Chemistry of food and food processing: composition, reactions during cooking/storage, flavour and colour formation, nutritional degradation. Large industrial domain and consumer-safety substrate.
food-chemistry
Maillard reaction
Non-enzymatic condensation of reducing sugar carbonyl with amine (amino acid, protein), followed by Amadori rearrangement and degradation…
Lipid oxidation / rancidity
Autocatalytic radical chain: initiation R–H→R•, propagation R• + O₂ → ROO•, ROO• + R'H → ROOH + R'•, decomposition into aldehydes (hexanal,…
Enzymatic browning
Polyphenol oxidase (PPO) in bruised apples, potatoes, bananas catalyses phenol + O₂ → o-quinone, which polymerises into melanin-like…
Starch gelatinisation
On heating in water above Tg (~60–75°C depending on source), amylopectin crystallites melt and amylose leaches, yielding viscous paste.…
Protein denaturation (cooking)
Heat, pH, or shear unfolds tertiary structure, exposing hydrophobic residues that aggregate (egg-white coagulation at ~62°C, myosin…
Food emulsion
Colloidal dispersion of immiscible liquids stabilised by surfactants (lecithin in mayonnaise, caseins in milk). Stability governed by…
Fermentation chemistry
Microbial anaerobic catabolism of sugars: Embden–Meyerhof glycolysis to pyruvate, then ethanol + CO₂ (yeast, beer/wine), lactate (LAB,…
Food additives
Functional chemicals with E-numbers: preservatives (E200–299), antioxidants (E300–399), emulsifiers (E400–499), colourants (E100–199),…
Food rheology & thixotropy
Food matrices show non-Newtonian rheology — power-law (ketchup), Bingham-plastic (mayonnaise), thixotropic (yogurt: shear-thinning +…
Flavour & volatile chemistry
Sensory flavour from volatile compounds (esters / aldehydes / sulfur / lactones) detected by olfactory receptors. GC-MS combined with…
Shelf-life prediction (Arrhenius)
Food-quality decays via temperature-dependent kinetics; accelerated-shelf-life-testing (ASLT) at elevated T extrapolated via Arrhenius k(T)…
Food fortification & nutrient bioavailability
Salt-iodisation / flour-folate-fortification / orange-fleshed-sweet-potato β-carotene-biofortification. Bioavailability depends on…
Maillard reaction (1912)
L Maillard 1912 amino-acid + reducing-sugar non-enzymatic browning; Hodge 1953 mechanism: Schiff base -> Amadori -> melanoidins; flavor +…
Emulsion stability (Bancroft 1913)
Bancroft rule: continuous-phase = phase preferred by emulsifier; HLB Griffin 1949 hydrophilic-lipophilic balance scale 0-20; basis of…
Water activity aw (Scott 1953)
W J Scott 1953 a_w = p/p0 ratio; food-stability map 0.6 mold/0.7 yeast/0.85 bacteria limits; basis of intermediate-moisture-food…
Lipid oxidation (Rancimat)
Schaal 1937 + Frankel 1980s lipid-peroxidation: chain-reaction R + O2 -> ROO peroxyl; tocopherol antioxidant H-donation; OSI Rancimat…
Starch gelatinization (Atwell 1988)
Atwell 1988 + Biliaderis 1991 gelatinization: starch + water + heat 60-75 C -> swollen amorphous; cooling -> retrogradation B-type…
Flavor thresholds (Rothe-Thomas 1963)
Rothe-Thomas 1963 odor-detection-thresholds (DTV) ng/L; OAV = c/threshold > 1 indicates flavor-relevant; Schieberle 1990s aroma-extract…
Maillard reaction (1912)
L Maillard 1912 amino-sugar browning; modern HMF + acrylamide + flavor-development; 200-step reaction-network 2024 high-res-MS.
Emulsion (Bancroft 1913)
W Bancroft 1913 oil-water + HLB-Griffin 1949; modern food-emulsion + nanoencapsulation + Pickering-emulsion solid-particle stabilization.
Water activity (Scott 1953)
W J Scott 1953 a_w concept; modern food-preservation prediction-model + osmolyte modulation + IDF Codex-Alimentarius standards.
OAV (Rothe-Thomas 1963)
M Rothe-G Thomas 1963 odor-activity-value c/c_threshold; modern GC-MS-O sniff-port + 2D-GC + AEDA aroma-extract dilution.
Starch (Atwell 1988)
Atwell 1988 starch-chemistry + Tester-Karkalas 2004; modern modern resistant-starch + amylose-amylopectin ratio + extrusion-cooking.
Lipid oxidation (Frankel 1998)
E Frankel 1998 'Lipid Oxidation'; modern peroxide-value + TBARS + 2024 anti-oxidant-screening 100k-cmpd HTS rancidity-prediction.