The Plant Lab
Glossary

The vocabulary of plant-based food science

A working dictionary of terms used in this course. Search by term or by context — "starch," "fermentation," "umami."

A

Aerobic
Requiring oxygen. Aspergillus oryzae (koji) is an obligate aerobe; Lactobacillus bacteria are facultative anaerobes.
Aerated foam
A dispersion of gas bubbles in a liquid or solid matrix; aquafaba meringue is a foam.
Agar
A polysaccharide from red seaweed; sets a firm, brittle thermoset gel.
Aleurone
The protein-rich outer layer of a cereal grain.
Alginate, sodium
A polysaccharide from brown seaweed that gels instantly with calcium ions ("egg-box" model). Used in spherification.
Amadori product
An intermediate in the Maillard reaction.
Amino acid
The building block of proteins. Twenty common ones; nine "essential" because the body cannot synthesize them.
Amylose / Amylopectin
The two polymers that make up starch. Amylose is mostly linear, gels firmly; amylopectin is highly branched, stays softer.
Anisotropy
Direction-dependent structure or property. The goal of HMMA and shear-cell technologies.
Antinutrient
A naturally occurring compound that interferes with nutrient absorption; phytic acid, oxalates, lectins.
Aquafaba
The liquid from cooked or canned chickpeas. Contains soluble proteins and saponins; functions as foam, emulsion stabilizer, and binder.
Aspergillus oryzae
The koji mold. Secretes a powerful enzymatic toolkit (proteases, amylases, lipases). Foundation of soy sauce, miso, sake.

B

Bioavailability
The proportion of a nutrient absorbed and used by the body. Highly variable for non-heme iron, calcium, B12.
Bioreactor
A vessel for growing microbes or cells under controlled conditions; central to precision fermentation and cultivated meat.

C

Caramelization
Thermal decomposition of sugar alone into bittersweet aroma compounds. No protein required (vs Maillard).
Carrageenan
A family of polysaccharides from red seaweed. Kappa, iota, and lambda forms each have distinct gelling behaviors.
Casein
The dominant protein family of dairy milk; gives cheese its structure. Now produced by precision fermentation in animal-free form.
Cellular agriculture
The production of agricultural products from cell cultures rather than from whole organisms; cultivated meat is the leading example.
Coagulation
The transition of a protein from soluble to insoluble, forming a gel or curd.

D

DIAAS
Digestible Indispensable Amino Acid Score. A protein-quality metric replacing PDCAAS in many regulatory contexts.
Denaturation
The unfolding of a protein from its native shape — by heat, acid, salt, or mechanical action.
DHA / EPA
Docosahexaenoic and eicosapentaenoic acids. Long-chain omega-3 fatty acids; algae are the original source.

E

Egg-box model
The mechanism by which calcium ions cross-link alginate or LM-pectin chains, locking them into a gel.
Emulsion
A stable dispersion of one liquid in another (oil-in-water or water-in-oil).
Emulsifier
A molecule with a hydrophilic and a hydrophobic end that stabilizes the interface between oil and water. Lecithin, mustard mucilage, aquafaba.
Enteric fermentation
Methane production by microbes in the digestive tract of ruminants. A major source of agricultural greenhouse gas emissions.
Extrusion
Forcing a dough through a die under heat and pressure. The dominant industrial process for textured plant proteins.

F

Fermentation
Microbial transformation of food. In strict biochemistry, anaerobic energy metabolism; in food science, used more broadly.
Flavor
The brain's combined perception of taste, aroma, mouthfeel, and trigeminal sensation.
Fortification
Deliberate addition of nutrients to foods to address population deficiencies; vitamin D milk, iodized salt, B12 in plant milks.

G

Gel
A liquid trapped inside a 3-D network of solid material. Most food gels are biopolymer networks holding water.
Gelatinization
The process by which starch granules absorb water, swell, and rupture under heat — releasing amylose into solution.
Gellan gum
A bacterial polysaccharide that forms either soft elastic (high-acyl) or brittle clear (low-acyl) gels.
Gluten
The viscoelastic protein network formed when wheat glutenin and gliadin hydrate and are mixed.

H

Hedonic test
A sensory test in which untrained consumers rate liking on a scale (typically 1–9).
HMMA / HMME
High-moisture meat analogue / extrusion. Industrial process for producing fibrous, anisotropic plant meats.
Hydrocolloid
A water-soluble long-chain polymer (usually a polysaccharide) that thickens or gels at low concentrations.
Hydrogenation
Saturating fat double bonds chemically, hardening a liquid oil. Largely abandoned for food due to trans-fat formation.

