What the origin supplies
Ukraine is a significant walnut origin and a growing one for hazelnut, alongside established volumes in sunflower, pumpkin, hemp, flax and sesame kernels. The commercial character of the two groups is different enough that they are usually bought by different desks.
Tree nut kernels – walnut and hazelnut – are graded on colour, presentation form and size, and priced primarily on colour. They carry an aflatoxin obligation that dominates the compliance file.
Seed kernels – sunflower, pumpkin, hemp, sesame, flax – are graded on purity, hull content, oil content and size, and the dominant technical risk is oxidation rather than mycotoxin. Hulled grades in particular have lost the seed coat that carried their natural antioxidant protection.
The grading conventions
There is no EU regulation that grades kernels. The UNECE standards for dry and dried produce are commodity-specific and set out presentation forms, quality classes, sizing and defect tolerances; the International Nut and Dried Fruit Council provides the industry’s own reference for sampling practice and defect vocabulary. Both are trade conventions, and a contract that does not name the standard and the class has not invoked them.
What is law is the safety layer underneath: aflatoxin maximum levels in Commission Regulation (EU) 2023/915 with sampling and analysis methods in Commission Implementing Regulation (EU) 2023/2782, and residues under Regulation (EC) No 396/2005. A higher grade carries no safety advantage.
The three things a kernel contract must contain
- Grade. The standard named, the class named, the colour grade referenced to a physical sample under stated lighting, the presentation form with a minimum percentage, and shell fragments given as a count per unit weight with the removal sequence described.
- Stability. Moisture and water activity together with methods, plus peroxide value and free fatty acids with the measurement point named.
- Conditions. The barrier packaging specification, the temperature ceiling in transport and storage, and the responsibility split for excursions.
The aflatoxin file
Aflatoxin contamination is carried by a handful of kernels per tonne, which means the variance of the sampling step dwarfs the variance of the analysis. Commission Implementing Regulation (EU) 2023/2782 prescribes incremental sample counts by lot weight, aggregate sample mass, sublot structure and comminution, and it is the instrument that matters most in this category. A certificate from an excellent laboratory on a badly drawn sample is worth very little.
Where to start
The grading and oxidation guide covers the specification and storage side in full, and the aflatoxin management guide covers the compliance side. Product records for the individual kernels set out the parameters line by line.