• How Is Meat Aged? What Is

Aging can be done in two ways, dry and wet. Dry aging is a process that takes place by balancing and monitoring temperature, humidity and airflow in a way that prevents microbial growth and minimizes weight loss. With dry aging, beef with a unique flavor and high added value can...

 
"Dry Aged Meats" How Is Meat Aged? What Is "Dry Aged"?
Cigdem MUŞTU
 
Summary
 
During the conversion of muscles to meat, postmortem changes occur in the muscles. The final stage of postmortem changes is maturation. Maturation is a process that results in the dissolution of the hardness of death by the hydrolysis of muscle and connective tissue proteins by proteolytic enzymes after slaughter, and accordingly the meat becomes more delicious, crispy and juicy. In practice, a few days are considered sufficient for maturation. However, when the meats are aged by keeping them in suitable conditions for much longer periods, maximum sensory quality product can be obtained. 
 
Aging can be done in two ways, dry and wet. Dry aging is a process that takes place by balancing and monitoring temperature, humidity and airflow in a way that prevents microbial growth and minimizes weight loss. With dry aging, beef with a unique flavor and high added value can be obtained. In this article, general information about the dry aging method is given; Controlled ambient conditions applied in the dry aging method are mentioned.
 
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Meat is an animal food that is obtained by slaughtering butchery animals in a healthy condition and in an appropriate environment and consumed by humans as fresh or processed (Anar, 2012). Red meat; It is a food that has an important place in human nutrition with its mineral substances, vitamins and especially essential amino acids and fatty acids in its structure in sufficient amount and with high biological value (Vural, 1992). In addition, the biological composition of red meat causes it to be a favorable environment for the development of microorganisms and tends to spoil more easily than many foods. 
 
Thus, since ancient times, human beings have been working on protective methods to increase the durability of red meat and to produce better foods with high microbial quality and organoleptic properties (Nychas and Arkoudelos, 1990; Çon et al., 2002, Koplay and Sezer, 2013).
 
The transformation of the muscles into meat after slaughter takes a certain period of time because it is a complex event and the vital functions of the muscles continue. During this process, various biochemical and physical changes occur in the muscles, which are called postmortem, directly related to the physiological state of the animal and the degree of blood flow (Yıbar and Çetin, 2013). The conversion of muscle to meat, the prerigor phase that occurs between the first few minutes and 30 minutes; It consists of three stages: the rigor phase, in which the elasticity of the muscles decreases and reaches maximum stiffness with rigor mortis, also called death stiffness, and the maturation phase, in which the death stiffness in the muscles disappears as a result of enzymatic activation, and maturation occurs (Ardıçlı, 2018).
 
How Is Meat Aged? What Is "Dry Aged"?
 
Ripening of Meat
 
Meat from freshly slaughtered butchery animals is tough, tasteless and bland. The ripening of fresh meat has become necessary to meet the high demands and expectations of the food industry in terms of consumption (Sitz et al., 2006; Warren and Kastner, 1992; Laster, 2007). The increase in the amount of lactic acid, which occurs as a result of the anaerobic breakdown of glycogen during the conversion of muscle to meat, causes a decrease in pH. Due to the decrease in pH values ​​in the muscles, proteolytic enzymes that break down muscle and connective tissue proteins become active. 
 
Maturation is a process that results in meat softening due to the release of hardness of death as a result of proteolytic enzymes breaking down muscle proteins (actomyosin) (autolysis), as well as maximizing the flavor properties of the breakdown products of amino acids and ATP released due to protein breakdown (Berger et al., 2018; Campbell et al., 2001; Oreskovich et al., 1988; Parrish et al., 1991). While optimum maturation takes a few hours in chicken and turkey meat, it can take days in butchery animals (Anar, 2012).
 
The proteolytic changes in the muscles after slaughter are part of the process called maturation. Maturation is a complex process in which various groups of endogenous proteases contribute, and this process begins soon after the animal is slaughtered (Kemp and Parr, 2012). In the maturation of meat; Three important proteolytic systems are effective: lysosomal proteases (cathepsins), calcium-dependent proteases (calpains), and protein oxidation (proteasome). 
 
The calpain system consists of calcium-dependent cysteine ​​proteases (calpains) and their specific competitive inhibitor, calpastatin (Goll et al., 2003), and plays an important role in regulating muscle protein proteolysis under postmortem conditions (Huff-Lonergan and Lonergan, 2005). Cathepsins are a group of enzymes consisting of both exo and endo peptidases and are found in lysosomes. At low pH levels, they become free with disruption of the lysosomal membrane and begin to hydrolyze myofibril proteins (Kemp et al, 2009). 
 
The proteasome is a multicatalytic protease complex that is formed by the degradation of proteins in the cytosol and nucleus responsible for the degradation of cellular proteins (Coux et al., 1996; Kemp et al., 2009). The structural integrity of muscle fibers changes as a result of the degradation of muscle proteins such as titin, nebulin and desmin under the influence of enzymes (Starkey et al., 2016). Intramuscular connective tissue integrity, which is a determinant on meat firmness, also decreases as a result of the action of β-glucuronidase or hyaluronidase and collagenase (Nishimura, 2015). 
 
