EFFECTS OF COOKING AND FERMENTATION ON THE CHEMICAL COMPOSITION, FUNCTIONAL PROPERTIES AND PROTEIN DIGESTIBILITY OF SANDBOX (HURA CREPITANS) SEEDS OMOLAYO R. OSUNGBADE 1 , OLASUNKANMI S. GBADAMOSI 1 and OLADIPUPO Q. ADIAMO 1,2,3 1 Department of Food Science and Technology, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria 2 Department of Food Science and Nutrition, King Saud University, Riyadh, Kingdom of Saudi Arabia 3 Corresponding author. TEL: 196-65-514-220-192; FAX: 196-65-514-220-192; EMAIL: adiamodipo@yahoo.com Received for Publication October 3, 2015 Accepted for Publication February 2, 2016 doi:10.1111/jfbc.12273 ABSTRACT The effects of cooking and natural fermentation on the chemical composition, functional properties and protein digestibility of Hura crepitans seeds were investigated. The results showed a high protein content and in vitro protein digestibility which increased with cooking (at 100C) and increase in fermentation period (24–96 h). Functional analyses showed a decrease in oil absorption, water absorption, foaming and emulsion properties while fermentation increased the pH, bulk density and least gel concentration. The protein solubility profile of H. crepitans was pH-dependent as higher solubility was observed in the alkaline than acidic region. The foaming and emulsifying properties were decreased with increase in salt (NaCl) concentration. Therefore, cooking and fermentation processes of H. crepitans seeds can enhance utilization of the seeds. PRACTICAL APPLICATIONS Sandbox (Hura crepitans) seed is one of the underutilized oilseeds in Nigeria that is rich in protein. This study shows that through cooking and fermentation processes, the chemical composition and functional properties of the seeds can be enhanced. These processes will also increase availability and digestibility of protein in the seeds. Therefore, cooked and fermented sandbox seeds can be used as ingredients in food fortification owing to the high protein content and good functional properties. INTRODUCTION A number of seed oils have been characterized but the vast majority has not been adequately evaluated (Oderinde and Ajayi 1998). This is also particularly valid for the Nigerian flora which is one of the most extensive in continental Africa (Oderinde and Ajayi 1998). Attention has, therefore, been shifted to under-utilized local seeds for possible development and use as there are several of these under-exploited plant seeds in Nigeria. Hura crepitans falls into this group of underutilized species of plants (Okolie et al. 2012). H. crepitans Linn. (also known as sandbox) is a tropical plant belonging to the family Euphorbiacea. In Nigeria, it is known as “Odan Mecca” by the Kabba people of Kogi State and “Aroyin” by the Ijesha people of Osun State (Fowomola and Akindahunsi 2008). Despite some earlier researches which indicated H. crepitans seeds may cause nausea, vomiting and purging (Allen 2000; Clarke 2000), the nutritional value has been revealed by several researchers. Also Barbieri et al. (1983) isolated and char- acterized the lectin present in the latex of H. crepitans L. that had haemagglutinating but not mitogenic activity. It was reported that the hemagglutinating activity was inhibited by D-galactose and by galactose-containing oli- gosaccharides. High protein and oil content of 37.64 and 53.81%, respectively, have been reported (Okolie et al. 2012; Muhammed et al. 2013). The amino acid profile investigated by Fowomola and Akindahunsi (2008) showed total amino acid content of 64.36 g/100 g protein Journal of Food Biochemistry 00 (2016) 00–00 V C 2016 Wiley Periodicals, Inc. 1 Journal of Food Biochemistry ISSN 1745–4514