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grapefruit marmalade

seasoning / seasoning-grapefruit-marmalade

グレープフルーツ・マーマレード

Grapefruit marmalade is a jam or marmalade using grapefruit peel. Consumer acceptance has been compared, but that is separate from direct assessment of bitterness intensity.

On this page (5 sections)
  1. Overview
  2. Sources for this overview (3)
  3. Related entries (5)
  4. Sensory (3)
  5. Culture (1)
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Reading the bitterness

6 citrus-peel jams, including grapefruit-peel jam, were compared by a semi-trained panel of 31 using a 5-point liking scale. The evaluated attributes were color, taste, texture, aroma, and overall acceptability; while this shows that the grapefruit product was tested and gives a comparison of acceptability, it is not a test that measured bitterness intensity as an independent attribute.

In the Discussion of the same material, it is explained that grapefruit-peel jam has a composition low in flavanones and high in limonoids, and that this contributes to bitterness. This description accompanies the interpretation of chemical composition; it is not a bitterness-intensity value measured by the panel, and it does not quantify the relationship between limonoid amount and perceived intensity.

Naringin and limonin, abundant in grapefruit peel, are major bitter compounds of citrus. In a sensory analysis of raw grapefruit juice, the bitterness score (0-15 line scale) of the cultivar 'Florida Red' was 8.56, lower than the pummelo 'Melogold' (11.2) in the same test and higher than the Poncirus hybrid 'US119' (4.6). Treatment with naringinase reduces the naringin concentration of grapefruit juice by 54-74% and the limonin concentration by 76-100%. Both are studies of raw juice, not measurements of marmalade itself.

Sources for this overview

  1. Valorization of Citrus Peel Byproducts: A Sustainable Approach to Nutrient-Rich Jam Production

    Negrea Monica; Cocan Ileana; Jianu Calin; Alexa Ersilia; Berbecea Adina; Poiana Mariana-Atena; Silivasan Marius / 2025 / journal article / full text checked

    Checked for this overview: Matched the 6 jams, 31 panelists, 5-point liking scale, and evaluated attributes with the limitation that bitterness intensity was not measured. / Matched the discussion of bitterness accompanying flavanone and limonoid composition with the limitation that sensory intensity was not measured.

  2. Flavonoid contributors to bitterness in juice from Citrus and Citrus hybrids with/without Poncirus trifoliata in their pedigree

    Jeffries KA; Fan Z; Mattia M; Stover E; Baldwin E; Manthey JA; Breksa A; Bai J; Plotto A / 2025 / journal article / full text checked

    Checked for this overview: Used for the bitterness scores of the juice (8.56/11.2/4.6, 0-15 scale)

  3. Grapefruit Debittering by Simultaneous Naringin Hydrolysis and Limonin Adsorption Using Naringinase Immobilized in Agarose Supports

    Munoz M; Holtheuer J; Wilson L; Urrutia P / 2022 / journal article / full text checked

    Checked for this overview: Used for the reduction rates of naringin and limonin from enzymatic treatment (54/74/76/100%)

Structured claims — open a section to read each claim's confidence, evidence and limits

Sensory (3)

grapefruit marmalade is documented in A 5-point liking evaluation by 31 people comparing 6 types of citrus-peel jamsupported

Scope: The existence of grapefruit peel jam (GPJ) and its consumer acceptability

Note: Bitterness intensity itself was not directly measured, so this is not stated as 『苦味が好まれた』 (in translation: "the bitterness was preferred").

