Gel Forming Ability and Other Properties of Eleven Underutilized Tropical Marine Fish Species

Abstract

The gel forming ability and other characteristics of the mince of 11 underutilized marine fish were studied. They were Bombay duck, silverbelly, sea catfish, silver jewfish, jewelled shad, queenfish, Spanish mackerel, hardtail, Indian tuna, tripletail and false conger eel. Mince was prepared from fillet and a portion of the mince was washed two times with cold water (5°C) containing 0.1% NaCl. Both washed and unwashed mince were ground with 3% NaCl. Ground paste was then stuffed into plastic tube and heated for one- and two-step heating. In the one-step heating, the tubes were subjected to 25°, 30°, 35°, 40°, 50°, 60°, 70° and 80°C for 60, 120 and 180 min. In the two-step heating, the tubes were pre-heated at 25°, 30°, 35°, 40°, 50°, 60°, 70° and 80°C for 60, 120 and 180 min. After the pre-heating, the tubes were immediately subjected to 85°C for 30 min. The gel was subjected to puncture, folding, expressible moisture and sensory tests.

Two-step heating distinctly improved the gel strength compared to the one-step heating. The improvement due to two-step heating was more at low preheating temperatures from 25-35°C. Washing improved the texture and color of all of the gels except Bombay duck and decreased the extent of gel-disintegration in silverbelly, queenfish, sea catfish and hardtail. The gels were set optimally at 35°-40°C for most species. Species variation in the disintegration of the gels was observed. Bombay duck mince produced very weak gel. Neither two-step heating nor washing could improve the gel quality of Bombay duck mince. Our data suggested that jewelled shad, queenfish, silver jewfish, sea catfish, tripletail and false conger eel could be suitable as the material for surimi.

Key Words:

• Underutilized species
• surimi
• washing of mince
• two-step heating
• gel forming ability