Food Spoilage Flashcards
What are rhe causes of food spoilage
Enzyme action
Moisture loss
Microbial contamination
What do enzymes bring about
Enzymic deterioration
Browning
Ripening
What changes does ripening bring
Sweeter as high starch changes to sugar
Colour vhange
Soft and easier to digest
What causes browning
If cut open oxidase from cell wall reacts with oxygen
What foods are easily effected by enzymic deterioration
Fish - purptrid odour
Veg- deteriorate even at low temps
How to prevent or control emzymic spoilage
Acids lower ph Heat Preservative Cold temps Blanching
What results from moisture loss
Shrinking eg mushrooms
Wrinkling skin on spples
Limp appearsnce
HIGH PROT FOOD ALSO GO HARD WHEN EXPOSED TO AIR
What are the different types of contamination
Yeasts and moulds
What is yeast or mould contamination like
Visible on exterior
Do not cause poisoning
Certain toxins may be prodcued
What is bacterial contamination
Food spoilage on exterior and interior
Commonly cause food poisoning
What are the types of food poisoning
Chemical
Biological
Bacterial
How is
Chemical
Biological
Bacterial food poisoning formed
Metal residues
Food with naturally occurring substances eg solanine in green potatoes
Pathogenic bacteria by cross contamination poor hygiene or water contaminatiom
What are the two types of bacterial food poisoning
Infectious - endotoxins made inside cell walls, released when bacterial cell died, easily destroyed ans long incubation period of 12 hrs
Toxic- exotoxins secreted by pathogenic bacteria and released while theybgrow, difficult to destroy (boil 30 mins) short incubation period 2 hrs
