Property glossary

• Nitrogen solubility index (NSI)

  10. Solubility and dispersibilitySolubility

  nitrogen solubility index

  Percentage of total nitrogen that is water-soluble under the standardized NSI protocol (slow stir). Assay-specific; not interchangeable with protein solubility measured by other protocols.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: nsi

  Method context: Standardized slow-stir NSI protocol; not interchangeable with other solubility protocols.

  Related, never merged by default: Protein solubility; Protein dispersibility index (PDI)

  Note: Seeded as its own term in the database ontology (migration 0009). Kept separate from generic protein solubility because the standardized protocol defines the number.

• Protein dispersibility index (PDI)

  10. Solubility and dispersibilitySolubility

  protein dispersibility index

  Percentage of total protein dispersible in water under the standardized PDI protocol (fast stir). PDI and NSI values from one sample differ; neither is converted to the other.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: pdi

  Method context: Standardized fast-stir PDI protocol; not interchangeable with NSI.

  Related, never merged by default: Protein solubility; Nitrogen solubility index (NSI); Polydispersity index (DLS)

  Note: NOT the DLS polydispersity index, which shares the abbreviation PDI and nothing else. See the ambiguous alias.

• Protein solubility

  10. Solubility and dispersibilitySolubility

  solubility

  Fraction of protein that stays in solution under the stated conditions (nitrogen solubility index, protein solubility).

  Units, basis and methodShowHide

  Accepted source units: %, mg/mL, g/L

  Canonical unit: %

  Dimension: percent, mass_volume_concentration

  Also written: protein solubility; solubility (%); soluble protein content

  Basis: A percent is soluble/total per the study definition; mg/mL and g/L state the soluble concentration and are never rewritten as %.

  Method context: Dispersion, stir and centrifugation protocol; NSI and PDI are separate standardized assays.

  Typical conditions: pH, ionic strength, temperature

  Related, never merged by default: Nitrogen solubility index (NSI); Protein dispersibility index (PDI)

  Note: A percent solubility is a percent of the study's own definition (soluble/total). It is never rewritten as % w/w. A solubility reported as a concentration (soluble protein content, mg/mL or g/L) is a different quantity and is stored as reported — mg/mL is never converted to % without the total protein, which is not part of the unit.

• Fat absorption capacity (FAC)

  7. Oil- and fat-interaction propertiesHydration & bindingsource unit preserved

  fat absorption capacity

  Fat absorbed by the sample under the study's protocol. Named separately from oil absorption capacity because the lipid differs: papers reporting a FAT absorption often use a semi-solid fat whose uptake is not the uptake of a liquid oil. Merged with oil absorption capacity only where the paper shows they used the same liquid oil and protocol.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: fac

  Basis: Denominator basis (per g sample vs per g protein) is study-defined; mL/g is never converted to g/g without the fat density, which is temperature-dependent.

  Carried with every value: denominator_substance

  Method context: The FAT and its state at the test temperature (a rendered fat is not a liquid oil), plus the absorption and separation protocol.

  Related, never merged by default: Oil absorption capacity (OAC); Oil holding capacity; Oil binding capacity (OBC)

  Note: Record WHICH fat or oil, and its temperature, in measurement_method.

• Hydration capacity

  6. Water-interaction propertiesHydration & bindingsource unit preserved

  hydration capacity

  Water taken up by the sample on hydration, as the study reports it, where the source does not identify the protocol as holding, absorption, binding or swelling. Related to all four and merged with none of them by default.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Basis: Denominator (per g sample vs per g protein) and dry vs as-is basis are study-defined and mandatory when the source states them; mL/g is never converted to g/g without the liquid density.

  Carried with every value: denominator_substance

  Method context: The hydration protocol as the authors named it. This term exists for sources that report "hydration capacity" WITHOUT specifying holding, absorption or binding; it is not a parent of those three and no value is moved between them.

  Related, never merged by default: Water holding capacity; Water absorption capacity (WAC); Water binding capacity (WBC); Swelling capacity

  Note: NO universal unit. Recorded under the authors' own term; promoting it to WHC, WAC or WBC is a reviewer decision made on the paper's method, never an import default.

• Oil absorption capacity (OAC)

  7. Oil- and fat-interaction propertiesHydration & bindingsource unit preserved

  oil absorption capacity

  Oil absorbed by the sample under the study's absorption protocol. Reported like oil holding capacity, but the protocols differ (absorption vs retention after separation), so the two are related concepts and are never merged by default.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: oac

  Basis: Denominator basis (per g sample vs per g protein) is study-defined; mL/g is never converted to g/g without the oil density.

  Carried with every value: denominator_substance

  Method context: Absorption protocol (excess vs limited oil, centrifugation force and time) and the OIL TYPE define the number.

  Related, never merged by default: Oil holding capacity; Oil binding capacity (OBC); Fat absorption capacity (FAC)

  Note: NO universal unit. Record the oil type, the denominator and the centrifugation conditions in measurement_method.

• Oil binding capacity (OBC)

  7. Oil- and fat-interaction propertiesHydration & bindingsource unit preserved

  oil binding capacity

  Oil bound by the sample under the study's binding protocol. Distinct from oil holding and oil absorption capacity by default; a study that defines them identically says so in measurement_method.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: obc

  Basis: Denominator basis (per g sample vs per g protein) is study-defined; mL/g is never converted to g/g without the oil density.

  Carried with every value: denominator_substance

  Method context: Binding protocol and oil type define the number; equivalence with oil holding or oil absorption capacity only when the paper states it.

  Related, never merged by default: Oil holding capacity; Oil absorption capacity (OAC); Fat absorption capacity (FAC)

• Oil holding capacity

  7. Oil- and fat-interaction propertiesHydration & bindingsource unit preserved

  oil holding capacity

  Oil retained by the sample after a defined absorption and separation protocol.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: ohc

  Basis: Denominator basis is study-defined, as for water holding capacity.

  Carried with every value: denominator_substance

  Method context: Oil type and centrifugation protocol are part of the method and are preserved (item 47).

  Related, never merged by default: Oil absorption capacity (OAC); Oil binding capacity (OBC); Fat absorption capacity (FAC)

  Why this group: Group 7, not 6: its legacy category 'Hydration & binding' held both liquids. Oil and water are different liquids with different protocols and different denominators, so they are separate groups.

  Note: Method-dependent like water holding capacity; denominators are not collapsed. The oil type and the centrifugation conditions are part of the method.

• Swelling capacity

  6. Water-interaction propertiesHydration & bindingsource unit preserved

  swelling capacity

  Volume or mass increase of the sample on hydration, under the study's swelling protocol. Part of the hydration family (item 46) but a distinct protocol from water holding/absorption/binding capacity; never merged with them by default.

  Units, basis and methodShowHide

  Accepted source units: %, g/g, mL/g, g/100 g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, ratio, mass_fraction

  Also written: swelling power; swelling index

  Basis: Numerator (volume vs mass gained) and denominator (per g sample vs per g protein) are study-defined; mL/g is never converted to g/g without the liquid density (item 57).

  Carried with every value: denominator_substance

  Method context: Swelling protocol (bed-volume vs centrifugation) defines the number.

  Related, never merged by default: Water holding capacity; Water absorption capacity (WAC); Hydration capacity

  Why this group: Group 6: swelling is measured against WATER uptake in this literature. A swelling measured in another solvent is recorded with that solvent in the method.

  Note: NO universal unit: the reported unit and basis are preserved.

• Water absorption capacity (WAC)

  6. Water-interaction propertiesHydration & bindingsource unit preserved

  water absorption capacity

  Water absorbed by the sample under the study's absorption protocol. Reported like water holding capacity but the protocols differ, so the two are related concepts, never merged by default.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: wac

  Basis: Denominator basis (per g sample vs per g protein) is study-defined; mL/g is never converted to g/g.

  Carried with every value: denominator_substance

  Method context: Absorption protocol (excess vs limited water, centrifugation) defines the number.

  Related, never merged by default: Water holding capacity; Water binding capacity (WBC)

  Note: Seeded as its own term in the database ontology (migration 0009), separate from water holding capacity.

• Water binding capacity (WBC)

  6. Water-interaction propertiesHydration & bindingsource unit preserved

  water binding capacity

  Water bound by the sample under the study's binding protocol. Distinct from water holding and water absorption capacity by default (item 100); a study that defines them identically says so in measurement_method.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: wbc

  Basis: Denominator basis (per g sample vs per g protein) is study-defined; mL/g is never converted to g/g.

