Abstract
High pressure treatment has been expected for the sterilized effect upon foods and for less effect upon the properties of foods than thermal treatment. In the present paper big-eyed tuna meat was treated by high pressure among 0.1-500MPa for 10 minutes and subsequent stored for 7 days at 5℃, and the changes in the properties of it were investigated. Immeadiately after treatment high pressure had not any effect upon the freshness of meat, while had a distinct effect upon the color of it according to the intensity of pressure. During the post-pressured storage for 7 days at 5℃, however, high pressure has an important effect upon the changes in the freshness of meat measured by K-value. K-value in high pressure treated (300-500MPa) meat was better than that in non- or low pressure treated (0.1-200MPa) ones, which suggests an inactivation of enzymes related to ATP-breakdown at the pressure of around SOOMPa. The color change measured by metmyoglobin was somewhat occured in every meat after storing for 4 days, but after storing for 7 days it was not occured in high pressure treated (300-500MPa) ones, while a distinct change in low pressure treated (0.1-100MPa) ones was occured, which suggests an acceleration of autoxidation from oxy- and deoxymyoglobin to metmyoglobin in the meat treated by high pressure and subsequent inactivation of enzyme related to the autoxidation. From the lowest value in 200MPa treated meat after storing for 7 days it seems that 200MPa pre-treatment has the most effect on the red color retention of tuna meat.
