Preparation and Keeping Quality of Vacuum-Packed and Seasoned-Dried Filefish Products

Abstract

Vacuum-packed and seasoned-dried products of filefish Navodon modestus, caught in large quantities off the coasts of Japan and Korea, were prepared tentatively and stored at 35°C for 3-4 months to test their keeping quality. Headed, eviscerated, and skinned filefish were purchased from Tokyo Central Whole Sale Market and filleted. The fillets were flavored with seasoning powders prepared from sugar, sorbitol, salt, glutamate, 5'-ribonucleotide, and either beef flavor (Flava-Beef, Kyowa Hakko Kogyo Co. Ltd.), red pepper, or Smoke flavor (Smok-EZ, Alpha Foods Co. Ltd). After seasoning, the fillets were dried at 39-41°C for several hours, vacuum-packed in plastic film bags, and cooked in water at 80°C for 40min. Two kinds of products different in moisture level were prepared; one contained moisture of 26-29% and the other 40-46%. The moisture level, water activity, color value (L, a and b values), texture, and viable counts of bacteria of these products were determined during storage at 35°C. The results showed that the products could be preserved in good condition for 3-4 months at 35°C, though they slightly decreased in softness with a decrease of moisture content and developed a pale brown during storage. Judging from organoleptic evaluation on their flavor, the products containing beef flavor as a seasoning were most desirable.