Parboiled sorghum: Development of a novel decorticated product

Abstract

The effect of parboiling on the milling yield and cooking quality of whole sorghum ( Sorghum bicolor [L. Moench]) kernels was examined. Cultivars differing widely in kernel characteristics were: (1) soaked overnight and boiled for 10 min (Soak-Boil or SB) and (2) brought to boiling point, soaked overnight and brought to boil again (Boil-Soak-Boil or BSB). The cooked samples were dried at ambient temperature prior to abrasive decortication. Both parboiling procedures significantly increased the yield of decorticated grain while reducing kernel breakage. The BSB process resulted in significantly higher decorticated grain yields with less ‘brokens’ than the SB process. The decortication yield of soft cultivars was increased by up to 2·2-fold by parboiling, compared with 1·2-fold for hard cultivars. Parboiled, decorticated sorghum produced a light-colored, cooked product with firm, intact kernels and acceptable appearance and aroma. Field trials in Mali with local sorghum and millet samples confirmed the improved decortication yields obtained under laboratory conditions. The cooked products were consumed with Malian dishes and condiments such as peanut sauce and were rated very acceptable. The process requires low-level technology that is available in villages in sorghum and millet producing areas. No specialized equipment is needed to parboil grain on a village scale. Parboiling may be a practical method by which shelf stable, processed products from sorghum and millet can be prepared while enhancing decortication yields, especially for soft cultivars.