Week 10 : Meaning of food Flashcards
[PART 1 : GROWING FOOD]
In the past, selective breeding was used to make desirable variations of crops. What is the the drawback with selective breeding?
It is a very random, long process
[PART 1 : GROWING FOOD]
What is a Genetically Modified Organism (GMO) ?
Organisms whose genetic material (DNA) which has been modified in a way that does not occur naturally(i.e. addition of gene from another organism into DNA of current organism)
[PART 1 : GROWING FOOD]
What are some of the common applications of GMOs?
- Plants with disease resistance
- Plants with natural insecticidal abilities (Bt crops, bacteria gene incorporated into plant DNA)
- Fruits that are resistant to enzymatic browning (by altering enzyme gene)
[PART 1 : GROWING FOOD]
What is trans-genic and cis-genic modification?
Trans-genic modification involves the introduction of genes from exogenous (outside) species into an organism
Cis-genic modification involves the introduction of genes from same species into an organism
[PART 1 : GROWING FOOD]
What is the CRISPR-cas system?
CRIPSR is a gene-editing technology that modifies DNA through :
- locating a targeted sequence (Ctrl+F)
- Cutting the sequence in half (Ctrl+X)
-dropping nucleotide bases in DNA –> so organism dont have instructions to produce certain genes
- copying certain bases and pasting it somewhere else
(Ctrl+C, Ctrl+V)
CRIPSR = Clustered Regularly Interspaced Short Palindromic Repeats (dont need memo name)
[PART 1 : GROWING FOOD]
Which product(s) is/are considered GMOs (based on definition)?
- Cis-genic modified foods
- Trans-genic modified foods
- CRIPSR modified foods
1 and 2.
GMOs involved introduction of a gene from another organism into current organism
However, for CRIPSR, you are only editing the gene without introducing genes from any other organism
[PART 1 : GROWING FOOD]
What are the 4 main principles of organic farming?
- No chemical residue
- No pesticide residue
- Using animal manure (shit) as fertiliser
- Allow use of chlorine compounds with limits in residual Cl
[PART 1 : GROWING FOOD]
Compare the chemical, biological, nutritive, environmental aspects of organic and non-organic food
Chemical : Although organic food has way lower number of samples with chemical residues than non-organic, it does not match with expectations that all organic foods are residue free
Biological : Pathogen load of organic foods higher due to use of animal poop.
Nutrition : Organic produce is not better in nutrition.
Environmental : Organic produces leads to
- less CO2 emissions
- higher biodiversity (creates more diverse and ecologically rich environments)
- better soil (low nitrate leeching out to pollute water, higher organic content)
[PART 1 : GROWING FOOD]
What are the 3 types of urban farming?
- Indoor farming
- Rooftop farming
- Vertical farming
- Community gardens
[PART 1 : GROWING FOOD]
What are the 3 technologies used in vertical farming?
- Hydroponics : usage of a liquid nutrient medium instead of soil. Roots of plants submerged in liquids
- Aeroponics : liquid nutrient nutrient is applied the roots of crops in mist form
- LED technology : utilises visible light spectrum to replicate sunlight
[PART 1 : GROWING FOOD]
What is the effect of light intensity on colour of leaves?
Higher light intensity triggers anthocyanin pigments in leaves as a form of protection against harsh light, causing leaves to turn red.
Leaves : green –> but expose to harsh intensity, stress –> red pigment released as a protection mechanism
[PART 1 : GROWING FOOD]
How does the wavelength of light affect the morphology (shape/appearance of leaves)?
As fraction of blue light increases (warm –> neutral –> cool), leaf expansion decreases, become smaller
(blue light suppresses growth. Natural sunlight : yellow, a warm colour)
[PART 2 : MAKING FOOD]
What are alternative proteins?
Proteins that are produced from sources that have low environmental impact, intended to replace established protein sources
[PART 2 : MAKING FOOD]
List the 5 different types of alternative proteins.
- Plant proteins
- Insect proteins
- Myco-proteins
- Algae protein
5.Lab cultured proteins
[PART 2 : MAKING FOOD]
What is the challenge faced in plant proteins?
Hard to emulate species-specific flavours derived from animal fat (pork/chicken/beef taste)
[PART 2 : MAKING FOOD]
What is extrusion used for in plant proteins?
It is to mimic meat fibres (myofibirils).
The temperature and mechanical action during extrusion denature protein and hence affect product texture. (tender, softer texture)
[PART 2 : MAKING FOOD]
Some insect species are complete protein sources. True or False?
True
[PART 2 : MAKING FOOD]
What are some challenges with insect proteins? [3]
- Flavour and texture
- Safety : potentially allergenic (shellfish allergies)
- Economic : no protein isolate due to large cost
[PART 2 : MAKING FOOD]
What is mycoprotein?
Protein made from filamentous fungus (mold), cultivated through fermentation.
[PART 2 : MAKING FOOD]
What are some challenges with mycoprotein? [2]
- Flavour : neutral taste, lacks species-specific meat flavours
- Safety : Lack of research on potential allergens; some consumers reported adverse reactions
[PART 2 : MAKING FOOD]
Algae proteins are usually complete and have comparable protein levels to traditional protein sources. True or False?
True
[PART 2 : MAKING FOOD]
What is the challenge with algae proteins?
Fishy aroma, taste is undesirable thus can’t e incorporated into many products.
[PART 2 : MAKING FOOD]
How is cultured meat produced?
- Stem cells are extracted from animal muscle tissue (tissues that haven’t differentiate into specific types of cells w specialised functions)
- Cells are placed in different growth mediums with different nutrients to trigger cells to differentiate into different types of cells – fat/muscle/connective tissues that make up meat
[PART 2 : MAKING FOOD]
What are the challenges in cultured meat? [2]
- Flavour and texture : requires texture development and fat cell inclusion to mimic slaughtered animal meat
- Production : Need to determine suitability of different cells for large-scale manufacturing and creation of specific product types.
