Histamine formation and microbiological changes in endemic Chalcalburnus tarichi Pallas 1811 (Inci Kefali) stored at 4 °C

The ingestion of foods containing substantial amounts of histamine is the cause of food poisoning episodes, a type of foodbome illness cornmonly associated to consumption of scombroid fish such as tuna and mackerel and some nonscombroid fish such as bluefish or mahi-mahi that have begun to spoil by the growth of particular types of bacteria (Merson et al 1974, Beling and Taylor 1982, Hughes et al 1991). Biologically active amines have been found in many foods such as fish and fish products (Merson et al 1974, Shalaby 1994, Becker et al 2001). Biogenic amines are organic bases with an aliphatic, aromatic, or heterocyclic structure that has been found in many foods that include fish and fish products, cheese, wine, beer and other fermented foods (Stratton et al 1991, Hemandez-Jover et al 1997). Histamine is formed by bacterial enzymatic decarboxylation of histidine during the final steps of protein breakdown (Koehlerand Eitenmiller 1978). Bacterial strains known to be capable of histamine production include Escherichia, Enterobacter, Pseudomonads, Salmonella, Shigella, Clostridium perfringens, Streptococcus, Lactobacillus and Leuconostoc (Edwards and Sandine 1981, Chang et al 1985, Stratton et al 1991, Santos et all998). Histamine may be involved in the onset of migraine attacks in susceptible subjects and may produce hypertensive crises in patients treated with monoamine oxidase inhibitor-type drugs (Khalid and Marth 1990). In addition to its toxicological properties, histamine is of interest as an indicator of food quality (Bover-Cidet al 2001, Ekici et al 2004) and of food spoilage (Valsamaki et al 2000). The minimal concentration of histamine in foodstuffs that would elicit a toxic response has been estimated to be 100mg/100g(Taylor et al l978). Fish are of great importance for human nutrition worldwide. Non-pathogenic and pathogenic bacteria have been found on the skin, gills and intestines of fish (Feldhusen 2000). Lake Van is the largest soda lake and fourth largest closed lake on earth. It is situated at 1, 648 m above sea level in Eastern Anatolia, Turkey. Many springs and freshwater rivers flow into this lake. Its high carbonate content makes it extremely alkaline, with a pH = 9, 8that is unsuitable for many fresh water species with exception of a fish locally known as "Inci Kefali" or Pearl Mullet, Chalcalburnustarichi, a memberof the cyprinidae family (Arabaci and Sari 2004). To date, there is no detailed information available on histamine formation and microbiological quality of Inci Kefali. The purpose of this study was to measure the amountofhistamine and microbiologicalchanges in pearl mullet for 15 days while stored at 4 °C to determine if this is a safe practice for handling this product, in order to evaluate whether the level of histamine and micrabial count would pose a health hazard.