This study was conducted to investigate the effect of dietary total mixed ration (TMR) supplementation and dry-aging period on the physico-chemical and sensory quality of striploin (longissimus lumborum) from multiparous Hanwoo cows. The experimental cows were divided into two treatments (n=3/treatment) according to the type of feed: in one treatment (slaughter age: 87±6 months old, parity: 5±1) the cows were fed on TMR for 7 months before slaughter, while in the other treatment (slaughter age: 83±9 months old, parity: 5±2) the cows were fed on concentrate and rice straw (CRS) for the whole rearing period. After slaughtering, the striploins were dry-aged for 20 or 40 days at 2±1℃, 85% relative humidity and 2 m/sec air flow velocity and then utilized for quality measurements. The pH value, cooking loss, and hypoxanthine content were higher (p<0.05) for the striploins dry-aged for 40 days than for those dry-aged for 20 days. Notably, the inosine 5’-monophosphate content was decreased (p<0.05) by increasing the dry-aging time. With regard to microbiological quality, the striploins dry-aged for 40 days exhibited lower (p<0.05) lactic acid bacteria counts and higher (p<0.05) coliform counts than those dry-aged for 20 days. Moreover, the tenderness and overall liking scores based on sensory evaluation were higher (p<0.05) for the dry-aged striploins of the TMR treatment and those dry-aged for 40 days than for the CRS treatment and those dry-aged 20 days, respectively. These findings suggest that dietary TMR supplementation leads to an increase in the sensory preference of dry-aged striploins from multiparous Hanwoo cows, and alteration of the CRS into the TMR may improve the quality of dry-aged Hanwoo beef.

ABSTRACT
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 실험동물 및 설계
    2. 공시재료
    3. pH
    4. 가열감량
    5. 전단가
    6. 표면육색
    7. 지방산화물 함량
    8. 휘발성 염기질소 함량
    9. 핵산 관련 물질 함량
    10. 미생물수
    11. 관능적 기호도
    12. 통계분석
Ⅲ. 결과 및 고찰
    1. pH, 가열감량 및 전단가
    2. 표면육색
    3. 지방산화물 및 휘발성 염기질소 함량
    4. 핵산 관련 물질 함량
    5. 미생물수
    6. 관능적 기호도
Ⅳ. 요약
사사
Ⅴ. 참고문헌

• 김영종((주)그린스마트) | Yeong Jong Kim (Green Smart Co)
• 강선문(농촌진흥청 국립축산과학원) | Sun Moon Kang (National Institute of Animal Science, Rural Development Administration)
• Dicky Tri Uta(브라위자야대학교)
• 장애라(강원대학교 동물생명과학대학) | Aera Jang (College of Animal Life Sciences, Kangwon National University)
• 박재인(강원대학교 동물생명과학대학) | Jae In Pak (College of Animal Life Sciences, Kangwon National University)
• 송영한(강원대학교 동물생명과학대학) | Young Han Song (College of Animal Life Sciences, Kangwon National University)
• 김동식(영양자원연구소) | Dong Sik Kim (Nutritional Resource Research Institute)
• 이성기(강원대학교 동물생명과학대학) | Sung Ki Lee (College of Animal Life Sciences, Kangwon National University) Corresponding author