curly endive
ingredient / ingredient-endive
エンダイブ / endive
Curly endive is a leafy vegetable in the daisy family (Cichorium endivia). International standards divide it into 2 groups: curled-leaved and broad-leaved. A small-scale sensory test found bitterness felt weaker with an acidic dressing, and in Japanese, the word (from the French "endive") often refers to Belgian chicory instead.
On this page (10 sections)
Reading the bitterness
Endive (Cichorium endivia) is divided, in international standards for trading fresh produce, into 2 groups: curled-leaved endives (curled-leaved endives, a cultivar group derived from Cichorium endivia var. crispum) and broad-leaved endives (broad-leaved / Batavian endives, including escarole, a cultivar group derived from Cichorium endivia var. latifolium). Japanese sources also point out a confusion of terms: when Japanese simply says 「アンディーブ」 (in translation: "andību"), it often refers not to this endive but to Belgian chicory (witloof).
A correlation analysis of sensory evaluation and chemical analysis on a germplasm collection of endive found that 2 compounds, lactucopicrin and kaempferol malonyl glucoside, were consistently related to the perception of bitterness, astringency, and herbaceous flavor. Significant differences in bitterness, astringency, and herbaceous flavor were found among cultivars, with curled-leaved endive (curly endive) showing a higher average score than broad-leaved endive (escarole), particularly for bitterness. Overall preference showed a mainly negative correlation with bitterness. This has been checked only at the abstract stage; the full text has not been confirmed.
A small-scale sensory test using an acidic dressing is also on record. All 6 panelists who ate freshly harvested endive leaves plain chose the option 「噛んでいると苦味がでてくる」 (in translation: "bitterness comes out as you chew"), but when a commercial acidic non-oil shiso dressing was added, all 6 chose 「苦味は弱くなる」 (in translation: "the bitterness becomes weaker"). This was a small-scale test using a single product, with no mention of blinding or randomization.
A 2011 paper explains why endive 「噛んでいるうちに苦くなる」 (in translation: "gets more bitter the more you chew it") through a change in the composition of the latex. The latex in the leaves is rich in the weakly bitter lactucopicrin 15-oxalate, and the strongly bitter lactucopicrin makes up only 0.9% of the total. However, in chewed material made by pouring water over 8 g of leaves and chewing for 30 seconds, the proportion on the strongly bitter side had risen to 45.5%. When chewed with an acidic non-oil shiso (perilla) dressing poured on, it stayed at 3.9%, and in a sensory test with 6 panelists, everyone who ate it plain chose 「噛んでいると苦味がでてくる」 (in translation: "the bitterness comes out as you chew"), while everyone who had the dressing on it chose 「苦味は弱く感じる」 (in translation: "the bitterness feels weaker"). The paper's conclusion is that the strongly bitter component forms as it mixes with saliva in the mouth, and that the dressing's acid suppresses that formation.
Sources for this overview
Checked for this overview: UNECE FFV-22's division into 2 groups, curled-leaved and broad-leaved
Checked for this overview: The terminological confusion in which Japanese 「アンディーブ」 (in translation: "andību") often refers to witloof chicory
Checked for this overview: The relation of lactucopicrin and other compounds to bitterness, astringency, and herbaceous flavor, and curled-leaved endive scoring higher in bitterness than broad-leaved endive
Checked for this overview: All 6 panelists felt the bitterness weaker with the acidic dressing / Supports the explanation that the strongly bitter component increases with chewing: 2011, 0.9%, 8 g, 30 seconds, 45.5%. / Supports the 3.9% figure when chewed with the dressing poured on, and the conclusion that the acid suppresses formation. / Supports the two choice results from the sensory test with 6 panelists.
Other names: Cichorium endivia L. (la), キクヂシャ (ja, identification medium), ニガチシャ (ja, identification medium)
Follow the connections
hindiba salatasi →includes→ curly endive
curly endive →Records of are often confl…→ witloof chicory
curly endive →— perceived bitterness is a…→ lactucopicrin →contributes to→ bitterness
Hypotheses and recipe candidates for this entry are on the Japanese page.
Structured claims — open a section to read each claim's confidence, evidence and limits
Composition and content (2)
Scope: Scope categories in UNECE FFV-22 (an international fresh-produce trading standard).
Note: This is a scope definition in the standard itself, not a claim based on chemical analysis or sensory testing, so it is treated as contextual (in accordance with the research protocol's evidence hierarchy). The same standard includes lettuces, but this claim covers only the 2 endive groups.
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ingredient-endive —has_variant→ "Curled-leaved endives (a cultivar group derived from Cichorium endivia var. crispum Lam.) and broad-leaved (Batavian) endives or escaroles (a cultivar group derived from Cichorium endivia var. latifolium Lam.)."Scope: HPLC analysis of edible parts from 32 endive and 64 chicory accessions (comparison among cultivars and types).
