Dry-aging of beef as a tool to improve meat quality. Impact of processing conditions on the technical and organoleptic meat properties

Comprehensive analyses of meat quality and metabolome alterations with aging under different aging methods in beef

The impacts of various aging techniques on meat quality and metabolism alterations over time were investigated. Meat tenderness improved with aging, whereas prolonged aging negatively impacted color and oxidative stability. Dry-aging (DA) group exhibited significantly higher (P < 0.05) weight loss, lipid oxidation, and carbonyl contents, along with significantly lower (P < 0.05) centrifugal loss, cooking loss, a* value, and sulfhydryl content compared to wet-aging (WA) group. Substantial amounts of small peptides, amino acids, and amino acid derivatives were detected in the 28 d aged samples. Higher abundances of benzenoids, lipids and lipid-like molecules, amino acids and their derivatives, and alkyl phosphates were found in the WA group, while dialkyl ethers, fatty acids, fatty acid metabolites, and hydroxy acids showed higher intensities in the DA and dry-aging in bag groups. These findings provide comprehensive metabolome information and their underlying relation with meat quality changes during aging under different aging methods.

Impact of UV pre-treatment on the Longissimus thoracis et lumborum muscle proteomes of dry-aged beef cuts: A characterisation within two sampling locations

This research aimed to explore the changes in two sampling locations (internal and external) of the Longissimus thoracis et lumborum (LTL) beef muscle proteomes subjected to ultraviolet light before dry-aging. It further compared the biological processes and associated proteins at interplay at the external locations of UV pre-treated and control dry-aged samples. Before dry-aging, proteins related to external stimuli were differentially abundant between both locations possibly due to the early post-mortem energy metabolism attempting to compensate for energy deficiencies and stress derived from slaughter and processing. The biochemical status of muscle during chilling and hanging of the carcasses and the impact of the UV pre-treatment may have also influenced the abundance of these proteins before dry-aging. Proteins associated to muscle structure, energy and fatty acids metabolism were differentially abundant between locations after 21 days of dry-aging. These dynamic changes in the meat proteome and related biological processes suggested that both evolved differently between the two sampling locations during dry-aging, and these may underlie the development of dry-aged beef properties. The proteome of the external locations sampled from UV pre-treated beef loins was compared to control counterparts during dry-aging. The results show that aging time appeared to outweigh the effect of UV since the differentially abundant proteins between both groups decreased as dry-aging progressed. These proteins were associated with mRNA stabilization, the matrisome, energy pathways and heat shock proteins (HSPs). Further research is warranted to better understand the role of these proteins in the production of dry-aged beef and their relation to the UV pre-treatment.

Assessment of the effects of dry and wet aging on dark-cutting Nellore beef meat by TD-NMR and 1H NMR approaches

This study assessed the physicochemical parameters, water distribution, and metabolic profiles of wet- and dry-aged dark-cutting Nellore beef meat using TD-NMR and 1H NMR techniques alongside chemometric analysis. We analysed eight Nellore carcasses (Longissimus lumborum) aged for 28 days using both wet and dry methods. Post-aging, we noted significant reductions in water activity and moisture content in dry-aged samples, while lipid levels remained largely unchanged compared to unaged samples. However, both protein and carbonyl contents increased significantly with aging. Wet- and dry-aged samples also showed enhanced tenderness compared to non-aged beef. TD-NMR analysis identified four typical T2 components related to water distribution. Significant correlations Pearson were found between Aw, moisture and shear force and muscle water properties with moderate correlation found between Aw (inner) and T2.1 time constant. 1H NMR metabolic profiling identified 29 metabolites, including amino acids, dipeptides, and organic acids. Notably, levels of isoleucine, valine, threonine, alanine, and fumarate increased significantly after both aging processes. Acetate, creatinine, and betaine levels also increased significantly, while arginine and glycerol showed slight increases. In contrast, IMP content decreased significantly, while hypoxanthine content increased. These changes suggest metabolite accumulation that contributes to the enhanced flavour, taste, and tenderness of aged beef. This pilot study offers valuable insights that could help define optimal aging protocols for dark-cutting beef, potentially increasing the value of these meat products.

