Dry-Aging Effects on Palatability of Beef Longissimus Muscle

Study on the Correlations between Quality Indicators of Dry-Aged Beef and Microbial Succession during Fermentation

Dry-aged beef has been long favored by people due to its unique flavor and taste. However, the inner relationship between its overall quality formation and microbial changes during dry aging has not yet received much attention and research. To deeply reveal the forming mechanism of the unique flavor and taste of dry-aged beef, correlations between its three main quality indicators, i.e., texture, free amino acids (FAAs), volatile flavor compounds (VFCs), and microbial succession were analyzed in this study. The results showed that Staphylococcus spp. and Macrococcus spp. were key strains that influenced the total quality of dry-aged beef and strongly correlated with chewiness, hardness, and sweet FAAs (Ala), providing beef with unique palatability and taste. Additionally, among VFCs, Staphylococcus spp. and Macrococcus spp. showed a strong correlation with octanal and heptanal, and meanwhile, those highly correlated with nonanal, pentanol, and oct-1-en-3-ol were Debaryomyces spp., Psychrobacter spp., and Brochothrix spp., respectively, providing beef with a unique flavor. Staphylococcus spp. was proposed to be the dominant genus for dry-aged beef. This study provides valuable reference for the understanding of the role of microorganisms involved in dry aging.

Umami Characteristics and Taste Improvement Mechanism of Meat

Taste is one of the five senses that detect vital information about what we are eating. Comprehending taste is crucial for enhancing the flavor of foodstuffs and high-protein foods like meat. Umami has global recognition as the fifth elementary taste, alongside sweetness, sourness, saltiness, and bitterness. Umami compounds are known to enhance the sensation of recognized flavors such as salty, sweet, bitter, and others. This could end up in greater food consumption by consumption by consumers. With the rising global population, meat consumption is rising and is projected to double by 2025. It is crucial to comprehend the umami mechanism of meat and meat products, identify novel compounds, and employ laboratory methodologies to gather varied information. This knowledge will aid in the development of new consumer products. Although very limited information is available on umami taste and compounds in meat through research data. This article discusses recent advancements in umami compounds in other foodstuff as well as meat to aid in designing future research and meat product development. Moreover, another objective of this review is to learn present techniques in foodstuffs to enhance umami taste and utilize that knowledge in meat products.

Freezing/thawing as an accelerating process of wet- and dry-aged Nellore beef

This study aimed to evaluate the use of freezing/thawing as a way of accelerating the aging processes of beef from Nellore animals. Non-frozen (NF) or freezing/thawing (FT) strip loins were aged (for 14 and 28 days) using two systems: bone-in dry-aging (DA); boneless wet-aging (WA). FT-treated samples had greater weight losses (P < 0.05) during aging than NF-treated samples, especially using the DA process. However, the weight loss of the FT 14-days DA beef samples was comparable to that of NF 28-days DA. FT beef had lower fragmentation index and shear force values (P < 0.05), as well as its maximum sensorial tenderness was achieved earlier (P < 0.05) than the NF counterpart. With 28 days of aging, DA beef showed higher (P < 0.05) tenderness and juiciness scores and lower lightness values than WA beef. The FT process decreased the reducing capacity of meat samples, generating more metmyoglobin and lower amounts of chroma than NF. The expected volatile profile of DA beef was achieved faster in FT-treated samples, but the freezing treatments did not compromise the microbial count for either aging system. Our findings indicate that accelerated DA by the FT process could improve the palatability of Nellore beef, allowing the desired tenderness and flavor profile to be achieved in a shorter time, without increasing costs with weight losses or adversely affecting physicochemical, chemical, and microbial characteristics.

Microbiota associated with commercial dry-aged beef in France

Meat dry aging consists in storing unpackaged meat in a cold room, and at a specific and controlled relative humidity (RH), for a period of 1 to 5 weeks or more. This practice has become widespread in recent years due to its positive effect on the tenderness of the meat but also on other organoleptic characteristics and therefore its market value. The objective of this work was to study the bacterial and fungal microbiota of dry-aged beef at the commercial stage by both culture-dependent and -independent approaches. Fifty-eight samples of dry-aged meat from different producer types (meat processing plants, artisanal and supermarket butchers) were studied. The dry-aging conditions (temperature, RH) of the meats, as well as the surface pH and aw, were measured. The main microbial groups were enumerated by culture on various dedicated media. Concerning fungi, isolates of yeasts and molds (n = 257) were identified after dereplication by FTIR spectroscopy and/or sequencing of taxonomically relevant genes (26S rDNA, ITS, β-tubulin, actin). Metagenetic analyzes targeting the V3-V4 regions of 16S rDNA and ITS2 were also performed. Overall, ripening practices were diversified with temperatures and RH between 0.5 and 2.8 °C (median = 2 °C) and 47 and 88 % (median = 70 %), respectively. The aerobic colony count varied between 1.97 and 10.91 log10 CFU/g (median = 8.32 log10 CFU/g) and was similar to that of Pseudomonas spp., indicating that this bacterial group was dominant. Yeast populations varied between <2 and 9.41 log10 CFU/g, while molds showed abundances between <2 and 7.7 log10 TFU/g, the highest values being found in meats matured with a high RH. Bacterial and mold counts were positively correlated with the dry-aging RH and, to a lesser extent, temperature. The main yeast species were Candida zeylanoides and Yarrowia alimentaria as well as Itersonilia pannonica (identified only in metagenetics). The dominant mold species were psychrophilic or psychrotrophic species, namely Mucor complex flavus and Helycostylum elegans/pulchrum that have already been shown to be associated with dry-aged beef meat. This study has identified the main microorganisms associated with dry-aged meat in France, which raises the question of their role in the organoleptic quality of these higher value products.

