Levels of aflatoxins in spices produced and/or marketed in Zanzibar and Arusha

Aflatoxins are a family of toxins produced by fungi species known as Aspergillus flavus and Aspergillus parasiticus. They invade various agricultural crops like maize (corn), oilseeds such as sunflower, groundnuts, cotton seeds, cashew nuts and spices when produced or kept under unfavorable conditions. The growth of aflatoxins producing fungi is favored at high temperature ranging from 25to 35°C and a relative humidity of 77 - 90%. Four aflatoxins (AFBi, AFB2, AFGi and AFG2) are common in foods and feeds with AFBi being regarded as the most toxic. Spices are substantial constituents in cooking, widely used as medicine and in cosmetics. In this study, 84 samples of spices (black pepper, turmeric, cardamom and garlic) collected from markets, stores and farms in Zanzibar, and Arusha were analyzed for the levels of aflatoxins. Samples were analyzed using high-performance liquid chromatographic (HPLC) system, coupled with fluorescence detector. The results obtained indicated that 64 samples (76%) were contaminated with aflatoxins of which 4 samples (5%) of cardamom exceeded the maximum tolerable limit for total aflatoxins (TAF) of 10 ngg'1.The mean levels of aflatoxins in most of the analyzed spices in each site did not exceed the maximum tolerable level of 10 ngg"1 set by European Commission/Tanzania Bureau of Standards (EC/TBS) for TAF in spices. A total of 7 (8.33%) samples out of all analyzed spice samples were found to be contaminated with Aflatoxin B\ exceeding the maximum tolerable limit of 5 ngg'1 set by EC/TBS.