Effects of preslaughter handling approach and aging on carcass and meat quality attributes in goats

This study aimed to assess the impact of preslaughter handling method and aging on carcass and meat quality traits in goats. Twenty-seven male goats of Ardi breed were assigned into three treatment groups viz., the control (C), ear pulling (EP), and hind-leg pulling (HP). The carcasses were stored for post-mortem aging periods of 1, 7, and 14 days. On day 0 and the respective aging days, samples of the Longissimus thoracic et lumborum (LTL) muscles were collected and examined for various meat quality parameters. The preslaughter handling of goats significantly increase the total bacterial count, total Enterobacteriaceae count, and total Clostridium count. It also had a significant effect on the pH of LTL muscle during aging. A significantly lower values for pH were recorded in the treatment groups (EP and HP) as compared to the pH of the C group on day 1 of aging. Notably, both treatment groups were found to increase the shear force, hardness, and chewiness of the meat, ultimately compromising its quality. The proper treatment of meat animals, especially goats, is crucial for enhancing carcass and meat quality. Careful preslaughter handling practices by avoiding ear and hind-leg pulling can minimize negative impacts on the final product. Therefore, the significance of conducting this study lies in its potential to enhance animal welfare, improve meat quality, boost economic benefits for producers, and foster consumer confidence in meat products.

Widely Targeted Metabolomic Analysis Reveals Dynamic Metabolic Changes in Yanbian Cattle during Dry-Aging Process

Dry-aging is a postmortem process that can substantially enhance the texture and flavour of beef. This study entailed suspending Yanbian cattle M. gluteus medius in the aging cabinet, maintained at a temperature of 2-4 °C and a relative humidity of 85 ± 5% for 35 days. Throughout this period, samples were systematically collected every 7 days. The widely targeted metabolomic analysis has been used in this investigation to analyse the dynamic changes in Yanbian cattle metabolites during dry-aging. A total of 883 metabolites were identified, with amino acids and their metabolites representing the largest proportion. Multivariate statistical analysis showed that 373 metabolites were identified as differential metabolites that changed significantly during the dry-aging process, including metabolites of amino acids, glycerophospholipids, and nucleotides and their metabolites. Additionally, 308 metabolites exhibited various increasing trends with time in dry-aging. The analysis of KEGG pathway analysis showed that ABC transporters, glycerophospholipid, and arachidonic acid metabolism are the most important metabolic pathways during dry-aging. These findings can guide technological developments in the meat processing sector and provide valuable insights into the metabolic traits and pathways of Yanbian cattle during the dry-aging process.

Microbiological safety of dry-aged meat: a critical review of data gaps and research needs to define process hygiene and safety criteria

Dry-aged meat is gaining popularity among food business operators and private consumers. The process is carried out in aerobic conditions by hanging beef carcasses or placing subprimal or primal cuts in a dedicated cabinet for several weeks or even months while controlling the environment through the management of process parameters such as temperature, relative humidity, and airflow. In this review, we present a critical evaluation of the literature to evaluate tools to manage the process to guarantee food safety and identify critical control points, as well as good hygiene and manufacturing practices. In controlled aging conditions, only Listeria monocytogenes and Yersinia enterocolitica can multiply, while a reduction in the number of Salmonella spp. and Escherichia coli O157:H7 is generally reported. Enterobacteriaceae usually decrease on the surface of the meat during maturation; thus, for the purpose of the hygiene evaluation of the production process, a count no higher than that of unmatured meat is expected. Besides, various studies report that the total bacterial count and the spoilage microorganisms significantly increase on the surface of the meat, up to 5-6 Log10 CFU/g in the absence of visible spoilage. Bacteria of the Pseudomonas genus tend to progressively replace other microorganisms during maturation; thus, the total mesophilic or psychrophilic bacterial load is not a good indicator of process hygiene for matured meat. Critical parameters for the control of the process are temperature, relative humidity, and ventilation, which should be monitored during the process. For this reason, equipment designed and certified for dry-aging must be used, and the manufacturer must validate the process. Food business operators must apply general good manufacturing practices (GMP) and good hygiene practices (GHP) for meat processing and some GMP and GHP specific for dry-aging. Several research needs were identified, among them the evolution of the populations of L. monocytogenes and Y. enterocolitica and the microbiology of the inner parts of the dry-aged meat.

