Production and Quality Evaluation of Young Thai Jasmine Rice Flake Using Drum Dryer

Abstract

Immature rice grains contain high bioactive compounds. Drying has been used for the food preservation and reduction of agricultural waste. This study aimed to produce the rice flake from young Thai Jasmine rice grain (light green and soft texture) using double drum dryer at 120 °C, drum rotation speed 0.5, 0.7, and 0.9 rpm, and the ratios of grain to water of 1:3 1:5 and 1:7w/w. The nutritional properties of rice flake were also investigated. The results showed that increasing rotation speed gives a significant effect on the higher moisture content and water activity. Using lower water ratio with slowing down rotation speed resulted in higher brightness of the flake products including quicker dehydration. The selected optimal condition of preparing rice flake was 1:5 w/w young grain to water at 0.5 rpm drum speed. The flake contains fat, protein, carbohydrate, ash, approximately 0.004%, 6.140%, 88.686% and 0.92%, respectively. Phenolic content and antioxidant capacity of rice flake were decreased after drying. Total phenolic content of the flake was 280.931 mg GAE/g and antioxidant activities; DPPH, FRAP and ABTS were 254.158, 123.172 and 372.298 mg TE/g, respectively. Young rice flake remains a great nutritional value which has potential in the food industry.

Keywords

• young rice grain
• thai jasmine rice
• double drum dryer
• rice flake
• total phenolic
• antioxidant activity