title: Quantitation and bitter taste contribution of saponins in fresh and cooked white asparagus (Asparagus officinalis L.).
abstract: A sensitive HPLC-MS/MS method was developed enabling the simultaneous quantification of bitter-tasting mono- and bidesmosidic saponins in fresh and processed asparagus (Asparagus officinalis L.). Based on quantitative data and bitter taste recognition thresholds, dose-over-threshold factors were determined for the first time to determine the bitter impact of the individual saponins. Although 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl]-(25R/S)-spirost-5-ene-3β-ol was found based on dose-over-threshold factors to be the predominant bitter saponin in raw asparagus spears, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25R)-22-hydroxyfurost-5-ene-3β,26-diol, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25S)-22-hydroxyfurost-5-ene-3β,26-diol, and (25R)- and (25S)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside were found as key bitter contributors after cooking. Interestingly, the monodesmosidic saponins 5a/b were demonstrated for the first time to be the major contributor to the bitter taste of fresh asparagus spears, while the bidesmosides 1a/b and 2a/b may be considered the primary determinants for the bitter taste of cooked asparagus.
authors.affiliation: Food Chemistry and Molecular Sensory Science, Technische Universität München, Liese-Meitner-Str. 34, 85354 Freising, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Dawid
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
mesh_terms: D027761:Asparagus Plant / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003296:Cooking; D012503:Saponins / Q000032:analysis* / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055697:Taste Perception
chemical_list: D012503:Saponins
keywords: Asparagus; Bitter; LC–MS/MS; Steroidal saponin; Taste