Food bourne hazards Flashcards
food technology
how different food can be used and made into food products from production to consumption
State and briefly describe intrinsic factors that affect food spoilage ( bacteria )
-nutrient conc - bacteria need water , source energy, nitrogen , vitamins and minerals
-natural antimicrobials
-PH -ability to resist ph change , optimum ph bacteria 7
-Oxidation reduction potential - ability to reduce redox change , aerobes need oxidation and anaerobes need reduction
-water activity = measure of how efficiently water can take part in chemical reaction
-mechanical barriers -skin
State and briefly describe extrinsic factors that affect food spoiling
-temp
-gaseous atmosphere - CO2 , ozone ,vaccum packing
-humidity
-time
D value
time taken for the population to pass through log cycle ( 90% of population killed ) at certain temp
D^121
time required to kill 90% of microorganism at 121
Z value
temp change that is required to change the D value by a factor of 10
What qualities are needed for fermented meat to be safe ?
-content - nitrated - supress gram negative , decolourisation , oxidative rancidity
-salt and drying - reduce water activity
- lactic acid - low ph
-natural/ starter culture
What can go wrong in the production of fermented sausage ?
-growth of green/black moulds
-bacterial slime
-souring - excess lactic acid production
-gassiness due to heterofermentative lactic acid
-greening of meat pigment from hydrogen peroxide from lactobacillus viridans
Ways of monitoring hygiene
-swabs - surfaces , equipment
-sample of water, soil
-personnel - hand swabbing , hand-rinsing
-air - exposure plates , air sampling machine
Conformance to microbial criteria
criteria created about the microorganism of concern in the finished product
-detection
-sampling plan
-microbiological limit
-guidance for interpreting results
