title: Investigation on Key Molecules of Huanglongbing (HLB)-Induced Orange Juice Off-flavor.
abstract: Orange fruits from huanglongbing (HLB)-infected trees do not fully mature and show a severe off-flavor described as bitter-harsh, metallic, and less juicy and fruity. The investigation of juice from HLB-infected (HLBOJ) and healthy control oranges (COJ) by gas chromatography-mass spectrometry showed higher concentrations of fruity esters, such as ethyl butyrate and ethyl 2-methylbutyrate, and soapy-waxy alkanals, such as octanal and decanal, in the COJ, whereas the HLBOJ showed higher concentrations of green aldehydes such as hexanal and degradation compounds of limonene and linalool such as α-terpineol. Application of aroma extract dilution analysis on terpeneless peel oil led to the identification of long-chained aldehydes such as ( E, E)-2,4-decadienal, ( Z)-8-tetradecenal, trans-4,5-epoxy-( E)-2-decenal, ( Z)-4-decenal, and octanal with the highest flavor dilution factors among 25 odor-active volatiles in the peel oil of healthy oranges. Taste-guided fractionation and identification of the HLBOJ secondary metabolites followed by sensory validation revealed that flavanoids such as hesperidin may modulate the flavor to evoke the unacceptable harsh/metallic taste impression. Quantitation of the bitter components showed good correlation between the limonoid and flavanoid concentrations with the off-flavor and quality of the oranges obtained throughout the season.
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Johannes
authors.identifier: http://orcid.org/0000-0001-6020-5583
authors.initials: J
authors.lastname: Kiefl
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Kohlenberg
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Hartmann
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Obst
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Paetz
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Krammer
authors.affiliation: Symrise AG , Flavors Division Research & Technology , P.O. Box 1253, D-37601 Holzminden , Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Trautzsch
mesh_terms: D032084:Citrus sinensis / Q000737:chemistry* / Q000378:metabolism / Q000382:microbiology; D005421:Flavoring Agents / Q000737:chemistry* / Q000378:metabolism; D005638:Fruit / Q000737:chemistry / Q000378:metabolism / Q000382:microbiology; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D006801:Humans; D036701:Limonins / Q000737:chemistry / Q000378:metabolism; D009174:Mycoplasma / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology*; D013649:Taste
chemical_list: D005421:Flavoring Agents; D036701:Limonins
keywords: Citrus sinensis; LC Taste; citrus greening; flavanoids; gas chromatography−olfactometry; huanglongbing (HLB); limonin; off-flavor