TY - JOUR

T1 - Production of an Anise-and Woodruff-like Aroma by Monokaryotic Strains of Pleurotus sapidus Grown on Citrus Side Streams

AU - Bürger, Friederike

AU - Koch, Maximilian

AU - Fraatz, Marco A.

AU - Omarini, Alejandra B.

AU - Berger, Ralf G.

AU - Zorn, Holger

N1 - Funding Information: Funding: This research was funded by the BMBF cluster Bioeconomy International 2015, grant number 031B0307B and funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—463380894. H.Z. is grateful for support by the Hessian initiative for scientific and economical excellence (LOEWE) within the project AROMAplus. A.B.O. was supported as a Georg Forster Research Fellow by Alexander von Humboldt Foundation.

PY - 2022/1/19

Y1 - 2022/1/19

N2 - The production of natural flavors by means of microorganisms is of great interest for the food and flavor industry, and by-products of the agro-industry are particularly suitable as substrates. In the present study, Citrus side streams were fermented using monokaryotic strains of the fungus Pleurotus sapidus. Some of the cultures exhibited a pleasant smell, reminiscent of woodruff and anise, as well as herbaceous notes. To evaluate the composition of the overall aroma, liquid/liquid extracts of submerged cultures of a selected monokaryon were prepared, and the volatiles were isolated via solvent-assisted flavor evaporation. Aroma extract dilution analyses revealed p-anisaldehyde (sweetish, anisic-and woodruff-like) with a flavor dilution factor of 218 as a character impact compound. The coconut-like, herbaceous, and sweetish smelling acyloin identified as (2S)-hydroxy-1-(4-methoxyphenyl)-1-propanone also contributed to the overall aroma and was described as an aroma-active substance with an odor threshold in air of 0.2 ng L−1 to 2.4 ng L−1 for the first time. Supplementation of the culture medium with isotopically substituted L-tyrosine elucidated this phenolic amino acid as precursor of p-anisaldehyde as well as of (2S)-hydroxy-1-(4-methoxyphenyl)-1-propanone. Chiral analysis via HPLC revealed an enantiomeric excess of 97% for the isolated product produced by P. sapidus.

AB - The production of natural flavors by means of microorganisms is of great interest for the food and flavor industry, and by-products of the agro-industry are particularly suitable as substrates. In the present study, Citrus side streams were fermented using monokaryotic strains of the fungus Pleurotus sapidus. Some of the cultures exhibited a pleasant smell, reminiscent of woodruff and anise, as well as herbaceous notes. To evaluate the composition of the overall aroma, liquid/liquid extracts of submerged cultures of a selected monokaryon were prepared, and the volatiles were isolated via solvent-assisted flavor evaporation. Aroma extract dilution analyses revealed p-anisaldehyde (sweetish, anisic-and woodruff-like) with a flavor dilution factor of 218 as a character impact compound. The coconut-like, herbaceous, and sweetish smelling acyloin identified as (2S)-hydroxy-1-(4-methoxyphenyl)-1-propanone also contributed to the overall aroma and was described as an aroma-active substance with an odor threshold in air of 0.2 ng L−1 to 2.4 ng L−1 for the first time. Supplementation of the culture medium with isotopically substituted L-tyrosine elucidated this phenolic amino acid as precursor of p-anisaldehyde as well as of (2S)-hydroxy-1-(4-methoxyphenyl)-1-propanone. Chiral analysis via HPLC revealed an enantiomeric excess of 97% for the isolated product produced by P. sapidus.

KW - (2S)-hydroxy-1-(4-methoxyphenyl)-1-propanone

KW - Aroma extract dilution analysis

KW - Monokaryons

KW - P-anisaldehyde

KW - Pleurotus sapidus

UR - http://www.scopus.com/inward/record.url?scp=85123094225&partnerID=8YFLogxK

U2 - 10.3390/molecules27030651

DO - 10.3390/molecules27030651

M3 - Article

AN - SCOPUS:85123094225

VL - 27

JO - MOLECULES

JF - MOLECULES

SN - 1420-3049

IS - 3

M1 - 651

ER -