Histamine intoxication, known as scombroid fish poisoning, is caused by the consumption of foods with high levels of histamine. This biogenic amine is formed as a result of histidine decarboxylation by bacterial decarboxylases present in food, including fish and fish products. The aim of this study was to investigate the content of histamine at different production stages of canned, marinated and smoked fish.

Histamine is one of the most important and toxic biogenic amines which may be present in food and may cause food poisoning in humans when contained at a high level. It is produced during bacterial decarboxylation of histidine in fish muscles. The aim of the study was to investigate the presence of histamine in fish and fish products available in Poland during 2014–2018.

Twenty-five samples of canned fish (tuna and mackerel), frozen fish (mackerel and mazelli) as well as smoked fish (herring); five samples of each were randomly collected from different localities of Alexandria city. Collected samples were subjected to biogenic amine examination. Histamine and Tyramine were determined by HPLC. The highest average value (mg/100g) for histamine was 6.94 (canned tuna) and the lowest was 0.76 (Frozen Mazelli), the respective values for Tyramine were 1.63 (canned tuna) and 0.06 (frozen mazelli) mg/100g. For improvement the quality of raw fish (fresh sardine, 10 kg) during preparation the fresh sardine prior chilling or freezing was dipped into crude potato extract (as protease inhibitor) to reduce biogenic amines production. In order to test the effect of heat treatment on the concentration of the biogenic amines in fish (Frozen mackerel and sardine) were subjected to oven baking at 1506 C for 20 min. This showed high reduction in the percentage of biogenic amine production due to heat treatment. The public health significance of the biogenic amines as well as the suggested measures for improving the quality of produced products has been discussed

In this study, the detection of biogenic amines in fresh and products of fish is focused and biological trials have been used to reduce their levels. 120 random samples of fresh fish (Lates niloticus), sardine salted, herring smoked, and tuna canned (for every thirty samples) were collected from different markets in Shibine, Menoufia, Egypt. The biogenic amine residues have examined in all samples that were collected (histamine, putrescine, cadaverine and tyramine). The average levels of biogenic amines in the samples under investigation of fresh fish, canned tuna, herring smoked, and sardine salted are 10.74 ± 0.54, 15.08 ± 0.76, 17.93 ± 0.81 and 26.12 ± 0.89 mg % for histamine, 7.61 ± 0.49, 11.13 ± 0.57, 14.35 ± 0.64 and 19.59 ± 0.81 mg% for putrescine, 5.96 ± 0.43, 10.22 ± 0.49, 12.41 ± 0.58 and 16.85 ± 0.62 mg% for cadaverine each, accordingly. Finally, the tyramine mean value was 2.05 ± 0.10 mg % in fresh fish, 6.37 ± 0.19 mg % in tuna canned, 7.9 ± 0.24mg % for herring smoked and10.44 ± 0.27 mg % for sardine salted. Fish fillets were experimentally inoculated with B. polymyxa culture (2x107), the effect was ideal, the level of histamine reduced to 31.4 mg/kg after eight hours, 19.5 mg/kg after 12 hrs and 12.8 mg/kg 24 hours later with reduction percentages of 37.2%, 61.0%, and 74.4%, respectively and cadaverine level reduced to 22.1 mg/kg after 8 hours, 15.4 mg/kg after 12 hrs and 9.7 mg/kg 24 hrs later with reductions percentages were 26.3%, 48.7%, and 67.7%, respectively.

Fish and fish products represent major contributors to supply humans with part of their needs of the essential amino acids, vitamins, minerals, omega -3-fatty acids, and other needed micronutrients. However, fish and fish products are highly perishable foods that can easily spoiled and decomposed, possibly because of its cross contamination from the surrounding environment. Fish attracts a vast array of microorganisms, of these; mould and yeast represent a major sector of these microbiota, which by turn van lead to rapid decomposition of fish or even produce several toxicological implications if ingested. In this review, we will highlight the available literature about mould contamination of fish and fish products with a special reference to its public health significance.

In the aquatic environment, pollution with heavy metals is a major issue. Some of them are essential heavy metals because they play biological roles for aquatic organisms. Other heavy metals, however, are regarded as dangerous even at low concentrations. Heavy metal levels that are harmful may be caused by industrial, mining, and agricultural operations. Water contamination and changes to the physicochemical properties of the aquatic environment will result from this. The harmful toxic consequences of this pollution on fish raise questions about its possible impacts on human health. The most prevalent heavy metals are arsenic, cadmium, lead, and mercury, which are systemic toxicants and have an impact on human health. These metals are classified as carcinogens by the United States Environmental Protection Agency and the international agency for research on cancer because they cause organ damage even at low exposure levels. This review was created to contribute to the understanding of the environmental impact, toxicology, and consequences of heavy metals on fish.