Hazelnut skin refers to the thin, papery layer that naturally encases the hazelnut kernel. This delicate covering is commonly observed on raw or lightly roasted hazelnuts, adhering closely to the nut’s surface.
Nutritional Compounds in Hazelnut Skin
Hazelnut skin contains several beneficial compounds, making it a source of various phytochemicals. It is particularly rich in antioxidants, including a range of polyphenols such as proanthocyanidins and flavonoids. These compounds are recognized for their capacity to neutralize free radicals, which can cause cellular damage.
The skin also contains tocopherols (a form of Vitamin E), which function as antioxidants. Dietary fiber is present in hazelnut skin, which supports digestive processes. The concentration of these compounds can vary based on the hazelnut variety and processing methods.
Flavor and Texture Impact
The presence of hazelnut skin influences the sensory experience of consuming hazelnuts. Tannins, naturally occurring compounds found in the skin, can impart a slightly bitter or astringent taste. This astringency creates a dry, puckering sensation in the mouth, contrasting with the inherent sweetness of the nut kernel.
Beyond taste, the skin also contributes a distinct texture. It is often described as papery or slightly chewy, which differs from the smooth, buttery, and rich texture of the peeled hazelnut kernel. For some culinary applications, this textural contrast may be undesirable, leading to skin removal.
Digestibility and Sensitivities
While generally safe for consumption, hazelnut skin can affect digestibility for some individuals. The tannins present in the skin may cause minor digestive discomfort. This discomfort is typically mild and not a widespread issue for most consumers.
The fiber content within the hazelnut skin contributes to overall digestive health, aiding in regular bowel function. Therefore, the decision to remove the skin often stems from personal preference regarding taste or texture, or a mild sensitivity, rather than a universal necessity for all individuals.
Techniques for Removal
Removing hazelnut skin is a common practice, particularly for culinary uses where a smoother texture or milder flavor is desired. The roasting method is highly effective because heat helps loosen the skin from the kernel. To do this, hazelnuts are spread in a single layer on a baking sheet and roasted at approximately 300-325°F (150-160°C) for about 10-15 minutes, or until fragrant and the skins begin to crack.
Once roasted, the warm hazelnuts are immediately transferred to a clean kitchen towel. The towel is then folded over the nuts, and they are rubbed vigorously, allowing the friction to slough off the loosened skins. For raw hazelnuts, a blanching method can be used, involving briefly boiling the nuts for about 30 seconds, then shocking them in ice water before rubbing them to remove the softened skins. Achieving complete skin removal is often not necessary for all recipes, as some preparations or personal preferences may incorporate the skin’s unique characteristics.