1. divide into 2
1.1. inorganic
1.1.1. phosphoric acid
1.1.2. hydrochloric acid
1.1.3. sulfuric acid
1.2. organic
1.2.1. carboxylic acid
1.2.1.1. monocarboxylic acid
1.2.1.1.1. acetic acid
1.2.1.1.2. propionic acid
1.2.1.1.3. lactic acid
1.2.1.1.4. New node
1.2.1.1.5. New node
1.2.1.2. dicarboxylic acids
1.2.1.2.1. malic acid
1.2.1.2.2. tartaric acid
1.2.1.2.3. adipic acid
1.2.1.2.4. fumaric
1.2.1.2.5. New node
1.2.1.2.6. New node
1.2.1.2.7. New node
1.2.1.2.8. New node
1.2.1.3. tricarboxylic acids
1.2.1.3.1. citric acid
1.2.2. phenolic acid
1.2.2.1. benzoic acid
1.2.3. fatty acid
1.2.3.1. sorbic acid
1.2.3.2. caprylic acid
1.2.3.3. bufyric acid
1.2.4. lactones
1.2.4.1. ascorbic acid
1.2.4.2. gluconolactone
1.2.5. amino acid
2. function
2.1. preservatives
2.1.1. if acid pH -Stop growth -enhance effectiveness of heat sterilization or anti microbial effect of solute
2.1.2. serves as anti browning agent -maintain normal flavor,colour and texture
2.2. pH control agents
2.2.1. f(x) -obtain certain pH range -maintain acidic pH and tartness of carbonated beverages
2.2.2. -accidulant have buffering capacity ---->buffering capacity: ability of weak/salt combination to control amount of hydrogen -need : to maintain acid fermentation process
2.3. chelating agent/antioxidant synergists
2.3.1. -food acidulant have ability to form ring structure with metal ion - process known CHELATION
2.3.1.1. CHELATION - prevent metal ion from reacting with other materials or from acting as catalyst for reaction ,formation of stable, water -soluble chelate ----> referred as sequestration
2.3.2. citric acid- strongest chelating agent
2.4. flavour adjuncts
2.4.1. -acidulant add tartness required to balance excessive sweetness of these product ''brix acid ratio''
2.4.2. -enhancement of certain flavors requires combination of flavour with appropriate acids ex : tartaric acid,phosphoric acids
2.5. control of gelation
2.5.1. play role in gelation of pectin and algins for gelling