Identification of Microorganisms Associated with the Quality Improvement of Dry‐Aged Beef Through Microbiome Analysis and DNA Sequencing, and Evaluation of Their Effects on Beef Quality

Abstract

The objective of this study was to isolate and identify the microorganisms, especially yeasts and molds, related to the improvement of beef quality during dry‐aging of beef through microbiome analysis, and to examine the possibility of using them as starter culture strains to improve the efficiency of dry‐aging beef production. Beef sirloins were dry‐aged for 28 days using different wind speeds (0, 2.5, and 5 m/s) at 1 to 3 °C and 75% relative humidity, and microbial compositions were confirmed by microbiome analysis. Mold and yeast samples were plated on potato dextrose agar supplemented with 10% tartaric acid, and the isolated colonies were identified by DNA sequencing. The isolates were subjected to microbial characterization (morphological characterization, growth condition, and enzyme activity). Microbiome analysis showed that the dominant microorganisms were molds and yeasts identified as Pilaira anomala SMFM201611 and Debaryomyces hansenii SMFM201707. Pilaira anomala SMFM201611 and D. hansenii SMFM201707 were inoculated into 24 sirloins of the lowest grade. All samples were dry‐aged for 0, 14, 21, and 28 days and analyzed for microbial growth, pH, shear force, ultrastructure, and flavor compounds (free amino acids and free fatty acids). Inoculation with P. anomala SMFM201611 and D. hansenii SMFM201707 improved tenderness and cause the breakdown of myofibrils by proteolysis. Both microorganisms also produced free amino acids and fatty acids through proteolytic and lipolytic activities. These results indicate that P. anomala SMFM201611 and D. hansenii SMFM201707 isolated and identified from dry‐aged beef can improve the quality of low‐grade beef during dry‐aging. Practical Application During dry‐aging, mold and yeast improve the quality of dry‐aged beef. Pilaira anomala SMFM201611 and Debaryomyces hansenii SMFM201707 isolated from dry‐aged beef can improve tenderness by breaking down myofibrils. Both microorganisms improve flavor by producing free fatty acids and amino acids, and the taste and aroma characteristics of low‐grade beef may be improved during the dry‐aging process.

Metabolomic approach to measuring quality of chilled chicken meat during storage

“…However, L-tryptophan and ornithine increased between 0 and 2 D of storage and between 0 and 4 D of storage, respectively, after which they both decreased. The actions of endogenous proteases and microorganisms are associated with free amino acid generation ( Yang et al., 2016 , Oh et al., 2019 , Wickramasinghe et al., 2019 ).…”

Characterization of the microbiota and chemical properties of pork loins during dry aging

“…Debaryomyces hansenii has been identified as one of the major microbes in DA beef (Oh et al, 2019), and its beneficial properties, including the degradation of biogenic amines and production of volatile sulfur compounds in meat products, have been reported (Baumlisberger et al, 2015; Perea‐Sanz et al, 2019). Therefore, this organism is a starter candidate for several meat products (Murgia et al, 2019; Oh et al, 2019; Ramos et al, 2017), but not yet for DA pork. Collectively, the present results and previous findings suggest that this organism is a promising starter for DA pork.…”

“…Therefore, this organism is a starter candidate for several meat products (Murgia et al, 2019;Oh et al, 2019;Ramos et al, 2017), but not yet for DA pork. Collectively, the present results and previous findings suggest that this organism is a promising starter for DA pork.…”

“…Debaryomyces hansenii was the sole yeast before DA and was recovered from all tested meat samples throughout DA. Debaryomyces hansenii has been identified as one of the major microbes in DA beef (Oh et al, 2019), and its beneficial properties, including the degradation of biogenic amines and production of volatile sulfur compounds in meat products, have been reported (Baumlisberger et al, 2015;Perea-Sanz et al, 2019).…”

Effect of Different Aging Methods on the Formation of Aroma Volatiles in Beef Strip Loins

“…Lee et al [8] observed significant increases in levels of flavor compounds of dry-aged beef between day 21 and 28, and explained that further proteolysis and lipolysis associated with microorganisms (especially mold and/or yeast) could develop aroma compounds of dry-aged beef. Oh et al [42] observed that dry-aged beef inoculated with Pilaira anomala had higher oleic, palmitic, and stearic acid content at day 21, while inoculation with D. hansenii resulted in higher amounts of free amino acids at day 28. Finally, the contribution of 2-methylpropanal, 2-methylbutanal, 2-methyl-2-propanethiol, ethyl propanoate, and possibly 2-methylpropanoic acid to dry-aged flavor should be noted when their low odor threshold values (Table 2) and concentration differences between dry-and wetaged beef are taken account (Tables 3, 5 and 7).…”