Analysis of Narrow-Leaf Lupin Proteins in Lupin-Enriched Pasta by Untargeted and Targeted Mass Spectrometry

Abstract

The supplementation of different food items with grain legumes and, in particular, with lupin has been demonstrated to provide useful health benefits, especially in the area of cardiovascular disease prevention. In this work, label free quantitative untargeted and targeted approaches based on liquid chromatography−electrospray ionization−tandem mass spectrometry (LC−ESI−MS/MS) for investigating the protein profile of three pasta samples containing different percentages of narrow-leaf lupin flour were carried out. The untargeted method permitted the identification of the main acidic globulins (α-conglutin, β-conglutin, and δ-conglutin) and the comparison of their profile with raw lupin flour. The targeted method, based on High-performance liquid chromatography electrospray ionization tandem mass spectrometry HPLC-Chip-Multiple Reaction Monitoring (MRM) mode, allowed the quantification of γ-conglutin, the main hypoglycemic component of lupin protein: its concentration was around 2.25 mg/g in sample A, 2.16 mg/g in sample D, and 0.57 mg/g in sample F.

Evaluation of the Major Seed Storage Proteins, the Conglutins, Across Genetically Diverse Narrow-Leafed Lupin Varieties

“…The γ-conglutin sequences have relatively few tryptic cleavage sites and unlike the other conglutin families (α, β, and δ) were previously reported to be undetectable through the untargeted analysis of the Tris-HCl extracted lupin samples (45). Nevertheless, herein unique tryptic peptides corresponding to the two γ-conglutin subfamilies were determined and measured for the evaluation of these proteins.…”

Quality Assessment of the Protein Ingredients Recovered by Ultrasound-Assisted Extraction from the Press Cakes of Coconut and Almond Beverage Preparation

“…An equivalent volume of protein extract and 50 mM of NH 4 HCO 3 was mixed. The reduction and subsequently alkylation was carried out according to a previously published study [ 14 ]. Then, 4 mg/mL of trypsin solution were added to the processed samples with a ratio of 1:50 ( w/w , E/S) and the reaction mixture was incubated for 16 h at 37 °C.…”

Proteins and Bioactive Peptides in High Protein Content Foods

“…Despite this, the identification and quantitation of bioactive peptides using empirical approaches is frequently necessary and peptidomic methodologies based on mass spectrometry in tandem are the most used. In this Special Issue, a label free quantitative untargeted and targeted approach based on liquid chromatography coupled to mass spectrometry in tandem (LC−MS/MS) has been used by Aiello et al to analyze the protein profile of different lupin-enriched pasta samples, using tryptic and peptic digestions [ 8 ]. The untargeted methodology permits a comparison between the profiles of proteins, whereas the targeted method, based on Multiple Reaction Monitoring, permits the absolute quantification of the main components of lupin.…”