Influence of Salt Concentration on Histamine Formation in Fermented Tuna Viscera ( Dayok)

Abstract

The formation of histamine in fermented tuna (Thunnus albacares) viscera (dayok) at different salt concentrations (10%, 17.5% and 25%) for 7 days at ambient temperature was investigated. Effect on chemical and microbiological changes on tuna viscera were monitored. Results demonstrated that the levels of pH, lactic acid, amino nitrogen and total volatile base nitrogen (TVB-N) increased as time of dayok fermentation progressed. The total plate count and lactic acid bacteria count decreased with increasing salt concentration. Histamine levels decreased during fermentation as salt concentration increased. Histamine levels above FDA standard limit of 50 ppm are formed at low salt concentration (10%) with a total plate count of 107 cfu/g. Results revealed that application of salt concentration greater than 17% can minimize the formation of histamine.