Effects of relative humidity on dry-aged beef quality

This study was conducted to evaluate the effects of relative humidity (RH) on moisture loss and flavor in dry-aged beef. Sixteen strip loins were assigned to one of the four aging treatments: vacuum (WET), dry-aging at 50% RH, dry-aging at 70% RH, or dry-aging at 85% RH and aged for 42 days at 2 °C. Loins were evaluated for evaporation loss, trim loss, tenderness, sensory, and microbiological characteristics. Results show that lower RH results in accelerated moisture loss during the first 3 days of the aging process without significantly affecting the total amount of moisture loss. Pseudomonadales dominated the aerobically dry-aged loins while Enterobacteriales was the most abundant in the wet-aged samples. Dry-aged samples had increased content of free amino acids in the cooked meat juice compared to the wet-aged counterpart. Dry aging at 50% RH tended to associate with more desirable flavor notes.

A current review of U.S. beef flavor II: Managing beef flavor

Beef flavor continues to be one of the largest drivers of beef demand and a differentiation point of beef from other competing proteins. Tenderness has long been identified as the most important palatability trait for consumer satisfaction. However, as technological advancements and industry practices evolve and improve in response to tenderness management, flavor has emerged as a key driver of consumer satisfaction. In response, the beef industry has recently invested in research focused on beef flavor development, measurement, and management to better understand the factors impacting flavor and help beef maintain this advantage. The current review paper is the second of two such papers focused on summarizing the present knowledge and identifying knowledge gaps. While the other review focuses on current practices related to beef flavor measurement, this review will cover research findings related to beef flavor management. Numerous production and product management factors influence beef flavor. Pre-harvest factors including marbling level, animal genetics/cattle type, diet, and animal age, can influence beef flavor. Moreover, numerous post-harvest product management factors, including product type, aging length and conditions, cookery methods, product enhancement, muscle-specific factors, packaging, retail display factors, and antimicrobial interventions, have all been evaluated for their impact on beef flavor characteristics. Results from numerous studies evaluating many of these factors will be outlined within this review in order to present management and production chain factors that can influence beef flavor.

Authentication of aged beef in terms of aging time and aging type by 1H NMR spectroscopy

Meat authenticity addresses parameters such as species, breed, sex, housing system and postmortem treatment. Seventy-four beef backs from two breeds ('Fleckvieh' and 'Schwarzbunt') and three cattle types (heifer, cow, young bull) were dry-aged and wet-aged up to 28 days and analyzed by 1H NMR spectroscopy. Statistical models based on partial least squares regression and discriminant analysis were performed to classify the beef samples by breed, cattle type, aging time, and aging type based on their 1H NMR spectra. The aging time of beef samples can be predicted with an error ± 2.28 days. The cattle type model has an accuracy of cross-validation of 99.2 %, the breed models of 100 % and the aging type model for 28-days aged samples of 99.6 %. These models allow the authentication of beef samples in terms of breed, cattle type, aging time, and aging type with a single 1H NMR measurement.

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.

Impact of a constant current electrical stimulation (CCES) system and hormonal growth-promoting (HGP) implants on meat quality and palatability of finished steers

This study evaluated the effects of a constant current electrical stimulation (CCES) system and hormonal growth-promoting (HGP) implants on the quality and palatability of the longissimus thoracis et lumborum (LTL) from yearling-finished steers. The experiment used a total of 46 Angus cross steers, which were either non-implanted (n = 20) or implanted with trenbolone acetate and estradiol benzoate (n = 26). The CCES was applied to one side of each carcass during the slaughter process, whereas the other side remained unstimulated. Regardless of the application of HGP implants, the CCES reduced pH at 3 and 72 h post-mortem and shear force at all ageing times (P < 0.05), improved colour at 72 h post-mortem and during the retail display (P < 0.05), increased initial and overall tenderness (P < 0.01), and decreased the amount of perceived connective tissue and the proportion of trained panelists detecting spongy texture (P < 0.05) compared to meat from unstimulated carcass sides. Although CCES increased meat purge losses and reduced moisture content (P < 0.05), this did not affect meat juiciness (P > 0.10). CCES interacted with HGP to prevent increase in drip loss (P > 0.10), increase frequency of panelists detecting bloody/serumy flavour and typical texture, and reduce the proportion of panelists detecting rubbery texture in meat (P < 0.05). Regardless of stimulation treatment, meat from implanted animals had a more pronounced pH decline at 72 h post-mortem (P < 0.05) and a higher proportion of panelists finding no off-flavours (P < 0.05) or bloody/serumy flavour (P < 0.01) than non-implanted cattle. The CCES system tested in this study improved LTL quality and palatability of heavier beef carcasses.

Aging mechanism for improving the tenderness and taste characteristics of meat

Tenderness and taste characteristics of meat are the key determinants of the meat choices of consumers. This review summarizes the contemporary research on the molecular mechanisms by which postmortem aging of meat improves the tenderness and taste characteristics. The fundamental mechanism by which postmortem aging improves the tenderness of meat involves the operation of the calpain system due to apoptosis, resulting in proteolytic enzyme-induced degradation of cytoskeletal myofibrillar proteins. The improvement of taste characteristics by postmortem aging is mainly explained by the increase in the content of taste-related peptides, free amino acids, and nucleotides produced by increased hydrolysis activity. This review improves our understanding of the published research on tenderness and taste characteristics of meat and provides insights to improve these attributes of meat through postmortem aging.

Effects of alternating electric field assisted freezing-thawing-aging sequence on longissimus dorsi muscle microstructure and protein characteristics

The current study investigates the influence of alternating electric field (AEF)-assisted freezing-thawing-aging sequence on the muscle microstructure and myofibrillar protein characteristics. Three treatments were used for longissimus dorsi (LD) muscle: only aging (OA), freezing-thawing-aging sequence (FA) and AEF-assisted freezing-thawing-aging sequence (EA). Compared with the FA and EA groups, the OA group showed considerably fewer cracks between muscle fibers and maintained the integrity of the Z-line as observed using scanning and transmission electron microscopy, respectively. Furthermore, the EA treatment effectively decreased myofibrillar fragmentation, myofibrillar protein aggregation, and protein oxidation, as shown by the myofibrillar fragmentation index, turbidity, and total sulfhydryl concentration. Analysis of surface hydrophobicity and the Fourier transform infrared, UV absorption, and fluorescence spectrums indicated that AEF minimized the alterations of protein secondary and tertiary structure alterations during aging after freezing.

