Hazelnuts
About Hazelnuts
Hazelnuts, kernel only. The shelled kernel of the hazel (Corylus avellana), known as cobnut when grown commercially in the UK. Eaten plain, in baking, in chocolate confectionery and as the basis of hazelnut spreads.
Per 100g, hazelnuts are a strong source of:
- Vitamin E: one of the most concentrated food sources.
- Manganese, copper and magnesium.
- Biotin (B7) and folate (B9).
Hazelnuts are calorie-dense (around 650 kcal per 100g) and high in unsaturated fat (mostly monounsaturated, similar to olive oil).
Hazelnuts in more detail
The hazel is one of the few nut trees genuinely native to Britain, and hazelnuts — cobnuts and filberts — have been eaten here since the Mesolithic. Kentish cobnuts are still grown commercially and sold fresh and green in late summer, which is a quite different product from the dried nuts available year-round.
Fresh cobnuts are milky, soft and sweet with a high moisture content, and they do not keep. Dried hazelnuts are the concentrated version: firmer, more strongly flavoured, and stable for months.
Roasting is the step that matters. Hazelnuts have a bitter, papery skin that clings, and the standard method solves both problems at once: roast at 180 °C for 10–12 minutes until fragrant, then tip them into a clean tea towel and rub vigorously. The skins come away, and the roasting has developed the pyrazines that give roasted hazelnut its characteristic aroma. Raw hazelnuts taste comparatively flat, which is why almost every classical use — praline, gianduja, dukkah, Piedmontese cake — specifies them roasted.
Allergy note: hazelnut is one of the most common tree-nut allergies in Europe, and it cross-reacts frequently with birch pollen — people with birch pollen hay fever often get oral itching from raw hazelnuts while tolerating roasted ones, because the responsible protein is heat-labile. That is a real pattern but not a safe general rule, and anyone with a diagnosed nut allergy should not test it.
Nutrients worth knowing about
Per 100 g, this page's panel shows Vitamin E at 25 mg (about 625% of the adult reference intake), Manganese at 4.9 mg (350%), Copper at 1.23 mg (103%), Phosphorus at 300 mg (55%), Magnesium at 160 mg (53%), Vitamin B1 (Thiamin) at 0.43 mg (43%), Vitamin B6 (Pyridoxine) at 0.59 mg (42%), Vitamin B7 (Biotin) at 76 µg (38%), Vitamin B9 (Folate / Folic acid) at 72 µg (36%), Vitamin B3 (Niacin) at 5.1 mg (30%), Zinc at 2.1 mg (22%), Iron at 3.2 mg (22%) and Calcium at 140 mg (20%).
Hazelnuts are among the most monounsaturated-rich nuts — of 63.5 g total fat per 100 g, only 4.55 g is saturated, a profile closer to Olive Oil than to most nuts. That, plus 6.5 g of fibre and 14.1 g of protein, is a genuinely good composition at 650 kcal per 100 g.
Other nuts
Micronutrients (per 100g, raw)
| Nutrient | Amount | % adult reference intake |
|---|---|---|
| Minerals | ||
| Iron | 3.2 mg | 22% |
| Calcium | 140 mg | 20% |
| Magnesium | 160 mg | 53% |
| Potassium | 730 mg | 21% |
| Sodium | 6 mg | 0% |
| Chloride | 18 mg | 1% |
| Phosphorus | 300 mg | 55% |
| Zinc | 2.1 mg | 22% |
| Copper | 1.23 mg | 103% |
| Manganese | 4.9 mg | 350% |
| Iodine | 17 ug | 12% |
| Selenium | 2 ug | 3% |
| Vitamins | ||
| Vitamin A | 0 ug | 0% |
| Vitamin C | 0 mg | 0% |
| Vitamin D | 0 ug | 0% |
| Vitamin E | 25 mg | 625% |
| Vitamin K | not measured | . |
| Vitamin B1 (thiamin) | 0.43 mg | 43% |
| Vitamin B2 (riboflavin) | 0.16 mg | 12% |
| Vitamin B3 (niacin) | 5.1 mg | 30% |
| Vitamin B5 (pantothenic acid) | 1.51 mg | 22% |
| Vitamin B6 | 0.59 mg | 42% |
| Vitamin B7 (biotin) | 76 ug | 38% |
| Vitamin B9 (folate) | 72 ug | 36% |
| Vitamin B12 | 0 ug | 0% |
Source: CoFID 2021 (McCance and Widdowson, UK), code 14-874 (matched record: "Hazelnuts, kernel only"). N = present but not quantified; Tr = trace; not measured = no value in the source.
What this food is a source of
High in by content (per 100g): Vitamin E (625%), Manganese (350%), Copper (103%), Phosphorus (55%), Magnesium (53%), Vitamin B1 (thiamin) (43%), Vitamin B6 (42%), Vitamin B7 (biotin) (38%), Vitamin B9 (folate) (36%), Vitamin B3 (niacin) (30%).
A source of by content (per 100g): Zinc (22%), Iron (22%), Vitamin B5 (pantothenic acid) (22%), Potassium (21%), Calcium (20%).
These figures are the amount in the food. How much the body absorbs can vary, see each nutrient's entry for detail.