Differences in physicochemical traits, bioactive and flavor compounds, and sensory attributes of Hanwoo beef loin according to slaughter age

This study investigated the effects of shortened rearing periods on meat quality and sensory attributes, aiming to identify an appropriate age range to ensure consumer satisfaction. A total of 320 Hanwoo cattle (n = 80 per age group) were reared from 6 months of age and slaughtered at 24, 26, 28, or 30 months. They were fed mixed concentrate and roughage under a three-phase feeding program (crude protein 13-16%; total digestible nutrients 70-75%). Older groups (28-30 months) exhibited significantly higher crude fat (+22%) and myofibril fragmentation index (+14%) than the younger groups (24-26 months). The 30-month group demonstrated a comparable water-holding capacity to that of the 28-month group (P > 0.05), while demonstrating higher values (+6%) than the younger groups (P < 0.01). Age-related differences were observed in bioactive compounds. Carnosine and anserine were significantly higher in the 24-month group than the 30-month group (by 25.52 and 14.21 mg/100 g, respectively), whereas l-carnitine was significantly higher in the 30-month group than the other groups (58.94 vs. 50.41-53.10 mg/100 g). Older groups also exhibited significantly higher levels of inosine monophosphate, guanosine monophosphate, oleic acid, and volatile compounds (e.g., lactones) than the younger groups (P < 0.001). In the sensory evaluation, the tenderness and juiciness scores were significantly higher in the older groups than in the 24-month group (P < 0.001). Collectively, these findings suggest that slaughtering Hanwoo at 28-30 months, rather than at younger ages, may contribute to improved beef quality and flavor characteristics.