redder and yellower meat (P < 0.05) and cows showed slightly higher Water Holding Capacity (WHC): Thawing Loss (TL) = P < 0.05; Drip Loss (DL) = P < 0.01; Pressure Loss (PL) = P < 0.01; Cooking Loss (CL) = P < 0.05. Ageing generated changes in meat colour, with increases in lightness (L*, linear pattern, P < 0.001) and oscillations in a* and b* (quadratic patterns; P < 0.05 and P < 0.001, respectively). Ageing affected TL (increasing, P < 0.001) and PL (decreasing, P < 0.05), and generated a significant improvement in Warner Bratzler Shear Force (WBSF) values (P < 0.001). Commercial type revealed changes in consumer panel ratings for flavour (P < 0.05), juiciness (P < 0.01), tenderness (P < 0.001) and overall acceptability (P < 0.001), with better results in these parameters for cull cows. In contrast to the usual, ageing did not affect the sensory traits. There was no significant interaction between commercial type and ageing time, except for beef flavour, which worsened with ageing (P < 0.05).

Enhancing stress resilience through the early life period in pigs could potentially improve pork quality. It was hypothesised that pigs receiving maternal contact or positive human contact during lactation would have improved carcass and pork quality. Seventy-nine mixed-sex pigs were selected from a 2 × 2 factorial randomised block design for treatments maternal contact (MC+) / reduced maternal contact (MC-); and positive human contact (HC+) / control (HC-). Modified farrowing crates were utilised to reduce maternal contact (MC-). Litters in the HC+ treatment received five minutes of daily positive human interaction (stroking). Treatments ceased at 22 days of age (weaning) and pigs were slaughtered after 21 weeks of age. The m. longissimus thoracis et lumborum pH was higher in HC+ than HC- pigs (P < 0.05) during chilling, from 90 min post slaughter. No HC effects (P > 0.05) were observed for cortisol or haptoglobin concentration, hot carcass weight, P2 backfat, carcass scratches, colour, drip loss, cook loss and shear force. MC+ tended (P < 0.086) to increase carcass weight, P2 and carcass scratch score compared to MC-, but no further impacts were observed. The impact of positive human contact during early life was observed 20+ weeks after treatment with reduced pH decline, potentially indicating a reduction in pre-slaughter stress, however there were no further impacts on pork quality. There is evidence that maternal contact is important for lifetime growth performance of pigs but the impacts on stress resilience are less apparent.

Belly is a widely consumed pork product with very variable properties. Meat industry needs real-time quality assessment for maintaining superior pork quality throughout the production. This study explores the potential of using visible and near-infrared (VNIR,386-1015 nm) spectral imaging for predicting firmness, fatness and chemical compositional properties in pork belly samples, offering robust spectral calibrations. A total of 182 samples with wide variations in firmness and compositional properties were analysed using common laboratory analyses, whereas spectral images were acquired with a VNIR spectral imaging system. Exploratory analysis of the studied properties was performed, followed by a robust regression approach called iterative reweighted partial least-squares regression to model and predict these belly properties. The models were also used to generate spatial maps of predicted chemical compositional properties. Chemical properties such as fat, dry matter, protein, ashes, iodine value, along with firmness measures as flop distance and angle, were predicted with excellent, very good and fair models, with a ratio prediction of standard deviation (RPD) of 4.93, 3.91, 2.58, 2.54, 2.41, 2.53 and 2.51 respectively. The methodology developed in this study showed that a short wavelength spectral imaging system can yield promising results, being a potential benefit for the pork industry in automating the analysis of fresh pork belly samples. VNIR spectral imaging emerges as a non-destructive method for pork belly characterization, guiding process optimization and marketing strategies. Moreover, future research can explore advanced data analytics approaches such as deep learning to facilitate the integration of spectral and spatial information in joint modelling.

