Food Deterioration, Spoilage & Microbial Growth
These are the three main causes of food deterioration and spoilage studied in Food Technology
microbial activity, enzymatic activity and environmental factors
Preservation works by slowing or stopping the processes that cause food to do this
deteriorate/spoil
This preservation method keeps food at a low temperature above freezing
refrigeration
This happens when the structure of a protein changes due to heat, acid or agitation.
denaturation
Colour, shape, size and presentation are all part of this sensory characteristic
Appearance
Bacteria need warmth, moisture and nutrients to multiply, but they also need sufficient amounts of this
Time
Keeping food cold preserves it mainly by slowing down this activity
microbial and enzymatic activity
This method preserves food by storing it at approximately –18°C or below
freezing
When starch is exposed to dry heat and becomes brown with a toasted flavour, this process occurs
dextrinisation
Sweet, salty, sour, bitter and umami describe this characteristic
flavour/taste
In the acronym FATTOM, the two Ts represent this factor affecting microbial growth.
time and temperature
Vacuum sealing preserves food by controlling this environmental factor.
air/oxygen
Milk is commonly treated using this process, where it is heated for a controlled period to destroy harmful microorganisms
pasteurisation
Oil and water normally separate. When substances such as egg yolk help them remain mixed, this process occurs.
Emulsification
Crisp, crunchy, smooth, chewy and creamy are words used to describe this characteristic
Texture
A sliced apple turns brown after being left exposed on the bench. What type of deterioration is occurring
enzymatic browning/enzymatic activity
Drying food preserves it because microorganisms require this to grow and reproduce
moisture/water
Aboriginal and Torres Strait Islander peoples traditionally used methods such as smoking, drying and this process involving salt to extend the life of meat
curing
During cooking, egg white changes from clear and runny to white and firm. Identify the functional property responsible.
protein denaturation/coagulation
A student evaluates toast as golden-brown, crunchy, warm, smelling toasted and making a crisp sound. Name three sensory characteristics being evaluated.
appearance, texture, aroma and/or sound
Cooked chicken is left on a bench for several hours on a warm day. Explain two FATTOM factors that make microbial spoilage more likely
Time - bacteria has time to grow
Temperature - the warm temps allows bacteria to multiply
A manufacturer vacuum-seals cooked meat and stores it in the refrigerator. Explain why using two preservation principles together is more effective than using only one
removing/reducing oxygen while low temperature also slows microbial and enzymatic activity
A café has a large amount of ripe fruit that cannot be used immediately. Name an appropriate preservation method and explain how it extends shelf life
freezing or heating then fridge
Mayonnaise contains oil, egg yolk and an acidic ingredient. Explain the functional property that prevents the oil and water-based ingredients from separating
emulsification, where an emulsifier allows normally immiscible liquids to remain combined
Two cinnamon scrolls use the same ingredients, but one is pale, dense and has little aroma while the other is golden, soft and strongly scented. Identify three sensory characteristics that would influence which product a customer prefers
appearance, texture and aroma