Effects of in-the-bag dry-ageing on meat quality, palatability and volatile compounds of low-value beef cuts

This study evaluated the effects of in-the-bag dry-ageing (BDA) (21 and 42 d) on meat quality, palatability, and volatile compounds of clod heart, brisket, and flat iron cuts from steers. In all cuts, BDA increased moisture losses (P < 0.05), but this did not reduce the juiciness of 21 d BDA versus wet-aged (WA) steaks. In clod heart, BDA increased overall tenderness at 21 d compared to 21 d WA (P < 0.01). Regardless of ageing period, BDA of clod heart increased beef flavour and salty taste and decreased sour-dairy and stale/cardboard flavours and concentrations of volatile compounds derived from lipid oxidation compared to WA (P < 0.05). In brisket, BDA increased salty taste and fatty aroma and reduced bloody/serumy flavour, whereas decreased beef and buttery flavours and intensified some unpleasant aromas/flavours (P < 0.05) for both ageing periods. The BDA of flat iron increased several undesirable aromas/flavours and decreased sweet taste and beef and buttery flavours (P < 0.05), regardless of ageing period. Overall, BDA for 42 d decreased meat quality and palatability and increased concentrations of volatile compounds from lipid oxidation, especially in flat iron cuts. Value could be recovered by customizing BDA periods by cut.

Influence of meat sample geometry on dehydration dynamics during dry-aging of beef

Meat geometry may impact on the dehydration kinetics during dry-aging influencing the drying rate and, potentially, aspects of meat quality. In this study, three meat geometries (slices, steaks and sections) were prepared from three bovine Longissimuss thoracis et lumborum at 3 days post-mortem and were dry-aged at 2 °C, 75% relative humidity with an airflow of 0.5-2.0 m/s for 22 days (slices), 48 days (sections) and 49 days (steaks). Weights were recorded during dry-aging and drying curves were obtained for the three geometries, with the larger sections showing limited dehydration due to internal resistance to moisture migration from the core to the surface. Seven thin-layer equations were fitted to the dehydration data in order to model the drying kinetics during dry-aging. Thin-layer models described reliably the drying kinetics of the three geometries. In general, reduced k values (h^-1) reflected the lower drying rates as thickness increased. The Midilli model provided the best fit for all geometries. Proximate analyses of the three geometries and bloomed colour of sections were measured at the start and the end of the dry-aging period. Moisture loss during dry-aging led to the concentration of protein, fat and ash contents; while no significant differences were found for L*, a* and b* values of sections before and after the dry-aging process. In addition, moisture content, water activity (a_w) and LF-NMR measurements were taken at different locations within beef sections to further explore water dynamics during dry-aging.

Microbiological safety of aged meat

The impact of dry-ageing of beef and wet-ageing of beef, pork and lamb on microbiological hazards and spoilage bacteria was examined and current practices are described. As 'standard fresh' and wet-aged meat use similar processes these were differentiated based on duration. In addition to a description of the different stages, data were collated on key parameters (time, temperature, pH and aw) using a literature survey and questionnaires. The microbiological hazards that may be present in all aged meats included Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, enterotoxigenic Yersinia spp., Campylobacter spp. and Clostridium spp. Moulds, such as Aspergillus spp. and Penicillium spp., may produce mycotoxins when conditions are favourable but may be prevented by ensuring a meat surface temperature of -0.5 to 3.0°C, with a relative humidity (RH) of 75-85% and an airflow of 0.2-0.5 m/s for up to 35 days. The main meat spoilage bacteria include Pseudomonas spp., Lactobacillus spp. Enterococcus spp., Weissella spp., Brochothrix spp., Leuconostoc spp., Lactobacillus spp., Shewanella spp. and Clostridium spp. Under current practices, the ageing of meat may have an impact on the load of microbiological hazards and spoilage bacteria as compared to standard fresh meat preparation. Ageing under defined and controlled conditions can achieve the same or lower loads of microbiological hazards and spoilage bacteria than the variable log10 increases predicted during standard fresh meat preparation. An approach was used to establish the conditions of time and temperature that would achieve similar or lower levels of L. monocytogenes and Yersinia enterocolitica (pork only) and lactic acid bacteria (representing spoilage bacteria) as compared to standard fresh meat. Finally, additional control activities were identified that would further assure the microbial safety of dry-aged beef, based on recommended best practice and the outputs of the equivalence assessment.

A comprehensive review of drying meat products and the associated effects and changes

Preserving fresh food, such as meat, is significant in the effort of combating global food scarcity. Meat drying is a common way of preserving meat with a rich history in many cultures around the globe. In modern days, dried meat has become a well enjoyed food product in the market because of its long shelf-life, taste and health benefits. This review aims to compile information on how the types of meat, ingredients and the used drying technologies influence the characteristics of dried meat in physicochemical, microbial, biochemical and safety features along with technological future prospects in the dried meat industry. The quality of dried meat can be influenced by a variety of factors, including its production conditions and the major biochemical changes that occur throughout the drying process, which are also discussed in this review. Additionally, the sensory attributes of dried meat are also reviewed, whereby the texture of meat and the preference of the market are emphasized. There are other aspects and concerning issues that are suggested for future studies. It is well-known that reducing the water content in meat helps in preventing microbial growth, which in turn prevents the presence of harmful substances in meat. However, drying the meat can change the characteristics of the meat itself, making consumers concerned on whether dried meat is safe to be consumed on a regular basis. It is important to consider the role of microbial enzymes and microbes in the preservation of their flavor when discussing dried meats and dried meat products. The sensory, microbiological, and safety elements of dried meat are also affected by these distinctive changes, which revolve around customer preferences and health concerns, particularly how drying is efficient in eliminating/reducing hazardous bacteria from the fish. Interestingly, some studies have concentrated on increasing the efficiency of dried meat production to produce a safer range of dried meat products with less effort and time. This review compiled important information from all available online research databases. This review may help the food sector in improving the efficiency and safety of meat drying, reducing food waste, while maintaining the quality and nutritional content of dried meat.

