Chemical and Nutritional Evaluation of Egyptian Velvet Beans „Stizolobium deeringianum Bort”︁

Abstract

Meal and oil isolated from Velvet Beans "Stizolobium deeringianum" were examined for the nutritive value and the possibility of using in human nutrition. Beside the nutritional studies, the oil analysis and the histological examination of the different organs of the rats used were made. It was found that the toxic factors are located only in the protein fraction of the beans.Chemische und erniihrungsphysiologische Beurteilung von iigyptischem ,.Stizolobium deeringianum Bort"Der Nahnvert des Mehls und des Ules aus Stizolobium deeringianum Bort wurde untersucht, um eine mogliche Anwendung fur die menschliche Ernahrung zu finden. Neben Futterungsversudvm an Ratten wurden die Analyse des Ules und histologische Untersuchungen an verschiedenen Organen der Versuchstiere durchgefuhrt. Es wurde festgestellt, daD sich die toxisdwn Bestandteile auss&lieDli& in der EiweiDfraktion dieser Bohnen befinden.In previous publications the velvet beans Stizolobium deeringianum Bort were examined for the nutritive value and the possibilities of using the beans in human nutrition. Metabolic and histological examinations proved the presence of toxic factors in the velvet beans. These toxic factors were found to be heat stable.The aim of the present work is to find whether the toxic factors are present in the protein fraction, in the oil fraction. or in both. E x p e r i m e n t a lThe velvet beans were ground to a fine powder. The powder obtained was then extracted with ether several times. Ether extracts were then dried over anhydrous Na,SO, and then distilled. The last traces of the solvent were removed under vacuum and pure nitrogen atmosphere at 40° C. The defatted protein was air-dried. The nitrogen content of the defatted protein was estimated by the modified Kjeldahl technique 2. Oil analysisSystematic characterisation of the oil sample was done by the determination of the refractive index, acid value, saponification value, iodine value and the unsaponifiable matter percentage according to the standard methods of analysis s. Fatty acid composition100 mg of the oil was interesterified with methanollHC1 in a sealed tube in a boiling water bath for 3 hours. The