Supawan Tirawanichakul, Oraporn Bualuang and Yutthana Tirawanichakul

pp. 557 - 568

Abstract

The effect of infrared (IR) and hot air (HA) drying conditions on drying kinetics of Leb Nok Pattani (LNP) rice and
Suphanburi 1 (SP 1) parboiled rice and their qualities was studied. Initial moisture content for LNP and SP 1 rice was 54±1 and
49±1% dry-basis, respectively. Drying temperatures of 60-100°C, IR power of 1.0 and 1.5 kW and hot air flow rate of 1.0±0.2
m/s were used for experiments. The results show that HA and IR parboiled rice drying can maintain high head rice yield
(HRY) and IR drying with 1.5 kW provided the highest HRY value. Additionally, the qualities analysis showed that whiteness,
water absorption, cooking time and pasting property were significantly different compared to reference samples. The specific
energy consumption of parboiled rice drying with IR of 1.0 kW at 100°C delivered a low value. Thus IR drying for parboiled
rice should promote.

Keywords

• energy consumption
• head rice yield
• medium and long-grain rice
• physicochemical quality