It has been suggested that differences in the antioxidant defense system between animals and/or muscles affect calpain activity and quality characteristics by affecting proteolysis (Huff-Lonergan and Lonergan, 2005). Oxidation rate in postmortem muscle due to oxidative defense system creates differences between muscles (Martinaud et al., 1997). There are differences in the rate of oxidation in muscle tissue according to animal species and muscle type (Juncher et al., 2001).
 
These differences may arise due to differences such as animal nutrition, breed, antemortem stress, postmortem use of carcasses. In addition, it was reported in a study that the activity of some enzymes that are effective in the oxidative defense system of muscles also cause differences between postmortem muscles (Daun et al, 2001; Nair et al., 2019).
 
Aging
 
The aging technique is a widely used application in the meat industry for luxury hotels and restaurants in recent years to increase the flavor and tenderness of meat as an advanced stage of ripening (Dikeman et al., 2013; Kim et al., 2016).
 
Aging occurs by keeping the meat in certain conditions (temperature, humidity, air velocity) for sufficient time to maximize its flavor characteristics. The effect of enzymes, which play the most important role in the aging process of meat, on meat proteins requires a certain period of time. For a perfect meat with a soft, crispy, juicy, aromatic and delicious texture, it needs to be aged for at least two weeks before being delivered to the consumer (Laster, 2007; Perry, 2012).
 
In the meat industry, there are two commonly used maturation methods, wet aging and dry aging (Laster et al., 2008; Smith, 2007). Wet aging, in which the parts separated by shredding the beef carcass are vacuum packed and stored at cooling temperature, is the most common method, especially in the retail meat industry today (Laster et al., 2008; Savell, 2008).
 
Dry aging, on the other hand, is a method in which parts of beef carcasses (preferably the back area) are developed in cold rooms for 1-5 weeks with natural enzymatic and biochemical processes, without packaging material (Kim et al., 2016).
 
How Is Meat Aged? What Is "Dry Aged"?
 
Until the 1960s, when vacuum packaging was introduced, the only method used for beef was dry aging. In these years, with the increase in international beef trade, it has gained importance to keep meat in vacuum packaging due to its low waste rate and ease of storage and transportation (Live ark., 2014).
 
 
In later studies, it has been revealed that vacuum packaging has a similar effect to dry aging in terms of flavor in meats as well as increasing the shelf life (Minks and Stringer, 1972). Sitz et al. (2006) conducted a study on determining the sensory preferences and values ​​of consumers by dry and wet aging of beef. It was determined that there was no significant difference in taste, juiciness, texture or general acceptability sensory properties between wet aged meat and dry aged meat samples. 
 
It has also been reported that a higher flavor evaluation was made for wet aged meat. Wet aging, also called vacuum aging, is used more in the meat industry due to its various advantages (low waste loss, no risk of contamination, ease of storage and transportation, not requiring controlled ambient conditions except temperature, etc.). However, consumers prefer dry aged meat more because of its flavor (DeGeer et al., 2009; Miller et al., 1985).
 
Dry Aging
 
A product with high added value and unique flavor development emerges with dry aging, which is carried out by keeping the meats under a controlled environment of temperature, humidity and air flow for a certain period of time (Kim et al., 2016). There are many studies showing that dry aging improves the eating quality of meat, especially its flavor (Campbell et al., 2001; Corbin et al., 2015; Warren and Kastner, 1992). In a study, glutamate, known as a flavor-enhancing compound, was detected at high levels in dry-aged meats (Kim et al., 2016).
 
King et al (1995) examined the changes in volatile compounds in dry and wet aged meats. The amount of heptane in dry aged meats was significantly higher than in wet aged meats. 
 
Researchers have associated this difference with the fact that oleate, one of the important fatty acids in meats, is more exposed to air during dry aging and is autooxidized. In this study, the amount of esters in dry aged meats was also found to be significantly higher. In addition to flavor, significant improvements have been made in crispness and juiciness (Campbell et al., 2001). However, traditional dry aging requires higher environmental control and higher drying loss (waste) resulting in increased costs (Li et al., 2014). Alternatively, dry aging can be done by packing the meat in a water vapor permeable package. 
 
In this method, the sensory quality obtained in traditional dry aging can be achieved, while the risk of moisture loss and microbial contamination can be minimized (Ahnstrom et al., 2006; DeGeer et al., 2009).
 
In dry aging systems, the enzymatic reactions associated with aging slow down when the storage temperature drops below the meatfreezing temperature (-2 to -3).
 
When the storage temperature is high, although the degree of enzymatic reactions related to aging is good, it may cause unpleasant odors and bad taste due to microbial change (Savell, 2008). In many scientific studies, dry aging was generally performed at an optimum temperature of 0 to 4 (Ahnstrom et al., 2006; Campbell et al., 2001; Smith, 2007; Warren and Kastner, 1992).
 
