Effects Of Germination Duration On Morphology, Physicochemical Properties And In Vitro Digestibility Of Starch Isolated From Mung Bean (Vigna Radiata (L.) R. Wilczek)

Abstract

Mung bean (Vigna radiata (L.) R. Wilczek) was subjected to germinate and then, the changes in granule morphology, physicochemical properties as well as in vitro digestibility of isolated starch were investigated. Germinated mung beans were obtained by germination at ambient temperature for 0, 6, 12, 18, and 24 h with light. Morphology analysis showed germination did not affect the shape of starch granules, but germinated mung bean starch exhibited damaged surface compared with smooth surface of native starch. Germination duration could not change the type of crystalline structure of mung bean starch, which were classified as A-type crystalline structure. As testing temperature increased from 50 to 90 °C, swelling power and solubility of starch isolated from native and germinated mung bean increased. Peak viscosity (PV), final viscosity (FV), and breakdown viscosity (SB) of germinated mung bean starch tended to increase gradually as germination duration prolonged to 24 h. Furthermore, the germinated mung bean starch resulted in higher level of RDS, but a lower level of SDS and RS compared to native starch. The lowest value of RS was reported at 24 hours of germination of about 8.79 %; whereas native mung bean starch obtained the highest value of RS of 13.59 %. The obtained results may help in understanding the influence of germination on physicochemical properties and in vitro digestibility of mung bean starch and choosing appropriate methods to produce mung bean starch as a low carb ingredients in food industry.