I

Isoelectric point (pI)
The pH at which a protein carries no net electrical charge. Proteins are least soluble and most likely to aggregate at this pH.
Isolate (protein)
A protein product purified to ≥ 85% protein content, typically by alkaline extraction and isoelectric precipitation.

K

Kala namak
"Black salt" — a sulfur-rich rock salt that imparts cooked-egg flavor due to natural hydrogen sulfide content.
Koji
Steamed grain colonized with Aspergillus oryzae; the enzymatic engine of soy sauce, miso, sake, and a growing world of vegan ferments.
Konjac glucomannan
A polysaccharide from konjac corm; sets a very firm, reheat-stable gel with alkali. Basis of shirataki noodles.

L

Lactic acid bacteria (LAB)
Microbes that ferment sugars to lactic acid; Lactobacillus, Leuconostoc, etc. Essential for sauerkraut, sourdough, vegan yogurts.
Lecithin
A phospholipid emulsifier; commercially extracted from soy or sunflower seeds.
Leghemoglobin
A heme-containing protein from the root nodules of legumes; produced via precision fermentation for the Impossible Burger.
Life-cycle assessment (LCA)
A method for quantifying the environmental impact of a product across its full life cycle.

M

Maillard reaction
The cascade of reactions between reducing sugars and amino acids under heat — responsible for crust, color, and roasted aromas.
Methylcellulose
A modified cellulose that gels when heated and melts when cooled — backwards from most hydrocolloids. The backbone binder of many plant burgers.
Mycelium
The vegetative network of filamentous fungi; naturally fibrous, edible, used for whole-cut plant meats (Quorn, Meati).

N

Nutritional yeast
Deactivated Saccharomyces cerevisiae; nutty/cheesy flavor, often fortified with B12, naturally rich in glutamate and 5'-GMP.

O

Oleogel
A liquid oil immobilized in a 3-D scaffold of edible structurants (waxes, ethylcellulose, proteins) so that it behaves like a solid fat.
Osmosis
Movement of water across a semipermeable membrane down its concentration gradient; the principle behind salt and sugar curing.

P

PDCAAS
Protein Digestibility–Corrected Amino Acid Score; a protein-quality metric. Capped at 1.0.
Pectin
A polysaccharide from plant cell walls. HM (high methoxyl) sets with sugar and acid; LM (low methoxyl) sets with calcium.
Phytic acid
A compound in seeds that binds minerals; reduced significantly by soaking, sprouting, and fermentation.
Precision fermentation
Programming microbes (yeast, fungi, bacteria) to produce specific target proteins at scale; the basis of modern animal-free dairy.

R

Retrogradation
The slow re-association of starch chains after cooking and cooling, leading to firming, syneresis, and staling.
Rhizopus oligosporus
The mold used to ferment tempeh. Knits cooked beans into a firm cake, develops nutty flavor, reduces antinutrients.

S

Saponin
A class of plant glycoside that lowers surface tension and contributes to foaming in aquafaba and quinoa cooking water.
Seitan
A meat-textured food made from vital wheat gluten; the original "wheat meat."
Shear cell
A device that applies steady simple shear to a heated protein mass, producing fibrous, anisotropic structure. An alternative to extrusion.
Smoke point
The temperature at which an oil begins to visibly smoke, indicating thermal decomposition of fatty acids.
Syneresis
The weeping of liquid out of a gel as the network contracts.

T

Tempeh
A fermented bean cake made by inoculating cooked beans with Rhizopus oligosporus; firm, sliceable, deeply flavored.
Texturized vegetable protein (TVP)
Defatted plant flour processed by low-moisture extrusion into dry, sponge-like granules or chunks.
Thermoreversible / Thermoset
A thermoreversible gel melts on reheating (agar, gelatin); a thermoset gel does not (egg whites, methylcellulose, alginate).
Triangle test
A discrimination panel in which judges identify which of three samples is different from the other two.
Triglyceride
The dominant form of dietary fat: a glycerol backbone esterified to three fatty acid tails.

U

Umami
The savory fifth basic taste, mediated by the T1R1/T1R3 receptor in response to glutamate and certain ribonucleotides.

V

Vital wheat gluten
Dehydrated wheat protein, ~75% pure. The starting material for seitan and many meat analogues.

W

Water activity (aw)
The proportion of "free" water in a food, on a 0–1 scale. Determines microbial growth, reaction rates, and shelf life.

Y

Yuba
The protein-fat film that forms on the surface of heated soymilk; lifted off and dried to make tofu skin.