Assessment of water relaxometry of meat under different ageing processes using time domain nuclear magnetic resonance relaxometry

This study assessed water relaxometry of beef exposed to different ageing techniques by examining the inner and surface regions using time-domain nuclear magnetic resonance (TD-NMR) relaxometry. Beef strip loins were aged under vacuum (Wet), under vacuum using moisture absorbers (Abs), under vacuum using moisture absorbers and with mechanical tenderisation (AbsTend), or without any packaging (Dry). The ageing technique significantly influenced various meat parameters, including dehydration, total loss, and the moisture content of the meat surface. The transverse (T2) relaxation times provided a more sensitive indicator of the changes in meat water relaxometry than the longitudinal (T1) relaxation times. The Dry samples exhibited distinct differences in the T2 signals between the surface and inner regions of the meat. In particular, for the inner region, there were significant differences in signal areas between the Wet and Dry samples, and the Abs and AbsTend samples were positioned closely together between the Dry and Wet samples. The principal component analysis supported these findings: it indicated some differentiation among the ageing techniques in the score plot, but the differentiation was more pronounced when analysing the surface region. Additionally, there was a strong correlation between dehydration and the T2 values, leading to a clustering of the samples based on the ageing technique. The overlap between the Abs and AbsTend samples, situated between the Dry and Wet samples, suggests the potential of these treatments to produce meat with properties that are intermediate to Wet and Dry meat. Furthermore, tenderisation did not lead to greater dehydration.

Hydrolysis of Beef Sarcoplasmic Protein by Dry-Aged Beef-Isolated Penicillium oxalicum and Its Associated Metabolic Pathways

Yanbian cattle have a unique meat flavor, and high-grade meat is in short supply. Therefore, in this study, we aimed to improve the added value of Yanbian cattle low-fat meat and provide a theoretical reference for the subsequent development of an excellent starter. Rump meat from Yanbian cattle was dry-aged and then screened for protease-producing fungi. Three protease-producing fungi (Yarrowia hollandica (D4 and D11), Penicillium oxalicum (D5), and Meesziomyces ophidis (D20)) were isolated from 40 d dry-aged beef samples, and their ability to hydrolyze proteins was determined using bovine sarcoplasmic protein extract. SDS-PAGE showed that the ability of Penicillium oxalicum (D5) to degrade proteins was stronger than the other two fungi. In addition, the volatile component content of sarcoplasmic proteins in the D5 group was the highest (45.47%) and comprised the most species (26 types). Metabolic pathway analysis of the fermentation broth showed that phenylalanine, tyrosine, and tryptophan biosynthesis was the most closely related metabolic pathway in sarcoplasmic protein fermentation by Penicillium oxalicum (D5). Dry-aged beef-isolated Penicillium oxalicum serves as a potential starter culture for the fermentation of meat products.

Extending the theory of planned behavior to examine the role of meat-eater identity: The case of dry-aged beef

Dry-aged beef provides superior qualities and a unique taste experience due to its exceptional sensory attributes, including tenderness, juiciness, and flavor, compared to traditional beef. Our study focused on the factors that impact consumers' intention to consume and willingness to pay for dry-aged beef. We implemented an extended version of the Theory of Planned Behavior (TPB) model that contains a measure of meat-eater identity to analyze the intention to consume and the willingness to pay a premium for dry-aged beef steak that has undergone 21-30 days of aging. An online survey was conducted with a stratified sample of Italian respondents (n = 944). The data were analyzed using partial least squares structural equation modeling (PLS-SEM). The TPB's effectiveness was enhanced by adding the meat-eater identity construct to the model. Specifically, it was found that the participants' meat-eater identity significantly influenced their intention to consume. The results also revealed that the most critical impact of identity comes from the mediated influence of attitudes, subjective norms, and perceived behavioral control. Finally, the intention to consume strongly influenced the willingness to pay for a dry-aged beef steak.

