| Primary (First) - bitter |
| FL | 2- | acetyl-5-methyl pyrrole |
| | odor: earthy roasted |
| | flavor: bitter earthy roasted |
| FL | | amarogentin |
| | flavor: very bitter |
| FL | (2S,5R)-N-[4-(2- | amino-2-oxoethyl)phenyl]-5-methyl-2-(propan-2-yl)cyclohexanecarboxamide |
| | flavor: moderate throat and mouth cooling that lingers with some bitter notes in background. Cooling lasts with breath in for 30 minutes. |
| FL | | angostura bark oil |
| | flavor: burning bitter |
| | 4-( | azepane-1-carbonyl)-1-(2-isopropyl-5-methyl cyclohexyl) pyrrolidin-2-one |
| | flavor: bitterness and cooling effect and both built up |
| | 2- | benzoyl pyridine |
| | flavor: bitter musty |
| | 4- | benzyl pyridine |
| | flavor: bitter |
| | | benzyl sulfide |
| | flavor: bitter roasted |
| FL | | bitters flavor |
| | 1-(2-tert- | butyl cyclohexyl)-4-(piperidine-1-carbonyl) pyrrolidin-2-one |
| | flavor: some bitterness and drying, powdery, and minimal cooling effect |
| | 1-(2-tert- | butyl cyclohexyl)-4-(pyrrolidine-1-carbonyl) pyrrolidin-2-one |
| | flavor: upfront bitterness, quinine, drying, greasy, and burning effect |
| FL | | campari flavor |
| FL | | chicory flavor |
| FL | | chicory root distillates |
| | flavor: chicory |
| | | cimicifuga racemosa root distillates |
| FD | red | cinchona bark |
| | odor: brown maple woody botanical rooty |
| | flavor: bitter astringent maple brown tea woody |
| FL | | cocoa distillates |
| | odor: sweet sulfury cocoa nutty chocolate creamy |
| | flavor: cocoa |
| FL/FR | | cocoa hexenal |
| | odor: aldehydic bitter cocoa nut skin green sweet chocolate fruity butyric |
| | flavor: Bitter cocoa, honey, aldehydic, coffee and nutty with a green nuance |
| FL/FR | | cocoa oleoresin |
| | odor: dark bitter cocoa chocolate powdery earthy coffee roasted |
| | flavor: bitter powdery cocoa earthy |
| FL | | cocoa pyrazines base (mixture of pyrazines) |
| | odor: nutty bitter chocolate |
| | flavor: bitter nutty chocolate |
| | 2,6- | diacetyl pyridine |
| | flavor: bitter, coffee-like |
| FL/FR | | dibenzyl ketone |
| | odor: bitter almond benzaldehyde plastic seedy |
| | flavor: Bitter with floral, rose and honey notes |
| | 2,3- | diethyl quinoxaline |
| | flavor: bitter earthy |
| FL | 3,4- | dihydroxybenzaldehyde |
| | odor: dry medicinal bitter almond |
| | flavor: bitter apricot seed |
| | 2,6- | dimethyl-dithio-gamma-pyrone |
| | flavor: bitter |
| | 2-(2- | ethoxyethyl) pyridine |
| | flavor: bitter, astringent, basic |
| FL/FR | | fenugreek oleoresin |
| | odor: sweet maple lovage caramellic cocoa coffee roasted molasses parsley |
| | flavor: bitter brown maple lovage molasses roasted coffee |
| FL/FR | | frankincense gum papyrifera |
| | odor: woody incense woody terpenic resinous |
| | flavor: bitter |
| FD | | glucose pentaacetate |
| | flavor: Bitters-like, with a citrus tonic flavor |
| FL | | glyceryl tributyrate |
| | odor: Cheese, waxy, fatty, acidic |
| | flavor: Bitter, waxy, fatty, cheese and butter nuances |
| | | helenalin |
| | flavor: bitter |
| | 2- | hydroxymethyl-6-methyl-pyridine |
| | flavor: bitter, burnt, coffee-like |
| FL | bitter | lemon flavor |
| FD | dextro,laevo-iso | leucine |
