cheese
ingredient / ingredient-cheese
チーズ
Cheese is a ripened dairy product in which chymosin and proteinases and peptidases from starter cultures drive both the generation and breakdown of bitter peptides through casein degradation.
Photographs (captions in Japanese)
チーズの一種（スイスタイプ、気孔のある熟成チーズ）をくさび形に切り分けた写真。白い背景の上で断面の気孔と側面が見える。特定の産地・銘柄を代表する写真ではない。
写っているもの: 該当分類群なし（スイスタイプ熟成チーズの断面）部位・状態: スイスタイプ（気孔=ホールのある）チーズのくさび形カット、断面と側面が見える状態
写真: Renee Comet (Photographer)／ Public domain／ 原画像／ 台帳の原画像
写真の範囲と来歴
被写体の確認: 原典の記載による同定。原典は米国国立がん研究所(NCI)提供の一般的な「チーズ」写真で、品種名・産地の記載なし。「cheese」という広い名称全体の標準形として扱わない。
掲載画像: Wikimedia Commons の1920px版。苦味研究所では切り抜き・色調変更なし。 表示用には幅1200px上限のWebPを配信し、台帳の原画像は上のリンクから確認できます。
On this page (7 sections)
Reading the bitterness
The bitterness of aged cheese is described as arising in part from peptides (fragments of several linked amino acids) formed when casein, a milk protein, breaks down. A study of the water-soluble fraction of aged Gouda identified 16 bitter peptides derived from casein, of which 11 were from β-casein and 6 from αs1-casein. Another study of aged sharp Cheddar identified the 5 peptides with the greatest bitterness intensity; all were derived from β-casein.
However, the concentration of any individual peptide alone does not strongly account for bitterness intensity. In reduced-fat Cheddar, correlations between concentrations of individual peptides and trained-panel bitterness scores were limited to r=0.56–0.58, whereas an index combining two peptides reached r=0.84. The authors also acknowledge that other peptides may contribute to bitterness. Cheese bitterness cannot be attributed to a single peptide.
Consistent with this view, a reconstructed model made by adding 5 peptides at the same concentrations to young mild Cheddar was reported not to differ significantly in bitterness intensity from authentic aged sharp Cheddar. One peptide, GPVRGPFPIIV, increased 28.7-fold during aging and is described as a major contributor to bitterness. Another study reported a correlation of 0.803 at 180 days of aging between the concentration of a related β-casein-derived peptide and trained-panel bitterness ratings. By 270 days, however, the correlation had fallen to 0.554; the authors raised the possibility that other bitter peptides or bitterness-mitigating compounds were involved.
Cheese bitterness also depends on the type of enzyme carried by the lactic starter. In an experiment with reduced-fat Cheddar, cheeses were made with Lactococcus lactis strains differing in the specificity of lactocepin, an extracellular proteinase, and a trained panel of 14 rated bitterness. Cheese made with a strain lacking the proteinase scored 1.8, whereas cheeses made with strains carrying lactocepin scored 3.5–4.7; the difference was statistically significant at 6 months of aging. This was a model experiment using reduced-fat cheese and single-strain starters, however, and may not apply directly to ordinary cheeses.
In an exploratory experiment on bitterness-masking activity targeting cheese, among 71 commercial brands the natural white-mold-type Baraka cheese showed the strongest activity. In a sensory test in which Baraka was eaten immediately before taking a sip of beer, the weakening of bitterness was greater than with any of Gouda, Brie, or Ricotta, and when the free-fatty-acid concentrations of the 4 cheeses were compared, the total concentration was also higher in the order of stronger activity. When Baraka's oil was fractionated, the fraction whose main component was free fatty acids masked quinine's bitterness most strongly, and the same suppressive effect was confirmed with a mixture that mimicked the cheese's fatty-acid composition.
Home-cooking practices that combine cheese with bitter leafy greens are also recorded. A recipe introduction for a salad combining watercress with roasted almonds and Parmigiano mentions the combination of watercress's bitterness and the almonds' toasty aroma, and states that Parmigiano's saltiness and umami are used to finish the dish without adding salt. A recipe introduction for a dish in which shungiku (garland chrysanthemum) is dressed with grated cheese and ground sesame states that the cheese mellows the bitterness of the shungiku. Both are the cooks' own introductions and are not experiments that measured the interaction of bitterness and umami.
