Preparation and physicochemical properties of cucurbit protein isolate from Lagenaria siceraria defatted seed flour

Abstract

Cucurbit seeds including Lagenaria siceraria seeds have been used from early times as a source of food. The protein constitutes about thirty-five percent of the weight of the decorticated seeds. Isolates are defined as the kind of protein that forms with a high concentration of protein that contains no dietary fiber. This study aims to investigate the preparation of protein isolated from Lagenaria siceraria defatted seed flour and to study their physicochemical properties. Protein was isolated from seed flours by using distilled water, salt solution, an alkaline solution, then precipitated with 0.1 N hydrochloric acid followed by centrifugation and freeze-drying. The findings reflected a high protein content (ranged from 80.67-91.04 g 100g-1) with the absence of fats. The functional properties of the protein isolate are said to be acceptable exhibiting a considerable range for all examined properties, water holding capacity 2.4-3.9 mL g-1 protein, fat binding ability 2.7-3.7 mL g-1 protein, emulsion capacity 51.0-57.8 mL of oil per g of protein, and bulk density 0.39-0.56 g mL-1, for all samples. The results of foaming stability indicated that the seeds were possibly utilized in food applications such as beverages and cakes processing. The maximum protein solubility (95%) occurred at the alkaline range pH 10 and11. The SDS page test detected that the three major polypeptides are those with molecular weights 10, 23, and 38 KDa. This study is the first to take place on the protein isolation from eight Lagenaria siceraria defatted seeds grown in Sudan, opening the way for further studies on these seeds