Abstract
The reduction of lipid content in fatty raw fish accelerates the penetration of smoke flavor during the production of smoke-dried fish. This study attempted to reduce the lipid with water content in hot boiled fish loins by vacuum treatment at a pressure of 400 Pa for 30min. The penetration rate of smoke flavor was measured from phenol content in the vacuumed boiled fish and compared with the unvacuumed boiled fish during smoking at 90±10°C in the metal kiln (inside: 24×24×70cm), using electric heater (1.2 kw) for heating and generating the smoke from wood chips of cherry tree. The vacuum treatment reduced the contents of lipid and water in the boiled skipjack by as much as 0.6% and 2.7% (w. b.), respectively, and 2.2% and 3.3% (w. b.) in the boiled mackerel. Many clearances were observed among the muscle fibers of the vacuumed boiled skipjack. The phenol content that penetrated into the vacuumed boiled fish were significantly higher (p<0.05) than those of the unvacuumed boiled fish during smoking for 6, 12 and 18 hours, suggesting that the vacuum treatment effectively accelerated the smoke flavor penetration.
