Structural and functional characterization of kidney bean and field pea protein isolates: A comparative study. (January 2015)

• Record Type: Journal Article
• Authors: Shevkani, Khetan; Singh, Narpinder; Kaur, Amritpal; Rana, Jai Chand
• Is Part Of: Food hydrocolloids. Volume 43(2015:Jan.)
• Page Start: 679
• Page End: 689
• Publication Date: 2015-01
• Subjects: Functional properties -- Legumes -- Proteins -- Rheology -- Structure -- Thermal analysis; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2014.07.024
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: Protein isolates were prepared from different kidney bean (KB) and field pea (FP) lines and their physicochemical (protein content, colour, electrophoretic profile & zeta potential), structural (thermal & conformational), dynamic rheological and functional (emulsification, foaming, water and fat absorption) properties were evaluated. These isolates differed significantly in colour-, structural-, thermal- and functional-properties. SDS-PAGE and size exclusion chromatography revealed that vicilins (∼150 kDa) were prominent proteins in KB isolates, while FP protein isolates contained both legumins and vicilins (∼330 and ∼155 kDa, respectively) as major components. FTIR spectroscopy revealed that β-sheets, β-turns and α-helix were main secondary structures in the KB and FP proteins. KB proteins had relatively more β-sheets (38.6%) while less α-helix (22.8%) than FP proteins (30.0 and 28.0%, respectively). The rheological properties of the protein isolates were measured as gelation temperature ( T gel ), gel reinforcement ( G reinforcement ) and tan δ . KB proteins had higher thermal denaturation temperature ( T d ), T gel and G reinforcement while lower tan δ than FP proteins. Principal component analysis (PCA) revealed that T d, T gel and G reinforcement related positively, whereas tan δ related negatively with the proportion of β-sheets. Protein solubility, emulsion stability, foaming capacity and stability were positively related to the charge on the proteins. Graphical abstract: Rheological properties of protein isolates from kidney bean (Pi 312296) and field pea (IC 291541). Highlights: Protein isolates from different kidney bean and field pea lines were evaluated. The isolates from both the sources differed in structural and functional properties. β-sheets, α-helix and β-turns were principal secondary structures of the proteins. Denaturation temperature and gel strength was dependent upon the proportion of β-sheets. Protein solubility, emulsification and foaming varied with charge on the proteins.