Food Science and Quality Management www.iiste.org ISSN 2224-6088 (Paper) ISSN 2225-0557 (Online) Vol.68, 2017 16 Essential Amino Acid Quality Profile in Neglected and Underutilized Legumes (NULs) Isaac W. Ofosu 1* William O. Ellis 1 Kwabena Nsiah 2 Ibok N. Oduro 1 1. Department of Food Science and Technology, 2. Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi. Ghana West Africa Abstract A large number of consumers use plant-based products instead of animal-based products for their nourishment. This calls for a thorough investigation of the capacity of NULs to supply nutrients such as amino acids. Five different NULs protein extracts were profiled to ascertain the presence of the essential amino acids. In order to evaluate the quality, the essential amino acids from each of the NULs were matched against the standard FAO/WHO dietary indispensable amino acids for infants, children and adults. It was found that two of the NULs; Vigna sp. and Phaseolus sp. were the most promising, out of the five studied. Vigna sp. could supply adequate quantities of histidine (26.2 mg/g) for all the three age groups. However, isoleucine (35.9 mg/g) and the aromatic amino acid (phenylalanine + tyrosine) (94 mg/g) can supply adequate quantities for only children and adults. Lysine (53.6 mg/g) and threonine (44 mg/g) on the other hand, could be adequately supplied by Phaseolus sp. for at least, the adults’ requirement. If the digestibilities of the two NULs proteins were evaluated to ascertain the levels of the post-prandial amino acids, and the two NULs were complimented with cereals, the NULs flour could eventually supply the essential amino acids for consumers who use them as food. Keywords: Essential amino acids, Quality, Neglected legumes, 1. Introduction In the past, pre-historic man lived a substantially vegetarian life much against what was previously believed (Hardy et al. 2012). People still continue to maintain vegetarian life-styles, either for religious purposes or for health reasons (Singh et al. 2007). Many people, though, continue to derive their protein sources from eating meat (Ruby et al. 2016). In the recent past however, scientific studies have provided evidence in support of the risks associated with the consumption of animal products (Brinkman et al. 2014; Tuso et al. 2013; Key et al. 2004). It is this belief that drive consumers to search for alternative sources of protein. The search for alternative protein sources have led to a number of studies into single cell proteins (Saeed et al. 2016; Nasseri et al. 2011). The production of single cell proteins has its own problems such as indigestibility of some of the proteins, and high levels of nucleic acids, resulting in the production of uric acid (Adedayo et al. 2011). Other studies also suggest plant-based proteins as a possible alternative protein resource. However, plant products alone are not able to fully provide the quality and the quantities of amino acids needed to support the nutritional needs of consumers (Ghadge et al. 2008). It is therefore, no surprise how the question of eating or not eating meat, has divided many communities (Ruby et al. 2016). In spite of the seemingly inadequate protein quality of plant products, in many of our communities, consumers depend on NULs as a major food resource (Adu-Dapaah & Sangwan 2004). These indigenous NULs are cultivated and consumed in many forms, and the various end uses, are signals to the extent to which traditional legumes are deeply imbedded in the cultural diets of the people (Quasem et al. 2009). The cultivation of these indigenous legumes persists because they do not require any extra agricultural inputs that have cost implications for the subsistent farmer. It is for these reasons that the frontiers for protein resources should be expanded to cover these indigenous legumes which currently have very little industrial applications. A number of processes for improvements of protein quality, such as genetic engineering and traditional crop breeding (Luciani et al. 2005; Roesler et al. 1997; White et al. 2001; Falco et al. 1995; Galili et al. 2002) have been developed. However, additional gains can be made when some resources are committed to study the factors impeding wider utilization of neglected and underutilized crops. Generally, to ascertain the quality of protein, the essential amino acid profile, together with the digestibility and bioavailability of amino acids need to be determined (FAO/WHO 1990). Several techniques are available that can evaluate the quality of proteins, these include chemical score and protein digestibility corrected amino acid score (PDCAAS)(Schaafsma 2000). Chemical score defines protein quality by comparing the most limiting amino acid to the same type of amino acid in a standard or reference protein. The PDCAAS is obtained when chemical scores are multiplied by protein digestibilities (%). These techniques are theoretical quantification methods that suggest potential availability of test amino acids. As a food security resource, NULs are increasingly gaining acceptance because their production requires less water, land and energy, compared to farmed animals (Chivenge et al. 2015). This trend is largely influenced by a growing consumer market demand for plant-based products (MIG 2013) such as meat substitutes and non-