Fruits are excellent sources of nutrients such as minerals, vitamins and carbohydrates in the form of soluble sugars, cellulose and starch. They form a vital portion of an adequate diet and also serve as food supplement and appetizer. Rural populace in most developing countries consume fruits, seeds and leaves of many wild plants. There are instances where the leaves, seeds and fruit are used in the preparation of traditional native dishes (Feng, 2014). Economically, pawpaw (Carica papaya Linn.) is the most important fruit in the Caricaceae family with over 22 species while only one member of the genus Carica is cultivated as the fruit tree (Claudia et al., 2014). Pawpaw was originally derived from the southern part of Mexico, and it is a constant plant that is presently distributed over the  whole tropical area (Claudia et al., 2014). According to Food and Agriculture Organization

(FAO, 2007), it is an invaluable plant that is prevalent throughout tropical Africa and Nigeria was reported to be the third largest producer globally. It is eaten because of its nutritional value and its medicinal properties (Mello et al., 2008; Krishna et al., 2008). This also makes it of economic value. The fruit is an excellent source of calcium, pro-vitamin A, and vitamin C (ascorbic acid); thus, it is widely used in diets (Serrano and Cattaneo, 2010).

The seeds account for about 16 % of the fresh fruit weight and each seed is made up of sarcotesta and endosperm (Pungasari et al., 2004). Pawpaw seed extracts had been shown to have several medicinal as well as nutritional properties (Mello et al., 2008). Several species of Caricaceae have been used as medication against a variety of diseases (Mello et al., 2008). It had been argued by scientists that all parts of a pawpaw plant, including the seeds, roots, rinds, and fruits have positive effects on general health preventing diseases (Seigler et al., 2002). It is worthy of mention that fermented Pawpaw seed had been used to produce analogue product of the locally produced “Daddawa” normally produced from locust beans as reported by Dakare et al.(2011).

The chemical composition of these seeds reported by Pungasari et al. (2004) revealed that they are rich in proteins content (27.3-28.3%). Previous studies on Carica papaya seed had focused on the seed functional properties (Adesuyi and Ipinmoroti, 2011), physiochemical properties (Claudia et al., 2014), antioxidant properties (Maisarah et al., 2014), amino acid profiling (Samia et al., 2012), proximate analysis (Adesuyi and Ipinmoroti, 2011) and oil (Syed et al., 2012). A more efficient method of utilizing oilseed flour is to process its flour into protein concentrate and isolate products with high protein content and desirable functional characteristics (Molina-Ortiz et al., 2004). In view of the protein content of pawpaw seed reported by previous studies, processing the whole flour to protein rich products such as defatted flour, protein concentrate and protein isolate could enhance its utilization as protein supplement. Presently, there are no literatures on the production and utilization of the defatted flour, protein concentrate and protein isolate from pawpaw which necessitated this study. However, the performance of any protein as functional ingredients in food processing will depend on the physicochemical, functional and nutritional characteristics of the protein products, hence the objectives of this study.