Characterization of Starch Fraction From Wet Protein Isolation Process in Pea (Pisum sativum L.)

The protein isolation process produces a protein isolate and a starch byproduct. This research focuses on characterizing the composition, pasting properties, and gel firmness (FM) of starch fractions of five yellow pea genotypes grown in six environments in the state of Washington, USA. Protein isolation yielded 17% protein and 60% starch fractions. The starch fraction had a purity range of 66.0%–84.8%. Pea starch exhibited a strong gel-forming property. The pasting temperatures (PTs) of the starch fractions from the five pea entries ranged between 73.2 °C and 77.1 °C. Viscosity measurements indicated significant seasonal variations. Specifically, the viscosity parameters for the starches from the 2020 to 2022 seasons were significantly higher than those from the 2021 season. Differences in weather conditions partly contributed to seasonal variations. The 2021 season experienced low rainfall, primarily in May and June, followed by high temperatures during late June and the first 3 weeks of July. The principal component analysis (PCA) of 344 viscosity measurements from the Rapid Visco Analyzer (RVA) test showed a clear separation of the 2021 samples from those of 2020 and 2022, emphasizing the impact of the differences in growing conditions.