Nutritional and anti-nutritional properties of lentil (Lens culinaris) protein isolates prepared by pilot-scale processing

Lentil (Lens culinaris) is a high-protein crop with a promising potential as a plant-based protein source for human nutrition. This study investigated nutritional and anti-nutritional properties of whole seed lentil flour (LF) compared to lentil protein isolates (LPIs) prepared in pilot-scale by isoelectric precipitation (LPI-IEP) and ultrafiltration (LPI-UF). Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) profiles showed significant reductions in total galacto-oligosaccharides (GOS) contents by 58% and 91% in LPI-IEP and LPI-UF, respectively, compared to LF. Trypsin inhibitor activity (TIA) levels based on dry protein mass were lowered by 81% in LPI-IEP and 87% in LPI-UF relative to LF. Depending on the stage of digestion, the in vitro protein digestibility (IVPD) of LPIs was improved by 35-53% compared to LF, with both products showing a similar long-term protein digestibility to that of bovine serum albumin (BSA). This work supports the use of purified LPI products as a novel source of high quality protein for food applications.

Automated summary

This study compared the nutritional and anti-nutritional properties of whole seed lentil flour and lentil protein isolates, showing significant reductions in oligosaccharides and trypsin inhibitor activity in the isolates, as well as improved protein digestibility. The findings suggest the potential of purified lentil protein isolates as a high-quality protein source for food applications.