Sources for this overview
Sensomics mapping and identification of the key bitter metabolites in Gouda cheese
Checked for this overview: Checked the identification of 16 bitter peptides in aged Gouda and the breakdown by casein origin.
Identification of bitter peptides in aged cheddar cheese
Checked for this overview: Checked that the 5 most intensely bitter peptides identified in aged Cheddar were derived from β-casein. / Checked the reconstruction experiment finding no significant bitterness difference between the 5-peptide model and the authentic cheese.
Checked for this overview: Checked the difference in correlations for single-peptide and combined-peptide indicators. / Checked the differences in bitterness scores among lactocepin specificity groups.
Checked for this overview: Checked how correlations between a single peptide's concentration and bitterness changed with aging time.
Identification of bitterness-masking compounds from cheese
Checked for this overview: Used for the screening of 71 brands, the sensory comparison of 4 cheeses against beer, and the correspondence with free-fatty-acid concentration / Used for the figures on quinine bitterness suppression by the fatty-acid fraction and the mixed fatty-acid solution
Checked for this overview: Used for the quotation from the recipe introduction for watercress, almonds, and Parmigiano
Checked for this overview: Used for the quotation from the introduction to the shungiku dressed with sesame and cheese
Follow the connections
cheese →— bitterness derives in par…→ bitter peptides
bitterness →reduces taste preference for→ cheese
cheese →has a defining sensory theme→ bitterness →can be measured separately …→ astringency
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
Sensory (8)
Scope: Aged Gouda and aged sharp Cheddar (water-soluble extracts).
Note: The explanatory power of any single peptide alone is limited: in Broadbent 2002, the correlation between a single peptide's concentration and the bitterness score stayed at r=0.56-0.58, versus r=0.84 for a combined 2-peptide index (see limits).
Show data
ingredient-cheese —derives_bitterness_in_part_from→ compound-class-bitter-peptidesScope: Aged sharp Cheddar versus young mild Cheddar. A taste-reconstitution experiment.
Note: The sequences are as given in the abstract (residue numbers are not written because they are not given in the abstract).
Show data
compound-class-bitter-peptides —reconstitute_bitterness_of→ ingredient-cheeseScope: Experimental fresh cheese (CoF) made using reconstituted casein concentrated-milk media (protein 3.4% and 8.5% w/v). Sensory evaluation by a trained bitterness panel.
Note: This paper's conclusion section summarizes that "the PrtP-negative strains did not produce bitterness," but this is at odds, in the strength of the assessment, with the figures in the results section (see the corresponding evidence's limits line).
Show data
ingredient-cheese —develops_bitterness_depending_on→ "Fresh cheese made from high-protein concentrated milk fermented with extracellular-proteinase (PrtP)-positive Lactococcus lactis strains (LTH 7123, LTH 7122) showed bitterness scores of 3.9 and 4.1 (0 = no bitterness to 5 = extremely bitter; panel n≥12, i=2 replicates), significantly higher (p<0.05) than the 1.7 and 2.8 scores of cheese made with PrtP-negative strains (LTH 7117, LTH 7112). Cheese made with the PrtP-negative strains was also more bitter than a commercial fermented concentrated fresh-cheese reference product (FCo, bitterness 0.5). A control cheese acidified directly without fermentation (CoF) was rated at bitterness 1.0 (very slightly bitter), and there was no significant difference between CoF and FCo."Scope: Cheddar cheese, aged 6 months. Sensory evaluation was carried out at the 6-month point.
Show data
ingredient-cheese —develops_bitterness_depending_on→ "Cheddar cheese made with a nisin Z-producing strain (Lactococcus lactis subsp. lactis biovar diacetylactis UL719) incorporated into the starter showed increased sourness and bitterness in sensory evaluation compared with control cheese. The same strain increased the generation of both hydrophilic and hydrophobic peptides in the cheese's water extract."Scope: Trained-panel sensory evaluation of 25 commercially available U.S. shredded Cheddar brands (2 lots each), followed by consumer preference ratings of 10 representative brands by 151 consumers; analyzed with analysis of variance, principal component analysis, and external preference mapping.