Physicochemical Properties and Young Adult Consumer Preference of Dry-Aged Beef after High-Intensity Ultrasonication

This study aimed to determine the effect of high-intensity ultrasound (HIU. F = 37 kHz, I = 28W/cm2, bath for 30 min, 5 °C) on physicochemical characteristics and sensorial preference of seven aged (23 d ageing) bovine muscles (L. dorsi lumborum, L. dorsi thoracis, Psoas major, Semimembranosus, Biceps femoris, Rectus femoris, and Gluteus medius). Muscles were randomly distributed in two treatments: with and without ultrasonication. Colour (L*, a*, b* and C*), water-holding capacity (WHC), and shear force (N) were determined before and after simulated retail display (SRD) in modified atmosphere packing (MAP; 75% O2: 25% CO2, 3 °C, 13 h led light exposition) for 5 d. Sensorial toughness was also evaluated at the end of the SRD. Ultrasonication slightly reduces 6–9% WHC of beef. HIU did not affect (p ˃ 0.05) water loss, meat colour, shear force and sensorial toughness of the meat. The Semimembranosus was the toughest muscle. Ultrasonication of 23-day-aged beef did not show improvements on quality characteristics, and despite minor changes in water loss and slight increase in shear force, consumers did not detect differences.

Consumer Characterization of Wet- and Dry-Aged Mutton Flavor Profile Using Check-All-That-Apply

The aim of this study was to assess if consumers could characterize wet- and dry-aged mutton flavor profiles using CATA (check-all-that-apply). A flavor lexicon was developed for mutton, and consumers assessed wet- and dry-aged mutton patties against this lexicon using CATA methodology. Results indicate that consumers most often associated caramel and roasted flavors with dry-aged patties, and “sheepy” and metallic flavors with wet-aged patties. Volatile analysis supported the consumer characterization as there were more Maillard reaction products, including pyrazines, which are associated with roasted and cooked flavors, found in the dry-aged patty volatile profile. More 1-octen-3-one, which is associated with metallic flavors, was found in the wet-aged patty volatile profile. These results provide validation that the lexicon utilized in this study (i) is suitable for the characterization of mutton flavor and (ii) will have applications for future investigations into the flavor components driving consumer liking for mutton.

Evolution of Sensory Properties of Beef during Long Dry Ageing

Ageing is an essential step in obtaining meat with satisfactory sensory properties. Dry-ageing, although being a niche practice, is increasingly being developed to enhance the taste experience of meat consumers. In this work, we studied the kinetics of the evolution of muscle properties with increasing ageing time, in order to propose an optimal duration, allowing a compromise between quality and meat weight loss reduction. Our study was performed on 32 samples from 8 animals for which the Longissimus thoracis sensory properties were analysed at different stages of ageing (7, 16, 35 and 60-days post-slaughter). This work showed an increase in the dry matter content of meat with increasing ageing duration, concomitant with a slight increase in pH. Although the luminance of the meat is stabilized after 14-days, the red and yellow indices decrease until 35-days of ageing. Iron content also decreases with ageing duration. Finally, the kinetic evolution of muscle rheological properties indicates that the toughness decreases at least up to 35-days on raw meat. Cooking seems to homogenise the tenderness of the samples, no difference was noticed between the different ageing durations when meat was cooked. These first experimental data need to be confirmed with different animal types.

Metabolic, proteomic and microbial changes postmortem and during beef aging

The purpose of this review is to provide an overview of the current knowledge about proteomic and metabolic changes in beef, the microbiological alteration postmortem and during aging, and observe the influence on beef quality parameters, such as tenderness, taste and flavor. This review will also focus on the different aging types (wet- and dry-aging), the aging or postmortem time of beef and their effect on the proteome and metabolome of beef. The Ca2+ homeostasis and adenosine 5'-triphosphate breakdown are the main reactions in the pre-rigor phase. After rigor mortis, the enzymatic degradation of connective tissues and breakdown of energy metabolism dominate molecular changes in beef. Important metabolic processes leading to the formation of saccharides, nucleotides, organic acids (e.g. lactic acid), creatine and fatty acids are considered in this context as possible flavor precursors or formers of beef flavor and taste. Flavor precursors are substrates for lipid oxidation, Strecker degradation and Maillard reaction during cooking or roasting. The findings presented should serve as a basis for a better understanding of beef aging and its molecular effects and are intended to contribute to meeting the challenges of improving beef quality.

Quality Properties of Dry-Aged Beef (Hanwoo Cattle) Crust on Pork Patties

This study evaluated the effects of crust derived from dry-aged beef (Hanwoo cattle) on the quality of pork patties. Pork patty samples were prepared with different amounts of crust (0—control, 1, 2, and 3%). The protein, fat, and ash contents in the crust samples were significantly higher than those in the control sample (p < 0.05). The CIE b* value of uncooked pork patties with crust added was significantly lower than that of the control patties (p < 0.05). The pH and CIE L* values of uncooked patty batter samples decreased with increasing concentrations of crust (p < 0.05). However, the viscosity increased proportionally with an increase in crust (p < 0.05). Samples containing 3% crust showed significantly higher uncooked and cooked CIE a*, water-holding capacity, cooking yield, and shear force than the control sample (p < 0.05). Moreover, samples containing 2% and 3% crust showed significantly lower diameter and thickness reductions than those of the control sample (p < 0.05). The sensory evaluation conferred by the crust was significantly higher than that of the control sample (p < 0.05). Overall, our results suggest that pork patties supplemented with 3% crust have improved properties.

