The hazelnut is a fruit of the hazelnut tree (Corylus), a tree that reaches some three to five metres high. They grow in the UK, Turkey, Spain, Italy and the USA, but is originally from Turkey. From the beginning of its growth, the hazelnut is protected by bracts that later form hard shells. As the nut ripens, the shell of the nut changes to a yellow orange. After when this happens the nuts are ready to be harvested[1].

Hazelnuts are used in confectionery to make praline, and also used in combination with chocolate for chocolate products. Hazelnuts can also be caramelised and used in products. Hazelnut oil, pressed from hazelnuts, is strongly flavoured and used as a cooking oil. Hazelnuts are rich in protein and unsaturated fat. They also contain amounts of thiamine, vitamin B6, and B vitamins[2].