Note: Bitterness was identified as one driver of overall dislike. A powdery appearance also lowered appearance and overall liking ratings.
Show data
sensation-bitter —reduces_taste_preference_for→ ingredient-cheeseScope: A study relating sensory profiles before and after heating to physicochemical parameters in 4 categories of AOP/PDO blue cheeses from France's Massif Central: Fourme d'Ambert, Fourme de Montbrison, Bleu d'Auvergne, and Bleu des Causses. Along with saltiness and sourness, bitterness was recorded as one of the basic tastes distinguishing these 4 categories after heating, and correlations with physicochemical parameters were also shown.
Note: The paper does not describe bitterness as either a 『欠陥』 (in translation: "defect") or a 『望ましい風味』 (in translation: "desirable flavor"). It treats it neutrally as an attribute distinguishing categories; this entry likewise does not overstate its significance. No peer-reviewed paper addressing bitterness in Gorgonzola itself was found, so the study of French AOP cheeses is included as a related blue-cheese lineage (see the corresponding research lead).
Show data
ingredient-cheese —has_defining_sensory_theme→ sensation-bitterScope: Layer: food. A human sensory panel (n=7) using 4 commercial cheeses and beer. Baraka was selected through a preliminary screening of 71 cheese brands.
Note: The correspondence between the total free-fatty-acid concentration and masking activity is a descriptive trend across 4 samples, and the fatty-acid composition ratio itself was nearly the same among the 4 cheeses (all shared the feature that oleic acid, palmitic acid, myristic acid, and stearic acid accounted for 60% or more of total free fatty acids). Details of the 71-brand screening results themselves are in the Supporting Information, and the main text gives no figures.
Show data
ingredient-cheese —can_reduce_perceived_bitterness_of→ sensation-bitterScope: Layer: solution (fractions of the cheese's oily extract; a mixture mimicking the cheese's fatty-acid composition). Human sensory evaluation (a method comparing against a 7-point scale of standard quinine solutions).
Note: The evaluation of the mixed fatty-acid solution had large variance among panelists (ANOVA F-test p=0.001). The authors cite the low solubility of the saturated fatty acids (myristic acid, palmitic acid, and stearic acid) as one cause. With oleic acid alone (0.5 mM), bitterness was suppressed down to the equivalent of 0.0032-0.0038%, and the variance among panelists was also small (F-test p=0.131) (a different part of the same experiment as the claim in the existing concept-taste-mixture-suppression entry).
Show data
ingredient-cheese —can_reduce_perceived_bitterness_of→ sensation-bitterHow processing and cooking change it (9)
Scope: 50% reduced-fat Cheddar, a single isogenic starter, a trained panel (n=14).
Note: A result from a model system (reduced-fat, single-strain starter). Extrapolation to ordinary cheese is limited.
Show data
ingredient-cheese —develops_bitterness_depending_on→ "Specificity groups of Lactococcus lactis lactocepin (an extracellular proteinase). Against proteinase-negative-strain cheese (bitterness 1.8/9), groups a/e/h scored 3.5-4.7 (at 6 months, P<0.0001), with group h the most bitter."Scope: A proposal envisaging high-protein fermented dairy products, including concentrated fresh cheese.
Note: Based on the statement 『a sensible selection and combination of prtP-positive and -negative starter strains might be a useful tool...and should be investigated in future studies』. This is not a demonstrated method.
Show data
ingredient-cheese —can_be_debittered_by→ "A proposed strategy of deliberately selecting and combining PrtP-positive and PrtP-negative Lactococcus lactis starter strains. The authors only propose this for future investigation; the paper itself did not experimentally test this combination design."Scope: Reduced-fat Cheddar cheese, ripened for 150 days. Chemical, microbiological, and sensory analyses were performed at regular intervals.
