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This study focused on using low-pressure plasma processing on polished “white” rice and unpolished “riceberry” brown rice. Plasma treatment reduced the water contact angle on riceberry rice from 120.6°±1.0° to 89.8°±1.5°. Scanning electron microscope (SEM) images showed morphology of an external surface and a cross sectional view of the interior just below the surface of a rice kernel. The SEM image revealed a µm thin layer, 10-µm square-like pockets, and an endosperm of a few-mm across. The underlying pockets contain a lot of starch granules. SEM images also showed many pores on the top surface opening down to the pocket-like structure underneath after low-pressure plasma treatment. This effect caused the rice kernel to be more hydrophilic and agreed well with lower water contact angle. This work has demonstrated the feasibility of applying low-pressure plasma to improve the cooking quality of rice.
2. C. Arpagaus, A. Sonnenfeld, PH. Rudolf, A Downer Reactor for Short-time Plasma Surface Modification of Polymer Powders, Chem. Eng. Technol, 2005, 23, 87-94.
3. C. Arpagaus, C. Rossi, PH. Rudolf, Short-time plasma surface modification of HDPE powder in a Plasma Downer Reactor- process, wettability improvement and ageing effect, Applied surface science, 2005, 252, 1581-1595.
4. C. Chan, M. Ko, H. Hiraoka, Polymer surface modification by plasma and photons, Surface Science Reports, 1996, 24, 1-54.
5. H. H. Chen, Investigation of Properties of Long-Grain Brown Rice Treated by Low-pressure Plasma, Food Bioprocess Technol, 2014, 7, 2484-2491.
6. H. H. Chen, H. Y. Chen, H. CH. Chang, Evaluation of Physicochemical Properties of Plasma Treatment Brown Rice, Food Chemistry, 2012, 135, 74-79.
7. C. Sarangapani, Y. Devi, R. R. Thirundas, U. S. Annapure, Effect of low-pressure plasma on physico-chemical properties of parboiled rice, Food Science and Technology, 2015, 63, 452-460.
8. R. Thirumdas, R. R. Deshmukh, U. S. Annapure, Effect of low temperature plasma processing on physicochemical properties and cooking quality of basmati rice. Innovative Food Science & Emerging Technologies, 2015, 31, 83-90.
9. W. Chaiwat, R. Wongsagonsup, N. Tangpanichyanon, T. Jariyaporn, P. Deeyai, M. Suphantharika, S. Dangtip, Argon Plasma Treatment of Tapioca Starch Using a Semi-continuous Downer Reactor. Food and Bioprocess Technology, 2016, 9, 1125-1134.