Incidence of aflatoxin in peanuts (Arachis hypogaea Linnaeus) from markets in Western, Nyanza and Nairobi Provinces of Kenya and related market traits

Abstract

Fungal contaminants in major food staples in Kenya have negatively impacted food security. The study sought to investigate peanut market characteristics and their association with levels of aflatoxin in peanuts from Western, Nyanza and Nairobi Provinces of Kenya. Data were collected from 1263 vendors in various market outlets using a structured questionnaire, and peanuts and peanut products from each vendor were sampled and analyzed for aflatoxin levels. Thirty seven per cent of the samples exceeded the 10 μg/kg regulatory limit for aflatoxin levels set by the Kenya Bureau of Standards (KEBS). Raw podded peanuts had the lowest (χ2 = 167.78; P < 0.001) levels of aflatoxin, with 96% having levels of less than 4 μg/kg and only 4% having more than 10 μg/kg. The most aflatoxin-contaminated products were peanut butter and spoilt peanuts, with 69% and 75% respectively, exceeding 10 μg/kg. A large proportion of peanuts in the country (44%) were traded through informal open air markets; 71.8% of products from supermarkets were safe according to KEBS and the EU regulatory limits, while only 52% from informal markets met this threshold (χ2 = 95.13; P < 0.001). Packaging material significantly (χ2 = 73.89; P < 0.001) influenced the amount of aflatoxin in the product, with the majority (68%) of peanut samples that were stored in plastic jars having >10 μg/kg of aflatoxin. Over 70% of all storage structures were poorly ventilated and dusty. Sorting comprised 53% of the various crop protection measures used by traders post-harvest. To reduce aflatoxin exposure to consumers, set standards need to be complemented by strict monitoring systems and education of producers, processors and consumers in crop commodities other than maize, which has received the most attention in Kenya. Alternative uses of contaminated produce need to be explored.