Spoilage Flashcards
What is food spoilage?
Food spoilage can be defined as ‘any sensory change this could be tactile, visual, olfactory or flavour’ which the consumer considers to be unacceptable.
List the major classes of food change that lead to spoilage.
- Enzymatic processes
- Chemical reactions with the environment
- Microbiological processes
What are extrinsic factors affecting microbial growth in foods?
- Temperature
- Humidity
- Oxygen
What are intrinsic factors affecting microbial growth in foods?
- pH
- Moisture
- Nutrient content
True or False: Most microorganisms grow at neutral pH.
True
What is microbial food spoilage?
Microbial food spoilage refers to the microbial change that renders a product unfit or unpalatable for consumption.
Identify signs of spoilage.
- Odour
- Sliminess
- Discolouration
- Mould growth
Fill in the blank: The predominant spoilage flora in meat is determined by _______ and _______ parameters.
[intrinsic] [extrinsic]
What is the impact of spoilage on food?
Food spoilage causes economic loss and loss of consumable foods.
What microorganisms are responsible for souring in dairy products?
Lactobacillus thermophilus
Name the spoilage microorganisms associated with green mould rot in fruits.
Penicillium italicum
What is autolysis in the context of food spoilage?
Autolysis is the process in which enzymes play a role in the decomposition of living tissue.
What causes enzymatic browning in fruits and vegetables?
Oxidation of phenolic substances in plant tissues by phenolases
Which microorganisms are involved in the spoilage of eggs?
- Pseudomonas
- Proteus
- Serratia marcescens
- Mucor
- Penicillium
What type of bacteria are primarily responsible for spoilage in vacuum packed meats?
Psychrotrophic facultative anaerobes and anaerobic bacteria
Fill in the blank: Microbial growth in food is associated with the metabolism of _______ components.
[carbohydrates, proteinaceous, non-protein nitrogen (NPN), lipids, vitamins, minerals]
What is the role of water activity (aw) in food spoilage?
Water activity affects the growth of microorganisms; high aw favors spoilage.
List the types of spoilage in milk.
- Bitterness
- Souring
- Sweet curdling
What is the effect of temperature on microbial growth?
Different microorganisms grow over a wide range of temperatures, some prefer cold, others room temperature, and others high temperatures.
What is the significance of pH in food spoilage?
Microorganisms have established response mechanisms to deal with stress, enabling them to survive in certain pH levels.
True or False: Spoilage can occur at any stage along the food chain.
True
What are common causes of food spoilage?
- Inadequate storage temperatures
- Prolonged storage times
- Cross contamination
- Excessive delays between receiving and storing
- Inadequate food safety standards
