Food Processing  and Preservation
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  • Nutritional evaluation of food processing, Food preservation 2nd edition, by Normal W. DesrosierDECRESE OXIDATION TO PREVENT RANCIDIFICATION OF FATPREVENT BROWNING OF FRUITSREDUCE FOOD MOISTURE AND BACTERIA


  • 2. FOOD PROCESSING WHAT? Food processing is the transformation of raw ingredients into food, or of food into other forms. Food processing is typically a mechanical process that utilizes large mixing, grinding, chopping and emulsifying equipment in the production process
  • 3. HOW? Food processing typically takes clean, harvested crops or butchered animal products WHY? To produce attractive, marketable and often long shelf-life food products
  • 4. ADVANTAGES OF FOOD PROCESSING 1. Toxin removal 2. Preservation 3. Easing marketing and distribution tasks 4. Increasing food consistency, improves taste
  • 5. 5. It increases yearly availability of many foods 6. Enables transportation of delicate perishable foods across long distances 7. Makes many kinds of foods safe to eat by de-activating spoilage and pathogenic micro-organisms. 8. Large profit potential for manufacturers
  • 6. RISKS AND DISADVANTAGES 1. Loss of nutritive value 2. Possible Contamination • physical ( hair, metals,fingernails,stones) • chemical (excess salt, sugar, acids,cleaning agents • Microbial (Salmonella, E. coli, parasites,fungi)
  • 7. Nearly every food preparation process reduces the amount of nutrients in food. In particular, processes that expose foods to high levels of heat, light, and/or oxygen cause the greatest nutrient loss. Nutrients can also be "washed out" of foods by fluids that are introduced during a cooking process. Similar losses also occur when you broil, roast, or fry in oil, and then drain off the drippings
  • 8. FACTORS TO BE CONSIDERED  Hygiene, e.g. measured by number of micro- organisms per ml of finished product  Energy efficiency measured e.g. by “ton of steam per ton of sugar produced”  Minimization of waste, measured e.g. by “percentage of peeling loss during the peeling of potatoes'  Labour used, measured e.g. by ”number of working hours per ton of finished product”  Minimization of cleaning stops measured e.g. by “number of hours between cleaning stops”
  • 9. FOOD PRESERVATION  Food preservation is the process of treating and handling food to stop or slow down food spoilage, loss of quality, edibility or nutritional value and thus allow for longer food storage.
  • 10. METHODS OF PRESERVING FOOD 1. Drying - one of the most ancient food preservation techniques, which reduces water activity sufficiently to prevent bacterial growth. 2. Refrigeration - preserves food by slowing down the growth and reproduction of micro-organisms and the action of enzymes which cause food to rot
  • 11. 3. Freezing- (0 to -17 C) 4.Vacuum packing A vacuum environment, usually in an air- tight bag or bottle strips bacteria of oxygen needed for survival, slowing spoiling. Vacuum-packing is commonly used for storing nuts to reduce loss of flavor from oxidation. 5. Addition of salt/ curing Salt draws water through Osmosis, Prague powder(NaNO2 + Salt) gives it a distinctive pink colour)
  • 12. 6. Sugar 7. Smoking Chemical components from the smoke of burning wood: a. Nitrogen oxides form nistrosamines with meat and fish b. Polycyclic aromatichydrocarbons,phenols,furans,tar 8. ArtificiaL Food Additives Common antimicrobial preservatives include calcium propionate, sodium nitrate, sodium nitrite, sulfites (sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.) and disodium EDTA. Antioxidants include BHA and BHT. Other preservatives include formaldehyde (usually in solution), glutaraldehyde (kills insects), ethanol and methylchloroisothiazolinone.
  • 13. 9. Jellying 10. Irradiation ( exposure to Xrays, gamma rays) 11. High Pressure processing 12. Burying in the Ground(lack of light, oxygen,lowpH,cool temp, dessicants in soil) 13. Biopreservation (addition of LAB) 14. Pickling a. Chemical (brine,vinegar, oil) b. Fermentation (lactic acid produced by the food itself) 15. Addition of Lye -NaOH prevents bacterial growth, saponifies fats 16. Canning and Bottling
  • 14. FOOD ADDITIVES These are substancesadded to food to preserve flavor or enhance its taste and appearance. a. Intentional(added on purpose) b. Incidental (unintentional)
  • 16.  Acids -added to make flavors "sharper", and also act as preservatives and antioxidants. Common food acids include vinegar, citric acid, tartaric acid, malic acid, fumaric acid, and lactic acid.  Acidity regulators are used to change or otherwise control the acidity and alkalinity of foods.  Anticaking agents keep powders such as milk powder from caking or sticking. Antifoaming agents  Antifoaming agents reduce or prevent foaming in foods.
  • 17.  Antioxidants such as vitamin C act as preservatives by inhibiting the effects of oxygen on food, and can be beneficial to health.  Bulking agents such as starch are additives that increase the bulk of a food without affecting its taste.  Food coloring are added to food to replace colors lost during preparation, or to make food look more attractive.  Color retention agents are used to preserve a food's existing color.
  • 18.  Emulsifiers allow water and oils to remain mixed together in an emulsion, as in mayonnaise, ice cream, and homogenized milk.  Flavors give food a particular taste or smell, and may be derived from natural ingredients or created artificially.  Flavor enhancers enhance a food's existing flavors.They may be extracted from natural sources (through distillation, solvent extraction, maceration, among other methods) or created artificially.  Flour treatment agents are added to flour to improve its color or its use in baking
  • 19.  Glazing agents provide a shiny appearance or protective coating to foods.  Humectants prevent foods from drying out.  Preservatives prevent or inhibit spoilage of food due to fungi, bacteria and other microorganisms.  Stabilizers thickeners and gelling agents, like agar or pectin(used in jam for example) give foods a firmer texture.While they are not true emulsifiers, they help to stabilize emulsions.
  • 20.  Sweeteners are added to foods for flavoring. Sweeteners other than sugar are added to keep the food energy (calories) low, or because they have beneficial effects for diabetes mellitus and tooth decay and diarrhea.  Thickeners are substances which, when added to the mixture, increase its viscosity without substantially modifying its other properties.
  • 21. ADULTERANTS  3-MCPD  Aldicarb  Cyanide  Formaldehyde  Lead poisoning  Melamine  Mercury in fish  Sudan I
  • 22. Pesticides  Chlorpyrifos  DDT  Lindane  Malathion  Methamidophos
  • 23. PRESERVATIVES  Benzoic acid  Ethylenediaminetetraacetic acid (EDTA)  Sodium benzoate
  • 24. Sugar substitutes  Acesulfame potassium  Aspartame  High-fructose corn syrup  Saccharin  Sodium cyclamate  Sorbitol  Sucralose
  • 25. Referrences  Riddervold, Astri. Food Conservation. ISBN 978-0- 907325-40-6.  Abakarov, Nunes. "Thermal food processing optimization: algorithms and software". Food Engineering (  Abakarov, Sushkov, Mascheroni. "Multi-criteria optimization and decision-making approach for improving of food engineering processes". InternationalJournal of Food Studies ( .pdf).
  • 26.  Fábricas de alimentos, 9th edition (in Spanish)  Nutritional evaluation of food processing,  Food preservation 2nd edition, by Normal W. Desrosier  Department of FoodTechnology, University College ofTechnology, Osmania University, Hyderabad, Andhra Pradesh, India  University of California directory of academic and industry literature  FOOD ADDICTION |The Perils of Processed Foods in America’s Diet