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

Marcel Skejovic Joehnke; Stephanie Jeske; Lilit Ispiryan; Emanuele Zannini; Elke K Arendt; Jürgen Bez; Jens Christian Sørensen; Iben Lykke Petersen

doi:10.1016/j.fochx.2020.100112

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

Food Chem X. 2021 Jan 7:9:100112. doi: 10.1016/j.fochx.2020.100112. eCollection 2021 Mar 30.

Authors

Marcel Skejovic Joehnke¹, Stephanie Jeske², Lilit Ispiryan², Emanuele Zannini², Elke K Arendt^{2

3}, Jürgen Bez⁴, Jens Christian Sørensen¹, Iben Lykke Petersen¹

Affiliations

¹ Department of Food Science, University of Copenhagen, Frederiksberg, Denmark.
² School of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
³ School of Food and Nutritional Sciences and APC Microbiome Institute Ireland, University College Cork, Ireland.
⁴ Fraunhofer-Institut für Verfahrenstechnik und Verpackung, Freising, Germany.

Abstract

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.

Keywords: AA, amino acids; ANC(s), anti-nutritional compound(s); ANOVA, analysis of variance; Alternative protein sources; DH, degree of hydrolysis; DM, dry matter; E:S ratios, enzyme:substrate ratios; FODMAPs; FODMAPs, fermentable oligo-, di- and monosaccharides, and polyols; FOS, Fructans and fructo-oligosaccharides; GOS, galacto-oligosaccharides; HPAEC-PAD, high performance anion exchange chromatography coupled with pulsed amperometric detection; IBS, irritable bowel syndrome; IEP, isoelectric precipitation; IVPD %, in vitro protein digestibility; IVPD P %, pepsin digestibility; IVPD PT % 1+1 h, short-term protein digestibility; IVPD PT % 1+24 h, long-term protein digestibility; IVPD PT % 1+3 h, medium-term protein digestibility; In vitro protein digestibility; LF(s), lentil flour(s); LP, lentil protein(s); LPC(s), lentil protein concentrate(s); LPI(s), lentil protein isolate(s); LPI–IEP, lentil protein isolate prepared by IEP; LPI–UF, lentil protein isolate prepared by UF; Lens culinaris; Lentil flour; Lentil protein isolates; MW(s), molecular weight(s); OPA, o-phthaldialdehyde; PD, protein digestibility; Pilot-scale processing; RFO, raffinose family oligosaccharides; TCA, trichloroacetic acid; TIA, trypsin inhibitor activity; TIU, trypsin inhibitor unit; TNBS, trinitrobenzenesulfonic acid; TU, trypsin activity unit; Trypsin inhibitor activity; UF, ultrafiltration; l–BAPA, N–α–benzoyl–l–arginine–4–nitroanilide.