Drying and tempering effect on milling process of paddy in unparboiled condition

Drying and tempering effect on milling process of paddy

Abstract

This research was conducted during the Aman season to assess the impact of drying and tempering on the milling performance of unparboiled rice (BRRI dhan49). Five treatments were tested, with temperatures ranging from 24.1 to 42.7 °C. Drying over three days at different time intervals led to reduced moisture content (from 23.42% to 9.24%), resulting in increased kernel hardness for reduced breakage during milling. The strongest kernel strength recorded was 34.933 N/m. Varying conditions like relative humidity, temperature, air flow, and solar radiation influenced the drying process. Treatment T4 (5 hours sun drying with 1-hour drying and 1-hour tempering) and T1 (4 hours drying with 1-hour drying and ½-hour tempering) exhibited the highest milling yield (19.03 kg) and head rice recovery (17.05 kg) respectively, with T1 having the minimum loss (1.9 kg). These treatments increased milling yield, head rice recovery, and reduced losses, showcasing their effectiveness in maximizing rice output.