Study on the characteristics of mochi made by waxy rice flour treated with ultrasound

In order to evaluate the effects of ultrasound on waxy rice flour, the characteristics of mochi made by native waxy rice flour (N-WRF) and ultrasound treated (the ultrasonic power was 130 W, ultrasonic time 10 min, and the ratio of material to liquid was 1:2) waxy rice flour (UT-WRF) were analyzed and compared. The results showed that mochi made by ultrasound treated waxy rice flour (UT-Mochi) was smoother, softer and more elastic than mochi made by native waxy rice flour (N-Mochi), the sensory score of UT-Mochi was higher, and the UT-Mochi was brighter and more transparent. Scanning electron micrographs showed that the pore size of the surface of UT-Mochi was smaller and more uniform than that of N-Mochi. The apparent viscosity, tensile breaking force and maximum tensile distance of UT-Mochi were higher than that of N-Mochi. The storage modulus, hardness and chewiness of UT-Mochi were lower than that of N-Mochi. The content of freezable water content in UT-Mochi, and the transverse relaxation time (T₂) and peak area A₂₂ of UT-Mochi were lower than those of N-Mochi, hence, the water distribution in UT-Mochi was more homogeneous. According to the above results, it is concluded that the appearance, texture and sensory characteristics of UT-Mochi were significantly improved by ultrasonic treatment.