One of the important issues related to dry aging parameters is relative humidity. High relative humidity during aging results in the proliferation of spoilage bacteria and, accordingly, the formation of undesirable odors and flavors. When the relative humidity is low, the waste rate due to water loss in the product is high and at the same time, there is a loss of quality due to excessive drying (Savell, 2008). When the results of the dry aging process at different relative humidity levels are examined in the studies, it is seen that the relative humidity of the aging environment is preferred around 80% (Ahnstrom et al., 2006; Parrish et al., 1991; Peryy, 2012; Smith, 2007; Warren and Kastner, 1992). .
 
Air flow rate is one of the important factors affecting meat quality in dry aging method.
 
Providing a continuous effective air flow around the aged beef minimizes the drying time, as well as causes rapid drying on the meat surface, minimizing spoilage and therefore the development of malodour. The air circulation velocity is between 0.5-2.0 m/s in the USA, which is one of the countries where aging is most commonly applied; In Australia, it is used between 0.2-0.5 m/s.
 
Yield loss is expected to increase in aging conditions where air velocity is high and relative humidity is low (Galletly, 2016). With the dry aging method, porous wire racks are used or the meat is suspended on hooks in order to provide even and uniform drying on all surfaces and to prevent undesired changes (Figure 1). In addition, additional fans can be used to speed up the drying process and assist air movement around the products.
 
How Is Meat Aged? What Is "Dry Aged"?Figure 1: Racks and hooks used in dry aging (Dashdorj et al., 2016)
 
Dry aging times differ in studies. During aging, water loss from beef occurs slowly. For this reason, with a long aging period, the flavor is concentrated in the cells (Perry, 2012).
 
In addition, as the aging time increases, lipid oxidation increases; thus, it causes the release of products that react with protein degradation products and give an intense flavor to aged meat. Beef aging time has been suggested as much longer times to achieve maximum texture and flavor characteristics, but the most appropriate aging time has been suggested as 14-21 days due to both economic reasons and possible undesirable changes (Khan et al., 2016).
 
Hulankova et al. (2018) investigated the effect of aging time (12-36 days) on the instrumental and chemical properties of meat. They reported that there was no significant change in the pH and color (L*, a* and b*) values ​​of the meat during the extended aging process.
 
Parrish et al. (1991) determined the sensory properties of different quality beef after 21 days of dry (80-85% relative humidity) and wet aging at 0-1. No significant difference was observed in the flavor characteristics of beef. However, an important difference between the aging methods was that the dry aged beef lost more weight and water. The wastage rate, which was 3.3-4.7% in dry aged meats compared to the 14th day region, changed between 5.06% and 6.55% on the 21st day. On the other hand, these rates remained between 0.55-1.17% in age-aged meats.
 
In a study on beef, Warren and Kastner (1992) produced dry-aged beef in an airflow-controlled environment where air circulated every 30 minutes. In this study, they compared the beef samples obtained by wet aging and dry aging (78% RH) at 3.1-3.6 β.
 
It has been determined that dry aged beef samples cause higher aging loss, less cooking time and less cooking loss, while wet aged beef samples have more intense bloody/serum flavor and more intense sour flavor. In addition, dry-aged beef has been reported to have brown/roasted flavor characteristics.
 
Smith (2007) aged beef in dry for 14, 21, 28 and 35 days (83% RH) and wet. When the flavor characteristics of the samples were compared on different days, although there were differences in terms of flavor and texture characteristics, it was determined that 21 days aged beef was better in flavor. On the other hand, it was determined that the yield in wet aged beef was higher than in dry aged beef. While the yield was 69.8% in dry aged meats after 35 days, this rate was 87.1% in wet aged meats. 
 
Laster (2007) also examined the yield rates in aged beef. After five weeks of aging, significant differences were observed in the meats of both the back and waist regions. At the end of the period, while the yield rate in dry aged loin and back meat was 52 and 63.5%, it was determined as 78 and 88.1% in wet aged meats, respectively.
 
Campbell et al. (2001) investigated the effect on flavor by dry aging beef for 7, 14 and 21 days in a refrigerator with 75% relative humidity at 2°C. It was evaluated in terms of sensory, physical and microbiological quality at different times (2nd, 9th and 16th days) during storage. It was observed that the beef that was dry aged for 14 and 21 days had superior flavor, texture and juiciness compared to those that were dry aged for 7 days.
 
It was determined that dry aged meat had a high roasted/brown flavor intensity, vacuum aged meat had a high blood/serum content and a higher sour and metallic flavor intensity compared to dry aged meat. Studying chemical changes in aged meats, King et al. (1995) also reported that the amount of acid in vacuum-packed aged meats was higher.
 
There are also some studies aiming to produce beef with the same flavor that significantly reduces shrinkage due to weight loss during dry aging. The aging method with packaging, which is permeable to water vapor, provides a less controlled environment requirement.
 
