Isolation and physicochemical characterization of starch from Marama Beans (Tylosema Esculentum)

Abstract

One of the most popular types of beans grown in South Africa is Marama bean seeds (Tylosema esculentum) which are still widely underused although it is being consumed by the local population. To determine its qualities and assess its appropriateness for application in various sectors, starch was isolated from the plant's seeds and subjected to physicochemical characterization. Starch was isolated from the seeds using the crushing method along with sodium metabisulphite to prevent fermentation. Physicochemical parameters were determined using standard procedures and amylose / amylopectin ratio evaluated using the UV method by comparison with a standard. The starch was physically and chemically characterized, and it was found to have physicochemical values as follows – gelatinization temperature 64 ℃; foam capacity 6%; bulk density 0.769 gcm^-3; emulsion capacity 38%; pH 7.77; water holding capacity 21.67%; tapped density 0.857 gcm^-3; browning temperature range 235.2 – 256.0 ℃; charring temperature range 271.9 – 287.3 ℃. At 95 ℃, the starch percentage solubility was 3.5%, and the swelling power was 11.059. Tylosema esculentum starch was found to be made up of 73.523 % amylopectin and 26.477 % amylose. Given that its qualities favorably compare with those of starch used in industries especially the pharmaceutical sector, the varied physicochemical parameters results of starch isolated from Tylosema esculentum demonstrated potentials as a promising starch source for use in industries like the pharmaceutical, food, paper and textile as a biomaterial.