Assessment of Toxic Histamine Contents in Processed Cheeses and the Effect of Salt and pH Levels on the Amount of Histamine

Background: Histamine is a chemical released by the body's immune system in response to allergens, which causes messages to be sent between different cells. There is a significant amount of histamine in certain foods, such as fermented foods and alcoholic beverages. Food allergy reactions occur after consuming contaminated foods with high amounts of histamine. Due to increased consumption of processed cheeses over the past decade, this study aims to measure histamine in cheeses processed by some dairy factories in Tehran. Methods: Sixty-eight samples of four types of processed cheese (Mozzarella, Gouda, Cheddar, and Parmesan) from seven brands were randomly collected in Tehran city and transferred to the laboratory (January to March 2021). Histamine concentration was measured with a UV-Visible spectrophotometer at 600 nm. The pH and salt of the samples were also measured. Statistical analysis was done with SPSS software version 24. Results: The lowest concentration of histamine was found in Gouda soft cheese and the highest concentration was in Parmesan cheese. A significant difference was observed in the histamine concentration of different cheese groups. Histamine concentration was higher in Parmesan cheese samples, which may be due to its longer ripening period than other cheese groups. A significant relationship (p-value<0.05) was observed in the effect of pH and salt on the increase in histamine concentration. Conclusion: The average histamine in all cheese groups was higher than the limit of histamine concentration in fermented foods in the European Union (200 mg/kg). Considering the high concentration of histamine in cheeses, it is suggested to investigate its health and safety aspects for the health of cheese consumers.