When controlled environmental conditions are not suitable, deterioration may occur in meat due to microbial growth. For this purpose, the aging process using the water vapor permeable packaging method suggests that it will be possible to produce more economically and with the desired microbiological quality (Ahnström et al., 2006).
 
Ahnstrom et al. (2006) subjected the beef to the aging process by packaging it with both classical dry aging and water vapor permeable packaging in the range of 2.5 -2.6, in an environment with a relative humidity of 87% for 14 and 21 days. No difference was observed between weight and water losses after 14 days for either of the two aging methods. However, after 21 days, less weight and water loss was found in beef aged with water vapor permeable packaging method compared to dry aged beef.
 
In addition, no change was observed in the water loss of the beef dried with the water vapor permeable packaging method between 14 and 21 days. As a result of balancing the cost of the packages with water vapor permeable properties with the increased efficiency, it has been concluded that it will create more positive results than the dry aging method.
 
Microbiology of Aged Meats
 
The deterioration process of meat is closely related to the bacterial load after slaughter. The more bacteria on the carcass surface, the faster the deterioration occurs. It is desirable to keep the initial microorganism load of the meat to a minimum. Otherwise, these microorganisms reproduce very quickly and cause the quality of meat to decrease or deteriorate (Feiner, 2006; Ingram and Roberts, 1977).
 
The meat (muscle tissue) of healthy animals is normally free of bacteria. However, this situation changes with the slaughter of butchery animals. Because the carcass is exposed to contamination from many different sources during or after slaughter. The most important contamination in meat occurs during removal of internal organs and skinning and constitutes approximately 35-40% of the total contamination.
 
How Is Meat Aged? What Is "Dry Aged"?
 
As a result of the development of the contaminated microorganisms in the meat, many biochemical changes (deamination of amino acids) occur and as a result of these changes, compounds such as hydrogen sulfide (H2S), ammonia (NH3), indole, cadaverine and putrescine are released, which characterize the spoilage. These compounds cause a change in the natural structure of the meat, as well as the problem of taste disorder in meat (Çelik, 2012; Öztan, 2003).
 
After slaughter, the microflora of the carcass consists mainly of enterobacteria, micrococci, fecal streptococci, lactobacilli and aerobic spore-forming bacteria. Bacteria belonging to the Enterobacteriaceae family, especially proteus, found in the microflora of fresh meat are very proteolytic and cause putrefaction of meat stored under aerobic conditions.
 
Another group found in fresh meats are microorganisms belonging to the micrococcaceae family. Micrococci and staphylococci break down carbohydrates to form acid and cause deterioration by acidifying the environment. The microflora of fresh meat changes during cold storage and a new flora becomes dominant. This flora is composed of psychrophilic and psychotrophic microorganisms, especially pseudomonas and acinetobacter-morexella group microorganisms. They form a sticky layer on the surface of the meat under humid conditions (Çelik, 2012; Nortje and Naudè, 1981; Wang et al., 2017).
 
During the dry aging of meat, changes in the number of microorganisms are observed depending on the environmental conditions. Pseudomonas, which is one of the leading microorganisms that cause spoilage in meat, can find the opportunity to develop on the outer surface of the meat, which is in contact with air, due to being both psychrophilic and aerobic (Blana and Nychas, 2014).
 
Although options such as very low temperature, high air circulation and low relative humidity are considered to eliminate the possible negative effects of microorganisms, they will not be sufficient to meet the quality criteria expected from aged meat. During aging, storage conditions and time have a significant impact on the quality of aged beef. For this reason, the aging process should be carried out at a low temperature above freezing temperature, at optimum relative humidity and time.
 
Hulankova et al. (2018) evaluated the effect of dry aging of beef at 1 °C for 12-36 days on its microbiological properties. It was determined that the total number of live bacteria, psychrophilic bacteria and lactic acid bacteria increased significantly in the first 2 weeks of aging, but the number of bacteria did not change significantly with the improvement of texture properties in the later stages of aging.
 
These results show the positive effect of dry aging on beef texture. In addition, as a result of the study, it has been suggested that if the microbiological quality of the meat before aging and the preservation conditions during aging are good, the microbiological quality of the aged meat as the final product will be good.
 
Li et al. (2013) produced wet aged beef with vacuum packaging and dry aged beef with water vapor permeable packaging.
 
It was determined that the aging process had a significant effect on the total number of viable bacteria, lactic acid bacteria and yeast counts. It was found that total bacteria and yeast counts were higher in dry-aged beef with water vapor permeable packaging than in vacuum-packed wet-aged beef.
 
However, the amount of lactic acid bacteria was found to be lower both before and after aging than in wet aged meats with vacuum packaging. It has been determined that dry aged meats with water vapor permeable packaging have superior texture properties and microbiological quality, preferred by consumers. Thus, by using the aging bag, which has a water vapor permeable feature, it has been possible to produce aged meat in a more controlled condition without causing negative effects on sensory or other quality characteristics.
 
