“Whole grain”: i. The parboiling process of rice includes soaking
of paddy rice to moisture level of 25e30 g/100 g (3e3.5 h, 70 C),
steaming under pressure, drying to a moisture-safe limit of 14 g/
100 g and milling (Bello, Baeza, & Tolaba, 2006). Fortification using
soaking method is similar to conventional parboiling but it is
usually applied to brown or milled rice. During fortification of
milled rice using soaking method, the nutrients are added at the
desirable concentration forming soaking water solutions. The
soaking temperature can be lower than that of typical parboiling
process, depending on the fortifier. Alternatively to the above
method, the removal of ricewater content, the soaking in hotwater
under pressure, steaming, cooling and drying or the addition of
nutrients in acidic solution (usually HCl 1%) during soaking for
30 min can take place. Last method gives better results for thiamin
and improves the taste but causes rice discoloration and a sticky
texture (Misaki & Yasumatsu, 1985).