Effects of microwave heating on native and resistant starches

Resistant starches (RSs) are broadly investigated as appropriate additives in starch-based products due to their well-known and proved health benefits. However, it was shown in previous studies that these starches are sensitive of the different heat treatments used in the food processing, which can cause changes, especially in the resistance. There is an increasing trend to use microwave (MW) energy in food processing; therefore, our aim was to investigate the changes of RSs compared to native starches caused by MW heating. Maize, wheat, RS2 and RS4 starches were MW-treated according to a 2×2 experimental design (300 and 600 W of power, 30 and 150 s of time). The changes of in vitro digestibility, rheological properties (rapid visco analyser, RVA) and near infrared (NIR) spectroscopic characteristic were studied. Two spectrophotometers were applied (dispersive and Fourier-transform (FT)) to compare their sensitivity in the analysis of the MW-treated starches.Results showed that the digestibility of starch...