| | flavor: bitter |
| | 2- | methyl-5-acetyl-pyrrole |
| | flavor: bitter, earthy, roasted |
| | 7- | methyl-1-benzofuran-2-carbaldehyde |
| | flavor: bitter, earthy |
| | 2- | methyl-3-butyl quinoxaline |
| | flavor: bitter acidic woody |
| | 2- | methyl-3-isobutyl quinoxaline |
| | flavor: bitter earthy woody |
| | 1-(2- | methyl cyclohexyl)-5-oxopyrrolidine-3-carboxylic acid methyl ester |
| | flavor: slight upfront bitterness for .about.20-30 seconds and mild cooling effect that slightly built up in a few minutes |
| FL | | methyl ethoxypyrazine |
| | odor: nutty hazelnut nut skin almond earthy pineapple |
| | flavor: bitter, fruity, anise-like |
| | 4-(5- | methyl-2-furyl)-2-butanone |
| | flavor: bitter, roasted |
| | 2- | methyl-3-pentyl quinoxaline |
| | flavor: bitter earthy fatty |
| | 2- | methyl-3-propyl quinoxaline |
| | flavor: bitter acidic earthy |
| | 2- | methyl-3-isopropyl quinoxaline |
| | flavor: bitter astringent |
| | 2- | methyl-6-vinyl pyridine |
| | flavor: bitter earthy roasted |
| CS | | nicotinyl alcohol |
| | flavor: bitter, green |
| FL | 1,3- | octane diol |
| | flavor: bitter |
| FD | alpha-dextro- | pentaacetyl glucose |
| | flavor: Bitters-like, with a citrus tonic flavor |
| FL/FR | | peru balsam resinoid |
| | odor: sweet balsamic cinnamyl vanilla amber powdery woody resinous |
| | flavor: bitter warm balsam cinnamon woody vanilla leather |
| FD | laevo- | phenyl alanine |
| | flavor: slightly bitter |
| | 4- | phenyl pyridine |
| | flavor: bitter caramellic |
| | 1-(2-iso | propyl-5-methyl cyclohexyl)-4-(piperidine-1-carbonyl) pyrrolidin-2-one |
| | flavor: slight upfront bitterness, herbaceous flavor, and built-up cooling effect |
| | 1-(2-iso | propyl-5-methyl cyclohexyl)-5-(piperidine-1-carbonyl) piperidin-2-one |
| | flavor: grapefruit-like bitterness, and very mild cooling and drying effect |
| | 1-(2-iso | propyl-5-methyl cyclohexyl)-5-(pyrrolidine-1-carbonyl) piperidin-2-one |
| | flavor: slight cooling, and bitter and drying effect |
| FD | | propylene glycol diacetate |
| | odor: fruity acetic |
| | flavor: bitter sweet |
| CS | 3- | pyridine carboxaldehyde |
| | flavor: bitter astringent |
| | 2-( | pyridyl-2)-methanethiol acetate |
| | flavor: bitter fatty |
| | 2-( | pyridyl-2)-methyl methyl sulfide |
| | flavor: bitter, green, earthy |
| | ( | pyrrolyl-2)-propan-1,2-dione |
| | flavor: bitter, roasted peanut |
| FL | | quassia amara bark extract |
| | odor: woody phenolic animal bitter chemical burnt medicinal balsamic |
| | flavor: bitter astringent medicinal fruity herbal green earthy |
| CS | | quinine |
| | flavor: bitter |
| FL/FR | | rhamnus purshiana bark extract |
| | flavor: bitter woody grassy dried fruit tea leafy herbal |
| FL | | terpin anhydrous |
| | flavor: bitter |
| FL/FR | | terpinyl isovalerate |
| | odor: sweet pine olibanum incense orange citrus |
| | flavor: bitter apple fruity |
| FL | | theobromine |
| | flavor: bitter |
| FL/FR | (E,Z,Z)-2,4,7- | tridecatrienal |
| | odor: citrus peel waxy fatty oily fruity |
| | flavor: bitter waxy sweet |
| | | trimethyl citrate |
| | odor: ethereal fruity |
| | flavor: bitter |
| FL | | twinberry flavor |
