Source of M.O in Foods

Sequence of microbial spoilage M.O have to get into food (type and number) Food environment must support the growth of Contaminated M.O (pH, aw , ORP, nutrients, ….) Food must be stored (abused) at temperature enable M.O to multiply Food must be stored for sufficient length of time

Specific spoilage microorganisms: M.O which can grow and cause spoilage under the storage conditions Food Spoilage: 1. 107 cfu/ g or ml or cm2 normally results in odor problems 2. 107 to 108 cfu per g or ml or cm2 usually results in foods having surface slime and odor.

Source of M.O in foods 1- Natural (internal source) Plants surface Animals Skin, feathers, GIT, respiratory tract, milk ducts 2- Contamination (external source). The types and level of M.O depends on the degree of sanitation used during handling

Cross Contamination The physical movement or transfer of harmful bacteria from one person, object or place to another.

Cross contamination is a key factor in food spoilage and food poisoning, It has four common sources: Food People Equipment Work surfaces.

Why it is important to know the source of M.O in foods to control the access of these M.O to food to develop method to inactivate (kill) them to determine the microbiological quality to set up microbiological standard and specifications of foods and food ingredients

1- Plants Molds, yeast, and bacteria The type and level varies depending on soil condition type of fertilizer quality of water used Improper handling and storage can increase the microbial numbers and vice versa.

2- Animals Carriers: can harbor the pathogens without showing symptoms Salmonella Enteritids: Ovaries (ovalution) egg yolk Pathogenic E.coli E.coli O157:H7

Many spoilage and pathogenic M Many spoilage and pathogenic M.O from animal origin can get into foods during production and processing (fecal material, skin, hair and feathers)

3-Water Microbial quality of water affects microbial quality of foods Pathogenic and spoilage M.O can be transmitted to foods via water

Chlorine treated potable water (drinking water) should be used in food processing industry (washing and sanitation). Higher microbial quality than the potable water should be used if water is used as an ingredient.

4- Soil M.O can multiply in soil Contaminated soil with fecal materials could be a source for enteric pathogenic bacteria and viruses. Washing and avoid soil contamination

5-Humans Improper cleaned hands Lack of personal hygiene (Skin, nasal cavity, mouth, gastrointestinal tract GIT)

6-Food Ingredients Spices mold and bacterial spores Starch, sugar, flour spores of thermophilic bacteria Packaging and wrapping material - set up acceptable microbiological specification - maintain sanitary conditions

7-Food Utensils and equipments Dead spots: small parts or inaccessible sections Proper cleaning and sanitation Prevent or reduce contamination from air water ……etc

8-Air Type of M.O depends on the surroundings M.O presents in dust and moisture droplets Dry air with low dust and higher temperature has low microbial level. Prevent air and dust access or using filtered air