Aspergillus flavus and aflatoxin contamination in the maize value chain and what needs to be done in Tanzania

Abstract

Maize (Zea mays L.) is a major dietary staple in Tanzania but is frequently prone to aflatoxin contamination (AC) caused mainly by Aspergillus species. The magnitude of AC is compounded by low input agricultural practices, improper handling and storage of grain, extreme weather conditions as well as inadequate knowledge and action in management of the problem. Moreover, stakeholders in Tanzania, notably smallholder farmers, are largely unaware of aflatoxins and the health and trade risks they cause. Due to the toxic nature of aflatoxins, their incidences and levels in different food commodities are strictly regulated in developed countries. However, strict regulatory control of AC in food commodities is difficult in Tanzania because the authority cannot effectively deal with widely scattered smallholder farmers who grow and consume their maize, while the rest of the population also obtain their food through numerous small scale processors. As such, AC continues to be one of the key mycotoxin challenges in East Africa, and Tanzania in particular because of its adverse effect on food safety and security. Despite the considerable research attention devoted to aflatoxin in the recent past, there is still room for strategic short-term interventions that could help to reduce AC in the country. Increased awareness among Tanzanians, and promotion of an integrated suite of intervention measures, hinged on host plant resistance and Aflasafe biocontrol, seems to be the ideal strategy that ought to be pursued for sustainable reduction of A. flavus and AC in maize. This review intends to shed more light to stakeholders about Aspergillus fungi and the conditions that favour maize colonisation and aflatoxin production as well as possible management strategies that can help smallholder farmers in Tanzania to reduce AC. The review ends with recommendations on what needs to be done in the short term.

Keywords

• Aflatoxin contamination
• Aflatoxin control
• Africa
• Aspergillus
• Food safety
• Maize