Vegetables, Legumes, and Pigments Flashcards
1
Q
Name the four major differences of plant cells.
A
- Cell Wall
- Plastids
- Vacuoles
- Intracellular air
2
Q
Name the four different plant fibres.
A
- Cellulose
- Hemicellulose & Pectin
- Lignin
- Gums and Polysaccharides
3
Q
Which plant fibre is the non carbohydrate fibre?
A
Lignin
4
Q
What plant fibre is often used in jams?
A
Pectin
5
Q
What is a fruit?
A
Seed bearing structure of flowering plants
6
Q
What is a seed?
A
Can create new plants, high in CHO
7
Q
What are vacuoles?
A
Storage of water, anthocyanins, flavor compounds, acids
8
Q
What contributes to crispness and volume?
A
Intercellular air
9
Q
What is the cell wall composed of?
A
Many indigestible fibers
10
Q
What is the major component of cell walls?
A
Cellulose
11
Q
What provides elasticity and firmness to cells?
A
Hemicellulose and pectin
12
Q
Why are gums and polysaccharides used as thickening agents?
A
Ability to absorb water and swell
13
Q
Which plant fiber’s concentration increases with time? What is it composed of?
A
Lignin
Polymer of phenolic alcohols
14
Q
What protects seeds?
A
Fruit
15
Q
What are flowers?
A
- Male and female parts
- Plant reproduction
- Pollination
16
Q
What are leaves? What do they contain?
A
• Actively metabolizing part
• Contains large
amounts of water
17
Q
What are stems used for?
A
- Transfer of water and nutrients
* Support
18
Q
What are roots used for? What are they high in?
A
- Draw nutrients and moisture in from the soil
* High in CHO
19
Q
What are tubers used for? What are they high in?
A
- Storage vessels
- Means to propagate new plants
- High in CHO
20
Q
What are bulbs used for?
A
• Storage organ during plant dormancy
21
Q
How do we classify vegetables?
A
By the part from which they come!
22
Q
Name the 8 parts of plant anatomy.
A
- Fruits
- Seeds
- Flowers
- Leaves
- Stems
- Roots
- Tubers
- Bulbs
23
Q
What is the identifying factor of legumes?
A
Grow as seeds within a pod
24
Q
Which legume is higher in protein and fat?
A
Soybean
Tofu, textured vegetable protein, meat analogs, fermented soy
25
What are legumes high in?
CHO, fiber and protein
26
How do we differentiate fruits?
* Usually derived from flowers
| * The part of the plant that contains seeds
27
How do we differentiate legumes?
* Identifying factor: seeds contained within a pod
| * High in CHO, fiber, protein
28
How do we differentiate vegetables?
* All other edible plant parts
| * Flowers, stems, leaves, roots, tubers, bulbs
29
If a nutrient content is low in calorie, what does that mean? What about high in calorie?
- Low kcal: high water content
| - High kcal: starchy vegetables and legumes
30
Which vegetables are high in fat (exceptions)?
Soybeans and peanuts
31
Which vegetables are high in cholesterol?
NONE
32
Which vegetables are higher in carbohydrates?
The starchy vegetables and legumes
33
Which vegetables are higher in protein?
Legumes (but incomplete) Limiting AA: methionine
34
Which vegetables contain vitamin A? What is their function?
* Orange and dark leafy green vegetables
| * Vision, antioxidant, anti- inflammatory, reproduction
35
Which vegetables contain riboflavin? What is their function?
* Leafy greens, mushrooms, sea vegetables
| * Metabolism, antioxidant
36
Which vegetables contain folic acid? What is their function?
* Legumes, dark leafy greens
| * DNA synthesis, repair, methylation, reduces NTDs
37
Which vegetables contain vitamin C? What is their function?
* Citrus, bell peppers, tomatoes, etc.
| * Enzymatic cofactor, antioxidant, immunity
38
Which vegetables contain potassium? What is their function?
* Most vegetables
| * Important role in fluid balance
39
Which vegetables contain calcium? What is their function?
* Dark leafy greens, broccoli
| * Promotes bone health
40
Which vegetables contain iron? What is their function?
* Legumes, dark leafy greens
| * Essential component of blood cells
41
Define functional foods.
have potentially positive effect on health beyond nutrition
42
Define phytochemicals.
non nutritive compounds in plants that are considered to have health protective benefits
43
Why are cruciferous vegetables functional foods?
* Contain indole glucosinolate
| * May have a protective effect against some cancers
44
Give examples of cruciferous vegetables.
* Brassica vegetables
| * Broccoli, cauliflower, cabbage, kale, turnips, rutabaga, etc.
45
Give examples of allium vegetables.
