The influence of variety and various process parameters on the total milling yield of parboiled rice

Abstract

The effect of steam pressures, specific volume of steam and variety on total milling yield was investigated.  Four rice varieties, ‘Faro 21’, ‘Faro 27’, ‘Faro 29’ and ‘Faro 35’ popularly adopted in Nigeria were used.  An insulated electric rice parboiler was used to steam the rice samples previously soaked in hot water for 6 hours under recommended conditions.  The samples were dried, milled and analysed. Results showed that a higher total milling yield of 71% was observed at the higher process steam pressure of 5.5 x 10⁴ N/m². The 1.29 m³/kg specific volume of steam also had higher milling yields while the 1.15 m³/kg and 1.58 m³/kg levels of specific volume of steam had lower values.  Rice variety, Faro 29 recorded the highest total milling yield of 71%.