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)
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
Valorization of Citrus Peel Byproducts: A Sustainable Approach to Nutrient-Rich Jam Production
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.
Checked for this overview: Used for the bitterness scores of the juice (8.56/11.2/4.6, 0-15 scale)
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)
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").
Show data
seasoning-grapefruit-marmalade —is_documented_in→ "A 5-point liking evaluation by 31 people comparing 6 types of citrus-peel jam"Scope: Layer: food. An interpretation of chemical composition in the Discussion concerning grapefruit-peel jam (GPJ) among 6 citrus-peel jams.
Show data
seasoning-grapefruit-marmalade —has_perceived_bitterness_associated_with→ "Limonoids (a chemical-composition feature: present in greater amounts than flavanones)."Scope: Jeffries et al. 2025 (USDA-ARS). A bitterness sensory analysis of juice from orange, grapefruit, pummelo, tangelo, mandarin hybrids, Poncirus, and others.
Note: The subject is raw juice; this is not a study that measured grapefruit marmalade itself (a processed product made by heating and sweetening the peel). It is cited to place the bitterness of grapefruit itself, the raw material for marmalade, in context.
Show data
seasoning-grapefruit-marmalade —has_perceived_bitterness_associated_with→ "The bitterness of grapefruit juice has been confirmed in a sensory analysis in which a trained panel of 11 rated it on a 0-15 line scale together with multiple citrus cultivars and hybrids. The bitterness score of the grapefruit cultivar 'Florida Red' was 8.56, and the score for the quinine hydrochloride (11.5 mg/L) used as a reference was set at 7 on the scale. In the same test, the most bitter cultivar was the pummelo 'Melogold' at 11.2, and the least bitter was the Poncirus hybrid 'US119' at 4.6."Culture (1)
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 data
seasoning-grapefruit-marmalade —is_used_as→ "Seasonings that add a bitter dimension to dishes"