The objective of this study was to investigate changes in drying yield, pH, water activity, microbial growth, and storage stability of bottom rounds of Hanwoo beef under four different dry-aging treatments (T1–T4) as temperature (2~4℃), relative humidity (65~86%) and dry-aging period (20~90 d). The drying yield decreased by 83.13–97.05% as the drying period increased. Among the four treatments, there were no significant differences in drying yield after 60 d of dry-aging. The total plate aerobic counts (TPC) increased by 1.07–4.39 log colony-forming units (CFU)/g as the dry-aging period increased. Of the four treatments, T4 at 40, 60, and 90 d had significantly higher TPCs than those observed for the other treatments on the same days (p<0.05). As the period of dry-aging increased, pH values increased by 5.35– 5.88 for knuckle and 5.34–5.62 for sirloin muscle, and water activity values decreased. For knuckle and sirloin muscle, the water activity values at 40 d and 60 d of T1 and T4 were significantly higher than those of the other treatments on the same days (p<0.05). The thiobarbituric reactive substances and volatile basic nitrogen values of the aged products increased as the dry-aging period increased. The results of this study showed that dry-aging conditions such as those in the T2 or T3 treatments (with a gradual increase in temperature and humidity) for less than 60 d would be best for yield, reduction of microbial growth and storage stability by dry the muscle surface quickly at the beginning period. Further research should include meat quality and economic analysis for these conditions that examines the benefits of these dry-aged products for the end processor.

ABSTRACT
 Ⅰ. 서론
 Ⅱ. 재료 및 방법
  1. 시험동물 및 공시재료
  2. 조사항목 및 분석방법
  3. 통계분석
 Ⅲ. 결과 및 고찰
  1. 건조수율
  2. 총균수 및 대장균군
  3. pH 및 수분활성도
  4. 지방산화도 및 단백질변패도
 Ⅳ. 요약
 Ⅴ. 참고문헌

• 조수현(농촌진흥청 국립축산과학원 축산생명환경부) | Soohyun Cho (Department of Animal Biotechnology & Environment, National Institute of Animal Science, RDA) Corresponding author
• 강선문(농촌진흥청 국립축산과학원 축산생명환경부) | Sun Moon Kang (Department of Animal Biotechnology & Environment, National Institute of Animal Science, RDA)
• 김윤석(농촌진흥청 국립축산과학원 축산생명환경부) | Yunseok Kim (Department of Animal Biotechnology & Environment, National Institute of Animal Science, RDA)
• Hoa Van Ba(농촌진흥청 국립축산과학원 축산생명환경부)
• 김영춘(농촌진흥청 국립축산과학원 축산생명환경부) | Youngchun Kim (Department of Animal Biotechnology & Environment, National Institute of Animal Science, RDA)
• 김진형(농촌진흥청 국립축산과학원 축산생명환경부) | Jinhyoung Kim (Department of Animal Biotechnology & Environment, National Institute of Animal Science, RDA)
• 박범영(농촌진흥청 국립축산과학원 축산생명환경부) | Beomyoung Park (Department of Animal Biotechnology & Environment, National Institute of Animal Science, RDA)
• 안달래(농촌진흥청 국립농업과학원 축업생물부) | Dalrae Ahn (Department of Agricultural Biology, National Institute of Agriculutural Science, RDA)
• 이은미(농촌진흥청 한우연구소) | Eunmi Lee (Hanwoo Research Institute, National Institute of Animal Science, RDA)
• 성필남(농촌진흥청 연구정책국) | Pilnam Seong (Research Policy Bureau, RDA)