Resource, Materials and Environment. Lesson 2: Food Chemistry. Food Components. Protein: Amino acids, Peptide and Polypetide Carbohydrates Fats and oils Food Additives Food Production. Proteins. proteins are essential parts of all living organisms. Amino acids.
Lesson 2: Food Chemistry
The pH at which an amino acid carries no net electric charge, this quantity can be determined by an analytical technique called electrophoresis
Useful for separating organic compounds.
A static phase, usually a solid or a liquid adsorbed on a solid supported
A dynamic phase, the components to be separated is carried through the stationary phase by the mobile phase
CH3CH(NH2)COOH alanine +
H2NCH2COOH glycine →
Which one yields more?
Long chains of amino acids will commonly fold or curl into a regular repeating structure.
Structure is a result of hydrogen bonding between amino acids within the protein.
Different reconstructed illustrations of protein molecule
Here is an example sequence of amino acids in a protein.
It also shows the abbreviations commonly used.
Sucrose (table sugar)
(sugar in milk)
R,R’,R’’ are hydrocarbon chains
CH3(CH2)nCOOH Size range:C12-C24
Always an even number of carbon
Saturated: no double bonds
Unsaturated: one or more double bonds
RCH=CHCH2CH2COOH—(H2,Ni)→RCH2CH2CH2CH2COOHUsed to convert unsaturated vegetable oils to margarine
-CH=CH- + I-I →-CHI-CHI-
Defined as the number of grams of iodine that reacts with 100 grams of fats/oils
Of unsaturation in the fat or oil.
Presence of double bonds reduces melting point.
Colourings, Antioxidants, Flavour Enhancers, Preservatives, Sweeteners, Emulsifiers, stabilizers, and thickeners, and etc.
Principles of food preservation
Principle of BHA/BHT as antioxidant
Inhibition of microbial growth
Killing of micro-organisms
Ratardation of chemical changes
Monitoring and legislation
Common food preservation techniques