Physicochemical and functional properties of modified adlay starch (Coix lacryma-jobi) by microwave and ozonation

Abstract

Adlay is a cereal that has been used as food, but its use is still limited. Adlay consists of high starch content, but native adlay starch has a low water absorption capacity and other functional properties. The characteristics of adlay starch can be improved; some of them are modified into porous starch. This study aimed to define porous adlay starch granules and improve the physicochemical properties by synergic modification of microwave heat treatment (MHT) and ozonation. This study consisted of MHT, ozonation, and synergic modification of MHT-ozonation on adlay starch (native, ozonation 20 min, MHT 3 min, MHT 6 min, MHT 3 min followed by ozonation 20 min, and MHT 6 min followed by ozonation 20 min). The results showed that the best treatment was the synergic modification of 6 min of MHT followed by 20 min of ozonation. It showed the highest swelling volume of 22.43 ± 0.39 mL/g and highest water absorption capacity of 3.31 ± 0.34 g/g, the best starch stability with the lowest breakdown viscosity of 3779,33 ± 191,81 cP, and formed the most porous adlay starch. The dual modification effectively created porous starch without changing the new functional groups in starch.