Li et al. (2014) performed conventional dry aging, dry aging by water vapor permeable packaging and wet aging by vacuum packaging for 8 and 19 days. Regardless of the aging method, it was observed that the microorganism load increased with increasing aging time. The microorganism load of the wet aged meats by vacuum packaging was found to be lower than the others, followed by the dry aged beef with water vapor permeable packaging.
 
Yeast counts were affected by the aging method and aging time, and the yeast counts of wet aged meat with vacuum packaging were found to be lower in both aging periods. In addition, it was determined that the yeast count after dry aging increased with the aging time, while the mold count did not change.
 
Berger et al. (2018) subjected beef to conventional dry aging, dry aging with water vapor permeable packaging, and wet aging with vacuum packaging. Traditional dry-aged and wet-aged beef samples had a lower total aerobic bacterial population compared to beef samples aged with water vapor permeable packaging.
 
Since the oxygen is removed by vacuum packaging, the growth of aerobic bacteria is limited, which is expected for wet aged meats, and similar results in traditional dry aged meats have been associated with the removal of water from the surface in traditional dry aged meats, forming a natural protective crust layer. 
 
A lower lactic acid bacteria count was determined in traditional dry aged meats compared to other aged meats. However, yeast counts were found to be lower in wet aged meats with vacuum packaging, and it was determined that aging methods had no effect on mold counts.
 
The risk of microbial spoilage can be minimized by both hygienic measures to be taken in the production of meat to be aged and by providing conditions to stop microbial growth during aging. Some of the commercially used dry aging chillers in the food industry use ultraviolet light as a way to delay microbial spoilage (Figure 2) (Peryy, 2012).
 
It is known that UV radiation at wavelengths between 200-300 nm is effective in killing or damaging microorganisms. UV radiation can also be used to disinfect the air in a cooler by circulating it through UV units (Galletly, 2016; Warren and Kastner, 1992).
 
How Is Meat Aged? What Is "Dry Aged"?Figure 2: Use of UV in dry curing (Perry,2012)
 
CONCLUSION
Significant improvements in meat flavor properties such as texture, flavor and/or juiciness with postmortem aging that occurs during the transformation of muscles into meat occur due to the structural deterioration of the muscle by proteolytic enzymes. As can be seen in the studies, dry aging yields high value-added products with unique flavor properties. However, dry aging requires higher environmental control than wet aging, and due to low efficiency, unit costs increase.
 
In order to prevent the negative effects of traditional dry aging, aging can be done using packaging with water vapor permeable properties. With this method, close results can be obtained in terms of flavor properties. At the same time, a more economical and microbiologically superior product can be obtained. 
 
Among the factors limiting the duration of dry aging is deterioration due to microbial growth. In this regard, it is especially important that the meat to be aged is produced and preserved under hygienic conditions. It is not possible to age meats that have been exposed to high levels of microbial contamination for a long time. On the other hand, although the level of microorganisms is low, microbial growth will occur, albeit slowly, during the aging process and their numbers may reach levels that will adversely affect the quality of meat. 
 
Further improvement can be achieved in this area by applying surface decontamination methods before the dry aging process, and by applying inhibitory rays and gases to the environment in order to minimize microbial growth during the process.
 
