Quality attributes of paddy dried by microwave heating

Bahram Fathi-Achachlouei¹ Alireza Allameh² Samad Sabouri³

1) Department of Food Science and Technology, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran. Email:
2) Agricultural Engineering Department, Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran. E-mail:
3) Agricultural Engineering Department, Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran. E-mail:

Publication : Second International Conference and Sixth Conference of Organic vs. Conventional Agriculture(umaorg.ir)
Abstract :
Abstract Drying is a time-taking and high fuel-consuming process which is accompanied by environment pollution. Microwave technology can be employed for drying as a remarkable approach due to lower cost of energy consumed, ease of application, reduction in time of process, and negligible environmental pollution. Nine different microwave treatments were compared with conventional hot-air oven (control) drying of Hashemi (a long-grain local cultivar). The results revealed that head rice yield (HRY) decreased when energy level increased. The lowest energy level (90 W) which had the least broken rice, showed a 3.66 % difference to control treatment. By increasing energy level, rice grains whiteness decreased significantly so that the least whiteness (23.13) was associated to energy level of 900 W. Also, grain hardness dropped from 101.8 (control) to 79.97 (the maximum energy level). Water absorption of rice samples represented an increase trend when energy level went up whereas gel consistency behaved inversely.
Keywords : Keywords: rough rice microwave drying quality head rice yield.