Composition/Nutrition

Question 1

OP is:

TP is:

Answer 1

osmotic pressure

turgor pressure

Question 2

What is dietary fibre?

What purpose do they serve in the plant? How do they differ?

Answer 2

cellulose, hemicellulose, pectin, lignin.
part of cell wall
differ in structure and bond types

Question 3

What is the role of fibre in nutrition?

Answer 3

Humans cannot digest -> pass through system
acts as bulking agent and laxative, prebiotic

prevent appendicitis, constipation, diabetes, gallstones, obesity, rectum tumors

Question 4

What is the factor and the effects (4) that give fibre its nutritive qualities?

Answer 4

absorb water and swell

1. non-digestible bulk -> feel full
2. increase retention time for nutrients, more absorption
3. restrict calorie intake
4. delay fat/glucose absorption after meal

Question 5

2 categories of fibre:

Answer 5

insoluble: cellulose, hemicellulose, lignin
soluble: pectin, gums

Question 6

What is a new class of carbs that is now considered fibre (nutritionally)? What benefits does it have (3)?

Answer 6

resistant starch

• not easily digestible
• remains longer in system
• good for diabetic patients

Question 7

Ripe fruits are higher in ____ than unripe fruits, which are higher in ____.

Answer 7

sugar

starch

Question 8

common sugars in fruits:

Answer 8

glucose, fructose, sucrose

Question 9

starch is found in:

What is the structure?

Answer 9

mature vegetables, unripe fruits

long chains of glucose (polysaccharides)

Question 10

The 2 digestible starch types:

Answer 10

amylose (a 1-4) straight chains

amylopectin (a 1-4 and a 1-6) branched chains

Question 11

How does cellulose differ from starch?

Answer 11

also made of glucose units, but b 1-4 bonds

Question 12

industrial sources of starch:

Answer 12

corn, potato

Question 13

What enzymes are used to hydrolyze starch and why?

Answer 13

b-galactosidase, a-amylase

produce sugar/syrup

Question 14

starches are used industrially as:

Answer 14

thickener

source of glucose/fructose

Question 15

4 types of resistant starch:

give examples

Answer 15

RS1: physically inaccessible or digestible RS (seeds, legumes, unprocessed grains)
RS2: natural granular form (uncooked potato, green banana flour)
RS3: formed when starchy foods are cooked and cooled (bread, cold potatoes, cold rice)
RS4: chemically modified to resist digestion (not in nature)

Question 16

Rich sources of pectin:

Answer 16

apple, citrus

Question 17

What is the chemical structure of pectin?

Answer 17

polymer of methyl ester of GALACTURONIC ACID

Question 18

pectin is important in the production of: ____ due to its ability to ___
what is the general procedure?

Answer 18

jams, jellies; form gel/viscous colloidal suspension

pectin + sugar + acid + cook -> jam

Question 19

What can be used to make diabetic jelly/jam? Why?

Answer 19

low methoxyl pectin (LMP)

form gel with Ca, no sugar needed

Question 20

What is the effect of pectin in juice?

Answer 20

cloudiness, thickening

Question 21

What is “PME?”

Answer 21

natural enzyme in fruit and veg that hydrolyzes pectin

Pectin methyl esterase

Question 22

Is PME inactivated in juice? Why or why not?

Answer 22

YES: if want cloudy juice
NO: if want to clarify -> then inactivated in pasteurization
NO: if need to filter

Question 23

What is the role of Ca chloride in fruit? Why?

