Impact of some Ghanaian local roasting methods on aflatoxin reduction in groundnuts (Arachis hypogaea L)

Abstract

Groundnut (Arachis hypogaea L) is an important cash crop in Ghana and a key component of many Ghanaians' diets. Groundnuts are mostly infected with aflatoxin, a secondary metabolite of the fungal species Aspergillus. The most popular form of traditional food processing of groundnuts is the application of heat, which involves boiling, baking, canning, frying, and roasting. This study characterized the effect of various local processing methods on aflatoxin levels in groundnut. Groundnut samples purchased from vendors in the Ho central market, Volta Region of Ghana, were processed by various local roasting methods viz- a- vis raw contaminated (control). High-Performance Liquid Chromatography connected to a fluorescence detector (HPLC-FLD) was used to determine the aflatoxin levels in the samples. The results revealed that through a combination of roasting + sand + pretreatment methods, the highest percentage of aflatoxin reduction of 97.38% was obtained. This was followed by the combination of roasting + sand – pretreatment (95.79%). Roasting + gari (a fermented partially gelatinized granular product) + pretreatment combination resulted in a percentage reduction of aflatoxins to 82.51%. Roasting + gari – pretreatment combination resulted in a percentage reduction of aflatoxins of 72.81% while Roasting with neither sand nor gari and without pretreatment resulted in an aflatoxin reduction of 43.62%. It was observed that the extent of aflatoxin reduction depended upon the duration of roasting of groundnuts as well as the type of roasting method used. The results of this research offer us the idea and extent of decontamination of aflatoxins in our foods by our local processing methods which will inform policymakers of the areas of prioritization when it comes to Food Safety.

Keywords

• Aflatoxins
• Roasting
• Local methods
• Physical treatment
• Heat
• Groundnuts