Poonsuk Prasertsan and Thiraratana Prachumratana

pp. 77 - 86

Abstract

Properties of visceral enzymes from yellowfin tuna (Thunnus albacares), skipjack tuna (Katsuwonus pelamis) and tonggol tuna (Thunnus albacares) were studied. The crude enzymes from viscera of yellowfin tuna and skipjack tuna exhibited the highest activities at pH 10.0 whereas it was at pH 9.0 for those from viscera of tonggol tuna. The enzymes were the most stable at their optima pH after 120 min incubation. The optimum temperatures for protease and lipase activities were at 50°C and 60°C, respectively but the extracted enzymes were more stable in the temperature range of 37- 40°C. The protease and lipase from spleen were the most thermostable with the half-life of 120 and 90 min at 60°C incubation, respectively. Protease activity from spleen accounted for 45.6% of the total protease activity of the whole tuna viscera.