The effects of cauliflower treated with atmospheric cold plasma (ACP), as a natural nitrite source, on the curing of ground ham and nitrosamine formation were investigated. Ground ham was prepared using sodium nitrite and ACP-treated cauliflower powder (PTCP) to achieve initial nitrite concentrations of 60 and 100 mg/kg, respectively. ACP treatment generated nitrite in cauliflower but significantly reduced the antioxidant activity (P < 0.05). As a nitrite source, PTCP had similar effects as sodium nitrite in the development of cured color in ground ham, with a comparable residual nitrite content (P ≥ 0.05). Three nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), and N-nitrosopyrrolidine (NPYR), were detected in ground ham. NPYR formation was significantly lower in ground ham treated with PTCP at an initial nitrite concentration of 100 mg/kg (P < 0.05). Therefore, the use of a natural nitrite source manufactured through ACP treatment can prospectively achieve suitable curing efficiency while simultaneously suppressing nitrosamine formation.

The objective of this study was to evaluate and improve the prediction models of the AutoFOM III and FOM II apparatuses (Frontmatec Group, Denmark) used to estimate the lean meat percentage (LMP) of pig carcasses in Belgium, since the current models underestimate the pig carcasses with a LMP higher than 66 %. Non-linearity in the backfat thickness (BT) parameters was identified as the main reason for this bias in prediction. Box-Cox transformation of the parameters R2P10, R2P8 and R2P4 from AutoFOM III allowed to lower the root mean squared error of prediction (RMSEP) of the model from 1.72 to 1.59, while simultaneously removing the bias of the high LMP carcasses. For the FOM II apparatus, there was no effect of the transformation of the only BT parameter on the RMSEP (2.15 before and 2.14 after transformation) and on the bias. Next to the transformation, it was investigated whether adding other information about the carcasses could also improve the RMSEP of the prediction models. The parameters hot carcass weight, carcass length, ham width, ham angle and sex were added to the original models without transformation and lowered the RMSEP from AutoFOM III and FOM II to 1.55 and 1.83 respectively. Finally, the best results were found by combining the Box-Cox transformation and adding other carcass parameters, resulting in RMSEP values of 1.50 and 1.82 for AutoFOM III and FOM II respectively, on top of the removal of the high LMP bias.

Implications

Accurate estimation of the lean meat percentage of pig carcasses is of great economic importance for the pig production and slaughtering sector, so every opportunity to increase precision should be seized. This study shows that the current linear prediction models can be improved by taking into account non-linearity, depending on the device. An even larger increase in precision can be achieved by adding carcass information that is currently not measured or not linked to the classification device but that is partly already available at the slaughterline.

Consumer demand for tastier and higher-quality pork is increasing. Probiotics have been reported to improve meat quality, but the species of probiotics are limited, and efficacy is discrete. This study investigated the effects of dietary Brevibacillus laterosporus BL1 (live and heat-killed form) supplementation on the meat quality of finishing pigs. Results revealed that both live and heat-killed B. laterosporus BL1 supplementation increased pH_24h and decreased drip loss (P < 0.05) compared to the control group (CON). Moreover, compared to the CON group, heat-killed B. laterosporus BL1 supplementation exhibited a stronger ability to improve meat quality (redness, shear force, inosine monophosphate, and intramuscular fat content, P < 0.05), antioxidant capacity, and free amino acid profiles of longissimus thoracis (LT) than live bacteria without impairing porcine growth performance. Further, heat-killed B. laterosporus BL1 supplementation favored up-regulating the expression of genes related to oxidative-type fiber in LT (P < 0.05). Proteomic analysis confirmed that Gene Ontology items related to oxidative metabolism were subsequently enriched with heat-killed B. laterosporus BL1 treatment in LT (P < 0.05). Overall, dietary heat-killed B. laterosporus BL1 supplementation may improve the meat quality of finishing pigs, which provides application guidance for B. laterosporus BL1 in producing higher-quality pork.