Note: The abstract does not give the specific score difference for "markedly lower," and the full text was not checked, so it is not written here.
Show data
ingredient-cheese —can_be_debittered_by→ "An integrated culture system combining 3 starter strains (Lactococcus lactis subsp. cremoris SK11, L. lactis subsp. lactis biovar diacetylactis JVI, and Lactobacillus casei 7A), with SK11 selected as the primary acid-producing strain. Cheese made with SK11 had markedly lower bitterness intensity than cheese made with a commercial Cheddar starter."Scope: An experiment conducted in South Africa. Aged Cheddar cheese compared across 4 groups: control, D. hansenii alone, Y. lipolytica alone, and both species combined.
Note: The specific sensory scale and panel size are not stated in the abstract.
Show data
ingredient-cheese —develops_bitterness_depending_on→ "Aged Cheddar cheese to which either Debaryomyces hansenii or Yarrowia lipolytica was added alone as an adjunct culture showed accelerated development of Cheddar-like flavor, but this was accompanied by the occurrence of bitterness as well."Scope: As above: the group combining both species in a 4-group comparative experiment in South Africa.
Note: The abstract does not explicitly say 『苦味を避けた』 (in translation: "avoided bitterness"). It only describes this group as having 『good strong flavour』, in contrast to the single-species groups; the absence of a mention of bitterness cannot establish 『苦味が生じなかった』 (in translation: "that no bitterness developed").
Show data
ingredient-cheese —can_be_debittered_by→ "A culture design incorporating both Debaryomyces hansenii and Yarrowia lipolytica into the starter at once. In contrast to adding either species alone, it was reported to yield cheese with good, strong Cheddar flavor even with a shortened aging period, and that flavor and aroma persisted for 9 months after production."Scope: Same as above (Cheddar cheese, aged 6 months).
Note: The combination that produced 『脱苦味効果』 (in translation: "a debittering effect") (Lb. casei + nisin-producing strain) and the combination rated as having 『風味強度が最高』 (in translation: "the highest flavor intensity") (Lb. casei + liposome-encapsulated nisin) are distinguished in the abstract, and this note is written so as not to conflate them.
Show data
ingredient-cheese —can_be_debittered_by→ "Cheddar cheese to which an adjunct culture of Lactobacillus casei-casei L2A was added in combination with a nisin Z-producing strain is reported to have shown a debittering effect and improved flavor quality. Separately, cheese to which Lb. casei and liposome-encapsulated nisin Z were added was rated highest in flavor intensity in sensory evaluation and ranked first."Scope: The same 1996 review of cheese bitterness.
Show data
ingredient-cheese —can_be_debittered_by→ "A review discusses in particular detail using selected Lactobacillus strains or their enzymes as adjuncts in the manufacture of accelerated-ripened cheese (ARC) or enzyme-modified cheese (EMC) to obtain products without bitterness."Scope: Layer: recipe (an introduction by a cook). Not a sensory experiment. Posted on the Japan Umami Seasoning Association's recipe site (Seiko Ogawa, 2020-04-02).
Note: What the original text explicitly links is the combination of 「クレソンの苦味」 (in translation: "the bitterness of the watercress") and 「アーモンドの香ばしさ」 (in translation: "the toasty aroma of the almonds"), and there is no direct statement that the cheese weakened the bitterness of the watercress. The role of the cheese is explained in the introduction as a substitute for salt and umami so the dish can be finished without added salt. This is recorded as the cook's practical knowledge, not as sensory data demonstrating the interaction of bitterness and umami.
Show data
ingredient-cheese —is_used_in→ sensation-bitterScope: Layer: recipe (an introduction by an instructor). Not a sensory experiment.
Note: This is a dressed dish involving salt-boiling, rinsing in water, ground sesame, soy sauce, and sugar, and is not a comparison isolating the cheese alone. The assessment 「まろやかにしてくれます」 (in translation: "mellows it") is stated by the instructor as a composite impression that includes the cheese's saltiness, umami, and fat content, and is not an experiment that measured the interaction of bitterness and umami.
Show data
ingredient-cheese —can_reduce_perceived_bitterness_of→ sensation-bitter