Assessment of Quality Indices and Their Influence on the Texture Profile in the Dry-Aging Process of Beef

The aim of this study was to investigate the effects of the dry-aging method on the sensory properties, chemical composition, and profile parameters of the texture of beef obtained from local farms. The qualitative characteristics of the beef were investigated for five samples, respectively, fresh meat, and dry-aged beef for 14, 21, 28, and 35 days, in aging rooms with controlled parameters: temperature (1 ± 1 °C), relative humidity (80 ± 5%), and air circulation speed (0.5–2 m/s). During the dry-aging period, there was a decrease in humidity by about 6.5% in the first 21 days, which allowed the concentration of fat, protein, and total collagen content. The dry-aging process considerably influenced the pH value of the meat, which, in the second part of the dry-aging process (14–35 days), increased from 5.49 to 5.66. These values favored the increase by 37.33% of the water retention capacity and the activation of the meat’s own enzymes (calpain, cathepsin, collagenase). This influenced the solubilization process of proteins and collagen, thus contributing to the improvement of the texture profile. Because variations in organoleptic and physicochemical parameters occurred simultaneously during dry-aging and storage, the method of analyzing the information was applied. Mutual information on the influence of physicochemical indicators on the texture profile parameters was followed, a factor of major importance in the consumer’s perception. The degree of influence of soluble proteins, sarcoplasmic and myofibrillar proteins, fats, and soluble collagen content on the texture profile parameters (hardness, cohesiveness, springiness, gumminess, and chewiness) of the dry-aged beef for 35 days was established. These investigations allowed the optimization of the beef dry-aging technological process in order to obtain a product with a sensory profile preferred by the consumer.

Impact of Various Dry-Aging Methods on Meat Quality and Palatability Attributes of Beef Loins (M. longissimus lumborum) from Cull Cow

The objective of this study was to determine the effect of various dry-aging methods on meat quality and palatability attributes of cull cow beef loins. Paired bone-in loins (m. longissimus lumborum) from 13 cull cow carcasses (Holstein, 42þ mo) were obtained at 5 d postmortem, divided into 4 equal sections, and randomly assigned into 4 aging methods (wet-aging [WA], conventional dry-aging [DA], dry-aging in water-permeable bag [DWA], and ultraviolet light dry-aging [UDA]). The beef sections were aged for 28 d at 2°C, 65% relative humidity, and 0.8 m/s airflow. Following aging, surface crusts and bones were removed, and loin samples were collected for the meat quality, microbiological, and sensory analyses. Results indicated that all dry-aged loins had greater moisture and trimming loss compared with WA (P &lt; 0.05), while DWA had lower loss than DA and UDA (P &lt; 0.05). No differences in shear force, cook loss, or both lipid and protein oxidation across all treatments were observed (P &gt; 0.05). Among all treatments, DWA exhibited the least color stability indicated by rapid discoloration observed in the sample, while UDA had color attributes comparable with WA throughout the whole display. Microbial analysis indicated that UDA had lower microbial concentration on the surface than the other samples (P &lt; 0.05). The consumer panel analysis found that all loins were acceptable, and the trained panel analysis indicated that DA loins decreased sourness and animal fat flavor (P &lt; 0.05) and had a trend of decreasing oxidized flavor (P = 0.07). The results indicate that dry-aging can potentially be utilized as an effective natural process by nullifying some of well-known off-flavor attributes associated with cull cow beef while not compromising other meat quality attrib- utes or microbiological shelf life.

Exploring the microbiological quality and safety of dry-aged beef: A cross-sectional study of loin surfaces during ripening and dry-aged beef steaks from commercial meat companies in Belgium

A cross-sectional survey was undertaken in Belgian beef producing companies to study the current practices and the microbiological load of dry-aged loins (during production) and trimmed steaks (final product). In each company, the temperature and relative humidity of the ripening chamber were measured, and two loins (each in a different stage of the ripening process) were sampled. From the surface of each loin, a lean meat and adipose tissue sample was analysed separately, and different groups of bacteria, yeasts and moulds were enumerated. The average relative humidity in the ripening chambers was 72 ± 13% and the temperature ranged between 0.0 °C and 5.9 °C. During the drying process, most of the lean meat and adipose tissue samples showed high numbers of total psychrotrophic aerobic bacteria, Pseudomonas spp., psychrotrophic lactic acid bacteria, and yeasts, but the variation between loins was high. The microbiological load on freshly cut dry-aged steaks was generally lower than on loin surfaces, but both psychrotrophic aerobic and anaerobic bacteria were present inside several steaks. The water activity inside dry-aged beef steaks was high (a_w ≥ 0.98), which could allow growth of psychrotrophic pathogens, though more in-depth studies are necessary to determine potential growth during the storage of (trimmed) steaks or even inside loins during the dry-aging process.

Liquid Chromatography-Tandem Mass Spectrometry for Detecting Myosin Light Chain 3 in Dry-Aged Beef

Liquid chromatography-tandem mass spectrometry (LC/MS/MS) is a more accurate technique for detecting proteins than electrophoresis-based methods such as western blotting. Because of its convenience, western blotting is commonly used for protein analysis in beef. We developed a method for detecting myosin light chain 3 (myl3) in beef samples, particularly dry-aged beef, using LC/MS/MS for quality testing. Musculus longissimus dorsi of Holstein was aged for 0, 2, 4, 5, 9, 11, 17, 20, and 24 weeks and used to measure the myl3 concentration. Because of the high molecular weight of myl3, the limitations of LC/MS/MS were overcome by implementing immunoprecipitation and digestion steps. Ultimately, a tryptic fragment of myl3 (13-mer), generated using immunoprecipitation and digestion by a biotinylated antibody, was detected using LC-MS/MS in positive ion mode through multiple reaction monitoring and analyte separation on a C18 column. Our method showed limits of detection and quantification of less than 0.3 and 0.8 μg/kg, respectively. However, differences in the myl3 concentrations according to the aging time were not significant (p > 0.05). After 12 weeks, myl3 disappeared in tested all samples, thus our analytical method can be used for accurate measurement of muscle protein in beef samples.

