Thirteen-year surveillance of aflatoxin contamination in nuts and nut products in Kenya (2012–2024)
Aflatoxin contamination in peanuts and tree nuts remains a persistent public health and food safety concern across Africa, including Kenya. Associated with hepatocellular carcinoma, acute toxicity, and exacerbation of conditions such as hepatitis B, aflatoxins pose severe health risks and significant economic burdens. This study provides a 13-year (2012–2024) evaluation of total aflatoxins and aflatoxin B1 in peanut kernels, peanut butter, cashew nuts, and macadamia nuts in Kenya. A total of 2,178 data points were analyzed for conformity with national (10 μg/kg) and international Codex (15 μg/kg) regulatory limits. Peanut kernels exhibited the lowest compliance, ranging from 50–62% (10 μg/kg) and 50–66% (15 μg/kg). Peanut butter performed moderately better, with compliance levels of 61–86% and 65–89%, respectively. In contrast, cashew and macadamia nuts consistently demonstrated >95% compliance across all years, with macadamia achieving 100% compliance. Although compliance rates were slightly higher under the Codex standard, statistical analysis revealed no significant difference (p > 0.05). These findings highlight the critical need to strengthen surveillance systems beyond formal markets to include informal outlets and farm-level production, particularly for peanuts. Enhanced pre- and post-harvest management, together with coordinated value chain interventions and stakeholder collaboration, will be essential to reducing aflatoxin risks and safeguarding both public health and trade in Kenya's nut sector.
1 Introduction
Edible nuts and seeds, including peanuts, cashews, almonds, coconuts, hazelnuts, macadamia, and others, are widely valued for their nutritional and health benefits. They are rich in proteins, lipids, essential minerals, antioxidants, fatty acids, and vitamins, contributing to reduced cardiovascular risk, improved metabolic regulation, and other protective effects (Brar and Danyluk, 2018; Moreda-Piñeiro et al., 2016). Global demand for these commodities continues to rise, with tree nut production nearly doubling over the past two decades, reaching 5.97 million metric tons in 2024/25, led by almonds, cashews, and walnuts (INC, 2024). Peanut production, likewise, remains strong at 50 million metric tons (United States Department of Agriculture, 2024). In Kenya, nuts also hold growing economic importance, with macadamia emerging as a leading export crop (Horticultural Crops Directorate, 2022; Agriculture and Food Authority-Nuts and Oil Crops Directorate, 2024).
Kenya's nut sector shows contrasting patterns in domestic consumption, export orientation, and the economic effects of aflatoxin contamination. Peanuts are predominantly a domestic commodity, with annual production ranging from about 12,900 to 56,000 MT between 2012 and 2024. Because production consistently falls short of demand, Kenya imports large volumes—peaking at over 19,500 MT in 2021—to close the consumption gap. No peanut exports occur, indicating nearly 100% local consumption. Cashew nuts show moderate production, declining from 29,026 MT in 2012 to 7,803 MT in 2024. Exports of shelled cashews remain small (97–544 MT annually), meaning most cashews are consumed locally, though occasional imports such as in 2024 supplement the domestic market. Macadamia nuts are Kenya's most export-oriented crop, with production rising sharply to nearly 49,200 MT by 2024. Exports of shelled and dry in-shell nuts frequently exceed 15,000–18,000 MT combined in recent years, indicating that a substantial share of production is sold abroad.
