Effects of Genotype and Environment on the Composition and Starch Functionality of Pea and Fababean and the Presence of Other Starches or Hydrocolloids on the Functionality of Pea Starch

Abstract

Genotype had a significant effect on protein and starch concentrations in pea and fababean, on pasting, trough, cooling and final viscosities of starch from pea and fababean, and on onset and peak temperatures of gelatinization of starch from fababean. Significant genotype x environment interactions were observed for the concentrations of starch in pea and fababean, the concentration of amylose, endothermic enthalpy and trough viscosity in starch from fababean, and pasting viscosities of starch from pea. The effects of genotype and environment on the physicochemical characteristics of starch from pea and fababean grown in western Canada would likely not be of practical significance. Native, heat-moisture-treated and pregelatinized blends of pea starch and starch from corn, waxy corn, high-amylose corn or potato exhibited a variety of functionalities due to differences in the functionalities of the constituent starches and to the effects of heat-moisture treatment and pregelatinization. Compared to calculated weighted average values, blends of pea starch and corn starch exhibited lower degrees of syneresis and lower shear stabilities, blends of pea starch and waxy corn starch exhibited higher degrees of syneresis and lower shear stabilities, and blends of pea starch and high-amylose corn starch exhibited lower viscosities and lower shear stabilities. In general, heat-moisture treatment of blends reduced pasting viscosities, swelling and degree of syneresis as compared to respective native starch blends. Compared to pea starch, combinations of pea starch and galactomannans (guar gum and locust bean gum) exhibited increased viscosities during pasting, whereas combinations of pea starch and anionic hydrocolloids (xanthan gum and carboxymethylcellulose) exhibited increased viscosities at lower inclusion rates only. Generally, combinations of pea starch and guar gum exhibited less syneresis than combinations of pea starch and locust bean gum, xanthan gum or carboxymethylcellulose. It was concluded that some blends of pea starch and starch from corn, waxy corn, high- amylose corn or potato may have potential in food applications such as confectionery, batters and breadings, breakfast cereals, retorted products, snack foods and baked goods, and that some combinations of pea starch and hydrocolloids might offer functionality that would be of practical use.