Fruits & Vegetables Flashcards
1
Q
- Give the botanical definition of fruit and state whether or not this includes fleshy or dried fruit.
A
- Mature seed-bearing structures of fruit
- Does not include fleshy fruit from growth from structures other than the ovary
- Does include dried fruit (nuts, grains, legumes)
2
Q
- Give the botanical definition of vegetables.
A
- Soft, edible structures that have developed in the main from other parts of the plant
3
Q
- Give the consumer definition of fruit in UK.
A
- Plant products with aromatic flavours, which are either naturally sweet or normally sweetened before eating
(includes rhubarb, normally a veg)
4
Q
- Give the consumer definition of vegetables in UK.
A
- Soft edible plant products that are commonly salted (or at least not sweetened), cooked, often eaten with meat or fish
- (includes tomato, cucumber, pepper, sweetcorn -> botanically fruits)
5
Q
- Does the composition of F&V change post-harvest and why?
A
- YES
- F&V are metabolically active and constantly change composition pre- and post-harvest
6
Q
- List factors which influence changes in F&V composition.
A
- Physiological role of plant tissue (seeds, leaves, roots)
- Stages of maturity of plant (fruit ripeness)
- Environmental conditions (soil, sunlight, rainfall, temp)
7
Q
- Give an example of how different physiological parts of a plant differ.
A
- Seeds contains lipid and starch used for purposes after germination
8
Q
- Give two important roles of F&V water content.
A
- Provides cell turgidity which affects the texture and crispness –> consumer preferences
- Important for stability and shelf-life –> bacteria grow well with lots of H2O available
9
Q
- Give a consequence of inadequate water supply and which plants this affects most.
A
- Wilting
- Affects harvested plants with a lot of leafy tissue -> more transpiration leads to greater water loss, faster
10
Q
- Give 3 vegetables and 3 fruits with high water contents.
A
- Veg: lettuce, tomato, celery
- Fruit: melon, rhubarb, strawberries
[though can have large standard deviations btwn batches]
11
Q
- State 4 CHO components present in F&V
A
- simple sugars (glucose, fructose, sucrose)
- fructans (e.g. onions, artichoke -> affect microbial fermentation and so gut function)
- starch (amylopectin 80%/amylose 20%)
- non-starch polysaccharides NSP
12
Q
- Name the 3 components of NSP and how dietary fibre is calculated.
A
- Hemicelluloses, pectins, cellulose
- H + P + C + non-CHO components = dietary fibre
[non-CHO = phenolic compounds e.g. cell wall]
13
Q
- Define hemicelluloses and cellulose.
A
- H: heterogenous group (arabinogalactans, xyloglucans, arabinoxylans, galactomannans)
- C: different pectins
14
Q
- State the main function of sugars in F&V and where they are mainly located.
A
- Sweetness
- Dissolved in cell sap
15
Q
- What determines the proportion of sugars in F&V?
A
- Post-harvest processing
- Environment
- Processing
16
Q
- Describe the sugar content of root vegetables and dried fruit.
A
- Root veg: rich in sugars (carrots,parsnips)
- Dried fruit: high sugar levels as fibre and sugar are concentrated when water is lost
17
Q
- Why do boiled peas and lentils contain less starch than raw counterparts?
A
- higher amount of water = lower proportion of starch (dilution)
18
Q
- Why do yellow bananas contain less starch than green bananas?
A
- Dramatic loss of starch as it breaks down into sugars over time (amylase enzymes active)
- Physical properties also change (becomes softer)
19
Q
- Describe the differences in blood glucose concentration after ingestion of yellow and green bananas.
A
- Green: slower glucose release, lower peak
- Yellow: faster increase, higher peak (more sugars)
20
Q
- Name the main NSP
A
-Cellulose
21
Q
- State which F&V aspect pectin affects and how this is affected by cooking.
A
- Affects texture
- Breaks down during cooking, cells no longer stick together -> softer texture
22
Q
- Define lignin and state its function.
A
- Non-CHO component of cell walls (esp. vascular tissue), present in small amounts
- complex polymer of aromatic polymers linked by propyl units
- provides rigidity and toughness (mechanical support)
23
Q
- Explain how lignin presence affects texture and bioavailability of nutrients.
A
- more lignin -> tougher texture
- lignin not easily digested -> affects fermentation in LI (nutrients it contains will not be released until broken down)
24
Q
- State the function of other phenolic compounds and give an example.
A
- Affect mechanical properties of cell wall (texture)
- Ferulic acid (example) is in Chinese water chestnuts and forms cross links with arabinoxylans (in parenchyma tissue) so cells do not separate after hydrothermal processing
25
Q
- Give 3 protein-rich vegetables
A
- Spinach
- Sweetcorn
- Leguminous seeds (legumes)
26
Q
- State what determines protein structure and function and what the main functions are in F&V.
A
- Amino acids present
- Overall structure, enzyme functioning
27
Q
- Define what protein quality is and identify the limiting amino acids in legumes and wheat.
A
- Amounts of essential amino acids present
- Wheat: lysine
- Legumes: methionine
28
Q
- Give two examples of non-protein N components in F&V.
A
- purines
- alkaloids (toxic at high conc)
- e.g. green potatoes have high conc of solanine (glucoalkaloid) which is a potent acetyl cholinesterase inhibitor (prevents Ach degradation once stimulus in removed)
29
Q
- Give two lipid-rich F&V sources
A
- avocado
- olives (olive oil)
- tree nuts
30
Q
- State the most common form of lipid and the 3 common fatty acids that these consist of.
A
- triacylglycerol
- palmitic (C16:0), oleic (C18:1), linoleic (C18:2)