| Secondary (Second) - bitter |
| | 4- | benzoyl pyridine |
| | flavor: astringent bitter musty |
| FL | bitter | chocolate flavor |
| FL | bittersweet | chocolate flavor |
| FL/FR | | citronellyl oxyacetaldehyde |
| | odor: fresh sweet waxy floral aldehydic honeysuckle muguet |
| | flavor: Citrus, bitter, floral with a slight soapy and woody nuance |
| FL | | cocoa flavor |
| FR | iso | cyclogeraniol (IFF) |
| | odor: spice floral carnation herbal green woody |
| | flavor: camphoraceous and bitter flavor |
| | 1,2- | dimethyl-5-acetyl-pyrrole |
| | flavor: fatty, bitter, roasted |
| | 1- | furfuryl-pyrrole-3-aldehyde |
| | flavor: astringent, bitter |
| FD | | glyceryl tripropanoate |
| | odor: Oily with a slight chemical nuance |
| | flavor: Oily, bitter with a fatty nutty aftertaste |
| FL | | horehound flavor |
| FL/FR | (Z)- | jasmone |
| | odor: woody herbal floral spicy jasmin celery |
| | flavor: Woody, bitter, tea, with a citrus and floral nuance |
| FD | | magnesium sulfate |
| | flavor: salty bitter |
| | 2- | methyl-3-ethyl quinoxaline |
| | flavor: hazelnut bitter roasted |
| FL/FR | | nerol |
| | odor: sweet natural neroli citrus magnolia |
| | flavor: lemon, bitter, green and fruity with a terpy nuance |
| FL | | paullinia cupana seed extract |
| | odor: rooty cocoa tobacco |
| | flavor: astringent bitter cereal nutty cocoa woody rooty |
| FL | | peru balsam |
| | odor: sweet balsamic vanilla woody powdery resinous |
| | flavor: balsamic bitter woody resinous |
| | 2-( | pyridyl-2)-ethyl methyl sulfide |
| | flavor: mushroom, bitter, green |
| FL | | quassia amara wood extract |
| | flavor: earthy bitter |
| FL/FR | | terpinyl valerate |
| | odor: fruity floral |
| | flavor: apple bitter sweet |
| FL/FR | | theobroma cacao extract |
| | odor: cocoa roasted powdery beany |
| | flavor: cocoa bitter powdery brown beany |
| Tertiary (Third) - bitter |
| | alpha- | allyl-4-methyl-3-cyclohexene-1-methanyl acetate |
| | odor: green, oriental, floral aroma |
| | flavor: green, floral and bitter flavor |
| FL | wild | cherry bark distillates |
| FL | | cherry guarana flavor |
| FL | | chocolate distillates |
| | flavor: chocolate |
| FL | | chocolate enhancers |
| | flavor: chocolate |
| FL | | chocolate flavor |
| FL/FR | | gentiana lutea root extract |
| | flavor: green earthy bitter resinous |
| FL | | ginseng distillates |
| | flavor: ginseng |
| FL/FR | | immortelle absolute |
| | odor: warm sweet caramel hay fruity honey tobacco tonka |
| | flavor: Green, tobacco, bitter, with an astringent brown fruity nuance, incense notes |
| FL | | juglans nigra shell extract |
| | flavor: brown roasted bitter earthy |
| FL/FR | | levisticum officinale root extract |
| | odor: Sweet, green, celery-like, with a brown herbal nuance |
| | flavor: Celery-like, with a bitter green and maple botanical nuance |
| FL | | limequat flavor |
| FL | bitter | orange flavor |
| FL/FR | bitter | orange peel oil brazil |
| | odor: citrus orange dry woody mandarin cognac terpenic aromatic |
| | flavor: Bitter, fruity, Madeira, cognac and woody with aromatic nuances |
| FL/FR | | prunus serotina bark extract |
| | flavor: woody fruity bitter |
