Effectiveness of atmospheric cold plasma technology on physicochemical and functional characteristics of ST25 fragrant rice (Oryza sativa L.) flour

Vietnam is one of the leading rice export countries in the world. ST25 fragrant rice (Oryza sativa L.) won the top prize for best rice in the world in 2019 and the second at World's Best Rice Contest 2020. Plasma has been considered as an innovative food processing technology. The aim of this study demonstrated the impact of time (4, 6, 8, 10, 12 min), power (160, 180, 200, 220, 240 W) and oxygen flow rate (0.2, 0.4, 0.6, 0.8, 1.0 ml/min) to the physicochemical and functional qualities of ST25 fragrant rice flour. Results showed that under plasma treatment time at 10 minutes, power 200 W, oxygen flow rate 0.8 ml/min, the amylose content (16.67±0.01 %), pasting temperature (83.21±0.02 oC), water absorption index (14.54±0.00 gm/gm sample), water solubility index (10.31±0.02 gm/100 gm sample), swelling power (14.96±0.00 gm/gm sample) were recorded. Under plasma treatment, surface of the ST25 fragrant rice flour became more hydrophilic to absorb more water resulting to shorter cooking time. Plasma treatment provides environmentally friendly processing of rice grain to limit pesticide abuse towards ecological farming.