title: Comparison of Characteristics of Myosin Heavy Chain-based Fiber and Meat Quality among Four Bovine Skeletal Muscles.
abstract: Muscle fiber characteristics account for meat quality and muscle fibers are mainly classified into three or more types according to their contractile and metabolic properties. However, the majority of previous studies on bovine skeletal muscle are based on myosin ATPase activity. In the present study, the differences in the characteristics of muscle fibers classified by the expression of myosin heavy chain (MHC) among four bovine skeletal muscles such aslongissimus thoracis(LT),psoas major(PM),semimembranosus(SM) andsemitendinosus(ST) and their relationships to beef quality were investigated. MHCs 2x, 2a and slow were identified by LC-MS/MS and IIX, IIA and I fiber types were classified. PM, which had the smallest size and highest density of fibers regardless of type, showed the highest myoglobin content, CIE L*, a*, b* and sarcomere length (p<0.05), whereas ST with the highest composition of IIX, showed high shear force and low sarcomere length (p<0.05). The correlation coefficients between muscle fiber characteristics and meat quality showed that type IIX is closely related to poor beef quality and that a high density of small-sized fibers is related to redness and tenderness. Therefore, the differences in meat quality between muscles can be explained by the differences in muscle fiber characteristics, and especially, the muscles with good quality are composed of more small-sized fibers regardless of fiber type.
authors.affiliation: Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Korea; Department of Animal Sciences, University of Illinois, Urbana-Champaign, IL 61801, USA.
authors.forename: Gap-Don
authors.initials: GD
authors.lastname: Kim
authors.affiliation: Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Korea; Division of Applied Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
authors.forename: Han-Sul
authors.initials: HS
authors.lastname: Yang
authors.affiliation: Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Korea; Division of Applied Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
authors.forename: Jin-Yeon
authors.initials: JY
authors.lastname: Jeong
keywords: beef; meat quality; muscle fiber characteristics; myosin heavy chain