Isolation of Debaryomyces hansenii and selection of an optimal strain to improve the quality of low-grade beef rump (middle gluteal) during dry aging

OBJECTIVE

The objective of this study was to evaluate the effect of Debaryomyces hansenii isolated from dry-aged beef on the tenderness and flavor attributes of low-grade beef during dry aging.

METHODS

Five D. hansenii strains were isolated from dry-aged beef samples. The rump of low-grade beef was inoculated with individual D. hansenii isolates and subjected to dry aging for 4 weeks at 5°C and 75% relative humidity. Microbial contamination levels, meat quality attributes, and flavor attributes in the dry-aged beef were measured.

RESULTS

Of the five isolates, the shear force of dry-aged beef inoculated with SMFM201812-3 and SMFM201905-5 was lower than that of control samples. Meanwhile, all five isolates increased the total free amino acid, glutamic acid, serine, glycine, alanine, and leucine contents in dry-aged beef. In particular, the total fatty acid, palmitic acid, and oleic acid contents in samples inoculated with D. hansenii SMFM201905-5 were higher than those in control samples.

CONCLUSION

These results indicate that D. hansenii SMFM201905-5 might be used to improve the quality of beef during dry aging.

Preliminary data on the microbial profile of dry and wet aged bovine meat obtained from different breeds in Sardinia

This study aimed to evaluate the influence of dry and wet aging on microbial profile and physicochemical characteristics of bovine loins obtained from four animals of two different breeds, namely two Friesian cull cows and two Sardo-Bruna bovines. During dry and wet aging aerobic colony count, Enterobacteriaceae, mesophilic lactic acid bacteria, Pseudomonas, molds and yeasts, Salmonella enterica, Listeria monocytogenes and Yersinia enterocolitica, pH and water activity (a_w) were determined in meat samples collected from the internal part of the loins. Moreover, the microbial profile was determined with sponge samples taken from the surface of the meat cuts. Samples obtained from Friesian cows were analyzed starting from the first day of the aging period and after 7, 14, and 21 days. Samples obtained from the Sardo Bruna bovines were also analyzed after 28 and 35 days. Wet aging allowed better control of Pseudomonas spp. during storage that showed statistically lower levels (P>0.05) in wet-aged meats with respect to dry-aged meats during aging and particularly at the end of the period (P>0.01) in both cattle breeds. At the end of the experiment (21 days), aerobic colony count and Pseudomonas in Fresian cows' dry-aged meats showed mean levels >8 log, while lactic acid bacteria mean counts >7 log were detected in wet-aged meats of both cattle breeds. In meats submitted to dry aging, pH was significantly higher (P<0.01) with respect to wet-aged meats at all analysis times and in both cattle breeds. A_w showed a stable trend during both dry and wet aging without significant differences. These preliminary results highlight the critical importance of the strict application of good hygiene practices during all stages of production of these particular cuts of meat intended for aging.

Molecular Changes of Meat Proteins During Processing and Their Impact on Quality and Nutritional Values

Meats are rich in lipids and proteins, exposing them to rapid oxidative changes. Proteins are essential to the human diet, and changes in the structure and functional attributes can greatly influence the quality and nutritional value of meats. In this article, we review the molecular changes of proteins during processing, their impact on the nutritional value of fresh and processed meat, the digestibility and bioavailability of meat proteins, the risks associated with high meat intake, and the preventive strategies employed to mitigate these risks. This information provides new research directions to reduce or prevent oxidative processes that influence the quality and nutritional values of meat.

Assessing Meat Freshness via Nanotechnology Biosensors: Is the World Prepared for Lightning-Fast Pace Methods?

In the rapidly evolving field of food science, nanotechnology-based biosensors are one of the most intriguing techniques for tracking meat freshness. Purine derivatives, especially hypoxanthine and xanthine, are important signs of food going bad, especially in meat and meat products. This article compares the analytical performance parameters of traditional biosensor techniques and nanotechnology-based biosensor techniques that can be used to find purine derivatives in meat samples. In the introduction, we discussed the significance of purine metabolisms as analytes in the field of food science. Traditional methods of analysis and biosensors based on nanotechnology were also briefly explained. A comprehensive section of conventional and nanotechnology-based biosensing techniques is covered in detail, along with their analytical performance parameters (selectivity, sensitivity, linearity, and detection limit) in meat samples. Furthermore, the comparison of the methods above was thoroughly explained. In the last part, the pros and cons of the methods and the future of the nanotechnology-based biosensors that have been created are discussed.

