Cultivation, breeding and nutritional uses of groundnut

Abstract

The groundnut (Arachis hypogaea L.), also called a peanut, is an important food legume and oilseed crop of the tropical and subtropical worlds. They are presently grown on about 29 million hectares of land in about 120 countries in different agro-climatic zones between latitudes 40ºS and 40ºN from where about 49 million tons of groundnut pods are harvested every year. It is native to South America and presently cultivated mainly in Asia (11.5 m ha), Africa (16.7 m ha) and the Americas (1.4 m ha) in their arid to semi-arid regions. On a large scale it is grown mainly in India, China, Nigeria, USA, Sudan, Myanmar, Argentina, Chad, Senegal and Tanzania. It is consumed world-wide due to its high-energy, protein and mineral contents. It is eaten raw, after roasting, frying, salting or boiling and is used in many preparations and confectionery products and its demand is increasing. Groundnut requires a warm growing season with well distributed rainfall of 500-1000 mm and is now cultivated across a wide range of climates, mostly rainfed with one or two types of protective irrigation. Though the world’s average productivity of groundnut is around 1650 kg ha-1, about 40% of countries had productivity of less than 1000 kg ha-1 due to poor soil fertility and erratic rainfall, and only 29% of the countries show their productivity >2000 kg ha-1. India and China which account for about 33% of the area, produce more than 51% of the groundnut and are major consumers as well as suppliers. However, in most of the African countries groundnut is grown on marginal soil under low input, and need the immediate attention of researchers and policy makers. India, USA, Argentina and the Shadong province of China have been producing the best quality groundnut in the world and had export demand the world over. On average the groundnut seed contains 45% oil, 25% protein, 6% sugar, 9% fiber, 6% moisture and 2% minerals besides several vitamins and phytochemicals. The consumption of groundnut is decided mainly based on its oil, protein and sugar contents and broadly categorized as oil types and confectionary types. The vitamins and minerals present in the seed increased its importance as medicinal and nutraceutical. The characteristics for confectionary uses are High sound mature seeds (SMS), no aflatoxin contamination, attractive seed size and shape, pink or tan seed color, flavour, low oil (<45%), low (<1%) free fatty acid (FFA), high sugars (> 6%), high protein (>24%) blanchability (>60%) and high Zn (> 50 mg kg-1).