Functional Uses of Peanut (Arachis hypogaea L.) Seed Storage Proteins

Peanut (Arachis hypogaea L.) is an important grain legume crop of tropics and subtropics. It is increasingly being accepted as a functional food and protein extender in developing countries. The seed contains 36% to 54% oil, 16% to 36% protein, and 10% to 20% carbohydrates with high amounts of P, Mg, Ca, riboflavin, niacin, folic acid, vitamin E, resveratrol and amino acids. Seed contains 32 different proteins comprised of albumins and globulins. The two-globulin fractions, arachin and non-arachin, comprise approximately 87% of the peanut seed proteins. Peanut worldwide is mainly used for oil production, consumption as raw, roasted, baked products, peanut butter, peanut flour, extender in meat product formulations, confectionary and soups. Peanut proteins have many properties such as good solubility, foaming, water/oil binding, emulsification that make them useful in various food products. Very limited studies have been carried out in peanut functional properties, which has been reviewed in the present article. Adequate modifications can be done in protein functionality that are influenced by pH, temperature, pressure etc. However, some individuals develop severe IgE-mediated allergies to peanut seed proteins. Thus, methods to improve nutrition and reduce allergenicity have also been discussed. Within the last decade, manipulations have been done to alter peanut chemistry and improve nutritional quality of peanuts and peanut products. Hence, improved comprehensive understanding of functional properties and nutritional chemistry of peanut proteins can generate better source of food grain to meet nutritional requirement of growing population. In the present review, composition of peanut seed proteins, functional properties, nutritional components and nutraceutical value have been discussed with respect to beneficial aspects to health, reducing hunger and usage in food end products.