Answer 23

firming of fruit slices

forms gel with LMP -> increased gel strength, structural rigidity

Question 24

____ are the major component of the plant cytoplasm

Answer 24

proteins

Question 25

True False: fruit and vegetable contain significant amounts of protein

Answer 25

``` false; not major contributors fruit<1% veg 2% peas 7% cereal/pulses 12% ```

Question 26

during storage, proteins will lower the _____ of _____, and increase ____ of crops

Answer 26

OP; amino acids | nutritive value

Question 27

common plant proteins:

Answer 27

albumins globulins, gliadins, glutenins

Question 28

gluten is form from: | It is important in:

Answer 28

gliadins, glutenins | dough rheology, baking, bread, etc

Question 29

Where are fats and oils found in plant cells?

Answer 29

in cytoplasmic layers

Question 30

are fruit/veg major contributors of fats?

Answer 30

no; <2% (dry weight basis)

Question 31

Fat content of produce is usually expressed in: ____ | Why?

Answer 31

dry weight basis (remove water) | very small %

Question 32

What fruits are high in fats?

Answer 32

avocado, palm kernel, olive

Question 33

fats and oils are higher in what plant tissues?

Answer 33

cuticle, epidermis, corky layers

Question 34

nutritional value of fats/oils depends on: (3)

Answer 34

degree of unsaturation, double bonds (omega 3 and 6), structural orientation

Question 35

intake of ___ and ____ fats should be limited.

Answer 35

trans | saturated

Question 36

plant oils rich in saturated fats | Which fatty acids are common?

Answer 36

palm kernel coconut lauric, myristic

Question 37

What plant oils are rich in unsaturated fats?

Answer 37

``` peanut corn olive sunflower soybean ```

Question 38

common unsaturated fatty acids: | if these are fully hydrogenated, it becomes:

Answer 38

linoleic linolenic oleic stearic (C18)

Question 39

___ fatty acids are important in ___ function and in high quantity in the ____. What are sources in plants?

Answer 39

omega 3; immune; brain flax, walnuts, pumpkin seeds

Question 40

True/False: fruit/veg contain excesses of organic acid, more than needed for metabolic activity

Answer 40

True

Question 41

Why do fruit/veg contain so many organic acids?

Answer 41

by products of metabolic activities | accumulated in vacuoles

Question 42

What are the dominant organic acids?

Answer 42

citric, malic

Question 43

Grapes and avocado are rich in ___ acid blackberry contains ___ acid spinach contains ___ acid

Answer 43

tartaric isocitric oxalic

Question 44

___ and ____ contain 3% acid

Answer 44

lime, lemon

Question 45

F&V are important sources of: (vitamins)

Answer 45

vitamin C (best source) vitamin A precursors folic acid

Question 46

Important minerals in F&V:

Answer 46

iron, calcium

Question 47

what factors need to be considered when evaluating miineral and vitamin content in F&V?

Answer 47

Amount consumed bioavailability concentration

Question 48

is spinach a rich source of calcium?

Answer 48

No, bound to oxalate (not bioavailable)

Question 49

3 major classes of pigments;

Answer 49

chlorophylls (green) carotenoids (yellow orange) flavonoids (various colors)

Question 50

role/location/properties of chlorophylls:

Answer 50

need for photosynthesis in chloroplasts (chlorophyll a and b) heat in acid -> turn brown/olive

Question 51

Difference between types of chlorophylls:

Answer 51

a: CH3 b: CHO group

Question 52

The enzyme ____ will remove the ____ group on chlorophyll, which will turn the color bright green

Answer 52

chlorophyllase | phytol

Question 53

carotenoids are ___ soluble, and found in ____.

Answer 53

fat; chromoplasts

Question 54

True/False: green leaves do not contain carotenoids

Answer 54

False; hidden by chlorophyll

Question 55

What carotenoids are found in carrots, tomato, and radish? what benefits do these compounds have?

Answer 55

carrot: b-carotene (pre vitamin A) tomato: lycopene (pharmaceutical properties) radish: xanthophylls

Question 56

Types of flavonoids:

Answer 56

anthocyanins (red/blue/purple) anthoxanthins (yellow) catechins leucoanthocyanins (colorless, can form brown)

Question 57

color of anthocyanins depends on _____. | What is the color in different conditions?

Answer 57

pH acid: red slightly basic: purple basic: blue

Question 58

Anthoxanthins can have nutraceutical properties as _____.

Answer 58

anti-hemorrhage factor

Question 59

What are tannins?

Answer 59

astringent compounds, can react with metal ions to give dark color (tan)

Question 60

"Tan" is produced by:

Answer 60

catechins polymerizing | tannins reacting with metal ions