  Carried with every value: denominator_substance

  Method context: Binding protocol defines the number; equivalence with WHC or WAC only when the paper states it.

  Related, never merged by default: Water holding capacity; Water absorption capacity (WAC)

• Water holding capacity

  6. Water-interaction propertiesHydration & bindingsource unit preserved

  water holding capacity

  Water retained by the sample after a defined hydration and separation protocol.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/g, g/100 g, mL/g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction, ratio

  Also written: whc

  Basis: g water per g SAMPLE vs per g PROTEIN differ by the protein content; mL/g needs the liquid density; a bare % is protocol-defined. Never merged (item 57).

  Carried with every value: denominator_substance

  Method context: Centrifugation force and time (or filtration) define the number - record them in measurement_method.

  Related, never merged by default: Water absorption capacity (WAC); Water binding capacity (WBC)

  Note: NO universal unit: %, g water per g sample and g water per g protein are different quantities with different denominators and are never merged; mL/g is a volume per mass and is never converted to g/g without the liquid density.

• Creaming index

  8. Emulsifying propertiesEmulsifying

  creaming index

  Height of the serum layer as a percentage of the total emulsion height after the stated standing time.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: creaming stability index

  Typical conditions: standing time and temperature - the number is meaningless without them

  Related, never merged by default: Emulsion stability

  Note: Record the standing time and temperature in measurement_method — the number is meaningless without them.

• Emulsifying activity

  8. Emulsifying propertiesEmulsifyingsource unit preserved

  emulsifying activity

  Emulsifying activity reported as a percentage (emulsified volume fraction or activity), as distinct from the turbidimetric EAI.

  Units, basis and methodShowHide

  Accepted source units: %, % v/v

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, volume_fraction

  Also written: ea; emulsion activity

  Method context: Protocol-defined percentage (e.g. emulsified layer after centrifugation); record the protocol.

  Related, never merged by default: Emulsifying activity index (EAI); Emulsifying capacity

  Note: Not interchangeable with EAI (m²/g) or with emulsifying capacity (mL oil/g protein) — three different measurements with three different units.

• Emulsifying activity index (EAI)

  8. Emulsifying propertiesEmulsifying

  emulsifying activity index

  Interfacial area stabilised per unit mass of protein, from turbidimetry.

  Units, basis and methodShowHide

  Accepted source units: m²/g, cm²/g

  Canonical unit: m²/g

  Dimension: area_per_mass

  Also written: eai; emulsifying activity index (eai)

  Method context: Turbidimetric (Pearce-Kinsella): wavelength, dilution factor and oil volume fraction are required for comparability (item 58).

  Typical conditions: protein concentration, pH

  Note: No legacy FoodProt column exists; the measurement is still fully valid.

• Emulsifying capacity

  8. Emulsifying propertiesEmulsifyingsource unit preserved

  emulsifying capacity

  Amount of oil one unit of protein (or sample) can emulsify before the emulsion inverts or breaks, as the study defines it — commonly mL oil per g protein, sometimes a percentage. A different measurement from emulsifying activity, from the turbidimetric EAI and from emulsion stability.

  Units, basis and methodShowHide

  Accepted source units: mL/g, g/g, %

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: ratio, percent

  Also written: ec; emulsion capacity

  Basis: mL oil per g PROTEIN and mL oil per g SAMPLE differ by the protein content; a percentage is of the study's own definition. Never merged, never converted.

  Method context: Oil type, addition rate, mixing speed and the END-POINT detection (conductivity drop, viscosity drop, visual inversion) define the number.

  Typical conditions: protein concentration, pH, temperature

  Related, never merged by default: Emulsifying activity; Emulsifying activity index (EAI); Emulsion stability

  Note: NO universal unit: mL/g is a volume of oil per mass of protein and is never converted to g/g (that needs the oil density) or to a percentage (that needs the study's own definition).

• Emulsion stability

  8. Emulsifying propertiesEmulsifyingsource unit preserved

  emulsion stability

  Persistence of the emulsion, however the study defines it.

  Units, basis and methodShowHide

  Accepted source units: %, min, h, 1

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, time, dimensionless

  Also written: es

  Method context: The reported unit decides the quantity (percent retained vs a half-life); nothing converts to the turbidimetric ESI.

  Typical conditions: standing or heating time and temperature

  Related, never merged by default: Emulsion stability index (ESI); Creaming index

  Note: Definition varies (percent retained, half-life in minutes, an index); the reported unit decides the quantity and nothing is converted between them.

• Emulsion stability index (ESI)

  8. Emulsifying propertiesEmulsifying

  emulsion stability index

  Turbidimetric emulsion stability index (Pearce–Kinsella): the half-time of the absorbance decay, in time units. A percent emulsion stability is a different quantity and is never converted into an ESI.

  Units, basis and methodShowHide

  Accepted source units: min, h

  Canonical unit: min

  Dimension: time

  Also written: esi; emulsifying stability index

  Method context: Pearce-Kinsella turbidity decay: record the time interval and dilution.

  Related, never merged by default: Emulsion stability; Emulsifying activity index (EAI)

  Note: Seeded as its own term in the database ontology (migration 0009, default unit min).

• Foaming ability

  9. Foaming propertiesFoamingsource unit preserved

  foaming ability

  Foam formed on whipping or sparging, as the study defines it. Reported like foaming capacity, but the two names are merged only when the paper states the same definition (item 100).

  Units, basis and methodShowHide

  Accepted source units: %, % v/v

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, volume_fraction

  Also written: fa; foamability; foam ability

  Method context: Whipping/sparging method, time and the volume the percentage is taken against; equivalence with foaming capacity only when the paper defines them identically (record it in measurement_method).

  Typical conditions: protein concentration, pH

  Related, never merged by default: Foaming capacity; Foaming stability

• Foaming capacity

  9. Foaming propertiesFoamingsource unit preserved

  foaming capacity

  Volume increase on whipping/sparging (overrun), as defined by the study.

  Units, basis and methodShowHide

  Accepted source units: %, % v/v

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, volume_fraction

  Also written: fc; foam capacity; overrun; foam expansion

  Method context: Whipping or sparging method, speed and time; the volume basis of the percentage is study-defined.

  Typical conditions: protein concentration, pH

  Related, never merged by default: Foaming ability; Foaming stability

• Foaming stability

  9. Foaming propertiesFoamingsource unit preserved

  foaming stability

  Persistence of the foam, however the study defines it.

  Units, basis and methodShowHide

  Accepted source units: %, min, h, 1

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, time, dimensionless

  Also written: fs; foam stability; foam stability index; foam half-life

  Method context: Definition varies (percent retained at a stated time, half-life); the unit decides and the observation time is part of the method (item 49).

  Typical conditions: time after foaming, temperature

  Note: May be percent, a half-life in time units, or another definition; confirm per study.

• Adhesiveness (TPA)

  5. Texture and mechanical propertiesGelation & texture

  adhesiveness

  Negative work of the withdrawal stroke in texture profile analysis.

  Units, basis and methodShowHide

  Accepted source units: gf·s, N·s, mN·s

  Canonical unit: gf·s

  Dimension: force_time

  Also written: tpa adhesiveness

  Method context: TPA settings; the withdrawal work depends on probe and contact surface.

  Note: The legacy "(g.s)" column means gram-force-second.

• Chewiness (TPA)

  5. Texture and mechanical propertiesGelation & texture

  chewiness

  Gumminess × springiness, from texture profile analysis.

  Units, basis and methodShowHide

  Accepted source units: gf, N

  Canonical unit: gf

  Dimension: force

  Also written: tpa chewiness

  Basis: Force form when springiness is a ratio; work (force x distance) form when springiness is a distance - the springiness definition decides the dimension (item 45).

  Method context: TPA settings and the springiness definition used.

  Note: Item 45: chewiness has a force dimension when springiness is the dimensionless ratio, and an energy dimension (force × distance) when springiness is a recovered distance. The legacy columns hold the force form; a paper reporting mJ or N·mm is refused rather than force-converted, and the springiness definition is recorded in measurement_method.

• Cohesiveness (TPA)

  5. Texture and mechanical propertiesGelation & texture

  cohesiveness

  Ratio of the second to the first compression area. Unitless by definition.

  Units, basis and methodShowHide

  Accepted source units: 1

  Canonical unit: 1

  Dimension: dimensionless

  Also written: tpa cohesiveness

  Method context: TPA settings (probe, compression ratio, speed).