| FL | | viburnum prunifolium extract |
| | flavor: woody earthy bitter |
| Quaternary (Fourth) - bitter |
| FL/FR | | camellia oleifera leaf extract |
| | flavor: fresh brewed tea green leafy bitter floral |
| FL | | citron flavor |
| FL/FR | | coffea arabica seed extract |
| | odor: coffee mocha |
| | flavor: coffee |
| FL | | cranberry distillates |
| | flavor: cranberry |
| FL | | cranberry flavor |
| FL | | cranberry fractions |
| | flavor: cranberry |
| | 1,8- | dimethoxy-para-menthane |
| | odor: sweet fruity minty green musty |
| | flavor: nutty fruity minty bitter musty waxy green citrus sweet sandalwood |
| FL | | elder berry flavor |
| | 2- | ethyl thiopyridine |
| | flavor: green, acid, cereal, bitter, sour |
| FL | | grapefruit flavor |
| FL/FR | | grapefruit oil c.p. california |
| | odor: sweet dry citrus bitter aldehydic terpenic fruity tropical orange |
| | flavor: grapefruit |
| FL/FR | | grapefruit oil replacer |
| | odor: grapefruit |
| | flavor: grapefruit |
| FL/FR | 2- | heptanol |
| | odor: fresh lemon grass herbal sweet floral fruity green |
| | flavor: fruity green earthy bitter |
| FL/FR | dextro,laevo- | muscone |
| | odor: sweet musk animal powdery fatty natural |
| | flavor: sweet, musk like, perfume, soapy with woody and bitter nuances |
| FL/FR | (+)- | nootkatone |
| | odor: grapefruit peel citrus gardenia woody |
| | flavor: Grapefruit, citrus, orange and bitter |
| FL | green | pepper distillates |
| | odor: cooked pepper bell pepper |
| | flavor: green watery weedy bitter vegetable roasted |
| FL | green | pepper flavor |
| Quinary (Fifth) - bitter |
| FL | | acer spicatum bark extract |
| | odor: sweet tobacco maple burnt |
| | flavor: brown roasted maple woody bitter caramellic fruity herbal |
| FL | green | banana flavor |
| FL | | broccoli flavor |
| FL/FR | roasted arabica | coffee bean oil |
| | odor: dark roast brewed coffee |
| | flavor: Beany roasted coffee with an astringent brown bitter afternote |
| FL | | lettuce flavor |
| FL | 2- | methyl thiophene |
| | odor: sulfurous alliaceous onion roasted green |
| | flavor: sulfurous roasted green cabbage onion bitter |
| Senary (Sixth) - bitter |
| FL | | apple cranberry flavor |
| FL/FR | | benzyl alcohol |
| | odor: floral rose phenolic balsamic |
| | flavor: chemical fruity cherry almond balsamic bitter |
| FL/FR | | hydroxycitronellol |
| | odor: mild clean floral lily green peony |
| | flavor: sweet powdery floral green dusty clean bitter |
| FL | | peanut oxazole |
| | odor: Musty, nutty, vegetative, cocoa, brown, bready and caramellic |
| | flavor: Musty, nutty, cocoa, brown, vegetative and bready with a slight bitter nuance |
| Septenary (Seventh) - bitter |
| FL | | cucumber flavor |
| FL/FR | | guaiacwood oil |
| | odor: sweet dry woody spicy powdery balsamic tea rose oriental copaiba |
| | flavor: woody balsamic spicy peppery powdery oily bitter resinous |
| FL | | hop flavor |
| Octonary (Eighth) - bitter |
| FL/FR | | vanilla bean absolute CO2 extract (vanilla planifolia) |
| | odor: sweet vanilla toffee custard creamy gourmand balsamic powdery marshmallow |
| | flavor: sweet vanilla tropical custard creamy gourmand balsamic cocoa bitter |