Post Harvest Diseases Flashcards
What is the purpose of food security production?
Ensuring enough food is produced to meet population demands (I.e Paddock to plate)
What are the three issues faced with food security?
Pest and diseases
Climate change
Available fertile land
What is food safety related to?
Pesticides
Plant diseases
Food processing additives
Environmental contaminants
What is Post Harvest Disease?
Reduction in fruit, vegetable and seed quantity and quality
What are the causes of post harvest diseases?
Fungi and bacteria
What are the three fungi phylum?
Ascocmycota
Oomycota
Glomeromycota
Can bacterial post harvest rot cause issues to human health if consumed?
Yes - specific species can be harmful
What are the three ways fungi can infect fruit and vegetables?
- Direct penetration of plant tissue
- Indirect penetrations
- Quiescent or latent infection
What is indirect penetration?
When infection occurs on a fruit or vegetable from a wound or natural openings (stomata)
What is Quiescent or Latent infection?
When the pathogen enters the fruit before harvest but remains inactive until harvested
In Strawberries (grey mould)
In Bananas (anthracnose)
In Mangos
What is direct penetration?
Enzymes causing the disease
What are the six control methods for fungi infection?
- Resistance breeding
- Fungicides
- Hygiene practices
- Prevention of injury
- Ionising radiation
- Manipulation of post-harvest environment to maintain host resistance
What are the two methods of fungicide control?
- Field application prior to harvest
- Post-harvest application
Why maintain host resistance through the manipulation of post-harvest environment?
To delay senescence and pathogen growth
How do you complete hygiene practices?
- Understanding pathogen lifecycle to reduce inoculum
- Prevent pre-harvest infections by pruning, removing dead branches and drip irrigation
- Prevent post-harvest infections with clean packaging sheds, clean water and disinfectants
What is ionising radiation?
- Used to control grey mould in strawberries
- Causes abnormal ripening, tissue softening and off flavours
- Low consumer acceptability
What are the emerging technologies for control?
- Biological control
- Natural fungicides
What are mycotoxins?
Secondary metabolites produced by some fungi during the infection and colonization of editable food parts
Are mycotoxins toxic to humans?
Yes. At low concentration and can be carcinogenic
What are the six major groups of mycotoxins?
- Aflatoxins
- Ochratoxin
- Citrinin
- Ergot alkaloids
- Patulin
- Fusarium toxins
What are aflatoxins found in?
- Cereal grain
- Corn
- Peanut
- Tree nuts
What are Ochratoxins found in?
Beverages and fruit juice
What are citrinins found in?
- Rice
- Many human foods
What are patulins associated with?
Mouldy fruit and vegetables
What are fusarium toxins toxic to?
- Pigs
- Horses
- Dogs