• Critical gel concentration

  11. Gelation propertiesGelation & texturesource unit preserved

  critical gel concentration

  Concentration at which a percolating gel network forms, determined rheologically (e.g. G′/G″ crossover extrapolation). NOT the tube-inversion least gelation concentration; the two are related concepts and never merged (item 100).

  Units, basis and methodShowHide

  Accepted source units: % w/v, g/L, mg/mL, % w/w

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: mass_volume_concentration, mass_fraction

  Also written: cgc; critical gelation concentration

  Method context: Rheological criterion (e.g. modulus crossover extrapolation); not the tube-inversion assay.

  Related, never merged by default: Least gelation concentration (LGC); Gel forming ability

  Why this group: Group 11, not 5, for the same reason as the least gelation concentration.

• Firmness

  5. Texture and mechanical propertiesGelation & texturesource unit preserved

  firmness

  Force resisting compression or penetration, as the study defines it — often a single-compression or penetration peak force rather than the TPA hardness cycle. Related to gel hardness but merged only when the paper states the same method.

  Units, basis and methodShowHide

  Accepted source units: gf, N, mN, kgf

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: force

  Method context: Probe, speed and compression or penetration depth decide comparability with TPA hardness.

  Related, never merged by default: Gel hardness (TPA); Gel strength

  Note: Seeded as its own term in the database ontology (migration 0009), separate from gel hardness. Method metadata (probe, speed, compression) decides comparability.

• Fracturability (TPA)

  5. Texture and mechanical propertiesGelation & texture

  fracturability

  Force at the first significant break during compression.

  Units, basis and methodShowHide

  Accepted source units: gf, N

  Canonical unit: gf

  Dimension: force

  Also written: brittleness; tpa fracturability

  Method context: TPA settings (probe, compression ratio, speed).

• Gel forming ability

  11. Gelation propertiesGelation & texture

  gel forming ability

  Whether the protein formed a gel under the stated conditions, as a qualitative categorical conclusion. Stays qualitative unless the study defines a quantitative measure — in which case that measure is stored as its own property (least/critical gelation concentration, gel strength, G′) and this one records the conclusion alongside it.

  Units, basis and methodShowHide

  Accepted source units: unitless

  Canonical unit: Unitless

  Dimension: dimensionless

  Also written: gelling capacity; gelling ability; gelation ability

  Basis: QUALITATIVE by default. The category is the authors' own conclusion; it is never converted into a number and never used to infer a gelation concentration.

  Method context: The observation protocol (tube inversion, visual self-support, rheological criterion), the concentration and the conditions under which the conclusion was reached — a "gels" with no concentration is not a property of the protein.

  Typical conditions: concentration, pH, ionic strength, heating time and temperature

  Evidence rule: The verbatim conclusion and the conditions it was reached under are both required. A qualitative gelation conclusion is NEVER promoted to a quantitative value, and never implies a gelation concentration the paper did not report.

  Related, never merged by default: Least gelation concentration (LGC); Critical gel concentration; Gel strength

  Note: Unitless because it is a category, not a magnitude. Storing it as "1" or as a percentage would invent a measurement.

• Gel hardness (TPA)

  5. Texture and mechanical propertiesGelation & texture

  gel hardness

  Peak force of the first compression cycle in texture profile analysis.

  Units, basis and methodShowHide

  Accepted source units: gf, N, mN, kgf

  Canonical unit: gf

  Dimension: force

  Also written: hardness; tpa hardness

  Method context: TPA settings: probe geometry, compression ratio, crosshead speed, trigger force (item 58).

  Related, never merged by default: Firmness; Gel strength

  Note: Texture force. The legacy FoodProt "(g)" column means GRAM-FORCE, not mass — write gf.

• Gel strength

  5. Texture and mechanical propertiesGelation & texturesource unit preserved

  gel strength

  Resistance of the gel, from a texture analyser (a force), a rheometer (a stress) or a Bloom-type test (a Bloom grade).

  Units, basis and methodShowHide

  Accepted source units: gf, N, mN, kgf, Pa, kPa, Bloom

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: force, modulus, bloom

  Also written: gel firmness; breaking force; rupture force; rupture strength; breaking strength

  Method context: Instrument and geometry decide the quantity: texture analyser force (probe, speed, distance), rheometer stress, or Bloom test. The reported unit fixes which it is (item 44).

  Related, never merged by default: Gel hardness (TPA); Firmness

  Note: A force (gf/N), a stress (Pa) and a Bloom grade are NOT interconvertible without the probe geometry, so the reported unit fixes the quantity (item 44).

• Gumminess (TPA)

  5. Texture and mechanical propertiesGelation & texture

  gumminess

  Hardness × cohesiveness, from texture profile analysis.

  Units, basis and methodShowHide

  Accepted source units: gf, N

  Canonical unit: gf

  Dimension: force

  Also written: tpa gumminess

  Method context: TPA settings (probe, compression ratio, speed); derived as hardness x cohesiveness.

• Least gelation concentration (LGC)

  11. Gelation propertiesGelation & texture

  least gelation concentration

  Lowest protein concentration that forms a self-supporting gel under the stated heating protocol.

  Units, basis and methodShowHide

  Accepted source units: % w/v, g/L, mg/mL, % w/w

  Canonical unit: % w/v

  Dimension: mass_volume_concentration, mass_fraction

  Also written: lgc; minimum gelation concentration; mgc

  Basis: % w/v and % w/w differ by the dispersion density and are never converted.

  Method context: Tube-inversion protocol (heating temperature and time).

  Related, never merged by default: Critical gel concentration

  Why this group: Group 11, not 5: a gelation concentration describes WHETHER AND WHEN a gel forms, not the mechanics of the gel that formed. Its legacy category was 'Gelation & texture', which merged the two.

  Note: % w/v and % w/w are different quantities here; converting between them needs the density and is never assumed.

• Resilience (TPA)

  5. Texture and mechanical propertiesGelation & texture

  resilience

  Ratio of the withdrawal to the compression area of the first cycle.

  Units, basis and methodShowHide

  Accepted source units: %, 1

  Canonical unit: %

  Dimension: percent, dimensionless

  Also written: tpa resilience

  Method context: TPA settings (probe, compression ratio, speed).

• Springiness (TPA)

  5. Texture and mechanical propertiesGelation & texture

  springiness

  Height the sample recovers between the two compression cycles.

  Units, basis and methodShowHide

  Accepted source units: mm, cm, %, 1

  Canonical unit: mm

  Dimension: length, percent, dimensionless

  Also written: elasticity; tpa springiness

  Basis: A recovered distance (mm, cm) and a ratio (%, 1) are different definitions; the unit decides and neither converts to the other (item 45).

  Method context: TPA settings; state which springiness definition the instrument software used.

  Note: Reported either as a recovered distance or as a ratio/percentage; the unit decides.

• Stretch distance

  5. Texture and mechanical propertiesGelation & texture

  stretch distance

  Distance a sample extends before it breaks in an extensibility test — the instrumented form of the fork- or hand-stretch observation used for high-moisture extrudates and fibrous analogues.

  Units, basis and methodShowHide

  Accepted source units: mm, cm

  Canonical unit: mm

  Dimension: length

  Also written: extensibility distance; stretchability; extension distance; distance to break

  Method context: Fixture geometry, gauge length and crosshead speed decide the number; a value with no fixture stated is comparable to nothing.

  Related, never merged by default: Work to extend; Gel strength

  Note: OPTIONAL AND METHOD-BOUND. Recorded only when the source reports an instrumented distance. A qualitative stretch description ('stretched well', a photograph of a fork pull) is NOT converted into a number here.

• Work to extend

  5. Texture and mechanical propertiesGelation & texture

  work to extend

  Area under the force-distance curve of an extensibility test: the energy taken to stretch the sample to break.

  Units, basis and methodShowHide

  Accepted source units: mJ, J, N·mm, g·mm, g·cm

  Canonical unit: mJ

  Dimension: work

  Also written: work of extension; extensibility work; area under the extension curve

  Method context: Same fixture, gauge length and speed as the stretch distance it accompanies; the two are reported together or not at all.

  Related, never merged by default: Stretch distance

  Note: OPTIONAL AND METHOD-BOUND. mJ and N·mm are the SAME quantity and convert exactly; g·mm and g·cm are gram-force distances and carry standard gravity, the same constant the gf force unit carries. Work is kept apart from the DSC enthalpy (J/g): converting between them needs a mass, which is not part of either unit. It is never derived from a stretch distance and a peak force — that product assumes a curve shape nobody measured.

