Supplementation of Sorghum (Sorghum bicolor L. Moench) Flour with Protein Isolate from Two Cultivars of Hyacinth Bean (Dolichos lablab L.)

Abstract

Supplementation of Sorghum (Sorghum bicolor L. Moench) Flour with Protein Isolate from Two Cultivars of Hyacinth Bean (Dolichos lablab L.) (M.Sc. Dissertation) By Wedad Mohamed Ahmed Dawod Salim ABSTRACT: This study was conducted to investigate chemical composition , in- vitro protein digestibility and amino acids profile of sorghum (Tabat) and two cultivars of hyacinth bean (White seeded – genotype SHDL08- 11W and Commercial).Protein isolate was prepared from the two cultivars of hyacinth bean . Its functional properties and electrophoresis (SDS-PAGE) were evaluate protein isolate of the two cultivars of hyacinth bean. White seeded- genotype cultivar showed highly significant (PX04; 0.05) high moisture, ash, protein, fat and available carbohydrates while Commercial cultivar was significantly higher (PX04; 0.05) in fibre. In vitro protein digestibility of Genotype (SHDL08- 11W) was significantly lower than the Commercial. Evaluation of protein isolate from two cultivars of hyacinth bean (White seeded – genotype SHDL08- 11W and Commercial) viewed the Genotype was significantly higher in moisture, ash, protein and fibre while the Commercial was significantly higher in available carbohydrates and in vitro protein digestibility, where as they have the same value in fat (0.03%). Sodium dodecyl sulphate polyacryl amide gel electrophoresis (SDS- PAGE) was used to compare native protein of the two hyacinth bean protein isolates. Functionality of protein isolate showed that the Genotype was significantly higher in emulsification capacity and fat absorption capacity where as the Commercial gave higher values of water holding capacity, emulsification activity and emulsification stability, while they have the same value of bulk density. Supplementation of sorghum flour with ratios (5, 10, 15%) of hyacinth bean protein isolate showed a significant increase in protein content, lysine and threonine content, with a slight increase in methionine level of kisra bread product. Sensory evaluation of kisra product made from sorghum flour with 10% protein isolate from genotype (SHDL08- 11W) hyacinth bean was better in favor, colour, texture, taste and over all acceptability than those made from sorghum with protein isolate from commercial hyacinth bean (5, 10, 15%) and genotype (SHDL08- 11W) (5, 15%