The hydration curve of the rice kernel with plasma treatment during the soaking process is illustrated in Fig. 3. Significant linear increases in the moisture content of regular brown rice were observed with the progressive increases in the soaking time, and the maximum quantity was 21.42% after 5 h of soaking. The hydration curves of brown rice with plasma treatment showed a rapid increase in the water content during the first three hours of soaking. In addition, brown rice with plasma treatment had higher water absorption than regular brown rice for all soaking times, and the maximum value was 24.78% after 5 h soaking. The bran layer of brown rice is a water-resistant material containing fat, fibre, protein and ash (Khatoon & Gopalakrishna, 2004). However, plasma treatment resulted in the bran layer of brown rice developing fissures, which accelerated water absorption during soaking. Enzymatic treatment also showed a similar effect of reducing the resistance to water absorption during soaking (Das et al., 2008b).