Resumen de Changes in Physical/chemical Composition and Histological Properties of Dorsal and Ventral Ordinary Muscles of Full-cycle Cultured Pacific Bluefin Tuna, Thunnus orientalis, During Chilled Storage
Yoshi-Nori Nakamura, Masashi Ando, Manabu Seoka, Ken-ichi Kawasaki, Yasuyuki Tsukamasa
Using full-cycle cultured Pacific bluefin tuna (BW: 33.5 ± 2.7 kg, cultured for about 33 mo), the physical/ chemical composition and histological properties of the cephalal parts of the dorsal ordinary muscles (DOMs) and ventral ordinary muscles (VOMs) were investigated during chilled storage at 4 °C for 69 h. VOM showed high fat content compared with DOM. The breaking strength of DOM increased up to 33 h but decreased thereafter, whereas VOM decreased gradually after 15 h. The pH and glycogen content of DOMs and VOMs decreased gradually after 9 h. The met-myoglobin (met-Mb)% and K-value of DOMs and VOMs increased gradually during storage. Extension of intercellular spaces of DOM was observed by LM during storage. The abundant quantity of glycogen granules that accumulated around the myofibrils of DOM was confirmed by TEM to decrease during storage (especially, from 15 h).
