Parboiling of paddy by simple soaking in hot water

Abstract

Abstract Parboiling of paddy by mere hot water soaking, without steaming, has the advantage of not requiring a boiler. Soaking at a temperature 10–15°C above the gelatinization temperature (i.e. generally at about 80–85°C) is necessary to achieve fair to moderate gelatinization (i.e. parboiling). However, soaking at such temperatures for a time sufficient for the water to penetrate and gelatinize the grain core invariably leads to over-imbibition of moisture, husk splitting and leaching; soaking for less time, on the other hand, leaves many grains with ‘white belly’. The best method therefore is to soak the grain for such time as to imbibe about 30% moisture (wet basis) (i.e. for about 1 1/2–2 hr), drain out the water, and temper the hot paddy for another 1–2 hr. This process yields optimally parboiled paddy without ‘white belly’ or grain splitting and with reasonably good milling quality and colour.