STUDY ON MODIFICATION OF YAM STARCH (Dioscorea alata L.) CREATING SLOW DIGESTING STARCH BY ACID HYDROLYSIS

Abstract

This study was conducted to modify yam starch to create slowly digestible starch (SDS) by the acid method to create the highest SDS starch on the basis of evaluating the effect of citric acid concentration (15 – 45%), temperature (37.5 – 52.5oC) and hydrolysis time (1.5 – 10.5 h) was performed based on the multivariable model by CCD method, and the starch content SDSmax was the dependent response. The results showed that the quadratic model obtained is significant (p < 0.05), the reliability of the model R2 = 0.979 showed that the built regression model is suitable for the data set whether 97.9%. As a result, the highest SDS starch content is 18.052% at an acid concentration of 40,009%, a temperature of 39.962oC and a hydrolysis time of 8.933 h. Solubility increases due to temperature, swelling increases in the range temperature of 50 – 70oC and decreases from 70 – 90oC; the viscosity of starch tends to decrease after denaturation.

Keywords

• acid hydrolysis
• slowly digestible starch
• starch modification
• yam starch