Improving food production Flashcards
Increasing food production efficiency in plants
- Improving growth rate of crops
- Increase the size of yield from each plant
- Reduce losses of crop due to disease and pests
- Make harvesting easier by standardising plant size
- Improve plant reponses to fertilisers
Increasing food production efficiency in animals
- Improve rate of growth
- Increase productivity
- Increase resistance to disease
Use of selective breeding in the food industry
- Increase productivity
- Increase resistance to disease
- Enhance appearance
- Enhance flavour and texture
Problem with selective breeding
Selective breeding involves line breeding and inbreeding so any recessive disease characteristics will be amplified
Difference between natural selection and selective breeding
In selective breeding, we have control over the outcome while in natural selection, nature has control
Three stages of selective breeding
- Isolation
- Artificial selection
- Inbreeding/Linebreeding
Isolation
Isolate species with the desired characteristics from original group of species
Artificial selection
Selected species will be forced to reproduce to produce offspring with similar characteristics
Inbreeding/Linebreeding
Best offspring are bred to produce more offspring with the desired characteristics
Difference between linebreeding and inbreeding
Inbreeding is breeding between siblings and parentsw while line breeding is breeding between less close relations e.g. uncle+niece, aunt+nephew
What is Progeny testing?
A test where a single male is bred with multiple females, creating many offspring that are subsequently exposed to different environments over a long period of time. The average performance of the offspring is then found giving the male’s respective value to the breeder.
How does Progeny testing help with selective breeding?
During selective breeding over a large area using a handful of cows, this test can show how well offspring from this cow will perform in different environmental conditions
What is marker-assisted selection (MAS)?
When a section of DNA is used as marker to recognise the desired characteristics from the parents in the offspring
Examples of MAS
- Apples being bred with higher tolerance to disease
- Disease resitant soybean (Glycine Max)
Benefits of MAS
- Simple in comparison to phenotypic screening
- Selection can be carried out at a seeding stage
- Single plants may be selected with high reliability
- This in turn leads to accelerated line development in breeding programs
How do fertilisers help improve food production?
- Fertilisers replenish depleted mineral content of the soil as minerals have been used up by previous crop
- Fertilisers contain nitrates, phosphates, potassium and magnesium that increase growth rate of plants
How do pesticides help improve food production?
- Pesticides kil organims that would otherwise eat the crop and sometimes cause disease
- This increases crop yield as less crop is killed
How do antibiotics help improve food production?
- Antibiotics kill bacteria
- This reduces the spread of diseases between animals that are intesively farmed
- This improves growth performance and quality
How do microorganisms spoil food?
- By secreting enzymes
- Borrowing on the surface of the food
- By causing infection
- By releasing toxins
Preventing food spoilage: Cooking
The heat denatures enzymes and proteins and kills the microorganisms
Preventing food spoilage: Pasteurisation
Heat the solution to 72 degrees then cool to 4 degrees to kill off any microorganisms
Preventing food spoilage: Drying
This process dehydrates microorganisms by removing water by osmosis
Preventing food spoilage: Smoking
- The food develops a hard outer coat protecting it from microorganisms
- Smoke also contains some anti bacterial chemicals
Preventing food spoilage: Pickling
An acid pH denatures enzymes and proteins and kills the microorganisms
Preventing food spoilage: Irradiation
Ionising radiation kills microorganisms by disrupting DNA structure
Preventing food spoilage: Cooling and Freezing
Microorganisms are not killed but enzyme activity and metabolism is slowed down significantly
Preventing food spoilage: Canning
- Heated to denature enzymes and proteins
- Canned so microorganisms cannot get in
Preventing food spoilage: Vacuum wrapping
Microorganisms cannot respire aerobically
Preventing food spoilage: Plastic or paper packaging
Microorganisms cannot get in
Examples of using microorganisms in the food industry
- Lactobacillus is used to make drinks, yoghurt and cheese
- Yeast is used in making bread and alcohol
- Fungi are used to make mycoproteins
Advantage of using mycoproteins
- It can be used as a protein substitute for vegetarians
- Healthier than meat as it contains no animal fat or cholesterol
Advantages of using microorganisms in food production
- Production of protein can be carried out faster than plants and animals
- Production can be adjusted according to demand
- There are no animal welfare issues
- They provide a good source of protein for vegtarians
- The protein contains no animal fat or cholesterol
- SCP production could be combined with removal of waste products
Disadvantages of using microorganisms in food production
- People may not want to eat fungal protein as it has been grown on waste
- Proteins must be isolated from the material its been grown on
- The protein has to be purified
- Care must be taken to prevent pathogenic infection
- Palatability: The protein doesn’t have the same texture or taste as traditional proteins
How does bacteria cause food spoilage?
- Bacteria digests the food and leaves waste products
- These waste products cause infection as they are toxic
- As the bacteria digest the food, they will grow all over the food until it is visible
- At this point, the food is classed as spoilt
Selective breeding
Where humans select the individual organisms that are allowed to breed according to chosen characteristics
