Groundnuts

The shell is a protective structure, and whether it stays on is a commercial decision with real consequences. In-shell lots are bulkier and cost more to move per unit of kernel, but the shell shields the kernel during handling and storage. Shelled kernels are denser to ship and are what most processors actually want, but they are exposed — once the shell is off, the kernel is vulnerable to mechanical damage, moisture uptake, and mould.

In-shell groundnuts

Pods traded whole, typically for roasting and snack markets; graded on pod appearance, fill, and freedom from damage as well as on kernel quality.

Shelled kernels

Kernels after shelling, graded on size and count, splits, and damage; the form bought by confectioners, peanut butter manufacturers, and crushers.

Blanched kernels

Kernels with the skin (testa) removed, a further processing step required by some food uses.

Market types — runner, virginia, spanish, and valencia among them — are traded as distinct articles because kernel size, shape, and roasting behaviour differ. A confectioner specifying large kernels and a crusher buying on oil content are not competing for the same lots.

Groundnuts are among the commodities most closely associated with aflatoxins, toxic compounds produced by certain Aspergillus species that can colonise the crop before harvest and continue to develop in inadequately dried or poorly stored lots. The association is well documented in the food-safety literature and is the reason groundnut supply chains are built around prompt drying, controlled storage, sampling, and sorting rather than around appearance alone.

Three points matter commercially. First, contamination is heterogeneous: it concentrates in a small proportion of kernels, which is why sampling design carries so much weight and why a clean sample does not certify a lot. Second, it cannot be reversed — a contaminated lot is managed by segregation and sorting, not repaired. Third, the risk is highest where drying is slow, storage is warm and humid, or kernels were damaged by insects or handling, which links this commodity directly to storage practice.

Groundnuts occupy an unusual position: they are both an edible nut and an oilseed, and the split between the two depends on the market. Where a confectionery and peanut butter industry pays a premium for sound, sized kernels, edible use takes the best lots and crushing takes what does not make grade. Where those industries are smaller, a larger share of the crop is crushed outright.

• Edible use — roasted and salted nuts, confectionery, and peanut butter
• Crushing — groundnut oil and groundnut cake, produced together
• Feed — cake as a protein feed; substandard lots diverted from food use
• Seed — retained or certified for planting

Diversion of food-rejected lots into feed is a real commercial pathway, but it is not an escape from the aflatoxin question: feed materials are subject to their own jurisdictional rules, and the fitness of such lots is determined by the applicable feed authority.

Groundnuts come out of the ground wet and must be dried without delay — this is the single most consequential step in the chain, and drying that is too slow permits mould development while drying that is too aggressive splits kernels and cracks skins. Once dried, lots are held cool and dry, kept away from moisture re-uptake, and protected from storage insects, whose damage opens kernels to fungal colonisation.

Sorting is a quality operation with a safety dimension for this commodity in a way it is not for cereals. Removing discoloured, shrivelled, damaged, and mouldy kernels is how lots are brought toward the specification a buyer requires, and electronic and manual sorting are standard in edible chains. Colour and appearance are used as proxies for a risk that cannot be seen directly, which is exactly why they are proxies and not proof.