Effect of Microwave Treatment on the Properties of Starch in Millet Kernels

Abstract

AbstractThe microwave is widely applied to process cereals and grains. However, its effects on their chemical components are still not explored clearly. In this study, millet kernels are treated by microwave. The physical and chemical properties of starch in microwave‐treated millet kernels (SMM) are investigated and compared to those in untreated millet kernels (SUM). The experimental results indicate that the peak viscosity of SMM reduces with the increase of microwave time and initial moisture content of millet kernels (IMM). The peak viscosity of SUM is 831.00 BU. Compared with that of SUM, the peak viscosity of SMM decreases after microwave treatment (MT). When the IMM is 35%, the peak viscosity of SMM decreases by 66.23%. MT significantly increases (p < 0.05) the rapidly digestible starch (RDS) and slowly digestible starch (SDS) content of SMM, which reduces its resistant starch (RS) content. Under MT time of 150 s, the SDS of SMM is up to 35.92%. When the IMM is 35%, after MT, the RDS content of SMM reaches 52.10%. Additionally, the relative crystallinity and short‐range order of SMM are both decreased after MT. Therefore, the microwave is a useful tool for improving the properties of the starch in millet.