Chapter 15 - Processing and Food Uses of Peanut Oil and Protein

Abstract

Peanut (groundnut, earth nut) oil production worldwide was about 5.4million metric tons and has remained fairly static over the past decade. In 2014, 291,000metric tons were crushed for oil (12%) in the US. A large portion of the US peanut crop is utilized as whole unshelled/salted peanuts and in peanut butter. Only four crushing plants in the US process peanuts into oil/protein with expeller pressing the technology of choice. Just one plant uses expellers followed by hexane extraction. Peanuts are a relatively high-oil oilseed (with about 50% oil) and the meal after expelling contains about 6–7% oil. Generally, the choice peanuts are used as confections (salted whole, in-shell). Lower grade peanuts are crushed for oil and meal. Processed (refined, bleached, deodorized) peanut oil is virtually free of aflatoxins, and the meal may contain traces of which 20parts per billion is the maximum allowed in virtually every country. Badly contaminated meal is disposed of and not sold for food or feed. Peanut meal is an excellent source of protein as flour, grits, concentrates, and isolates. Research has shown a number of potential uses in various food applications. Processing of peanuts into edible oil is reviewed. Peanut oil is an excellent food ingredient in many applications. Although more expensive than other commodity oils, the superior performance as a frying oil will ensure adequate supplies for the retail/food service sectors. Over the past several decades trait-modified peanut oils (high oleic acid) have been developed to enhance use in both food and industrial applications. The marked improvement in oxidative stability offered by high oleic peanuts and oil should stimulate commercialization. Industrial uses for high oleic peanut oil include engine lubricants, oleochemicals, and hydraulic fluids.