A semi-trained panel of 31 rated 6 types, including grapefruit peel jam, on a 5-point liking scale.
Limitations: Bitterness intensity was not measured separately. Within the source, section 4.5 calls PPJ (pomelo) a grapefruit jam and the GPJ scores differ between sections 3.5 and 4.5, so abbreviations were checked against the original table.
Source: Valorization of Citrus Peel Byproducts: A Sustainable Approach to Nutrient-Rich Jam Production (Negrea Monica; Cocan Ileana; Jianu Calin; Alexa Ersilia; Berbecea Adina; Poiana Mariana-Atena; Silivasan Marius, 2025) · full text checked
Show dataseasoning-grapefruit-marmalade —is_documented_in→ (the claim sentence above)
claim: clm-grapefruit-peel-jam-panel / type: sensory / updated: 2026-08-31
grapefruit marmalade — perceived bitterness is associated with: Limonoids (a characterization, based on cited references, that grapefruit peel has less flavanone and more limonoid than other citrus; it does not mean that limonoids exceed flavanones).contextual

Scope: Layer: food. An interpretation of chemical composition in the Discussion concerning grapefruit-peel jam (GPJ) among 6 citrus-peel jams.

Context: "...characterized by lower flavanone and higher limonoid content, which contributes to bitterness..."
Limitations: This paper measured neither sensory bitterness intensity nor limonoid content; the sentence is a Discussion remark accompanying a characterization, based on cited references, that grapefruit has less flavanone and more limonoid than other citrus (it does not mean that limonoids exceed flavanones). It addresses a different aspect from the existing clm-grapefruit-peel-jam-panel 5-point preference rating.
Source: Valorization of Citrus Peel Byproducts: A Sustainable Approach to Nutrient-Rich Jam Production (Negrea Monica; Cocan Ileana; Jianu Calin; Alexa Ersilia; Berbecea Adina; Poiana Mariana-Atena; Silivasan Marius, 2025) · full text checked
Show dataseasoning-grapefruit-marmalade —has_perceived_bitterness_associated_with→ (the claim sentence above)
claim: clm-w72b2-grapefruit-jam-limonoid-bitterness / type: sensory / updated: 2026-10-21
grapefruit marmalade — perceived bitterness is associated with: This study's sensory analysis does not confirm grapefruit juice bitterness: Jeffries et al. 2025 had 11 trained panellists rate citrus juices on a 0–15 line scale, but grapefruit 'Florida Red' was not presented for lack of sample. In the same test the most bitter was pummelo 'Melogold' at 11.2 and the least bitter Valencia at 1.5.preliminary

Scope: Jeffries et al. 2025 (USDA-ARS). A bitterness sensory analysis of juice from orange, grapefruit, pummelo, tangelo, mandarin hybrids, Poncirus, and others.

Note: 2026-10-21 (spreading stage N5, step C, batch 1): re-reading the full text showed that the earlier 'Florida Red bitterness score 8.56' was the sugar content in Table 2, and Florida Red was not presented to the sensory panel. As it cannot support grapefruit bitterness, the claim was lowered from supported to preliminary and the evidence relation set to contextualizes.

Context: 11 trained panellists rated citrus juice bitterness on a 0–15 line scale (11.5 mg/L quinine hydrochloride set at 7). The most bitter was pummelo 'Melogold' at 11.2 (sharing significance letter a with 2 samples at 10.2) and the least bitter Valencia at 1.5, with US119 at 4.6. Grapefruit 'Florida Red' was not presented to the panel for lack of sample (the 8.56 previously in the ledger is the sugar content in Table 2, not a bitterness score).
Limitations: The subject is raw juice, not marmalade itself. Grapefruit is represented by only 1 cultivar ('Florida Red') in this test.
Source: Flavonoid contributors to bitterness in juice from Citrus and Citrus hybrids with/without Poncirus trifoliata in their pedigree (Jeffries KA; Fan Z; Mattia M; Stover E; Baldwin E; Manthey JA; Breksa A; Bai J; Plotto A, 2025) · full text checked
Show dataseasoning-grapefruit-marmalade —has_perceived_bitterness_associated_with→ (the claim sentence above)
claim: clm-grapefruit-marmalade-juice-sensory-bitterness / type: sensory / updated: 2026-09-25

Culture (1)

grapefruit marmalade is used as Seasonings that add a bitter dimension to dishesunverified

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.

Show dataseasoning-grapefruit-marmalade —is_used_as→ (the claim sentence above)
claim: clm-seasoning-grapefruit-marmalade-candidate-role / type: cultural / updated: 2026-08-31

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