• Complex modulus (G*)

  13. Rheological and viscoelastic propertiesRheology & flow

  complex modulus

  Magnitude of the complex shear modulus in oscillatory rheology, |G*| = √(G′² + G″²), at the stated frequency, strain and temperature.

  Units, basis and methodShowHide

  Accepted source units: Pa, kPa, MPa, dyn/cm²

  Canonical unit: Pa

  Dimension: modulus

  Also written: g*; complex shear modulus; |g*|

  Method context: Geometry and gap; strain must sit in the linear viscoelastic region (item 53).

  Typical conditions: temperature, frequency (Hz vs rad/s differ by 2 pi), strain

  Related, never merged by default: Storage modulus G'; Loss modulus G″; Complex viscosity (η*)

  Note: A modulus (Pa), never a viscosity: G* and η* differ by the angular frequency and are separate measurement types with separate dimensions.

• Complex viscosity (η*)

  13. Rheological and viscoelastic propertiesRheology & flow

  complex viscosity

  Magnitude of the complex viscosity from oscillatory rheology at the stated frequency. Related to steady-shear viscosity only through the Cox–Merz rule, which is an empirical assumption this product never applies.

  Units, basis and methodShowHide

  Accepted source units: mPa·s, Pa·s, cP, P

  Canonical unit: Pa·s

  Dimension: viscosity

  Also written: η*; eta*

  Typical conditions: oscillation frequency (Hz vs rad/s) and temperature

  Related, never merged by default: Viscosity; Storage modulus G'; Loss modulus G″

  Why this group: Group 13, not 12: eta* comes from an OSCILLATORY measurement and is not the steady-shear viscosity, even though both are Pa.s. Cox-Merz is an empirical rule, not an identity, and is never applied here.

  Note: Seeded in the database ontology (migration 0009, default unit Pa.s). Record the oscillation frequency in the frequency column — Hz and rad/s differ by 2π.

• Consistency coefficient (K)

  12. Viscosity and flow behaviorRheology & flow

  consistency coefficient

  Power-law (Ostwald–de Waele) consistency coefficient. Its unit, Pa·s^n, depends on the flow behavior index n, so K values are comparable only at the same n and are never converted to a viscosity (item 52).

  Units, basis and methodShowHide

  Accepted source units: Pa·s^n

  Canonical unit: Pa·s^n

  Dimension: power_law_consistency

  Also written: consistency index

  Method context: Fitted model (power law, Herschel-Bulkley) and shear-rate range; n is always recorded alongside.

  Related, never merged by default: Flow behavior index (n); Viscosity

  Note: Seeded in the database ontology (migration 0009, unit Pa.s^n). Always record n alongside K; the fitted model (power law, Herschel–Bulkley) goes in measurement_method.

• Flow behavior index (n)

  12. Viscosity and flow behaviorRheology & flow

  flow behavior index

  Power-law flow behavior index. Dimensionless by definition; n < 1 is shear-thinning, n > 1 shear-thickening.

  Units, basis and methodShowHide

  Accepted source units: 1

  Canonical unit: 1

  Dimension: dimensionless

  Also written: flow index; power law index; power-law index

  Method context: Same fit as the consistency coefficient; record the model and shear-rate range.

  Related, never merged by default: Consistency coefficient (K)

• Loss modulus G″

  13. Rheological and viscoelastic propertiesRheology & flow

  loss modulus

  Viscous component of the complex modulus in oscillatory rheology.

  Units, basis and methodShowHide

  Accepted source units: Pa, kPa, MPa, dyn/cm²

  Canonical unit: Pa

  Dimension: modulus

  Also written: g''; g double prime; viscous modulus

  Method context: Geometry and gap; strain must sit in the linear viscoelastic region (item 53).

  Typical conditions: temperature, frequency (Hz vs rad/s differ by 2 pi), strain

• Loss tangent (tan δ)

  13. Rheological and viscoelastic propertiesRheology & flow

  loss tangent

  G″/G'. Unitless by definition.

  Units, basis and methodShowHide

  Accepted source units: 1

  Canonical unit: 1

  Dimension: dimensionless

  Also written: tan delta; tanδ; damping factor

  Typical conditions: temperature, frequency, strain

• Shear stress

  12. Viscosity and flow behaviorRheology & flow

  shear stress

  Shear stress at the stated shear rate, as read from a flow curve. Meaningful only with its shear rate and temperature (item 52); a full flow curve is a series (items 97/98), never one number.

  Units, basis and methodShowHide

  Accepted source units: Pa, kPa

  Canonical unit: Pa

  Dimension: modulus

  Method context: Geometry and shear protocol.

  Typical conditions: shear rate (s⁻¹) and temperature — part of the row identity

  Related, never merged by default: Viscosity; Yield stress

  Why this group: Group 12: the stress variable of a steady-shear flow curve. It is a Pa and a modulus is a Pa, and they are DIFFERENT quantities — which is exactly why they sit in different groups.

• Storage modulus G'

  13. Rheological and viscoelastic propertiesRheology & flow

  storage modulus

  Elastic component of the complex modulus in oscillatory rheology.

  Units, basis and methodShowHide

  Accepted source units: Pa, kPa, MPa, dyn/cm²

  Canonical unit: Pa

  Dimension: modulus

  Also written: g'; g prime; elastic modulus

  Method context: Geometry and gap; strain must sit in the linear viscoelastic region (item 53).

  Typical conditions: temperature, frequency (Hz vs rad/s differ by 2 pi), strain

  Note: Record the frequency, strain regime and temperature — a modulus without them is not comparable.

• Viscosity

  12. Viscosity and flow behaviorRheology & flow

  viscosity

  Dynamic (apparent) viscosity at the stated shear rate and temperature.

  Units, basis and methodShowHide

  Accepted source units: mPa·s, Pa·s, cP, P

  Canonical unit: mPa·s

  Dimension: viscosity

  Also written: apparent viscosity; dynamic viscosity; shear viscosity

  Method context: Geometry (cone-plate, concentric cylinder) and shear protocol.

  Typical conditions: shear rate and temperature - part of the row identity (item 52)

  Related, never merged by default: Complex viscosity (η*); Consistency coefficient (K)

  Note: Pa·s is a viscosity; Pa is a modulus. They are different quantities and are never converted into one another. An apparent viscosity is meaningful only with its shear rate and temperature (item 52) — record them in the shear_rate and measurement_temperature columns, which are part of the row identity.

• Yield stress

  12. Viscosity and flow behaviorRheology & flow

  yield stress

  Stress below which the material does not flow, from a stress ramp, an oscillatory amplitude sweep, or a model fit (e.g. Herschel–Bulkley σ₀).

  Units, basis and methodShowHide

  Accepted source units: Pa, kPa

  Canonical unit: Pa

  Dimension: modulus

  Also written: yield point

  Method context: The determination method (model fit vs direct ramp vs amplitude sweep) changes the value; record it. A stress, never a force: no conversion to gf or N exists (item 52).

  Related, never merged by default: Consistency coefficient (K); Viscosity; Shear stress

  Why this group: Group 12, not 13: a yield stress is the onset of FLOW, measured on a steady-shear or stress-ramp experiment, not an oscillatory viscoelastic modulus.

• Denaturation enthalpy (ΔH)

  14. Thermal propertiesThermal

  denaturation enthalpy

  Enthalpy of the thermal denaturation endotherm, per unit mass.

  Units, basis and methodShowHide

  Accepted source units: J/g, mJ/mg, kJ/kg, cal/g

  Canonical unit: J/g

  Dimension: energy_per_mass

  Also written: delta h; δh; enthalpy of denaturation

  Basis: Per g SAMPLE vs per g PROTEIN differ by the protein content and are not interconvertible without it; the basis is recorded with the method (items 54/57).

  Carried with every value: denominator_substance

  Method context: DSC scan rate, sample mass, baseline construction; state the mass basis.

  Related, never merged by default: Denaturation temperature (Td); Thermal stability

  Note: State whether the mass basis is sample or protein in measurement_method — the two differ by the protein content and are not interconvertible without it. Multiple endotherms produce multiple rows; enthalpies of separate transitions are never summed or averaged here.

