Effects of various radio frequency treatment protocols on physicochemical properties and sensory quality of packaged milled rice

Abstract

Many studies have shown that non-chemical radio frequency (RF) disinfestation method can maintain the original quality of grains. But there is a lack on developing effective RF treatment protocols based on physical and sensory quality of commercially packaged milled rice for industrial applications. A pilot-scale, 27.12 MHz, 6 kW RF system was used to study the physicochemical properties and eating quality of packaged milled rice under three sample weights (2.5, 5, and 10 kg) and treatment protocols (6, 11, and 26 min exposures to 54, 52 and 50 °C, respectively). The results showed that the same bottom area packaging was feasible based on the cooling time and the suitable electrode gaps of 9, 10 and 14 cm were chosen to develop the RF treatment protocol for 2.5, 5, and 10 kg samples, respectively. Although some influence on moisture content, water activity and amylose content, the RF treatment had no significant effect on fat, fatty acid, protein content, color, fissure ratio, and broken rate for packaged milled rice samples, and the overall score of the cooked rice. This study provides valuable information about the physicochemical properties and sensory quality of packaged milled rice under different RF treatment protocols.