Effect of Dry-Aging on Quality and Palatability Attributes and Flavor-Related Metabolites of Pork Loins

This study evaluated the effect of dry-aging on quality, palatability, and flavor-related compounds of pork loins. Ten pork loins were obtained at 7 days postmortem, divided into three equal portions, randomly assigned into three different aging methods (wet-aging (W), conventional dry-aging (DA), and UV-light dry-aging (UDA)), and aged for 21 days at 2 °C, 70% RH, and 0.8 m/s airflow. The results showed similar instrumental tenderness values across all treatments (p > 0.05), while DA and UDA had a greater water-holding capacity than WA (p < 0.05). Both DA and UDA were observed to have comparable color stability to WA up to 5 days of retail display (p > 0.05). Greater lipid oxidation was measured in both DA and UDA at the end of display compared to WA (p < 0.05). The UV light minimized microorganisms concentration on both surface and lean portions of UDA compared to other treatments (p < 0.05). The consumer panel was not able to differentiate any sensory traits and overall likeness between the treatments (p > 0.05). Metabolomics analysis, however, identified more flavor-related compounds in dry-aged meat. These findings suggested that dry-aging can be used for pork loins for value-seeking consumers, as it has a potential to generate unique dry-aged flavor in meat with no adverse impacts on meat quality and microbiological attributes.

Influence of aging time, temperature and relative humidity on the sensory quality of dry-aged Belgian Blue beef

The objective of this study was to evaluate the effect of aging period (0, 3, 6 or 9 weeks), aging temperature (2 versus 6 °C at 75% relative humidity, experiment 1) and relative humidity (70 versus 90% at 2 °C, experiment 2) on the sensory traits, oxidative stability and proteolysis of Belgian Blue beef. For each experiment, eight loins (M. longissimus thoracis et lumborum) from four animals (left and right side) were assigned to one of the two treatments (n = 4). Results showed no further tenderization after three weeks of aging, whereas metmyoglobin formation and lipid oxidation increased until nine weeks of aging (P < 0.05). During the nine weeks of aging, atypical flavor, odor and flavor intensity was affected (P < 0.05). This was accompanied by an increase of small peptides and other nitrogenous compounds. Aging temperature and relative humidity had only a very limited effect on the quality traits.

Effect of Hanwoo Crust on the Physicochemical Properties of Emulsion-Type Sausages

This study aimed to investigate the effects of Hanwoo crust, inedible surface layer formed during dry aging, on the physicochemical properties of emulsion-type sausages. Sausage samples were prepared with various amounts of Hanwoo crust—0% (i.e., control), 1%, 2%, and 3%. The physicochemical properties studied included the proximate composition, pH, color, water holding capacity (WHC), cooking yield (CY), and viscosity. Texture profile analysis (TPA) and sensory evaluation were also carried out. Protein, fat, and ash contents of the Hanwoo crust-treated samples were found to be significantly higher than those of the control (p<0.05). Moreover, the CIE b* value of cooked sausage with Hanwoo crust treatments was significantly lower than that of the control (p<0.05). The CIE L* value of uncooked and cooked samples with 3% Hanwoo crust was significantly lower than that of the control (p<0.05). In contrast, the CIE a* value of uncooked and cooked samples with 3% Hanwoo crust was significantly higher than that of the control (p<0.05). The viscosity of the uncooked samples increased with increasing Hanwoo crust content. Samples containing 3% Hanwoo crust exhibited significantly higher WHC and CY than the control (p<0.05). In the TPA, samples containing 2% and 3% Hanwoo crust showed significantly higher hardness, gumminess, and chewiness than the control (p<0.05). Overall, the sensory properties of Hanwoo crust treatments were significantly better than those of the control (p<0.05). In conclusion, adding 3% Hanwoo crust to emulsion-type sausage leads to optimal physicochemical properties.

Quality Properties of Bulgogi Sauce with Crust Derived from Dry-Aged Beef Loin

This study aimed to determine the physicochemical properties (proximate composition, color, pH, salinity, water holding capacity (WHC), curing yield, and shear force) and sensory properties (electric nose and sensory evaluation) of Bulgogi sauce with added crust derived from dry-aged beef loin. Increasing the amount of crust in the Bulgogi sauce tended to increase the protein content, fat content, and pH. Uncooked Bulgogi also tended to have elevated fat content, ash content, pH, and shear force. Increasing the crust content tended to decrease the water content, lightness, redness, and yellowness of Bulgogi sauce. The yellowness of uncooked Bulgogi with 6%–12% crust in sauce was significantly lower than that of the control (no crust) and the sample with 3% crust in sauce (p<0.05). The redness of the cooked control Bulgogi was significantly lower than that of the samples with crust in sauce (p<0.05). The WHC of uncooked Bulgogi with 6%–12% crust in sauce was significantly higher than that of the control and the sample with 3% crust in sauce (p<0.05). The flavor, texture, and overall acceptability of the Bulgogi with 9% crust in sauce were significantly higher than those of the control (p<0.05). These findings showed that the crust did not degrade the physicochemical properties of Bulgogi sauce and meat. The sensory characteristics of Bulgogi marinated with 9% crust in sauce were rated the best as persensory evaluation. Therefore, crust is a suitable flavor enhancer for Bulgogi sauce, and a 9% addition amount is optimal in terms of quality.

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

Meat consumers are demanding products of higher and consistent quality, with a distinctive flavor and aroma, able to provide a particular sensorial experience when consuming beef. The impact of all the factors affecting the final eating quality, known as the farm to fork approach, has been extensively studied in the last decades. This includes genetic factors, production system, transport, carcass intervention, aging, packaging and cooking method, among others. Aging is, one of the most important steps in producing high quality tender beef. During this step, flavor is developed and the meat is tenderized. Dry-aging although considered a traditional method, is currently attracting attention from consumers, producers and researchers because of the characteristics of the final products in terms of flavor, aroma and texture. This chapter will describe the series of biochemical changes, which combined with the loss of water, generates a final product that is highly appreciated by niche consumers. This will include the changes that the muscle undergoes to be transformed to meat, the main factors driving the dry-aging process and how the flavor and aroma compounds are generated during this process.