• Denaturation temperature (Td)

  14. Thermal propertiesThermal

  denaturation temperature

  Peak temperature of the thermal denaturation endotherm.

  Units, basis and methodShowHide

  Accepted source units: °C, K, °F

  Canonical unit: °C

  Dimension: temperature

  Also written: td; peak temperature; tp; thermal denaturation temperature

  Basis: Preserve the moisture basis and the protein fraction the peak belongs to.

  Method context: DSC scan rate, sample mass and pan type; each endotherm is its own row (peak_or_replicate_label).

  Typical conditions: moisture or solids content, pH, scan rate

  Related, never merged by default: Onset temperature (To); Glass transition temperature (Tg); Thermal stability

  Note: Preserve the moisture basis and the protein fraction; multiple Td peaks stay separate rows and are never averaged — give each peak its own `peak_or_replicate_label`. "Peak temperature" is a method-supported alias: the DSC endotherm peak IS the denaturation temperature. "Thermal stability" is deliberately NOT an alias — it is method-dependent shorthand, never a canonical Td (item 54). It is a property of its OWN (group 14, no preferred unit, four allowed dimensions) so the measurement is stored instead of discarded, and it is a RELATED concept here, which is exactly what an alias must not be.

• Endset temperature (Te)

  14. Thermal propertiesThermal

  endset temperature

  Endset (conclusion) temperature of the thermal transition — where the endotherm returns to the baseline. A third point on the same thermogram as onset and peak (item 54); the three are never merged.

  Units, basis and methodShowHide

  Accepted source units: °C, K, °F

  Canonical unit: °C

  Dimension: temperature

  Also written: te; end temperature; conclusion temperature; tc (endset)

  Method context: Same thermogram metadata as the peak temperature (DSC scan rate, sample mass, pan type); record which peak it belongs to in peak_or_replicate_label.

  Related, never merged by default: Onset temperature (To); Denaturation temperature (Td)

• Glass transition temperature (Tg)

  14. Thermal propertiesThermal

  glass transition temperature

  Glass transition temperature from DSC or DMA. Depends strongly on moisture content — record it; °C↔K conversion is safe and affine (item 54).

  Units, basis and methodShowHide

  Accepted source units: °C, K, °F

  Canonical unit: °C

  Dimension: temperature

  Also written: tg; glass transition

  Method context: DSC or DMA protocol; moisture content dominates Tg and must be recorded.

  Related, never merged by default: Denaturation temperature (Td)

• Onset temperature (To)

  14. Thermal propertiesThermal

  onset temperature

  Onset temperature of the thermal transition — where the endotherm departs the baseline. A different point on the same thermogram as the peak (Td); the two are never merged.

  Units, basis and methodShowHide

  Accepted source units: °C, K, °F

  Canonical unit: °C

  Dimension: temperature

  Also written: onset denaturation temperature; to (onset)

  Method context: Same thermogram metadata as the peak temperature; record which peak it belongs to.

  Related, never merged by default: Denaturation temperature (Td)

  Note: Seeded as its own term in the database ontology (migration 0009).

• Thermal stability

  14. Thermal propertiesThermalsource unit preserved

  thermal stability

  How much of a stated property the protein retains after a stated heat treatment — kept as the quantitative measure the study actually reported where there is one, and preserved as the authors' qualitative conclusion where there is not. Distinct from the denaturation temperature, which is a transition, not a retention.

  Units, basis and methodShowHide

  Accepted source units: %, °C, K, min, h, 1

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, temperature, time, dimensionless

  Also written: heat stability; thermal resistance

  Basis: NOT one quantity. A residual-activity or residual-solubility percentage after a stated heat treatment, a temperature at which a stated fraction is lost, a time to a stated loss, and a qualitative conclusion are FOUR different things. The reported unit (or its absence) fixes which one, and none converts into another.

  Method context: The heating temperature AND time, the medium (pH, ionic strength, protein concentration), and WHAT was measured to call it stable (residual solubility, residual activity, retained Td, unchanged G′ …). Without those the number has no meaning.

  Typical conditions: heating temperature, holding time, pH, ionic strength

  Evidence rule: The heat treatment (temperature and time) and the property that was measured to support the claim must both be recorded. A qualitative "thermally stable" is stored as the verbatim conclusion and is NEVER given a number.

  Related, never merged by default: Denaturation temperature (Td); Denaturation enthalpy (ΔH); Degree of denaturation

  Note: NO universal unit, deliberately. A percentage retained, a temperature, a time and a qualitative conclusion are stored as reported and are never converted into one another or into a denaturation temperature.

• Interfacial tension

  3. Particle and colloidal propertiesColloidal & surface

  interfacial tension

  Tension at the oil–water (or air–water) interface, in mN/m.

  Units, basis and methodShowHide

  Accepted source units: mN/m, N/m

  Canonical unit: mN/m

  Dimension: surface_tension

  Method context: Name the phase pair (air-water vs oil-water) and method (pendant drop, Wilhelmy plate, du Nouy ring).

  Why this group: Group 3: an interfacial property of the colloidal system. Surface tension against air and interfacial tension against oil are the same dimension but different systems; the phase pair is part of the method.

  Note: Seeded in the database ontology (migration 0009, mN/m). Surface tension against air and interfacial tension against oil are the same dimension but different systems — name the phases in measurement_method.

• Particle size

  3. Particle and colloidal propertiesColloidal & surface

  particle size

  Characteristic particle or droplet diameter.

  Units, basis and methodShowHide

  Accepted source units: nm, μm, mm

  Canonical unit: μm

  Dimension: length

  Also written: droplet size; particle diameter; d43; d32; z-average; d10; d50; d90; d[3,2]; d[4,3]

  Method context: Technique (DLS, laser diffraction) and WHICH statistic (D10, D50, D90, d[3,2], d[4,3], z-average) - different numbers from one sample, never interconverted (item 42).

  Note: Record which statistic it is (D10, D50, D90, d[3,2], d[4,3], z-average) in measurement_method — they are different numbers from the same sample and are never interconverted (item 42).

• Polydispersity index (DLS)

  3. Particle and colloidal propertiesColloidal & surface

  polydispersity index

  Width of the particle-size distribution reported by dynamic light scattering, dimensionless, conventionally 0-1.

  Units, basis and methodShowHide

  Accepted source units: 1

  Canonical unit: 1

  Dimension: dimensionless

  Also written: polydispersity; polydispersity index (pdi); dls pdi; pdi (dls); size distribution width

  Method context: Cumulants analysis from DLS. A PDI from a laser-diffraction span or a polymer-chemistry Mw/Mn is a different quantity and is not stored here.

  Related, never merged by default: Particle size; Protein dispersibility index (PDI)

  Note: NOT the protein dispersibility index. The bare abbreviation `pdi` deliberately does NOT resolve to this term: it is owned by protein dispersibility index, where it is flagged ambiguous, so a source that writes only 'PDI' is routed to a human rather than silently filed as either quantity.

• Surface hydrophobicity (H₀)

  2. Molecular and structural propertiesColloidal & surface

  surface hydrophobicity

  Fluorescence-probe surface hydrophobicity index.

  Units, basis and methodShowHide

  Accepted source units: a.u., 1

  Canonical unit: Unitless

  Dimension: dimensionless

  Also written: h0; ho; surface hydrophobicity index

  Method context: Fluorescence probe (ANS, PRODAN, CPA) and protocol; the index is method-specific and is never normalized across methods (item 42).

  Why this group: Placed in group 2, not group 3: the fluorescent probe reports on the FOLDED MOLECULE's exposed apolar patches, which is a structural property, not a property of the dispersed phase. Its legacy category was 'Colloidal & surface'.

  Note: Instrument-relative (arbitrary units). Values are comparable only within one study and are never converted.

• Turbidity

  3. Particle and colloidal propertiesColloidal & surfacesource unit preserved

  turbidity

  Optical turbidity (absorbance or scattering) of the dispersion. Instrument- and wavelength-relative.

  Units, basis and methodShowHide

  Accepted source units: a.u., 1, NTU

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: dimensionless, turbidity_ntu

  Also written: optical density; od

  Method context: Wavelength and path length; instrument-relative, comparable only within one study.

  Evidence rule: An absorbance-based turbidity requires the WAVELENGTH and, where the source gives it, the path length; an NTU value requires the nephelometric instrument. A turbidity with neither is stored with that gap explicit.

  Why this group: Group 3: turbidity here is the optical signature of the DISPERSED PHASE (droplets, aggregates), which is a colloidal observable.