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ingredient-endive —has_composition→ "HPLC measurements of edible parts of Cichorium endivia (curled-leaf var. crispum and broad-leaf var. latifolium; 32 accessions in total) found total sesquiterpene lactones ranging from 128–2045 mg/kg dry matter. The study quantified 6 compounds, including lactucin, lactucopicrin, 8-deoxylactucin, and their 11(S),13-dihydro derivatives, as well as 20 phenolic compounds. In 64 chicory accessions in the same study (headed radicchio, sugarloaf, leaf radicchio, and witloof), the range was 383–2497 mg/kg dry matter. Discriminant analysis clearly separated endive and chicory species, although witloof chicory was reported to show some features similar to endive."Sensory (2)
Scope: Sensory evaluation (bitterness, astringency, herbaceous flavor, overall preference) and chemical analysis correlation study on a germplasm collection of Cichorium endivia var. crispum (curly endive) and var. latifolium (escarole).
Note: According to the abstract, 2 compounds—lactucopicrin and kaempferol malonyl glucoside—were consistently related to perceptions of bitterness, astringency, and herbaceous flavor. Overall preference showed a significant negative correlation primarily with bitterness. Significant differences in bitterness, astringency, and herbaceous flavor were found among varieties, with curly endive scoring on average higher than escarole, particularly notably so for bitterness. The abstract also notes that the general statement 『セスキテルペンラクトンとフェノールが苦味等の決定要因』 (in translation: "sesquiterpene lactones and phenolics are determinants of bitterness and the like") is not fully consistent with the data, and that the balance of compounds has a complex effect (with a dominant negative contribution from phenolics).
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ingredient-endive —has_perceived_bitterness_associated_with→ compound-lactucopicrinScope: A sensory test with 6 panelists using endive leaves harvested that day and a commercial non-oil shiso dressing.
Note: A single product, 6 panelists, a fixed comparison order; no mention of blinding or randomization. This is not a direct sensory test of lettuce.
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ingredient-endive —has_perceived_bitterness_suppressed_by→ "An acidic commercial non-oil shiso dressing. In a sensory test of endive with 6 panelists, everyone chose the option that the dressing made the bitterness feel weaker."Mechanism and receptors (2)
Scope: Horie 2011, Tables 1 and 2. Leaves of endive (Takii Seed) harvested that day. For the chewed material, concentrations in the juice pressed out with a garlic press, n=4
Note: That L forms from LO under neutral to weakly alkaline conditions and is suppressed under weakly acidic conditions was confirmed by buffer extraction (proportion of L 1% or less, 4%, and 9% at pH 5.5, 6.5, and 7.5). The 45.5% seen after chewing cannot be explained by pH alone, and the authors note that the involvement of inorganic ions, enzymes, and microorganisms in saliva remains a topic for future work.
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ingredient-endive —has_bitterness_generated_by→ "That the strongly bitter lactucopicrin (L) forms from the weakly bitter lactucopicrin 15-oxalate (LO) in the latex as it mixes with saliva during chewing. In chewed material made by pouring 3 mL of water over 8 g of leaves and chewing for 30 seconds (about 60 chews), the proportion of L in the L+LO total reached 45.5% (LO 13.3 μM, L 11.0 μM). In the latex itself, L is only 0.9% of the total"Scope: Horie 2011, Table 2 and the main text. A comparison with the water control chewed at 45.5%, n=4. A non-oil dressing was used to avoid the possibility that fat would mask the bitterness
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ingredient-endive —has_debittering_most_likely_due_to→ "That the dressing's acid suppresses the formation of lactucopicrin (L) during chewing. In chewed material made by pouring 3 mL of a commercial non-oil shiso (perilla) dressing (pH 3.8) and chewing for 30 seconds, the proportion of L in the L+LO total stayed at 3.9% (LO 22.4 μM, L 0.9 μM), and the pH of the chewed material was 4.6–5.0. Leaves dipped for 3 seconds in 5% acetic acid also kept the proportion of L suppressed low"How processing and cooking change it (1)
Scope: A candidate structural component of a dish. Regional variation in ingredients is unconfirmed
Note: Source not connected. Does not indicate quantities or cooking conditions.
No source connected — this claim has not been verified yet. It is a general-knowledge placeholder, not a confirmed statement.
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dish-hindiba-salatasi —includes→ ingredient-endiveCulture (2)
Scope: A candidate at the level of general knowledge. Regional and naming differences have not been confirmed.
No source connected — this claim has not been verified yet. It is a general-knowledge placeholder, not a confirmed statement.
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ingredient-endive —is_used_as→ "A vegetable/ingredient carrying bitterness"Scope: The account in the Japanese Wikipedia article 「エンダイブ」 (in translation: "Endive").
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ingredient-endive —is_often_conflated_in_records_with→ ingredient-witloof-chicory