RESOURCES
Ahnström, ML, Seyfert, M., Hunt, MC, Johnson, DE (2006). Dry aging of beef in a bag highly permeable to water vapor. Meat Science, 73(4): 674-679.
Anar, S. (2012). Meat and Meat Products Technology. Dora Publishing, Bursa.
Ardicli, S. (2018). Effect of Genetic and Postmortem Mechanisms on Color Characteristics of Beef. Uludag University Journal of The Faculty of Veterinary Medicine, 37(1): 49-59.
Berger, J., Kim, YHB, Legako, JF, Martini, S., Lee, J., Ebner, P., Zuellya, SMS (2018). Dry-aging improves meat quality attributes of grass-fed beef loins. Meat Science, 145: 285-291.
Blana, VA, Nychas, GJE (2014). Presence of quorum sensing signal molecules in minced beef stored under various temperature and packaging conditions. International Journal of Food Microbiology, 173:1-8.
Campbell, RE, Hunt MC, Levis, P., Chambers, E. (2001). Dryβaging effects on palatability of beef longissimus muscle. Journal of Food Science, 66(2): 196-199.
Corbin, CH, O'Quinn, TG, Garmyn, AJ, Legako, JF, Hunt, MR, Dinh, TTN, Miller, MF (2015). Sensory evaluation of tender beef strip loin steaks of varying marbling levels and quality treatments. Meat Science, 100: 24 –31
Coux, O., Tanaka, K., Goldberg, AL (1996). Structure and functions of the 20S and 26S proteasomes. Annual Review of Biochemistry, 65: 801-847.
Celik, P. (2012). Determination of Quality Characteristics of Meatballs Obtained with Poultry Meat (Turkey Meat and Chicken Meat) and Red Meat Mixture. Master Thesis, Namık Kemal University. Tekirdag.
Çon, AH, Doğu, M., Gökalp, HY (2002). Periodic Determination of Some Microbiological Properties of Sausage Samples Produced in Large Capacity Meat Farms in Afyon. Turkish Journal of Veterinary and Animal Sciences, 26: 11-16.
Dashdorj, D., Tripathi, VK, Cho, S., Kim, Y., Hwang, I. (2016). Dry aging of beef; review. Journal of Animal Science Technology, 58: 20.
Daun, C., Johansson, M., Önning, G., Åkesson, B. (2001). Glutathione peroxidase activity, tissue and soluble selenium content in beef and pork in relation to meat aging and pig RN phenotype. Food Chemistry, 73(3): 313-319.
DeGeer, SL, Hunt, MC, Bratcher, CL, Croizer-Dodson, BA, Johnson, DE and Stika, JF (2009). Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times. Meat Science, 83: 768-774.
Dikeman, ME, Obuz, E., Gök, V., Akkaya, L., Stroda, S. (2013). Effects of dry, vacuum, and special bag aging; USDA quality grade; and end-point temperature on yields and eating quality of beef Longissimus lumborum steaks. Meat Science, 94(2): 228-233.
Feiner, G. (2006). Meat Products Handbook, Woodhead Publishing (1st ed.), pp. 574-594.
Galletly, J. (2016). Dry aged beef – design and good manufacturing. Meat and Livestock Australia Limited, Project code: P.PSH.0679.
Goll, DE, Thompson, VF, Li, H., Wei, W., Cong, J. (2003). The calpain system. Physiological Reviews, 83(3): 731-801.
Huff-Lonergan, H., Lonergan, SM (2005).
Mechanisms of water-holding capacity of meat: the role of postmortem biochemical and structural changes. Meat Science, 71(1): 194-204.
Hulankova, R., Kamenik, J., Salakova, A., Zavodsky, D., Borilova, G. (2018). The effect of dry aging on instrumental, chemical and microbiological parameters of organic beef loin muscle. LWT-Food Science and Technology, 89: 559-565.
Ingram, M., Roberts, TA (1976). The microbiology of the red meat carcass and the slaughterhouse. Royal Society of Health Journal, 96(6): 270-276.
Juncher, D., Rønn, B., Mortensen, E., Henckel, P., Karlsson, A., Skibsted, L., Bertelsen, G. (2001). Effect of pre-slaughter physiological conditions on the oxidative stability of color and lipid during chill storage of pork. Meat Science, 58(4): 347-357.
Kemp, CM, Sensky, PL, Bardsley, RG, Buttery, PJ, Parr, T. (2009). Tenderness – An enzymatic view. Meat Science, 84(2): 248-256.
Kemp, CM, Parr, T. (2012). Advances in apoptotic mediated proteolysis in meat tenderisation. Meat Science, 92: 252–259.
Khan, MI, Jung, S, Nam, KC, Jo, C. (2016).
Postmortem aging of beef with a special reference to the dry aging. Korean Journal For Food Science of Animal Resources, 36(2): 159–169.
Kim, YH, Kemp, R., Samuelsson, LM (2016). Effects of dry-aging on meat quality attributes and metabolite profiles of beef loins. Meat Science, 111: 168-176.
King, MF, Matthews, MA, Rule, DC, Field, RA (1995). Effect of beef packaging method on volatile compounds developed by oven roasting or microwave cooking. Journal of Agricultural and Food Chemistry, 43: 773-778.
Koplay, Z., Sezer, C. (2013). The effect of nisin and clove essential oil on shelf life of beef. Atatürk University Journal of Veterinary Sciences, 8(1): 9-19.
Laster, MA (2007). Tenderness, flavor, and yield assessments of dry aged beef. Master of Science Thesis, Texas A and M University, College Station.
Laster, MA, Smith, RD, Nicholson, KL, Nicholson, JD, Miller, RK, Griffin, DB, Harris, KB, Savell, JW (2008). Dry versus wet aging of beef: Retail cutting yields and consumer sensory attribute evaluations of steaks from ribeyes, strip loins, and top sirloins from two quality grade groups. Meat Science, 80(3): 795-804.
Li, X., Babol, J., Bredie, WLP, Nielsen, B., Tománková, J., Lundström, K. (2014). A comparative study of beef quality after aging longissimus muscle using a dry aging bag, traditional dry aging or vacuum package aging. Meat Science, 97(4): 433-442.
Li, X., Babol, J., Wallby, A., Lundström, K. (2013). Meat quality, microbiological status and consumer preference of beef gluteus medius aged in a dry aging bag or vacuum. Meat Science, 95(2): 229-234.
Martinaud, A., Mercier, Y., Marinova, P., Tassy, ​​C., Gatellier, P., Renerre, M. (1997). Comparison of oxidative processes on myofibrillar proteins from beef during maturation and by different model oxidation systems. Journal of Agricultural and Food Chemistry, 45 (7): 2481–2487.
Miller, MF, Davis, GW, Ramsey, CB (1985). Effect of subprimal fabrication and packaging methods on palatability and retail caselife of loin steaks from lean beef. Journal of Food Science, 50(6): 1544-1546.
Minks, D., Stringer, WC (1972). The influence of aging beef in vacuum. Journal of Food Science, 37: 736-738.
Nair, MN, Canto, ACVCS, Rentfrow, G., Suman, SP (2019). Muscle-specific effect of aging on beef tenderness. LWT- Food Science and Technology, 100: 250-252.
Nishimura, T. (2015). Role of extracellular matrix in development of skeletal muscle and postmortem aging of meat. Meat Science, 109: 48 –55
Nortje, GL, Naudé, RT (1981).
Microbiology of beef carcass surfaces. Journal of Food Protection, 44(5): 355-358.
Nychas, GJE, Arkoudelos, JS (1990).
Staphylococci: their role in fermented sausages. Journal of Applied Bacteriology Symposium Supplement, 19:167-188.
Oreskovich, DC, McKeith, FK, Carr, TR, Novakofski, J., Bechtel, PJ (1988). Effects of different aging procedures on the palatability of beef. Journal of Food Quality, 11(2): 151-158.
Oztan, A. (2003). Meat Science and Technology. TMMOB Chamber of Food Engineers Publications Books Series. No: 1, Ankara.
Parrish, FC, Boles, JA, Rust, RE, Olson, DG (1991). Dry and wet aging effects on palatability attributes of beef loin and rib steaks from three quality grades. Journal of Food Science, 56(3): 601-603.
Perry, N. (2012). Dry aging beef. International Journal of Gastronomy and Food Science, 1(1): 78-80.
Savell, JW (2008). Dry-aging of beef. Executive summary, National Cattlemen's Beef Association, Centennial, CO, 1-16.
Sitz, BM, Calkins, CR, Feuz, DM, Umberger, WJ, Eskridge, KM (2006). Consumer sensory acceptance and value of wet-aged and dry-aged beef steaks. Journal of Animal Science, 84(5): 1221-1226.
Smith, RD (2007). Dry aging beef for the retail channel. Master of Science Thesis, Texas A and M University, College Station.
Starkey, CP, Geesink, GH, Collins, D., Oddy, VH, Hopkins, DL (2016). Do sarcomere length, collagen content, pH, intramuscular fat and desmin degradation explain variation in the tenderness of three ovine muscles. Meat Science, 113: 51–58.
Vural, H. (1992). Studies on the Use of Starter Culture in Turkish Fermented Sausage Production. Doctoral Thesis, Hacettepe University. Ankara.
Wang, Y., Zhang, W., Fu, L. (2017). Food Spoilage Microorganisms: Ecology and control (1st ed.) pp192.
Warren, KE, Kastner, CL (1992). A comparison of dry-aged and vacuum-aged beef striploins. Journal of Muscle Foods, 3(2): 151-157.
Yibar, A., Cetin, E. (2013). Effects of Animal Welfare on Meat Quality. Uludag University Journal of The Faculty of Veterinary Medicine, 32(2): 31-37.
 
