The effect of quality grade and muscle on collagen contents and tenderness of intramuscular connective tissue and myofibrillar protein for Hanwoo beef

Six muscles were seamed out randomly from Hanwoo carcasses (n = 12) of each quality grade (quality grades 1, 2 and 3). Samples were analysed for their total and soluble collagen contents, IMCT (intramuscular connective tissue) and Warner-Bratzler shear force (WBSF). Simple correlation (n = 21) was determined for WBSF among major muscles. For LT (longissimus thoracis), total collagen content was significantly higher (p < 0.05) for quality grade 3 than those for quality grades 1 and 2. For semitendinosus (ST), semimembranosus (SM), psoas major (PM) and serratus ventralis (SV), total collagen content of quality grade 1 was lowest (p < 0.05) of all quality grades. IMCT shear force for gluteus medius (GM) decreased (p < 0.05) with better quality grade, and those for other muscles, with the exception of GM, were higher (p < 0.05) for quality grade 3 than for quality grades I and 2. WBSF values showed GM and LT to be decreased (p < 0.05) with better quality grade, and PM to be higher (p < 0.05) for quality grade 3 than those for quality grades 1 and 2. SM, ST and SV from quality grade I had lower (p < 0.05) WBSF value than those from quality grades 2 and 3. Total collagen content of ST was highest (p < 0.05) of all muscles, whereas that of PM was lowest (p < 0.05). Soluble collagen contents of LT and SV from quality grades 1 and 2 were, in general, higher (p < 0.05) than other muscles, but that of SM was lowest (p < 0.05). ST and SM had higher (p < 0.05) WBSF values for three quality grades when compared to other muscles, whereas PM was lowest (p < 0.05). LT had the strongest simple correlation with SV (r = 0.78) and GM (r = 0.77), and SM had the strongest correlation with ST (r = 0.73) and LT (r = 0.73). Also, PM had the strongest correlation with SV (r = 0.62).