Histamine in Fish Products Randomly Collected in Southern Italy: A 6-Year Study.

In total, 4,615 fresh and processed fish samples collected from 2010 to 2015 were analyzed for histamine by ultrahigh-performance liquid chromatography with diode array detection. Histamine levels were detected in 352 (7.6%) samples, with a maximum of 4,110 mg kg(-1) and mean values of 908.9 +/- 1,226.79 and 344.01 +/- 451.18 mg kg(-1) for fresh and processed fish samples, respectively. No histamine levels were found in canned tuna and smoked fish samples in contrast to most of the data reported in the literature. A low percentage (2.79%) of noncompliant samples was found. The highest mean values were found during 2011 and 2015 for fresh and processed fish samples, respectively, showing a significant (P, 0.05) difference between the sampling years. The histamine contents found in fresh fish samples were significantly higher (P, 0.05) than those of processed samples. Most of the positive samples came from street vendors, suggesting the need to improve inspection measures in these commercial categories to ensure fish product safety.