nigella seed
spice or herb / spice-nigella-seed
ニゲラシード
Nigella seed (black seed), a spice. A source exists in which people rated the bitterness of oil pressed from the seeds, but no source that measured the seeds themselves has been found.
On this page (5 sections)
Reading the bitterness
For the bitterness of nigella (black seed, black cumin), the only human-rated source is one study of oil pressed from the seeds; no source measured the seeds themselves. Ten trained assessors scored 7 commercial cold-pressed black seed oil samples on a 0-10 scale. Mean bitterness scores ranged from 3.9-7.1 and differed significantly between samples. The bitterness reference was a 0.2% caffeine solution, set at an intensity of 7. The oils were 7 brands bought in Poland, with seeds from Poland, Egypt and India. The values come with a caution. The authors state that the sample with the highest score, 7.1, is suspected of being adulterated with linseed oil; without it the bitterness range is 3.9-6.5. The body of the methods says each assessor rated each sample 3 times, while the table note gives n = 20 (10 assessors x 2 sessions), so the numbers of repetitions disagree. In any case, this is an evaluation of oil and does not show the bitterness of the seeds or of cooked dishes.
In the same evaluation, astringency ranged from 4.6-9.0 and tingling pungency from 6.0-9.1, appearing as strongly as bitterness. The authors state that pungency, astringency and bitterness were moderate to high in all samples, and suggest that polyphenols and similar compounds may contribute. However, the components were not analyzed, and the reference cited to support the suggestion is a paper on the bitterness of olive oil, not on black seed. This paper does not state a relationship between thymoquinone and bitterness. The authors also used a quality scoring table for the oil. It tolerates slight bitterness and astringency even in oil rated good (4 points), and scores low the oils in which bitterness, astringency and tingling appear at low intensity (3 points), moderate intensity (2 points) and high to very high intensity (1 point). This is a criterion set by the researchers, not a measure of preference, and because it comes from the same paper it is not an independent confirmation.
On the taste of the seeds, 4 sources describe it as "slightly bitter, peppery taste", "pungent and bitter taste and smell", "bitter and aromatic taste" and similar. All are background descriptions without measurement, and some give no source for the taste description. Because tracing the original references may lead back to the same group of reviews, the 4 sources are not counted as independent confirmation. Neither the strength of the bitterness nor the components can be known from these descriptions.
Sources for this overview
Checked for this overview: Used for the mean scores and significant differences in paragraph 1, and for the suspected adulteration and the disagreement in numbers of assessors / Used for the ranges of astringency and pungency in paragraph 2, the authors' suggestion, and its limits / Used for the criteria of the quality scoring table in paragraph 2 and for the point that it is not independent
Spices and Essential Oils in Food Preservation: From Natural Additives to Active Packaging Systems
Checked for this overview: Used for the description "slightly bitter, peppery taste" in paragraph 3
Checked for this overview: Used for the background description "pungent and bitter" in paragraph 3
The Use of Nigella sativa in Cardiometabolic Diseases
Checked for this overview: Used for the description "pungent and bitter taste and smell" in paragraph 3
Checked for this overview: Used for the description "bitter and aromatic taste" in paragraph 3
Structured claims — open a section to read each claim's confidence, evidence and limits
Sensory (3)
Scope: 7 brands of oil bought in Poland (seeds from Poland, Egypt and India). Trained panel of 10 people, 10 cm scale (0 = not perceived, 10 = very strong).
Note: This is an evaluation of oil pressed from the seeds, not of the seeds or of cooked dishes. The authors suspect the sample with the highest score of being adulterated with linseed oil. The highest-scoring sample, 7.1 (CPBCO4), is suspected by the authors of linseed oil adulteration; without it the mean bitterness range is 3.9-6.5.
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spice-nigella-seed —has_sensory_attribute→ (the claim sentence above)Scope: 7 commercial cold-pressed black seed oil samples from Poland, trained panel of 10 people
Note: The component responsible for the bitterness was not identified, and the suggestion is the authors' discussion and was not tested. This paper does not state a relationship between thymoquinone and bitterness. The reference the authors cite to support the suggestion is a paper on polyphenols in the bitterness of olive oil, not on black seed.
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spice-nigella-seed —has_sensory_attribute→ (the claim sentence above)Scope: The scoring table (Table 2) used in the same study
Note: These are scoring criteria the researchers set themselves, not a measure of consumer preference. The row comes from the same paper and is not counted as an independent source.
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spice-nigella-seed —has_sensory_attribute→ (the claim sentence above)Culture (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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spice-nigella-seed —is_used_as→ (the claim sentence above)Scope: Statements in reviews and introductions (4 sources)
Note: All 4 are summaries of other sources or background descriptions, and none of these papers measured bitterness itself. The strength of the bitterness and the components are not given. Because tracing the original references may lead back to the same group of reviews, they are not counted as independent.
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spice-nigella-seed —has_sensory_attribute→ (the claim sentence above)