REMOVAL OF MICROORGANISM IN FOOD WASHING

Food microbiology

1. CONTENT Introduction Principle Filtration Centrifugation Washing Trimming Maintenance of anaerobic condition Canning process Physical methods Pasteurization High Temperature Low Temperature

2. INTRODUCTION IT Contamination of food by Spoilage organisms is not prevented , spoilage of food still as prevented by removing contaminated microorganisms from food. The methods of removing microorganisms from food depends on the type of solid food,semi food liquid food etc. Removed can be clone by centrifugation filtration, trimming,and washing. The main purpose of clening is of remove dirt particles and contaminants on the surface and removes pesticide and chemicals .

3. PRINCIPLE While keeping microorganisms away [asepsis] By removing microorganisms [filtration] By inhibition the growth as well as activity of microorganisms [using low temperatures,Implementing anaerobic conditions,by applying chemicals]. By killing microorganisms [by heat or radiation]

4. FILTRATION It is only one succesful method for removd microorganisms from contamination food Unfortuenately , this method is appicable only for cleans liqiud like friut juies and averges etc. To remove microorganisms, liqiud food’s filtrated streile bacteria filter. In many filtration process a cause filter is used 1 to response and then ultra filtration is used.

5. CENTRIFUGATION Centrifugation removes some but not all microorganisms from contaminated liqiud food When liqiud food is centrifuged suspended peticle , debres and some microorganism settle to bottam which is later separaed and remove from the food, This technique is commonly used in dairy indurtiest for milk. Centrifugation can be divided into three group; Separation of immiscible liquid Removal of solids

6. WASHING This Method is commonly used for vegetables and fruits. Cuts and microorganisms present on the surface of whole vegetables and fruits are removed by washing with sterile water. One limitation of washing is that it increases water activity of some food and hance facilitates growth of remaining organisms. Further more washing water is not sterile it adds spoilage organisms in food.

7. TRIMMING Trimming is the process of removing spoiled part of food like vegetables,and fruits by cutting . Trimming prevent spread of micro-organisms from spoiled part into healthy tissue.

8. MAINTANCE OF ANAEROBIC CONDITIONS Anaerobic conditions within the containes may be a preservative for realed packed food Anaerobic conditions can be achived by a complete fill,the evacuation of any anfilled space and the replacement of the air with carbondioxiode or an in gas like nitrogen

9. canning Father of canning – Nicholar appert ( 1809) Canning is a food preservation process in which the food is process and thermostable,plastic are multiple layer agency of heat

10. PHYSICAL METHODS PAUTEURIZATION: Heat Treatments that kills most but not all microorganisms Example: milk 63 ℃,30 mins 72℃, 15 mins Juice 77℃, 30 mins 88℃,30 sec The pasteurized product are cooled promptly after the heat treatment

11. HIGH TEMPERATURE It is a mild heat treatment in which food is heated below 100 ℃ effective for killing pathogenic microorganisms. Low acid food [ph 4.5 ] minimize pathogenic microbes and extented self life at [90.5℃]. Acid foods [ph= 4.5 ] destruction of spoilage microbs [yeast and molds ] inactivates enzyme at 79.5℃ to 85℃].

12. LOW TEMPERATURE Freezing [- 10℃ to 40℃ ] Inhibit microbial growth by lowering water activity air freezing- blaet freezers, fluidized, freezing, tunnel freezing temperature Plate freezing Liquid immersion-liquid NO2 Deep and quick freezing Freeze drying