As the head chef Ahmet ÖZDEMİR, I see the source:
Ms. I sincerely thank Çiğdem MUŞTU for her academic studies on "Dry Aging in Meats" and wish her success in her professional life . It will definitely be considered as an example by those who need it in professional kitchens and the gastronomy and culinary community.
 
Turkish cuisine chef
 
According to the information received from Doga Cooling Source;
 
How is Meat Aging Made? What is Aged Meat? How Long Is Meat Aged? What Do You Need to Age Meat? Where is the Meat Aging (Dry Aged) Cabinet Used? What are Dry Meat Resting Cabinets?
 
How is Meat Aging Made?
 
The aging process has the power to increase the flavor of meat and offer a healthier meat when it comes to indispensable culinary delights such as meat. This is especially true for dry-aged meats, which offer a richer flavor and softer texture than their fresh-cut counterparts. So how does the dry aging process work such magic on meat?
 
The effect of a dry aged meat specialty on the palate is admirable. The nuances of how meat provides such a superior experience may be a matter of curiosity for consumers and business owners. Now, let's explain in detail what meat aging is and how it happens.
 
What is Aged Meat?
 
In short, aged meat undergoes a process of resting under controlled and ideal climatic conditions. The lower tissues of the meat aged with a dry meat locker are exposed to oxygen, which allows the natural enzymes in the meat to work. Aerobic bacteria in the inner layers of meat also need oxygen to survive. As these beneficial bacteria come to life, the molecular bonds of the meat begin to dry up. The process literally affects the flavor and texture of the meat in a positive way.  
 
