Storage Temperature Effect on Histamine Formation in Big Eye Tuna and Skipjack

Abstract

ABSTRACT Notable histamine formation (>30 mg/100g) was detected in big eye tuna ( Thunnus obesus ) and skipjack ( Katsuwonus pelamis ) captured in Azorean waters and stored for 1,3 and 6 days at 22,10 and 4°C, respectively. Higher levels ( p <0.05) of histamine were produced by skipjack reflecting its higher histidine content. Measurements of pH or volatile basic nitrogen were not adequate for estimating the extent of histamine‐related health hazard. Counts of histamine‐forming bacteria increased during storage at 4 and 10°C, and histamine formation was suppressed at 4°C. Storage temperature and histidine content were the main factors controlling histamine levels in tuna.