Properties and Industrial Potential of Walnut Growing in Nigeria

Abstract

African walnut (Tetracarpidium conophorum) is one of the underutilised plant species in Nigeria.  It is often found growing wild as a climber in the forest region of Africa and India.  The vine is mostly found between 4^o 15^N and 8^N of the equator where it is usually cultivated by subsistence farmers. The fruit is a very good source of vitamins A, B, B2, B6 and E and of minerals, such as foliate, sodium, potassium, manganese, copper, chloride, iron and ascorbic acid.  The immature fruit is a good source of vitamin C.  The nut is a good source of carbohydrate (16.9%) and calories of about 600J.  The protein content ranged between 3.1% - 43.1%.  It is an excellent source of polyunsaturated acids such as alpha linolenic acid (ALA) and an excellent source of anti-inflammatory omega 3 essential fatty acids.  The oil content is very high at about 60%.  The nuts which contain uncommon fatty acids are used in protective coatings, dispersants, pharmaceuticals, cosmetics and a variety of synthetic intermediates.  It is also used as stabilizers in plastic formulations.  It is very rich in ascorbic acid.  The oil is good for soap making and it competes favourably with edible oils. Alkyd resins produced from walnut oil compared with commercial alkyd resin as its film air dried within a few hours and show chemical resistance to various solvent media such as water, brine and acid.  The plant also has a number of health benefits.  Photochemical analysis of the nuts, leaves and roots showed that they contain bioactive compounds such as oxalates, phytates, tannins, saponins, alkaloids, flavonoids and terpenoids and are used in wound healing, disease prevention and as anticancer agents. The development of walnut for industrial use locally will save the nation about US$200 million annually apart from providing employment for the citizens.  It will also act as a vehicle for poverty alleviation.

Keywords: Walnut, Sodium, Potassium, Oil, Monosaturated Fats.