• Garlic, onions, shallot, and leek
46
Why are allium vegetables functional foods?
* Crushing of these plants, especially garlic, releases allicin
* Allicin = Antimicrobial
47
What are rich sources of lycopene?
Tomato, watermelon
48
Why is lycopene beneficial? What colour is it?
* Red carotenoid pigment
* Powerful antioxidant
* May reduce risk of prostate and digestive tract cancers
49
When is the activity of lycopene maximized?
when cooked and in the presence of fat
50
What are rich sources of lutein?
broccoli, celery, cabbage, spinach, green peppers, cauliflower
51
Why is lutein beneficial? What colour is it?
* Yellow carotenoid pigment
* Antioxidant activity
* May decrease growth of cancer cells
* May have anti-inflammatory properties
52
Why are soybeans considered to be a functional food? Which compound in soy is responsible for these effects?
* High dietary levels of soy associated with decreased risk of breast and uterine cancers
* Genistein
53
Give examples of moist and dry cooking methods for vegetables.
Moist: simmering, steaming, braising, microwaving
Dry: baking, roasting, sautéing, deep-frying
54
Name the 6 changes that arise when you cook vegetables.
Texture, flavour, odour, colour, reduction in pathogenicity, nutritive value
55
What changes in texture happen when cooking vegetables? Why?
* Reduction in “crunchiness”
* Gelatinization of starch
* Softening of cellulose
56
What can lead to a mushy texture during cooking?
Cooking in alkaline environment
57
Name a desirable flavour change.
Caramelization
58
How do we reduce leeching of flavour into water?
Use minimal water
59
Define degorging.
removal of bitter compounds using salt/osmotic pressure
60
Why would some odours be undesirable? Where are they found?
* Some odors are undesirable due to sulfur compounds
| * Cruciferous and allium vegetables
61
Name 3 ways to reduce bad odours.
* Shortening cooking time
* Adding vinegar to cooking water
* Removing cooking lid occasionally to let volatiles escape
62
What are pigments sensitive to?
heat, light, pH, presence of metals, etc.
63
What adjustments can you make to minimize effects in colour change during cooking?
time, temperature, pH, and cookware can minimize these effects
64
Give 3 examples of changes in colour during cooking.
- Maillard reaction (Rx between AA and reduced sugar, gives browned food its flavour)
- Caramelization
- Enzymatic browning
65
How is there a reduction in pathogenicity during cooking?
Denaturation of microorganisms and decreasing bacterial load
66
What is the greatest cause of nutrient loss?
Leaching
67
Which nutrients are most prone to being lost during cooking?
Minerals and water-soluble vitamins
68
What nutrient can cooking increase?
- Increase fat
| - Increase the bioavailability of some nutrients
69
What can nutrients be sensitive to?
Heat, light, pH
70
Name 4 tips for retaining nutrients.
* Cook for a short as possible (do not overcook)
* Use minimal amounts of water
* Cook vegetables with skins on
* Cut food in bigger chunks (reduces surface area)
71
Name the 2 major purposes of storage.
1) Reduce the respiration rate (faster resp rate, faster deterioration)
2) Prevent moisture loss
72
How can respiration rate be controlled?
* Refrigeration, freezing
| * Controlled atmospheric storage, Modified atmosphere packaging
73
What does water loss of vegetables result in?
Deflation and wilting, acceleration the deterioration process
74
What is the optimal humidity for storage? What can too much moisture lead to?
85-95%
| Can lead to rot
75
Name 3 ways that moisture can be retained.
* Spraying with mist
* Wrapping with paper towel in ventilated bag
* Wax coatings
76
Name 5 ways that vegetables can be stored.
* Refrigeration
* Freezing
* Dry storage
* Controlled Atmospheric Storage
* Modified Atmosphere Packaging
77
What is storage time ultimately determined by?
Water content
78
What does refrigeration do? How long do vegetables last?
- Reduces respiration rate
| - Most veggies: 3 days
79
Vegetables have to be what before frozen?
Blanched
80
Why is there a loss of quality when freezing vegetables?
Due to bursting of cell membranes
81
What is dry storage used for?
- To retain flavour and texture
| - Speed up the ripening process
82
Give examples of vegetables that used dry storage.
Tomatoes, squash, potatoes, dried legumes, bulbs
83
Why are potatoes stored in dry storage and not the refrigerator?
Refrigeration causes conversion of starch to sugars, leading to waxy texture
84
Why is it important to keep potatoes in a DARK, dry, cool place?
• Exposure to sunlight produce
solanine
• Solanine appears as a greenish tinge on potatoes and is toxic
85
How does controlled atmospheric storage prevent vegetables from spoiling?