  Note: Seeded in the database ontology (migration 0009). Absorbance/OD and NTU are different quantities in different dimensions and NEVER convert into one another; absorbance values are comparable only within one study at one wavelength.

• Zeta potential

  3. Particle and colloidal propertiesColloidal & surface

  zeta potential

  Electrokinetic potential at the slipping plane. Sign is part of the value.

  Units, basis and methodShowHide

  Accepted source units: mV, V

  Canonical unit: mV

  Dimension: electric_potential

  Also written: ζ-potential; zeta-potential

  Method context: Electrophoretic mobility model (e.g. Smoluchowski).

  Typical conditions: pH and ionic strength - the value is not interpretable without them

  Note: Negative values are normal and the minus sign must be kept.

• Alpha-helix content (%)

  2. Molecular and structural propertiesMolecular characterization

  alpha-helix content

  Fraction of secondary structure assigned as α-helix, from circular dichroism or FTIR deconvolution, as a percentage.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: alpha helix; α-helix; α-helix content; alpha helix content (%)

  Method context: CD or FTIR band assignment and deconvolution method decide the number.

  Related, never merged by default: Beta-sheet content (%)

  Note: The deconvolution method decides the number; record it in measurement_method.

• Amino acid composition

  1. Composition and purityMolecular characterizationsource unit preserved

  amino acid composition

  Content of one amino acid (name it in peak_or_replicate_label or measurement_method), as mg per g, g per 100 g protein, or mole percent.

  Units, basis and methodShowHide

  Accepted source units: mg/g, g/100 g, mol%, %

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: ratio, mass_fraction, mole_percent, percent

  Also written: amino acid profile; aa composition; amino acids composition

  Basis: mg/g and g/100 g are per mass (protein or sample, study-defined); mol% is per mole of residues; never interconverted (item 42).

  Carried with every value: denominator_substance

  Method context: Hydrolysis protocol (acid hydrolysis; performic acid oxidation for cysteine and methionine); name the amino acid in peak_or_replicate_label.

  Why this group: Composition, not molecular structure, for the same reason as protein content.

  Note: Item 99: singular "Amino acid composition". mg/g, g/100 g, mol% and % of total amino acids carry different denominators (mass of protein, mass of sample, moles of residues, share of the total) and are never interconverted; the denominator basis is recorded with the method.

• Apparent molecular mass (SDS-PAGE)

  2. Molecular and structural propertiesMolecular characterization

  apparent molecular mass

  Apparent molecular mass of a protein band or peak, from SDS-PAGE (or SEC), in daltons. Method-qualified on purpose: gel migration gives an APPARENT mass, and values from different methods are compared only with the method in view.

  Units, basis and methodShowHide

  Accepted source units: kDa, Da

  Canonical unit: kDa

  Dimension: molar_mass

  Also written: molecular weight; molecular mass; mw; apparent molecular weight; molecular weight (sds-page)

  Method context: SDS-PAGE reducing vs non-reducing and gel percentage, or SEC column and standards.

  Note: Item 99: the preferred display name is "Apparent molecular mass (SDS-PAGE)"; "molecular weight" resolves here as an alias. kDa is a molar mass, never a gram mass. State the method (SDS-PAGE reducing/non-reducing, SEC) in measurement_method.

• Ash content

  1. Composition and purityMolecular characterization

  ash content

  Inorganic residue after incineration, as a percentage. Read alongside protein content as part of a proximate composition.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/100 g

  Canonical unit: %

  Dimension: percent, mass_fraction

  Also written: ash; total ash; ash (%); mineral content

  Carried with every value: reporting_basis

  Method context: Muffle-furnace temperature and duration are recorded as stated.

  Related, never merged by default: Moisture content; Protein content

  Note: An ash on a dry basis and an ash as-is are different numbers. The basis is recorded; it is never inferred from the size of the value.

• Beta-sheet content (%)

  2. Molecular and structural propertiesMolecular characterization

  beta-sheet content

  Fraction of secondary structure assigned as β-sheet, from circular dichroism or FTIR deconvolution, as a percentage.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: beta sheet; β-sheet; β-sheet content; beta sheet content (%)

  Method context: CD or FTIR band assignment and deconvolution method decide the number.

  Related, never merged by default: Alpha-helix content (%)

• Beta-turn content (%)

  2. Molecular and structural propertiesMolecular characterization

  beta-turn content

  Fraction of secondary structure assigned as β-turn, from circular dichroism or FTIR deconvolution, as a percentage.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: beta turn; β-turn; β-turn content; turn content; beta turn content (%)

  Method context: CD or FTIR band assignment and the deconvolution algorithm decide the number; they are recorded with it.

  Related, never merged by default: Alpha-helix content (%); Beta-sheet content (%); Random-coil content (%)

  Note: The four secondary-structure fractions are reported per the study's own deconvolution and are NOT required to sum to 100%, are never rescaled so that they do, and a missing fraction is never computed as the remainder.

• Degree of denaturation

  2. Molecular and structural propertiesMolecular characterization

  degree of denaturation

  Fraction of the protein denatured, as a percentage — only where the study defines it (item 42). Often derived as 1 − ΔH/ΔH_native; a derived value is stored only with the formula and the native reference it was computed against.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: denaturation degree; degree of protein denaturation

  Method context: The defining method (DSC enthalpy ratio, solubility loss, CD) and, for derived values, the formula and reference state.

  Evidence rule: A derived degree of denaturation requires the formula and the native reference recorded in measurement_method; without them only a directly reported number is stored.

  Related, never merged by default: Denaturation enthalpy (ΔH); Denaturation temperature (Td)

• Disulfide bond content (-S-S-)

  2. Molecular and structural propertiesMolecular characterization

  disulfide bond content

  Disulfide bond content, in µmol per gram. A SEPARATE measurement from free sulfhydryl groups (item 99); assays differ and neither is computed from the other.

  Units, basis and methodShowHide

  Accepted source units: μmol/g

  Canonical unit: μmol/g

  Dimension: amount_per_mass

  Also written: disulfide bond content; ss bonds; disulphide bonds; s-s bonds; disulfide bonds; disulphide bond content

  Basis: Per g protein vs per g sample is study-defined and recorded with the method (item 57).

  Carried with every value: denominator_substance

  Method context: Assay (e.g. NTSB, difference method); never computed from free -SH here.

  Related, never merged by default: Free sulfhydryl content (-SH)

  Note: TERMINOLOGY (2.1.0): a content in µmol/g, not a count of bonds. 'disulfide bonds' stays an alias; the id disulfide_bonds is unchanged, because it is a key.

• Extraction yield

  Process yield and recovery — Extraction yield and protein recoveryMolecular characterization

  protein extraction yield

  Mass of extracted product (isolate, concentrate, fraction) obtained per mass of starting material, as a percentage.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: extraction yield; yield; isolate yield; protein isolate yield; extraction yield (%)

  Basis: Mass of product / mass of feedstock, on the study's own basis. Never protein / protein — that is protein recovery, a different term.

  Method context: Solvent, pH of extraction and precipitation, solid-to-liquid ratio and number of extraction steps all move this number; a yield is a property of the RUN, not of the protein.

  Related, never merged by default: Protein recovery; Protein content; Protein purity

  Note: NEVER COMPARED ACROSS STUDIES AS A PROPERTY OF THE PROTEIN, and never converted to or from a protein recovery: that conversion needs the protein content of both streams, which are separate measurements this system does not invent.

• Free sulfhydryl content (-SH)

  2. Molecular and structural propertiesMolecular characterization

  free sulfhydryl content

  Free (exposed + buried, per the assay) sulfhydryl content, typically by Ellman's reagent, in µmol per gram. A SEPARATE measurement from disulfide bonds — the two are never derived from one another here.

  Units, basis and methodShowHide

  Accepted source units: μmol/g

  Canonical unit: μmol/g

  Dimension: amount_per_mass

  Also written: free sh; free sh groups; free sulfhydryl; sulfhydryl content; sh content; free sulfhydryl content; free sulfhydryl groups; free sulphydryl content; free thiol content

  Basis: Per g protein vs per g sample is study-defined and recorded with the method; a denominator-qualified unit spelling is refused rather than equated (item 57).

  Carried with every value: denominator_substance

  Method context: Ellman reagent variant (native vs denaturing buffer).

