Food preservation methods

TEACHING UNIT 1. AIMS AND METHODS FOR PREVENTING FOOD CONTAMINATION.

1. Prevention of chemical and physical changes. Chemical changes: Oxidation of fats.
2. Non-enzymatic browning. Enzymatic browning. Physical changes. Colour changes.
3. Changes in texture.
4. Prevention of microbial spoilage and foodborne illnesses. Factors influencing the type and number of microorganisms present in food. Microbial spoilage in different food groups. Foodborne illnesses.
5. Asepsis. Hygiene of raw materials. Hygiene, cleaning and disinfection of premises and equipment. Cleaning. Disinfection. Carrying out cleaning and disinfection procedures. Staff hygiene.
6. Preservation treatment. Physical treatments. Chemical treatments.
7. Product conditioning and consumer information. The use of controlled and modified atmospheres. Packaging. Consumer information and labelling.

TEACHING UNIT 2: PHYSICAL METHODS OF FOOD PRESERVATION.

1. Various physical preservation treatments. Mechanical cleaning. Wet methods. Dry methods. Combined methods. Filtration. Drying. Conventional dehydration. Freeze-drying. Smoking.
2. Salting. Pressure. Osmotic pressure. High pressure. Ultrasound. Electricity.
3. Temperature-related physical preservation treatments. Low-temperature treatments. Refrigeration. Freezing. High-temperature treatments. Scalding (or blanching).
4. Pasteurisation. Sterilisation.
5. Physical conservation treatments involving radiation. Microwaves. Infrared radiation. Ultraviolet radiation. Ionising radiation.

TEACHING UNIT 3: CHEMICAL TREATMENTS FOR FOOD PRESERVATION.

1. General information on food additives. Definition and use. Organisations responsible for food additives. FAO / WHO. Council of Europe. European Union (EU). Spanish food legislation.
2. Health considerations. Criteria for assessing the safety of a food additive. Toxicological testing of food additives. The concept of Acceptable Daily Intake (ADI).
3. Preservatives. The legal status of preservatives. Preservatives authorised for use in food. Uses and mode of action of preservatives authorised for use in food. Sorbic acid and its salts. Benzoic acid, its salts and the esters of hydroxybenzoic acid. Acetic acid and lactic acid. Propionic acid and its salts. Sulphur dioxide and sulphites. Nitrites and nitrates. Antibiotics. Other preservatives.
4. Antioxidants and antioxidant synergists. Legal status of antioxidants. Antioxidants authorised for use in food. Antioxidant synergists authorised for use in food. Mode of action and uses of antioxidants authorised for use in food. Ascorbic acid and its derivatives. Tocopherols. Gallates. Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Sulphur dioxide and its derivatives. Lecithins. Mode of action and uses of antioxidant synergists authorised for food use. Lactic acid and its salts. Citric acid and its salts. Tartaric acid and its salts. Phosphoric acid and its salts.
5. Legislation on preservatives, antioxidants and antioxidant synergists. Royal Decree 142/2002 on food additives other than colourings and sweeteners.

TEACHING UNIT 4. PRODUCT PACKAGING AND CONSUMER INFORMATION.

1. The use of modified atmospheres. Advantages and disadvantages of modified atmosphere packaging. Gases used in modified atmosphere packaging. Packaging materials and equipment. Areas of application for modified atmosphere packaging.
2. Packaging. The need for packaging. Packaging materials. Wood. Paper and cardboard. Metal. Glass. Plastics. Polymer films. Filling and sealing of packaging.
3. Food packaging requirements. Meat. Poultry. Fish. Milk and dairy products. Eggs. Fruit and vegetables. Other products.
4. Consumer information: labelling. Introduction. Labelling regulations. Articles of Royal Decree 1334/1999 relating to food preservation.