caffeoyl quinides
compound class / compound-class-quinides
カフェオイルキニド類（クロロゲン酸ラクトン）
Bitter lactone compounds generated from chlorogenic acids (caffeoylquinic acids) during coffee roasting. They exhibit a coffee-like bitter profile.
On this page (7 sections)
Reading the bitterness
During coffee bean roasting, 3-, 4-, and 5-O-caffeoylquinic acids (CQA) and dicaffeoylquinic acids with multiple caffeoyl groups (diCQA) undergo esterification, isomerization, and lactonization to transform into mono- and dicaffeoyl quinides (CQL, diCQL). One paper positions these quinide compounds as bitter-tasting substances, but this description is based on prior research cited in that paper and does not represent new bitterness measurement in the paper itself.
In a study examining extracts from systematically varied roasting conditions, mono- and dicaffeoyl quinides are generated preferentially in light to medium roasting, then undergo degradation at stronger roasting levels to transform into 4-vinyl catechol oligomers, another bitter-tasting component. This transformation matched the change in bitter quality observed in sensory evaluation. In a separate study, a new bitter lactone, 3-O-caffeoyl-epi-gamma-quinide, was isolated and characterized from a model system of 5-caffeoylquinic acid subjected to dry heating. Its recognition threshold for bitterness was 58 µmol/L, and it was confirmed as the 6th bitter quinide—in addition to 5 known caffeoyl quinides—to be present in coffee beverages. Both findings are confirmations within the scope of abstracts.
In a separate study tracking the roasting process of 2 arabica varieties and robusta, 7 chlorogenic acid lactones (quinides) were identified: 3-CQL, 4-CQL, 3-pCoQL, 4-pCoQL, 3-FQL, 4-FQL, and 3,4-diCQL. The most abundant, 3-CQL, reached maximum concentration (arabica 230±9, robusta 254±4 mg/100 g) at a light-to-medium roast level corresponding to approximately 14% weight loss. The maximum total production of quinide compounds reached approximately 30% of the precursor chlorogenic acid content. The second most abundant, 4-CQL, was present at arabica 116±3 and robusta 139±2 mg/100 g. The reversal in the ratio of 3-CQL to 4-CQL content from their ratio in raw beans suggests a pathway involving isomerization followed by lactonization during roasting. This quantification was confirmed within the scope of abstracts, and did not include measurement of bitterness itself.
In a study examining 19 samples of raw and roasted beans from arabica and robusta varieties grown in Brazil, Colombia, Ethiopia, and Guatemala using high-resolution mass spectrometry, 2 dicaffeoyl quinide (diCQL) isomers (3,4-di-O-caffeoyl-1,5-quinide and 4,5-di-O-caffeoyl-1,3-quinide) were tentatively identified. The authors cite prior research and state that similar isomers have been reported in roasted coffee beans as bitter compounds, but this statement is based on citation of prior research and does not represent new bitterness measurement in this study itself.
Sources for this overview
Impact of Interactions between Melanoidins and Caffeine on the Bitter Taste of Coffee Beverages
Checked for this overview: Used for the description of the pathway generating quinide compounds from CQA/diCQA.
Checked for this overview: Used for the switching between quinide generation and degradation as roasting level changes.
Checked for this overview: Used for the isolation of a new quinide and its recognition threshold of 58 µmol/L.
Effect of Roasting on the Formation of Chlorogenic Acid Lactones in Coffee
Checked for this overview: Used for the maximum 3-CQL content by roasting level and the suggested pathway for its generation. / Used for the names of 7 chlorogenic acid lactones (CGL) and the numerical content of 4-CQL.
Checked for this overview: Used for the tentative identification of 2 diCQL isomers by mass spectrometry.
Follow the connections
caffeoyl quinides →contributes to→ bitterness →can be measured separately …→ astringency
Structured claims — open a section to read each claim's confidence, evidence and limits
Composition and content (1)
Scope: Layer: Food. Raw beans and roasted beans from C. arabica and C. robusta grown in Brazil, Colombia, Ethiopia, and Guatemala; 19 samples total.
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compound-class-quinides —is_documented_as_having→ "Analysis of 19 coffee raw bean and roasted bean samples using QToF-MS resulted in the identification of 2 dicaffeoyl quinide (diCQL) isomers (3,4-di-O-caffeoyl-1,5-quinide and 4,5-di-O-caffeoyl-1,3-quinide) as peaks. Prior research has reported similar isomers in roasted coffee beans as bitter compounds."How processing and cooking change it (2)
Scope: Formed preferentially at light-to-medium roast. At heavy roast it decomposes, generating harsh-bitter 4-vinylcatechol oligomers
Note: The chemical basis for how the bitterness signature of coffee changes with roast degree and extraction conditions.
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compound-class-quinides —contributes_to→ sensation-bitterScope: Layer: Literature. Background description of the pathway by which quinide compounds are generated from chlorogenic acids in roasted coffee.
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compound-class-quinides —contributes_to→ sensation-bitter