  Related, never merged by default: Disulfide bond content (-S-S-)

  Note: Seeded in the database ontology (migration 0009, µmol/g). The denominator basis (per g protein vs per g sample) is study-defined: record it in measurement_method; a spelling like "μmol/g protein" is refused rather than silently equated (item 57). TERMINOLOGY (2.1.0): the property is a CONTENT — an amount per unit mass — not a count of groups. The canonical term is 'free sulfhydryl content'; 'free sulfhydryl groups' is kept as an alias so every stored row and every prior import still resolves. The stable id free_sulfhydryl_groups is unchanged on purpose: an id is a key, not a label.

• Hydrophilic amino acid content

  1. Composition and purityMolecular characterizationsource unit preserved

  hydrophilic amino acid content

  Share of the protein's amino acids the authors classify as hydrophilic. Stored independently of the hydrophobic fraction: many classifications leave residues in neither class, so the two do not necessarily sum to 100 %.

  Units, basis and methodShowHide

  Accepted source units: %, mol%

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mole_percent

  Also written: hydrophilic amino acids; hydrophilic aa; % hydrophilic amino acids

  Basis: Depends on WHICH amino acids the authors classified as hydrophilic and on the DENOMINATOR. Recorded with the method; not the arithmetic complement of the hydrophobic fraction unless the paper defines the two as exhaustive.

  Carried with every value: denominator_substance

  Method context: The amino-acid classification used and the denominator, exactly as for the hydrophobic fraction.

  Evidence rule: The residue classification and the denominator must be recorded with the value. This value is NEVER computed as 100 minus the hydrophobic fraction.

  Related, never merged by default: Amino acid composition; Hydrophobic amino acid content

  Note: A bare % is never rewritten as % w/w, and the complement is never derived.

• Hydrophobic amino acid content

  1. Composition and purityMolecular characterizationsource unit preserved

  hydrophobic amino acid content

  Share of the protein's amino acids the authors classify as hydrophobic. A derived compositional quantity, not a measured surface property — distinct from surface hydrophobicity, which probes the folded molecule.

  Units, basis and methodShowHide

  Accepted source units: %, mol%

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mole_percent

  Also written: hydrophobic amino acids; hydrophobic aa; % hydrophobic amino acids

  Basis: The number depends ENTIRELY on two study choices: WHICH amino acids the authors classified as hydrophobic, and the DENOMINATOR (% of total amino acids, of total protein, or of the sample). Both are recorded with the method; two values built on different classifications are never compared or averaged.

  Carried with every value: denominator_substance

  Method context: The amino-acid classification used (list the residues, or name the scale — Kyte-Doolittle, Eisenberg, "non-polar residues") AND the denominator. Without the classification the percentage is not interpretable.

  Evidence rule: The residue classification and the denominator must be recorded with the value; a percentage whose classification is unstated is stored with that gap explicit and is never compared across studies.

  Related, never merged by default: Amino acid composition; Hydrophilic amino acid content; Surface hydrophobicity (H₀)

  Note: A bare % is never rewritten as % w/w. This is NOT surface hydrophobicity and the two are never merged.

• Isoelectric point (pI)

  2. Molecular and structural propertiesMolecular characterization

  isoelectric point

  pH at which the net charge is zero. Dimensionless (a pH value).

  Units, basis and methodShowHide

  Accepted source units: 1

  Canonical unit: 1

  Dimension: dimensionless

  Also written: pi; iep; isoelectric ph

  Method context: Determination (zeta-potential-vs-pH crossover, isoelectric focusing).

  Related, never merged by default: Zeta potential

  Why this group: Group 2: pI is a property of the molecule's charge distribution. It is commonly DETERMINED from a zeta-potential-vs-pH curve (group 3), which is a method relationship, not a group membership.

• Moisture content

  1. Composition and purityMolecular characterization

  moisture content

  Water content of the sample, by oven drying or an equivalent stated method, as a percentage. The quantity every dry-matter basis is computed against.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/100 g

  Canonical unit: %

  Dimension: percent, mass_fraction

  Also written: moisture; water content; moisture (%)

  Method context: Oven drying (temperature and duration), vacuum oven, Karl Fischer or thermogravimetry give different numbers; the method is recorded.

  Related, never merged by default: Ash content; Total nitrogen; Protein content

  Note: Moisture is what converts an as-is basis to a dry-matter basis. It is recorded because a conversion cannot be performed without it, and this system never performs one from an assumed moisture.

• Protein content

  1. Composition and purityMolecular characterizationsource unit preserved

  protein content

  Protein content of the SAMPLE as a measured result (Kjeldahl, Dumas), with its basis. Distinct from protein_concentration (the concentration of the dispersion that was tested) and from protein purity (the ingredient's characterisation, which is its own canonical term).

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/100 g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction

  Also written: crude protein; crude protein content

  Basis: Dry basis vs as-is and the nitrogen factor (N x 6.25 vs N x 5.7) change the number; both are carried as structured basis qualifiers on the row AND recorded with the method (item 43). Two values on different bases, or with different nitrogen factors, are never equated.

  Carried with every value: reporting_basis, nitrogen_conversion_factor

  Method context: Kjeldahl or Dumas, with the nitrogen conversion factor.

  Related, never merged by default: Protein purity

  Why this group: Composition, not molecular structure: it says how much protein the material is, not what the molecule is like. Its legacy category was 'Molecular characterization'.

  Note: Item 42/43: the BASIS (dry basis vs as-is, and the nitrogen factor N×6.25 vs N×5.7) changes the number and must be recorded; % and % w/w dry basis are never silently equated, and an unstated basis never matches a stated one.

• Protein purity

  1. Composition and purityMolecular characterizationsource unit preserved

  protein purity

  Protein content of the INGREDIENT as the paper characterises it - the number that separates an isolate from a concentrate from a flour. Reported on the paper's own basis, with the nitrogen factor it used.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/100 g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction

  Also written: protein purity; ingredient protein content; protein content of ingredient; protein purity %; purity

  Basis: Dry basis vs as-is and the nitrogen-to-protein conversion factor (N x 6.25, N x 5.7, N x 5.5) change the number and are carried as structured basis qualifiers on the row. A bare % is never rewritten as % w/w; a dry-basis purity is never equated with an as-is one; a purity computed with a different nitrogen factor is a different number.

  Carried with every value: reporting_basis, nitrogen_conversion_factor

  Import columns mapped onto this property: protein_purity

  Method context: The determination (Kjeldahl, Dumas, or the supplier specification the paper quotes) with the nitrogen conversion factor and the reporting basis.

  Evidence rule: The basis and the nitrogen factor are recorded where the paper states them and left explicitly unstated where it does not. An unstated basis is never filled in with a default, and a purity with an unstated basis is never compared with one that has a stated basis.

  Related, never merged by default: Protein content

  Why this group: Group 1 promises composition AND PURITY, and purity was the half it did not carry: protein_purity existed only as a structured material/import field, so an ingredient characterisation could be imported but had no canonical term, no glossary entry, no alias table, no accepted-unit list and no place in the grouping. It is a property of the MATERIAL (how much protein the ingredient is), which is exactly what group 1 holds, and it is kept separate from protein content because one characterises the ingredient and the other reports a measurement made on the sample under test.

  Note: The import column protein_purity and the extraction field of the same name are MAPPINGS onto this canonical term, not a second quantity: one representation, with the column as its alias. A bare % and % w/w are different statements about the basis and are never merged.

• Protein recovery

  Process yield and recovery — Extraction yield and protein recoveryMolecular characterization

  protein recovery

  Protein in the extracted product as a percentage of the protein in the starting material — how much of the feedstock's protein the process kept.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: protein yield; protein recovery (%); recovery; nitrogen recovery

  Basis: Protein in product / protein in feedstock. Both protein contents are themselves measurements with their own basis and conversion factor; when the source states them, they are recorded as their own rows.

  Method context: Whether the accounting is on nitrogen or on converted protein matters, and the conversion factor used for each stream is recorded when stated.

  Related, never merged by default: Extraction yield; Protein content; Total nitrogen

  Note: A recovery above 100% is recorded as reported and flagged, not clipped: it usually means the two streams were quantified with different conversion factors, and silently correcting it would destroy the evidence of that.

• Random-coil content (%)

  2. Molecular and structural propertiesMolecular characterization

  random-coil content

  Fraction of secondary structure assigned as random coil or unordered structure, from circular dichroism or FTIR deconvolution, as a percentage.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: random coil; unordered structure; unordered; random coil content (%); aperiodic structure

  Method context: CD or FTIR band assignment and the deconvolution algorithm decide the number; they are recorded with it.

