Please enable JavaScript.
Coggle requires JavaScript to display documents.
Food Microbiology - Coggle Diagram
Food Microbiology
Food-Bore Illness
CDC Estimates:
- 48 Million FBI cases yearly
- 128,000 hospitalisations
- 3,000 deaths
Microorganisms in Food
Pathogenic - Microorganisms that can cause illness
Spoilage - Microorganisms cause food to smell/ taste/ look bad
Fermentation - Microorganisms produce desired product
-
Intrinsic Factors
Carbohydrates
Mold predominates
- Degrades food via hydrolysis
- Ergotism (hallucinogen, can cause death)
Proteins/ Fats
Bacterial growth predominates
- Putrefaction (breakdown of proteins; foul smelling amine compounds)
- Unpasteurized milk spoilage (acid production and putrefaction)
- Butter (short-chained fatty acid production, rancid butter)
-
Extrinsic factors
-
Relative Humidity
- High levels promote growth
Atmosphere
- Oxygen promotes growth, modified atmosphere packaging (MAP)
Preservation Strategies
Temperature
- Low temp slows but doesn't stop growth
-> Can still cause spoilage with extended storage
.
- High temp kills spoilage microbes, not all
-
-
-
-
Pasteurisation - kills pathogens, reduces spoilage
Water Availability - Dehydration, increases solute conc.
Chemical- Based
GRAS "Generally recognised as safe"
- pH of foods affect chemical preservative effectiveness
High Hydrostatic Pressure
Applies pressure from 100-800 mPa without big temp change
- Harmful to membranes
- Effective at eukaryotic elimination/ less for gram +ve
Irradiation
Radappertization - use of ionizing radiation to extend shelf life
- Excellent penetrating power, food not radioactive
- Kills microbes in moist foods