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Food hygiene - Coggle Diagram
Food hygiene
Effect of PH on microorganisms
The presence of acids in the food produces survival of microorganisms.
strong acid (inorganic) produce a rapid drop in external pH
Most microorganisms grow at a pH between 5 and 8.
Mechanisms of action and interaction with other factors
Organic acids
the antimicrobial activity of an organic acid is due to the undissociated molecules of this compound, it is more soluble in cell membranes.
Ionizing radiation
It is highly lethal, its dose can be combined to produce pasteurizing effects and its uniform penetration power.
ultraviolet radiation
produces an exponential decrease in the number of cells. vegetative or live spores.
Relationship with oxygen: Redox potential
It is an important selective factor in all environments, it influences the organisms present and their metabolism.
indicates the oxygen ratios of living microorganisms.
Water Activity And Microbial Growth.
Crop substrate water vapor pressure (P)
and the water vapor pressure of pure water (P0)
It gives us the idea of the amount of water available metabolically.
Water
is a substrate in many biochemical reactions
For example
Proteases
Lipasas
microorganisms
require water activity values to be able to grow
mushrooms
are able to grow on substrates with lower water activity (drier)
Influence of water activity on food spoilage
Each microorganism has a characteristic optimal water activity (aw) and a given range of aw at which it can grow under certain environmental conditions.
Humidity
Loss of moisture from a food causes diffusion of water from the interior to its surface.
Hydrogen Ion Concentration (pH)
Hydrogen ions (H+) are very relative molecules
and come from different molecules called acids
and are able to release the internal environment.
Availability of nutrients and growth factors
Nutritional requirements
Carbon
nitrogen
sulfur
match
inorganic ions
growth factors
Water