* Reduces amount of O2 available, and increases amount of CO2, thus slowing respiration.
* Used by commercial food companies
86
How does modified atmospheric storage prevent vegetables from spoiling?
• Altering permeability of packaging to vapors
87
Name the 3 major classes of plant pigments.
- Carotenoids
- Flavenoids
- Chlorophylls
88
What colours are chlorophylls?
Blue-green or green
89
What colours are carotenoids?
Yellow-orange, red-orange or yellow
90
What colours are flavonoids?
Red-purple, cream/white, purple-red/yellow
91
What is the structure of chlorophyll?
Porphyrin ring structure with magnesium ion in center
92
Which pigment is essential for photosynthesis?
Chlorophylls
93
Name 3 characteristics of chlorophylls.
- Fat soluble
- Found in plastids
- Very sensitive to heat
94
Name the 2 types of chlorophylls.
- Chlorophyll a: blue/green, methyl group
| - Chlorophyll b: more common, green, aldehyde group
95
What happens when chlorophylls degrade over time?
Allows underlying pigments to show (ex: fall leaves and yellowing of parsley)
96
What does the degradation of chlorophyll occur in?
* Older plants
| * Plants picked and exposed to sunlight
97
Explain what happens when chlorophyll is exposed to excessive heating.
- Rupturing of plant cells, release of organic acids
- H+ ions from acids displace Mg2+ ion in chlorophyll
- Formation of pheophytin, change of colour
98
Name 4 ways to keep foods green (chlorophylls).
Minimize heating time
• Minimize water use in cooking process
• Cook food uncovered (allows volatile acids to escape)
• Using alkaline cooking water (compromises texture)
99
Why does blanching heighten the green colour in foods with chlorophylls? What happens right after blanching? Why?
- causes the air to bubble away, so that it no longer clouds the colours
- Shocked in cold water to stop carry over cooking
100
Name the 3 major types of carotenoids.
- Carotenes (orange)
- Lycopenes (red-orange)
- Xanthophylls (yellow)
101
Which pigment contributes to vitamin A activity? How can it be destroyed?
- Carotenoids
| - Prolonged cooking
102
Name 2 characteristics of carotenoids.
- Fat soluble
| - Found in plastids
103
What is the chemical structure of carotenoids?
Polymers of isoprene
104
Which carotenoids have vitamin A activity?
- Carotenes (a, b, gamma)
| - Cryptoxanthin
105
Name 2 effects of cooking on carotenoids.
* Excessive heat decreases vitamin A activity
| * Changes intensity of color (becomes lighter) due to isomerization
106
What is the percentage of dietary lycopene that comes from tomato products?
85%
107
Which carotenoid is a powerful antioxidant? What is its health consequence?
Lycopene
| Decreased risk of cancers
108
Name the 3 major types of flavonoids.
- Anthocyanins (red-blue)
- Anthoxanthins (cream to white)
- Betalains (red or yellow)
109
What is the chemical structure of flavonoids?
Characterized by flavylium-ion structure
110
Name 2 characteristics of flavonoids.
* Water soluble
| * Found in vacuoles
111
Which pigment is sensitive to pH?
Flavonoids
112
Anthocyanins are highly sensitive to pH. How are they in acid, neutral, and basic environments?
Acid: red
Neutral: purple
Basic: blue to green
113
How do acids influence anthoxanthins? Bases?
Acids: intensify white colour
Bases: yellow
114
What are anthoxanthins sensitive to? What colour do they become?
- Excessive heating or in presence of Fe or Cu
| - Blue black or red brown
115
What is the deep purple-red pigment of betalains called? The yellow pigment?
Purple-red: betacyanins
| Yellow: betaxanthins
116
Where are betalains primarily found?
Beets
117
Betalains are highly sensitive to pH. What colour do they become in acid? In base?
Acid: purple -> red
Base: red -> yellow
118
What is the ion central to chlorophyll?
Magnesium
119
Why does broccoli become tougher with age?
Lignin increases
120
What is the pH of most vegetables?
5.0 to 5.6, tomatoes are lower (4.0 to 4.6)
121
Which pigments are fat soluble? Where are they found?
- Carotenoids and chlorophylls
| - Found in plastids
122
What is degorging?
To peel and slice vegetables, sprinkle them with salt, and allow them to stand at room temperature until droplets containing bitter substances form on the surface
- Removal of bitter compounds using salt/osmotic pressure
123
What is the Maillard reaction?
chemical reaction between amino acids and reducing sugars that gives browned food its desirable flavor
124
What group does chlorophyll a contain? What group does chlorophyll b contain?
Chlorophyll a: methyl group
| Chlorophyll b: aldehyde group
