Evaluation of quality characteristics of ultrasound–treated browntop millet grains

Abstract

Modification of grains using green technologies receiving more attention in today's world for better utilization. Browntop millet was treated at a frequency of 20 kHz using probe ultrasound at 100 & 200 W for 5–35 min of 5 min intervals between the treatment at the ratio of 1:5 (w/v). The impact of treatment on grains was evaluated utilizing several parameters, such as relative crystallinity (RC) of the treated samples, which decreased from 59.78 % to 34.41 % at 100 W and 22.84 % at 200 W. Change in the surface morphology of the samples was observed by SEM which had a positive impact on water absorption as it increased from 164% to 179.2%; thus, the cooking time in treated samples is reduced from 18.8 to 7.9 min. Thermal and pasting properties showed a decrease in temperature and increase in viscosity of the treated samples from 74 to 70.7 °C, and 4.23 Pa.s to 11.50 Pa.s this shows that grains with lesser gelatinized temperature tends to cook fast and has the softer texture, thus sonicated samples have better eating quality. Among all the trials 200 W 20 min were the optimal conditions for the browntop millet with lesser cooking time, relative crystallinity.