Dry aged cabinets are used for meat resting. While dry aging is done in special cabinets, the meat is hung in a humidity-controlled environment with unobstructed air flow to expose all sides. Then the meat gradually begins to ripen. Moisture is drawn from the meat over time. This increases the lifespan of the meat and increases its flavor.
 
The taste of dry aged meat with a meat aging cabinet is much better than a fresh and wet meat. Moisture loss is a factor that alters the flavor of dry-aged meat. This process is essentially concentrating the rest of the tissue. About 75 percent of meat is water. A certain part is lost as a result of evaporation. The rest is more concentrated and therefore tastes better. Just as the evaporation of moisture while cooking in the pot creates a more intense food taste, the juice of the meat evaporates with the dry aged cabinet and the natural meat taste becomes even more intense.
 
There are many important components in the muscle cells of the meat. Meat contains proteins that enable muscles to contract and molecules such as glycogen, DNA and RNA that feed this process. During meat aging, these large, tasteless molecules are broken down into smaller, flavorful pieces. Meat, which is rested in suitable humidity, temperature and weather conditions, offers bitter and salty with its decomposed amino acids, taste with RNA and DNA material, and sweetness with glycogen.
 
The texture of the meat dried with the meat aging cabinet also changes. Under normal conditions, meat has a very complex internal structure that can be difficult to bite and chew. Breaking down the proteins and other important ingredients into smaller pieces makes the meat softer. This makes it easier to chew and digest the meat.
 
How Long Is Meat Aged?
 
The ideal time for dry aged meat really depends on personal taste. The time required for meat to mature, taste and tenderness to suitable conditions is generally 30 to 35 days. Meat aged for 35 days for retail customers and 18 to 20 days for restaurant customers will be appropriate. Also, if a firm's customers in the restaurant industry are unfamiliar with dry-aged beef, the initial reaction may be negative. For this reason, dry-aged meat for 18-20 days may be the right choice for restaurants. Some customers may prefer to consume meat that has been rested for a longer period of time. In fact, the longer the meat rests, the better flavor it provides. Ripe meat has a distinctive smell and taste. Meat that is generally aged up to 35 days,
 
What Do You Need to Age Meat?
 
Because wet aging is a much cheaper process than dry aging, it is a popular method for many businesses. However, presenting meat to customers with wet aging may reduce its flavor and quality. This leads to loss of customers. While dry aging is a time-consuming method, the returns are financially rewarding. Meat aging refrigerators are used for aging meat. This special equipment, known as the dry aged cabinet, allows the meat to be aged under suitable conditions, typically in 4-6 weeks. This means that without the need for additional equipment and processing, only the meat aging cabinet can be rested.
 
How Is Meat Aged? What Is "Dry Aged"?
 
The use of standard refrigerators for dry aging in the home environment will not meet expectations. Because domestic refrigerators are not produced for this purpose and cannot provide the conditions that meat needs. Instead, you can choose from household dry aged cabinets. Household dry aged cabinets, which do not take up much space and are designed for use in small spaces, automatically adjust humidity, temperature and weather conditions while preserving the meat well.
 
Where is the Meat Aging (Dry Aged) Cabinet Used?
 
Meat aging cabinet is used for butcher shops, restaurant businesses, food suppliers and all kinds of commercial kitchens. Even meat-loving individual customers can get a dry aged cabinet. Meat resting cabinet models offer many different options. This is a great advantage for those who need a meat aging cabinet individually and institutionally.
 
What are Dry Meat Resting Cabinets?
 
Meat aging cabinet prices vary according to the model, features and sizes of the products. The dry aged cabinet, which is suitable for a small-square-meter business, and the cabinet that will meet the requirements of a large food supplier may be different. Therefore, meat resting cabinet options are of the type that will appeal to different customer expectations.
 
How Is Meat Aged? What Is "Dry Aged"?
 
For small butchers and most commercial kitchens, separate cold room storage can often create a restriction. That's why single and double door dry aging cabinets are widely used in butcher shops, restaurants and food production kitchens. Meat aging cabinet, which is the right choice for both aging and displaying meat, can be a complementary element in decoration as it can be produced in different colors and design styles.
 
Meat settling refrigerators provide the right balance of temperature, humidity and air circulation required while controlling bacteria levels during the aging process of meat.
 
Temperature and humidity management provides the opportunity to adjust according to the climatic conditions of the region where the business is located. Interchangeable stainless steel shelves create ease of use. In addition, meat resting cabinets can be cleaned simply because they are designed with clean and hygiene in mind. Dry aged cabinets are available in various widths, depths and heights. Meat proofing cabinets for preserving, displaying and aging meat provide a simple, easy-to-install and easy-to-operate solution for all businesses.
 
In addition, dry aged cabinets, which allow the same group of meats to be kept together to prevent the wrong type of bacteria from entering the storage area, make it easier to keep, for example, beef and other ingredients in different sections. While this makes it possible to preserve the meat in healthy conditions, it also prevents the negative changes that may occur in the smell of the meat.