Parboiling of paddy helps in retaining:

(Thiamine) Parboiling (paial cooking in steam) is ancient Indian technique of preserving the nutritive quality of rice. Technique of parboiling recommended by Central food technological research institute, Mysore is known as the 'hot soaking process'. The process stas with soaking the paddy (unhusked rice) in hot water at 65-70oC for 3-4 hours, which swells the grain, which is followed by draining of water and steaming the soaked paddy in the same container for 5-10 minutes. The paddy is then dried, and later home-pounded or milled.