Pawel Malczewski
Types of nuts can be categorized using either botanical or culinary definition.
Types of nuts – Botanical definition
Botanical definitions vary depending on the source, making it even more confusing.
However, most of the botanical dictionaries agree with the following characteristics:
A nut is a dry fruit composed of a hard/woody covering (pericarp – a part of a fruit formed from the wall of the ripened ovary), with one seed inside, although it never opens to release its seed even after completing full maturity.
Botanical nuts are inedible by humans except for the hazelnut.
In the botanical sense, walnuts, almonds, macadamia nuts, coconut, cashews and pecans are not called nuts but “dry drupes”. (1)
A drupe is a fruit where the hard shell with a seed inside is surrounded by the fleshy part of the fruit.
Drupes are also stone fruit such as peaches, cherries, plums, etc., although these fruit have a fleshy rather than dry outside layer which distinguishes them from nuts.
Types of nuts – Culinary definition
Nuts in the culinary sense refer to any seeds with nut-like characteristics – fruit composed of large oily kernels (but not always e.g. chestnuts contain mostly carbohydrates) enclosed in hard covering.
Note on chestnuts
In spite of being considered as nuts, the culinary and the nutritional characteristics of chestnuts are quite different to other nuts. Actually, they resemble more whole grains in their carbohydrate to fat ratio.
Chestnuts can be a good substitute in a meal for carbohydrate components such as potatoes or rice.
Although the micronutrients (vitamin and minerals) contents are similar to other nuts, the main macronutrients are carbohydrates, instead of fat as in other nuts.
According to USDA’s National Nutrient Database, fat and protein contents in chestnuts are quite low as shown in the comparison table below. (2)
| Food | Carbohydrates (g) | Fat (g) | Proteins (g) |
|---|---|---|---|
| Chestnut | 14.8 | 0.6 | 0.9 |
| Walnut | 3.8 | 18.3 | 4.3 |
| Multigrain bread | 12.2 | 1.2 | 3.8 |
The definition or criteria can be sometimes harder to understand than simply becoming familiar with the list of culinary nuts as shown in the table below. (1)
Culinary nuts and their biological fruit type
| Nuts in a culinary sense | Fruit type (botanical definition) |
|---|---|
| Almond | Drupe |
| Brazil nut | Capsule |
| Cashew | Drupe |
| Chinese water chestnut | Corn |
| Coconut | Drupe |
| Hazelnut | Nut |
| Macadamia | Follicle |
| Peanut | Legume (bean) |
| Pecan | Drupe |
| Pine nut | Gymnosperm. A naked seed enclosed in a protective shell. |
| Pistachio | Drupe |
| Sweet chestnut | Follicle |
| Walnut | Drupe |
NUTRITION FACTS VS NUTRITION MYTHS
You will find a summary of the most common nutrition myths and evidence-based nutrition facts here.
