Macadamia nuts, otherwise referred to as bush nuts, are kernels that form from a fruit bearing tree, while the hazelnut is classed as an edible seed. Both types of nut are popular food items that can be eaten raw or cooked. Although each nut has its own unique size, colour, taste and texture, both contain a selection of minerals, proteins and essential fatty acids, making them part of a healthy balanced diet.
Hazelnuts have a round or oval shape and grow to a size that is approximately 10 to 15mm in diameter and 15 to 20mm in length. They have a medium brown coloured husk shell, while the kernel has a thin edible dark brown covering and is light cream in colour with a hollow centre. Macadamia nuts have a dark green shell, which develops into a brown colour after it is picked from the tree; the actual macadamia kernel is a creamy, off-white colour.
Macadamia nuts contain more saturated fat and calories than the hazelnut. One oz. of macadamia nuts has approximately 204 calories and 3.3g of saturated fat, compared to the hazelnut's 178 calories and 1.2g of fat. Both nuts have essential nutrients such as calcium, potassium, iron, magnesium, zinc and copper. They both contain vitamin B6 and vitamin E, while hazelnuts also contain a small amount of vitamin K. Macadamia nuts are toxic to dogs.
Macadamia nuts are the only plant food native to Australia; they are also commercially grown in Sulawesi, Indonesia. The two species that are grown for consumption are Macadamia integrifolia and Macadamia tetraphylla; the other macadamia species contain toxic ingredients that make them inedible for humans. Hazelnuts are commercially grown in Italy, Oregon and Washington, with the biggest worldwide producer being Turkey. There are over 20 species of hazelnut, each with its own unique flavour.
Both types of nuts can be eaten raw or used in cooking. The famous chocolate spread Nutella is made with processed hazelnuts, while macadamia nuts are an ingredient used in confectionery items and in baking. Macadamia oil is made from cold-pressing the macadamia nut, and it contains high levels of palmitoleic oil, making it a useful ingredient for cosmetic and skincare products such as moisturisers.