application of ozone for microbial safety .pptx

food safety

1. Applications of ozone for enhancing microbiological safety and quality of food Muhammad Umair Farooq 2011-ag-4245

2. Outline Introduction History Antimicrobial action of ozone Ozone formation Ozone Applications Limitations & toxicity Conclusion References

3. Introduction Ozone (O3) is a powerful gas molecule consists of three oxygen atoms It formed by dissociating two atoms that compose the oxygen gas Ozone has great oxidative power to kill the microbes.

4. History

5. Antimicrobial action of ozone

6. OZONE FORMATION By Lightening An electrical discharge splits an oxygen molecule Unstable oxygen atoms combines with oxygen molecule to form ozone By UV light (Sun) Oxygen in the presence of 185 nm UV light creates ozone (Naturally) Oxygen exposed to 185 nm UV light from a UV bulb (Artificially)

7. Applications of ozone in food industry

8. GASEOUS AND AQUEOUS OZONE Ozone gas used in 2 states Gaseous Ozone Gaseous ozone is a strong sanitizer Inactivate the bacterial spores Disinfect storage rooms and food surfaces Aqueous Ozone Sanitation of water in washing systems Washing of fruits and vegetables Aqueous O3 is used as an alternative to chlorine ( Nadas et al, 2003) ( Forney, 2003)

9. Targeted Microorganisms The efficacy of ozone as a sanitizer depends on the Target microorganisms Microorganisms inherently vary in sensitivity to ozone Gaseous and aqueous ozone is effective against Bacteria, (gram-positive vegetative cells, bacterial spores) Molds & yeasts, (conidiophores and ascospores ) Parasites Viruses (Kim and Yousef, 2000)

10. INACTIVATION KINETICS AND MECHANISMS Ozone efficacy measure by indicator microorganisms or spores Bacillus stearothermophilus spore as an indicator of ozone sanitization ( Khadre and Yousef (2001b)

11. Alternative Sanitizer Chlorine used in food industry for sanitization Chlorination may lead to the formation of toxic residues Ozone is more powerful antimicrobial It leaves no toxic residues) Can be Used for Food Preservation Shelf Life Extension Equipment Sterilization ( Hampson , 2000)

12. Ozone Applications at Different Stages Ozone can be applied at different stages in food industry Pre-processing More beneficial on raw than processed product Reduces ozone usage Minimizes damage to the sensory quality Aqueous ozone used to decontaminate raw Beef Poultry Meat Fruits and vegetables ( Mcloughlin , 2000; achen and yousef , 2001)

13. Continue Processing Minimize environmental contaminants in processing facility Storage Extend the shelf-life of food during storage Minimized growth of surface contaminants on Meat, Fish and Other commodities ( Hampson , 2000)

14. APPLICATIONS OF OZONE IN SELECTED FOOD RAW POULTRY AND MEATS FRUITS AND VEGETABLES FISH PROCESSING

15. Raw Poultry and Meats Microbes reduce the shelf-life of raw poultry and meat Raw poultry and meat may carry pathogenic microorganisms Campylobacter Salmonella L. Monocytogenes E. Coli. Ozone disinfection in poultry processing: Carcass sanitation Direct contact meat sanitation Surface sanitation Process equipment, e.g. knives, cutters, saws and gloves ( Zhao et al., 2001)

16. Fruits And Vegetables Good alternative sanitizer for fresh fruits and vegetables Chlorine induce off- flavors and alter the taste of the treated fruits and vegetables ( hassenberg et al., 2008) Improves the resistance level of fruits and vegetable against pathogens Ozone application of fresh-cut Improve the microbial safety Extend the shelf-life (Das et al. 2006 )

17. Fish Ozone pretreatment prolong Quality characteristics( at 0˚C for 1 month) Storage life of fish (Nash 2002; Gelman et al. 2005) The higher concentrations and longer treatment times is more effective in shrimp Ozone –Water treatment not increase lipid oxidation in the shrimp ( Chawla et al. 2007)

18. Water Treatment Ozone treatment units are installed as a point-of-entry treatment system. At the point where the ozone mixes with the water, turbulence and bubbles are created; these ensure that the ozone contacts as much of the untreated water as possible. The greater the water flow rate, the greater the pressure differential and turbulence, and the more effective the treatment . The effectiveness of ozonation depends in part on the contact time. In general, ozone requires a shorter contact time than chlorine. The contact time required varies with the water treatment. The solubility of ozone in the untreated water also affects treatment. In general, the lower the water temperature, the more ozone is dissolved in the water. Ozone has been found to be effective over a wide range of pH, but a pH slightly above 7 increases treatment efficiency. The ozone demand is related to the level of contamination in the water. When substances in the untreated water react with ozone, part of the ozone is used up, which may leave less ozone available to treat the targeted contaminants. Ozone treatment can produce harmful by-products in drinking water. For example, if bromide is present in the raw water, ozone reacts with it to form bromate , shown to cause cancer in rats The ozone dose required will vary according to water quality, but a typical ozone dose is 1.0 to 2.0 milligrams per liter , which is sufficient to kill most bacteria and control tastes and odors . The capacity of the storage tank determines how much water is available for use. The amount of storage required depends on household water use

19. Ozone treated drinking water can be expected to be: Cleaner clearer colorless nonstaining odorless palatable oxygenated

20. (1) Disinfection. (2) Oxidation of inorganic and organic pollutants: (a) iron and manganese; (b) taste and odour compounds; (c) phenolic pollutants; (d) pesticides . (3) Oxidation of organic macropollutants (i.e. nonspecific target organics): (a) bleaching of colour; (b) increasing the biodegradability of organics; (c) destruction of trihalomethane formation potential (THMFP), total organic halide formation potential (TOXFP) and chlorine demand. (4) Improvement of coagulation

21. Limitations and toxicity Sensory attributes altered Depend on the chemical composition of food, Ozone dose and treatment conditions Surface oxidation of food Discoloration, Undesirable odors Oxidative spoilage Ozone toxicity cause pulmonary congestion In high concentrations it may be fatal to humans ( Guzel-seydim Et Al, 2004)

22. The current permissible exposure limit ( PEL ) to ozone allowed by OSHA regulations is 0.1 ppm

23. Conclusion OZONE IS A POTENT SANITIZER WITH PROMISING APPLICAtions in the modern food industry. The sanitizer is effective against a wide spectrum of microorganisms, and it can be used in an environment-friendly manner . Exposing some products ( e.g. fruit or vegetables) to ozone during their storage period extends their shelf life