Effect of Palm-Based Shortenings of Various Melting Ranges as Animal Fat Replacers on the Physicochemical Properties and Emulsion Stability of Chicken Meat Emulsion

This study evaluated the effects of palm shortenings (PS) with varying melting ranges (MR) on the physicochemical, emulsion stability, rheological, thermal, textural, and microtextural properties of chicken meat emulsions. Six emulsions were developed: control (chicken skin), sample A (PS at MR of 33-36 °C), sample B (PS at MR of 38-42 °C), sample C (PS at MR of 44-46 °C), sample D (PS at MR of 45-49 °C), and sample E (PS at MR of 55-60 °C). There were no significant differences in cooking loss, pH, and water-holding capacity between the meat emulsions, with sample E providing a more stable emulsion with the lowest fat content and highest moisture content. The colour profiles and protein thermal stabilities of the fat-replaced meat emulsions were not significantly different from the control. The hardness, shear force, storage, and loss moduli increased when palm shortenings with higher melting range were used, with sample E having the highest values. Sample E also exhibited a smaller pore size and more compact structure, and thus was well-emulsified compared to the other samples. Overall, palm shortenings-particularly those with a melting range of 55-60 °C-have the potential to replace chicken skin in meat emulsions.

Effects of Feeding Regimes and Postmortem Aging on Meat Quality, Fatty Acid Composition, and Volatile Flavor of Longissimus Thoracis Muscle in Sunit Sheep

The effects of different feeding regimes on antioxidant activity, meat quality, fatty acid composition, lipid oxidation, and volatile matter production in the longissimus thoracis (LT) of Sunit sheep at 0, 24, 48, 72, and 96 h postmortem were investigated. The results showed that the activity of antioxidant enzymes, tenderness, water retention, and percentage of unsaturated fatty acids were significantly higher in the pasture-fed sheep (PF) than in the concentrate-fed sheep (CF) (p < 0.05). During postmortem aging, antioxidant activity, water retention, and the proportion of unsaturated fatty acids decreased in the PF and CF (p < 0.05), while malondialdehyde (MDA) content, the proportion of saturated fatty acids, and the content of flavor substances resulting from fat oxidation increased. After 24 h of LT muscle aging, the pH and shear force of the meat started to increase and the color stabilized. The differences between shear force values and lipid volatile flavor substance content of sheep meat under different feeding regimes disappeared with increasing aging time. PF had better oxidative stability and fatty acid composition. Postmortem aging changed the oxidative stability of sheep meat, thus affecting meat quality and fatty acid composition and consequently meat flavor composition, while aging also eliminated to some extent the differences caused by feeding regimes.

A Comparative Study on the Effect of Ultrasound-Treated Apple Pomace and Coffee Silverskin Powders as Phosphate Replacers in Irish Breakfast Sausage Formulations

Ultrasound (US) technology can be used to improve the techno-functional properties of food ingredients, such as apple pomace (AP) and coffee silverskin (CSS), which can be used in meat products to enhance their quality. This study evaluated the changes produced by US-treated AP and CSS, when used as phosphate replacers, in the physicochemical properties of Irish breakfast sausages, i.e., their water holding capacity (WHC), cook loss, emulsion stability, proximate content, lipid oxidation, color, and textural parameters. Three sausage formulations with reduced phosphate concentrations were used to study the effect of US-treated AP and CSS, and an interactive relationship between US treatment and formulations using two-way ANOVA. The results showed that the addition of US-treated AP and CSS to all the formulations produced a significant interactive effect that increased the WHC (p < 0.05) and emulsion stability (p < 0.05), decreased cook loss (p < 0.05), and increased day 9 TBARS (p < 0.05) values of specific formulations. No significant changes were observed for the parameters of; color, texture, or proximate content values. Thus, this study demonstrated that the addition of US-treated AP and CSS improved the quality of phosphate-reduced sausages.