สำนักราชบัณฑิตยสภา

The Journal of the Royal Institute of Thailand √–∫∫∑ÿ ππ‘ ¬¡¿“¬„µâ √–∫Õ∫ª√–™“∏‘ ª‰µ¬·∫∫‰∑¬ °“√º≈‘ µ¢â “«°≈â ÕßÀÕ¡¡–≈‘ ÿ ¢¿“æ ‚¥¬„™â ‡∑§π‘ §ø≈Ÿ Õ‘ ‰¥‡´™— π√à «¡°— ∫°“√‡°Á ∫„π∑’Ë Õ— ∫Õ“°“» Vol. 32 No. 1 Jan.-Mar. 2007 124 Abstract Producing Healthy Jasmine Brown Rice Using Combined Techniques of Fluidization and Tempering Donludee Jaisut School of Energy, Environment and Materials, King Mongkut’s University of Technology Thonburi, 126 Prachautid, Tungkru, Bangkok 10140 Somkiat Prachayawarakorn Faculty of Engineering, King Mongkut’s University of Technology Thonburi, 126 Prachautid, Tungkur, Bangkok 10140 Warunee Varanyanond Patcharee Tungtrakul Institute of Food Research and Product Development, Kasetsart University, 50 Phahonyotin, Lad Yao, Jatujak, Bangkok 10903 Somchart Soponronnarit Fellow of the Academy of Science, The Royal Institute, Thailand; School of Energy, Environment and Materials, King Mongkut’s University of Technology Thonburi, 126 Prachautid, Tungkru, Bangkok 10140 Although, Jasmine brown rice (Khao Dawk Mali 105) is a favor consuming healthy product in Thailand but it has a short shelf life due to rancidity. Also, having Jasmine brown rice could result to rapid increase of blood sugar and insulin levels after ingestion due to fast absorption of carbohydrate and risk of type 2 diabetes. Therefore, the purpose of this research is to reduce brown rice rancid and starch hydrolysis rate of brown rice whereas the other qualities of brown rice which are head rice yield, whiteness, rice germ, white belly and pasting properties of brown rice flour, still accepted. Fluidized bed drying was used to reduce moisture content of paddy cv. Khao Dawk Mali 105 from 28.2% dry basis and 33.3% dry basis to 21.9% dry basis. After that, grain was tempered and ventilated with ambient air to reduce moisture content to 16.5% dry basis. The operating conditions used in the experiments were the drying temperatures of 130 and 150 ˚C and the tempering times of 30, 60 and 120 min. The results showed that the average drying rate and head brown rice yield were increased with increasing of fluidized bed drying temperature and initial moisture content whereas the whiteness and the fat acidity of brown rice were decreased. However, the white belly was slightly different. Regarding to the head rice yield and the rate of moisture reduction during ventilation, paddy which contained initial moisture of 28.2% dry basis, after fluidized bed drying should be tempered for 30 min and tempered for 60 min in the case of initial moisture content of 33.3% dry basis. Further, peak viscosity of brown rice paste was slightly changed but final viscosity and setback were increased as tempering time increased. Starch hydrolysis of brown rice was reduced as initial moisture content, drying temperature and tempering time increased. Key words : brown rice, drying, fat acidity, fluidized bed, paddy, rancidity, starch hydrolysis