Relationship between image analysis traits and fatty acid composition and sensory score in cattle, Tokachi-wakaushisup(R)

Tokachi-wakaushisup(R) is defined as young fatting cattle of Holstein and the cattle are raised on 6 different farms in Shimizu, Hokkaido, Japan. Because of the cattle are slaughtered at young age (about 12 to 16 months old), the beef products believe that Tokachi-wakaushi has a smooth texture and produce tender meat and lean carcasses. In this study, we investigated relationship between image analysis traits and fatty acid composition and sensory scores of Tokachi-wakaushi. 412 Tokachi-wakaushi carcass data were collected in June and November, 2016. The carcass was ribbed between 6-7th rib. 10mg of intermuscular fat between longissimus muscle (LM) and rhomboideus muscle was collected for fatty acid analysis. Fatty acid compositions were analyzed by using gas chromatography. 15g of rib-eye steak sample was collected from each LM and cut into 1 cm thickness at the processing plant for the sensory evaluation. Eating quality (taste, flavor, fat flavor, tenderness and juiciness) was scored on scales of 1-3-5 (3 points) by more than 3 panels and each of its averages used as individual sensory scores. Image analysis traits, include marbling % of LM and image beef color standard (iBCS), were calculated by using BeefAnalyzer-II. iBCS is an index for the precise assessment of meat color of LM. Analysis of variance was examined by SAS. Averages and standard deviations of carcass weight, marbling % of LM. iBCS and C18 : 1 content were 352.8 ± 23.4kg, 17.8 ± 5.2%, 3.6 ± 0.8 and 45.3 ± 2.8%. The correlation coefficients between C18 : 1 content and sensory scores were extremely low (0.00 to 0.07). Farm location had significant effects on flavor, fat flavor and tenderness score (P < 0.05). Animals slaughtered in November tended to have higher scores of flavor (P < 0.05). However, C18 : 1 content had no significant effects on sensory scores of Tokachi-wakaushi.