Dry aging creates a unique taste and flavor in beef; however, the process also causes rancidity, which is harmful to humans. During dry aging, the microbial flora in beef changes continuously; thus, this change can be used as an indicator of rancidity. The objective of this study was to analyze the correlation between microbial flora in beef and rancidity during dry aging. The round of beef (2.5–3 kg) was dry aged under 1.5 ± 1 °C and 82 ± 5% moisture for 17 weeks. The microflora in the dry aged beef was analyzed by pyrosequencing. The volatile basic nitrogen (VBN) and thiobarbituric acid reactive substance (TBARS) values were also measured. Primers were designed to detect and quantify bacteria using real-time polymerase chain reaction (RT-PCR). The VBN and TBARS values in the dry aged beef depreciated from week 11 of aging. The levels of Streptococcus spp., Pantoea spp., and Pseudomonas spp. significantly changed at around week 11. Quantitative RT-PCR showed that the levels of Pantoea spp. and Streptococcus spp. could be used to identify rancidity during dry aging. Thus, among the microbial flora in dry aged beef, Pantoea spp. and Streptococcus spp. can be used to determine the rancidity of dry aged beef.

Food Science of Animal Resources (Food Sci. Anim. Resour.) is an international, peer-reviewed bimonthly journal publishing original research and reviews on basic and applied aspects of the use of animal resources including the meat, egg, and dairy product. Food Sci. Anim. Resour. is published and distributed by the Korean Society for Food Science of Animal Resources.

The objective of this study was to evaluate the microbiological properties of commercially available traditional Korean salted shrimp (Saeu-jeot) and to analyze the effects of saltwater immersion and ultraviolet (UV) irradiation on the reduction of Staphylococcus aureus in Saeu-jeot. A microbiological analysis was conducted across 56 commercially available Saeu-jeot samples from the Korean, Chinese, and Vietnamese markets. The microbiological analysis revealed no presence of Escherichia coli, coliforms, or Vibrio parahaemolyticus in any commercial samples. The total viable count and S. aureus were 3.8 ± 0.4 and 0.6 ± 0.3 log CFU/g, respectively. An investigation of the procedures conducted on Saeu-jeot samples at various production stages by Hazard Analysis Critical Control Point (HACCP)-certified companies demonstrated the substantial relevance of the raw material (tiny shrimp) on S. aureus counts. In order to reduce S. aureus in Saeu-jeot, saltwater immersion and UV irradiation treatments were applied, which reduced the S. aureus counts by 1.4 log CFU/g and 0.3 log CFU/g, respectively, and S. aureus’s efficacy was limited to the food’s surface. These results suggest that a co-treatment of saltwater immersion and UV irradiation could be effective in reducing S. aureus. The maintenance of hygienic handling and cleanliness are essential in the modern manufacturing processes of Saeu-jeot.