title: Aroma-Active Compounds in Bartlett Pears and Their Changes during the Manufacturing Process of Bartlett Pear Brandy.
abstract: Application of aroma extract dilution analysis to Bartlett pears and the fermented mash produced thereof revealed 24 and 34 aroma-active compounds in the flavor dilution (FD) factor range between 8 and 8192. Twenty-eight compounds, which have not been described before in Bartlett pears or in fermented pear mash, were identified. While ethyl (E,Z)-2,4-decadienoate (pear-like, metallic odor impression), hexyl acetate (green, fruity), and acetic acid (vinegar-like) showed the highest concentrations in Bartlett pears, ethanol (ethanolic), acetic acid, 3-methyl-1-butanol (malty), 1-hexanol (grassy, marzipan-like), (S)-2- and 3-methylbutanoic acid (sweaty), and 2-phenylethanol (flowery, honey-like) were present at the highest amounts in the fermented mash. The key aroma compounds were quantitated in each pear brandy production step (pears, fermented mash, distillate, and aged distillate) by stable isotope dilution analysis showing a clear influence of each step on the overall aroma of the spirit and, consequently, revealing clearly changing concentrations (e.g., of ethyl (S)-2-methylbutanoate, (E)-β-damascenone, ethyl (E,Z)-2,4-decadienoate, and ethyl (E,E)-2,4-decadienoate) and different aroma perceptions during the manufacturing process. In addition, the concentrations of the so-called "pear esters" ethyl (E,Z)-2,4-decadienoate and ethyl (E,E)-2,4-decadienoate were determined in 6 different pear varieties (Abate Fetel, Anjou, Bartlett, Forelle, Kaiser Alexander, and Packham's Triumph) clearly demonstrating the aroma potential of the variety Bartlett, which is mostly used for brandy production due to the high amounts of both esters eliciting a typical pear-like odor impression.
authors.affiliation: Lehrstuhl für Lebensmittelchemie, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany.
authors.forename: Bianca
authors.initials: B
authors.lastname: Zierer
authors.affiliation: Lehrstuhl für Lebensmittelchemie, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Schieberle
authors.affiliation: Lehrstuhl für Lebensmittelchemie, Technische Universität München , Lise-Meitner-Straße 34, D-85354 Freising, Germany.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0003-1281-9999
authors.initials: M
authors.lastname: Granvogl
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis*; D000431:Ethanol / Q000032:analysis; D005285:Fermentation; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D000441:Hexanols / Q000032:analysis; D006801:Humans; D009812:Odorants / Q000032:analysis*; D000439:Pentanols / Q000032:analysis; D031989:Pyrus / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000737:chemistry*
chemical_list: D000441:Hexanols; D000439:Pentanols; D055549:Volatile Organic Compounds; D000431:Ethanol; C036260:1-hexanol; C029683:isopentyl alcohol
keywords: Bartlett pear brandy; Bartlett pears; aging; aroma extract dilution analysis; distillation; fermentation; production; stable isotope dilution analysis