Assessment of anti-nutritional factors and in vitro protein quality in yellow pea and its derivatives under different food processing methods

Background: Pea seeds offer an excellent and sustainable source of plant-based proteins. However, similar to other pulse crops, yellow peas inherently possess anti-nutritional factors (ANFs). These substances negatively affect their nutritional value by impacting nutrient bioavailability and protein digestibility, thus limiting the protein quality of pulses compared to animal sources. Food processing treatments could contribute to inactivate ANFs and improve the protein quality of legumes.

Objectives: This study examined the effect of different food processing methods on the ANFs and in vitro protein quality of yellow pea and its derivatives.

Methods: Whole yellow pea seeds were subjected to thermal (i.e., boiling, autoclaving, micronization, and baking) and non-thermal (i.e., high hydrostatic pressure (HHP)) processes. Additionally, their derivatives, including protein concentrate, 80% and 90% protein isolates only underwent baking and HHP. Trypsin inhibitor activity (TIA), phytic acids, amino acid profile, in vitro protein digestibility (IVPD), and in vitro Protein Digestibility Corrected Amino Acid Score (IVPDCAAS) were determined. Additionally, the ANFs results were expressed in both dry matter and protein bases.

Results: When compared to unprocessed forms, all thermal treatment significantly reduced (p < 0.05) TIA and phytic acid contents of yellow pea and its derivatives, ranging from 70.1% to 89.8% and 20.3% to 48.2%, respectively. Significant changes (p < 0.05) after HHP were only observed in the TIA and phytic acid content of the yellow pea and protein concentrate, which fell by up to 24.8% and 19.3%, respectively, with the exception of phytic acid (DM basis) in yellow pea. Furthermore, there was no significant difference in in vitro protein quality between unprocessed and processed yellow pea samples.

Significance: This research is expected to overcome the constraints of ANFs, aiming to enhance the utilization of pea proteins and promote the adoption of sustainable plant-based protein ingredients for researchers and food processors.