  Related, never merged by default: Alpha-helix content (%); Beta-sheet content (%); Beta-turn content (%)

  Note: Reported per the study's own deconvolution. It is never derived as 100 − (helix + sheet + turn): that arithmetic assumes a closed four-state model the source may not have used.

• Total nitrogen

  1. Composition and purityMolecular characterizationsource unit preserved

  total nitrogen

  Total nitrogen of the sample as MEASURED, by Dumas combustion or Kjeldahl, before any conversion to protein. Recorded separately from protein content so the measured quantity and the calculated one are never confused.

  Units, basis and methodShowHide

  Accepted source units: %, % w/w, g/100 g

  Canonical unit: Method-dependent — source unit and basis preserved

  Dimension: percent, mass_fraction

  Also written: nitrogen content; total n; n content; crude nitrogen

  Basis: Dry-matter and as-is nitrogen differ by the moisture content. The basis is recorded as stated and never assumed.

  Carried with every value: reporting_basis

  Method context: Dumas combustion and Kjeldahl digestion are different methods with different recoveries; which one produced the number is recorded.

  Related, never merged by default: Protein content; Moisture content

  Note: TOTAL NITROGEN IS NOT CRUDE PROTEIN. Crude protein is nitrogen × a conversion factor, and the factor is a choice — 6.25, 5.7, 5.4, 5.71 are all in the literature for plant proteins. This term stores the MEASURED nitrogen. A missing factor is never filled in with 6.25; see the nitrogen_conversion_factor basis qualifier on protein content.

• Angle of repose

  4. Powder and bulk propertiesPowder & handling

  angle of repose

  Angle of the powder heap against the horizontal, in degrees of arc. One of the three separate flowability quantities (item 42).

  Units, basis and methodShowHide

  Accepted source units: °

  Canonical unit: °

  Dimension: angle

  Also written: repose angle

  Method context: Heap formation method (fixed funnel, tilting box).

  Related, never merged by default: Carr index; Hausner ratio

• Bulk density

  4. Powder and bulk propertiesPowder & handling

  bulk density

  Mass per volume of the loosely packed powder. kg/m³, g/mL and g/cm³ interconvert deterministically (item 56).

  Units, basis and methodShowHide

  Accepted source units: kg/m³, g/mL, g/cm³

  Canonical unit: kg/m³

  Dimension: density

  Also written: loose bulk density

  Method context: Loose vs tapped protocol (container, tap count) in measurement_method.

  Related, never merged by default: Tapped density; Carr index; Hausner ratio

  Note: This is the LOOSE density. A tapped density is a separate property below; a solution concentration (g/L, mg/mL) is a different dimension and never lands here.

• Carr index

  4. Powder and bulk propertiesPowder & handling

  carr index

  Compressibility index from bulk and tapped density, as a percentage. One of the three separate flowability quantities (item 42).

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: compressibility index; carr's index

  Method context: Computed from bulk and tapped density; record both protocols.

  Related, never merged by default: Hausner ratio; Angle of repose; Bulk density

• Hausner ratio

  4. Powder and bulk propertiesPowder & handling

  hausner ratio

  Tapped density over bulk density. Dimensionless by definition. One of the three separate flowability quantities (item 42).

  Units, basis and methodShowHide

  Accepted source units: 1

  Canonical unit: 1

  Dimension: dimensionless

  Method context: Computed from bulk and tapped density; record both protocols.

  Related, never merged by default: Carr index; Angle of repose; Bulk density

• Tapped density

  4. Powder and bulk propertiesPowder & handling

  tapped density

  Mass per volume of the powder after a defined tapping protocol. Distinct from the loose bulk density, and the input from which Carr index and Hausner ratio are computed.

  Units, basis and methodShowHide

  Accepted source units: kg/m³, g/mL, g/cm³

  Canonical unit: kg/m³

  Dimension: density

  Also written: tap density; tapped bulk density

  Basis: The TAP COUNT (and the tapping apparatus) is part of the number: a density after 100 taps is not a density after 1250 taps and the two are never equated.

  Method context: Tap count, tapping amplitude/apparatus and container geometry.

  Evidence rule: Record the tap count. A tapped density without one is stored with that gap explicit and is not compared across studies.

  Related, never merged by default: Bulk density; Carr index; Hausner ratio

  Note: kg/m³, g/mL and g/cm³ interconvert deterministically. A tapped density is never stored as a bulk density, and neither is derived from a Carr index or a Hausner ratio without the other density.

• Degree of hydrolysis

  2. Molecular and structural propertiesDigestibility

  degree of hydrolysis

  Proportion of peptide bonds cleaved during enzymatic hydrolysis, by the stated assay.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: dh

  Placement condition: Degree of hydrolysis keeps its molecular and structural placement ONLY when (a) the value is defined as the proportion of peptide bonds cleaved, and (b) the assay that measured it is recorded with the row. Without the assay the number is not comparable with any other degree of hydrolysis, so the row is flagged for review rather than silently accepted, and the engine refuses to equate it with anything.

  Related experimental family (a facet, never an equivalence): proteolysis_susceptibility

  Method context: The hydrolysis assay MUST be recorded (pH-stat, OPA, TNBS): values from different assays differ and are not merged. The enzyme, enzyme-to-substrate ratio, pH, temperature and hydrolysis time are part of the method.

  Evidence rule: The assay must be recorded with the value. A degree of hydrolysis whose assay is not stated is stored with that gap explicit, flagged for review, and never compared with another value.

  Related, never merged by default: In vitro protein digestibility

  Why this group: Hydrolysis extent is a covalent change to the molecule - peptide bonds cleaved - so it sits with the molecular and structural properties even though the assay is enzymatic and its legacy category was 'Digestibility'. THIS PLACEMENT IS CONDITIONAL: it holds only while the value is the proportion of PEPTIDE BONDS CLEAVED and the assay that measured it is recorded. A "degree of hydrolysis" that is really a digestibility, or that names no assay, does not qualify - see methodRequirement.

  Note: NOT an in vitro protein digestibility. Both numbers come from enzymatic peptide-bond cleavage, which is why they share the proteolysis-susceptibility facet, but a degree of hydrolysis reports how far a PROCESSING hydrolysis went and a digestibility reports what a DIGESTION protocol liberated. They are never equated, never resolve to each other and share no alias.

• In vitro protein digestibility

  Nutritional and protein-quality properties — Protein quality and digestibilityDigestibility

  in vitro protein digestibility

  Protein hydrolysed under a defined in vitro digestion protocol, as a percentage of the protocol's own definition. A nutritional protein-quality property, not a functionality.

  Units, basis and methodShowHide

  Accepted source units: %

  Canonical unit: %

  Dimension: percent

  Also written: ivpd; digestibility; protein digestibility; in vitro digestibility

  Related experimental family (a facet, never an equivalence): proteolysis_susceptibility

  Method context: Digestion protocol and its enzymes (INFOGEST, pepsin-pancreatin, pH-drop) with the digestion time and the calculation the authors used - the number is protocol-specific and two protocols are never merged.

  Related, never merged by default: Degree of hydrolysis

  Why this group: PLACEMENT CORRECTED. An earlier round placed in vitro protein digestibility in functionality group 2 (molecular and structural) on the ground that it measures the molecule's susceptibility to proteolysis. That placement is REJECTED: IVPD is a NUTRITIONAL quality property, it answers a question about human or animal digestion rather than about the protein's behaviour in a food system, and putting it in a functionality group made the functionality taxonomy claim something it does not measure. It now sits on its own axis — the nutritional and protein-quality domain — which is NOT a fifteenth functionality group. The genuine relationship to degree of hydrolysis (both count enzymatically cleaved peptide bonds) is recorded as the proteolysis-susceptibility FACET, which relates the two without equating them.

  Note: State the protocol (INFOGEST, pepsin-pancreatin, pH-drop, ...) in measurement_method - the number is protocol-specific. NOT a degree of hydrolysis: a digestibility asks how much protein a digestive system liberates under a digestion protocol, a degree of hydrolysis asks what fraction of peptide bonds a processing hydrolysis cleaved. The two are never equated, never resolve to each other and share no alias.

“Method-dependent — source unit and basis preserved” means the literature reports this property under more than one definition, so no single target unit exists and nothing is converted; the reported unit and basis are stored exactly as published.