Improving the cooking quality of black glutinous rice by using the low-pressure cold plasma technology

Abstract

Black glutinous rice grains are hard cooking even though they have been soaked in water for a long period of time. This study aimed to improve the cooking quality of black glutinous rice by the low-pressure cold plasma. The low-pressure cold plasma significantly increased the lightness of the rice grains, especially the oxygen and air plasma. The water uptake of the rice grains was significantly increased after plasma treatment. No difference among the plasmas generated by Ar, Air or O₂ gases. SEM examination showed that the surface structure of rice grains changed from smoothness to roughness throughout the break and reduced the contact angle. Air and O₂plasma increased the softness and stickiness of cooked rice. Anthocyanin content was significantly increased in the range of 14.59 to 25.97 mg/100g in treated sample than those of untreated (10.72 mg/100 g). Air and O₂plasma could modify the surface structure of rice grains due to increased softness and stickiness while reducing hardness. Therefore, low-pressure cold plasma could be a potential innovative technology for improving the cooking quality process while maintaining the nutritional value of black glutinous rice grains.