Studies on some properties of starches from three Mucuna species

This study was carried out to characterize starches extracted from Mucuna pruriens, Mucuna rajada and Mucuna veracrux into chemical, functional and pasting properties as well as the turbidity during storage. Starches were isolated from matured seeds with the amylose content varying between 24.61 and 71.33%. The turbidity values increased progressively during refrigerated storage in all the starches isolated. The swelling power of the starches differs significantly at the same temperature of 90°C and it ranged between 5.83 – 6-68% while the solubility ranged between 7.04 – 8.13%. The water binding capacity ranged between 170 – 178% with MV having the highest water binding capacity. Pasting properties measured using RVA, also differed significantly. Pasting temperatures, peak viscosity, and final viscosity of Mucuna starches separated from different Mucuna cultivars varied between 61.73 – 62.30°C, 71.63 – 323.0 and 123.0 – 378.30cP, respectively. It was observed that there was an increase in viscosity up to the end of the cooling time and also starches from cultivars with high swelling power had higher final viscosity and pasting temperature. Increase in final viscosity might be due to the aggregation of the amylose molecules. The high setback values shown by these starches make them unsuitable for food applications where low rate of syneresis is required such as in frozen or refrigerated foods. These Mucuna starches can however be suitable for industries where thermo-stable paste without breaking down and with restricted swelling is required.