Use of Rapid Evaporative Ionisation Mass Spectrometry fingerprinting to determine the metabolic changes to dry-aged lean beef due to different ageing regimes

Rapid Evaporative Ionisation Mass Spectrometry (REIMS) was used to determine the impact of in-bag ageing regimes (stepwise-ageing at different air velocities and straight-dry-ageing) and trimming on the metabolic profile of dry-aged lean beef. Orthogonal projection to latent structures-discriminant analysis (OPLS-DA) models based on 1705 tentatively identified m/z features were found for ageing methods (Q² = 0.85), ageing time (0 vs. 21 days, Q² = 0.95) and sampling locations (surface meat vs. trimmings, Q² = 0.94). No significant (P > 0.05) difference in metabolites due to air velocities. Small metabolites such as dipeptides and amino acids were more abundant, especially on the surface of untrimmed lean beef, following 21 days of straight-dry-ageing. Stepwise-ageing produced different metabolic profiles from straight-dry-ageing, suggesting that the two methods may differ in dry-aged meat quality and flavour. This work demonstrates REIMS's potential for real time differentiation of meat on processing parameters.

The Physicochemical and Sensory Properties of Whey-Fed Pork Loin after Salting, Dry Aging, and Sous Vide Cooking

This study was conducted to evaluate the physicochemical properties of whey-fed pork loin subjected to salting, dry aging, and sous vide cooking. We compared raw and treated pork loin from pigs fed a basal diet (control) and those fed a diet supplemented with whey powder. Treated pork was salted, dry aged for 0–30 d, and then cooked using sous vide. The crude fat, total lipid, and cholesterol content and shear force of raw whey powder-fed pork loin were significantly lower than those of the control, while the crude protein content was higher. Cooking loss, hardness, and gumminess were found to decrease with the aging period in sous vide-treated pork. Dietary supplementation with whey had positive effects on pork color stability, texture, and sensory evaluation, and it significantly inhibited the growth of bacteria. The results suggest that supplementing the diet of pigs with whey powder can enhance meat quality, especially when combined with salting, dry aging, and sous vide cooking.

The effects of time and relative humidity on dry-aged beef: Traditional versus special bag

The objective of this study was to evaluate the effects of relative humidity (RH) and different dry aging methods on the quality of beef. Sixteen loins, from eight carcasses, were used in this experiment. Each pair of loin was cut into eight sections with equal size, which were evenly assigned to eight treatments, by the combination of two dry aging methods (traditional and highly moisture-permeable special bag), two relative humidity (65 and 85% RH) and two aging times (21 and 42 days). At 85% RH, neither special bag nor the traditional dry aging methods were viable, since samples presented high microbiological counts, mucus and bad odor. At 65% RH, Enterobacteriaceae and lactic acid bacteria were not detected in any treatment. The highest aerobic plate count and psychrotrophic count were observed in the samples of the traditional dry-aged process whereas the special bag showed the greatest mold and yeast count. Regarding dry aging in special bag, there was a reduction in the weight loss (P < 0.05) and no change in the physical-chemical characteristics (P > 0.05) compared to traditional dry aging. The values of pH, moisture and Warner-Bratzler shear force were not affected (P > 0.05) by aging method and relative humidity. Thus, the results indicate that high RH should be avoided for both dry aging methods. Furthermore, the special bag dry aging can be considered an alternative to produce dry-aged beef, as it reduces weight losses even at conditions of lower relative humidity.

Elucidating mechanisms involved in flavor generation of dry-aged beef loins using metabolomics approach

The present study was conducted to identify flavor-related chemical compounds and to elucidate beef flavor development in response to dry-aging. Paired grass-fed beef loins (n = 18) were obtained at 7 d postmortem, cut into two sections and assigned to 3 aging methods: conventional dry-aging (DA), vacuum packaged wet-aging (WA) and dry-aging in a bag (DW) for 28 days. Following aging, samples were analyzed for UPLC-MS metabolomics, volatile, fatty acid profiling, and consumer sensory comment analysis. Greater number of proteins and nucleotides derived metabolites were liberated in dry-aged samples compared to WA (P < 0.05). In particular, the liberation of gammaglutmayl peptides and glutamine metabolites through the glutathione metabolism were identified. While fatty acid profile was not affected by treatments (P > 0.05), higher concentrations of volatile compounds were found in the dry-aged (P < 0.05). Dry-aging process decreased the presence of terpenoid and steroid lipid group, which could possibly result in reducing undesirable flavor of grass-fed beef.

Ultimate pH effects on dry-aged beef quality

This study aimed to evaluate pH effects on moisture loss and meat quality characteristics of dry-aged beef. Strip loins from six normal pH carcasses (pH = 5.47 ± 0.02) and dark cutting (DC) strip loins from six high pH carcasses (pH = 6.69 ± 0.09) were obtained. One strip loin from each carcass was dry aged and one was wet aged, giving four treatments: DRY, DRY-DC, WET, and WET-DC. Loins were aged for 42 d. Ultimate pH did not affect the rate or amount of moisture loss, trim loss, yield, or tenderness in dry-aged beef (P > 0.05). In general, DC steaks had the lowest lightness (L*), redness (a*), and yellowness (b*) values, regardless of aging method (P < 0.05). Discoloration scores and TBARS values for DC steaks remained low throughout retail display. Dry aging significantly reduced bacterial counts mitigating the microbial damages associated with DC. Flavor characteristics of DC were not improved by dry aging when compared to dry-aged loins from carcasses with normal pH.

