Isolation and characterization studies of Dioscorea dregeana (Kunth) root starch as a potential pharmaceutical and industrial biomaterial

Abstract

The study focused on the physicochemical characterization of starch extracted from Dioscorea dregeana as a way of determining its suitability for use in pharmaceutical and other industries. The starch was isolated using 1% w/v sodium metabisulphite solution and the obtained starch was found to be a brilliant white, crystalline, non-hygroscopic powder with a yield of about 18.5%. The starch had low foam and emulsion capacities of 2 and 5.5% respectively, gelatinization temperature of 66 ^oC and it had appreciably high water absorption capacity of 99.81 mg/100g. The amylose content of the starch was observed to be 7.48 %, while the browning and charring temperatures were 260.4 – 266.9^oC and 270.1 – 285.5^oC respectively. The swelling and solubility profiles of the starch were quite high and showed a trend of increase with the increase in temperature. The various results from the physicochemical characterization of starch from Dioscorea dregeana indicates that it is a potential biomaterial that may be employed as a pharmaceutical/industrial starch since its properties compare favourably with those of starch being used in the pharmaceutical, cosmetics, textiles, food, and other industries.