Flavor, Tenderness, and Related Chemical Changes of Aged Beef Strip Loins

Varying aging times and methods were evaluated for their effect on flavor, tenderness, and related changes involatile compounds and flavor precursors. Strip loin sections from USDA Choice beef carcasses (n = 38) were randomly assigned to treatments: (1) 3 d wet-aged, (2) 14 d wet-aged, (3) 28 d wet-aged, (4) 35 d wet-aged, (5) 49 d wet-aged, (6) 63 d wet-aged, (7) 21 d dry-aged, and (8) 14 d wet-aged followed by 21 d dry-aged. Samples were analyzed for trained sensory attributes, shear force, volatile compounds, and flavor precursors (fatty acids, free amino acids, and sugars). Discriminant function analysis was used to identify sensory attributes contributing the greatest to treatment differences. Flavor notes were not differentiated in beef aged up to 35 d, regardless of aging method. A shift in flavor occurred between 35 d and 49 d of wet-aging time that was characterized by more intense sour and musty/earthy notes. Both shear force assessment and trained panelists agreed that tenderness was not affected (P &gt; 0.05) by additional aging beyond 28 d. Volatile compound production and liberation of amino acids and sugars increased (P &lt; 0.01) during the progression of aging time, with no change (P &gt; 0.05) in fatty acid composition, which may be a result of metabolic processes like microbial metabolism. Chemical properties shared strong positive relationships (r &gt; 0.50, P &lt; 0.001) with sour, musty/earthy, and overall tenderness. These results substantiate the deteriorative effect of extended aging times of 49 d or greater on flavor of beef strip loins without tenderness improvement.

The dry aged beef paradox: Why dry aging is sometimes not better than wet aging

An increasing consumer demand for a higher quality and eating experience has led to a revisit to the dry aging process. Therefore, research also focuses on the effects of different dry aging methods and aims to improve the dry aging process. However, an optimal process cannot be defined and, unfortunately, most of the dry aging results only hold true for the individual experiment. If one repeats a dry aging process in a different facility, the result might differ. The same dry aging process in two different ripening chambers does not inevitably contribute to equal tenderness and flavor. Since this is still not been understood well, this review presents results of the most relevant dry aging studies by illustrating different process parameters and cuts. Some conclusions which may be useful to explain the paradox are derived from the literature in order to understand the crucial factors and commonalities in the dry aging process.

Analysis of aging type- and aging time-related changes in the polar fraction of metabolome of beef by 1H NMR spectroscopy

The tenderness and taste of beef is improved by either dry- or wet-aging or a combination of both. The objective was to develop a validated method for detecting differences in the polar fraction of metabolome in dry-aged and wet-aged beef over the aging time and quantifying the metabolites of interest by ¹H NMR spectroscopy using beef. Sixty strip loin (M. longissimus dorsi) samples aged in different ways (wet-aging vs. dry-aging) and aging times (0, 7, 14, 21, 28 days) were analyzed. The aging type could be defined by linear discriminant analysis with an accuracy of 95%. Ten (lactic acid, alanine, methionine, fumaric acid, inosine, inosine monophosphate, creatine, betaine, carnosine and hypoxanthine) out of eighteen metabolites differ significantly (p < 0.05) in content depending on the aging type. Fifteen metabolites in dry-aged and ten in wet-aged beef correlate with the aging time (r > 0.7, <-0.7), which shows significant aging time-related effects on the polar fraction of metabolome.

The Effects of Processing and Preservation Technologies on Meat Quality: Sensory and Nutritional Aspects

This review describes the effects of processing and preservation technologies on sensory and nutritional quality of meat products. Physical methods such as dry aging, dry curing, high pressure processing (HPP), conventional cooking, sous-vide cooking and 3D printing are discussed. Chemical and biochemical methods as fermentation, smoking, curing, marination, and reformulation are also reviewed. Their technical limitations, due to loss of sensory quality when nutritional value of these products is improved, are presented and discussed. There are several studies focused either on the nutritional or sensorial quality of the processed meat products, but more studies with an integration of the two aspects are necessary. Combination of different processing and preservation methods leads to better results of sensory quality; thus, further research in combinations of different techniques are necessary, such that the nutritional value of meat is not compromised.

Physicochemical properties of crust derived from dry-aged Holstein and Hanwoo loin

This study evaluated the quality characteristics of crust derived from dry-aged Holstein and Hanwoo loins and their effects on food as additives. With respect to physicochemical properties, we examined the proximate composition, pH value, salinity, color, water and fat absorption, emulsifying capacity, and swelling yield. The protein and ash contents in the Holstein crust were significantly higher than those in the Hanwoo crust (p < 0.0001). The fat content in the Hanwoo crust was significantly higher than that in the Holstein crust (p < 0.01). The salinity, lightness, and yellowness of the Hanwoo crust were significantly lower than those of the Holstein crust (p < 0.001). Furthermore, the pH value and emulsifying capacity of the Hanwoo crust were significantly higher than those of the Holstein crust (p < 0.001). The fat absorption of the Holstein crust was significantly higher than that of the Hanwoo crust (p < 0.001). The swelling yield of the Holstein crust was significantly higher than that of the Hanwoo crust at pH 3 and 4 (p < 0.001), whereas the swelling yield of the Hanwoo crust was significantly higher than that of the Holstein crust at pH 7 (p < 0.001). Principal component analysis of dry-aged Hanwoo, Holstein, and non-aged Holstein showed different flavor patterns for each sample. Finally, the results showed that the crusts derived from dry-aged Hanwoo and Holstein loins were suitable flavor enhancers.

Comparison of Effects of Two Aging Methods on the Physicochemical Traits of Pork Loin

The objective of this study was to compare effects of two different aging methods on physical, chemical, and microbial traits of pork loin: Dry and wet-aged meat was hung in the cooler at 8±1°C and 85±2.1% humidity for 14 days, while wet-aged meat was immersed in a 3.5% salt solution of brine in vacuum pouches. On day 7, pH and moisture content were higher in dry-aged loins than in wet-aged, while drip loss and total plate counts (p<0.05) were lower on day 14. As aging continued, the pH and drip loss of dry-aged loins decreased, while their total plate counts and water holding capacity (WHC) increased (p<0.05). After 7 and 14 days of aging, redness in dry-aged loins was higher than that in wet -aged muscles (p<0.05). On day 14 of aging, hardness, chewiness, and adhesiveness were lower in dry-aged pork loin as compared to those in wet-aged samples (p<0.05). Consequently, the results suggested that dry and wet aging methods differently affects meat quality traits of pork loin.