FRUITS 1

Question 1

what does growing fruit in middle of city help with

Answer 1

shelf life because less transportation

Question 2

what are fruits

Answer 2

edible part of a plant with seed that grows
from a flower

Question 3

how are fruits classified

Answer 3

by part of flower they develop from

Question 4

whats a simple fruit

Answer 4

develop from one flower; pomes and drupes

Question 5

whats drupe

Answer 5

fleshy, thin, seed enclosed in pit; date, cherry, coconut

Question 6

whats a pome

Answer 6

thick flesh with seed in core; like apple

Question 7

what do the seeds of stone fruit break into

Answer 7

hydrogen cyanide (bc of a compound called amygladin), which is a poison

Question 8

whats an aggregate fruit

Answer 8

One flower several ovaries, like raspberry, strawberry, blackberry

Question 9

whats mulptlie fruit

Answer 9

develop from cluster of several
flowers; several flowers, several ovaries e.g., Pineapples, figs

Question 10

what are botanical fruits?

Answer 10

fruits that are normally treated like vegetables, like tomatoes, squash, okra, peppers, cucumbers

Question 11

what is rhubarb

Answer 11

vegetable usually treated as fruit

Question 12

how are fruits similar to vegetables

Answer 12

similar cell structure and pigments

Question 13

describe acidity of fruits

Answer 13

Most fruits have pH < 5.0, Acidity affects flavor
* Range from very acidic (lemons and limes: pH ~2) to mildly acidic (cucumbers and squash: pH ~5)

Question 14

what do organic acids contribute to

Answer 14

tartness

Question 15

what are the major organic acids

Answer 15

citric acid and malic acid

Question 16

what makes up citric acid

Answer 16

citrus fruits, berries, and tropical fruits

Question 17

what contains malic acid

Answer 17

drupes and pomes

Question 18

what are the three other kinds of organic acids

Answer 18

• Tartaric acid (grapes)
• Oxalic acid (rhubarb)
• Benzoic acid (cranberries)

Question 19

what does pectin act as

Answer 19

cement between cell walls, contribute to
structure and firmness; contains several polysaccahrides; Water-soluble, forms gel

Question 20

what does all pectin contain

Answer 20

methyl pectate: chain of repeating
galacturonic acid units – responsible for gelling

Question 21

how does pectin change during ripening

Answer 21

Protopectin (immature fruit, no gel) -> pectin (ripe fruit, gels) -> pectic acid(overripe, no gel)

Question 22

whats protopectin

Answer 22

Large, insoluble molecule, cannot form gel

Question 23

what do the molecules in pectin do

Answer 23

Linear molecules form a net-like structure that is able to trap water

Question 24

what happens as fruit overripens

Answer 24

enzymes convert pectin to pectic
acid, which Cannot form gel

Question 25

what enzymes are critical in softening of fruits

Answer 25

pectinase

Question 26

whats the relationship between pectin degradation and softening

Answer 26

as one increases, so does the other

Question 27

whats another method to hydrolyze pecin into pectic acid

Answer 27

heating; texture also becomes soft

Question 28

what can contribute to gelling between pectin, protopectin, and pectic acid

Answer 28

Only pectin (not protopectin or pectic acid) can
contribute to gelling

Question 29

what is pectin commercially used for

Answer 29

jelling of fruit preserves

Question 30

what is pectin derived from when used commercially for jelling

Answer 30

from the pulp (pomace) remaining after apples are pressed for juice and the albedo (white inner rind of citrus)

Question 31

what do pectic substances causes when juice is extracted

Answer 31

cloudiness, but can clarify with pectinases

Question 32

what are tannins responsible for

Answer 32

browning and bruising in fruits such as
avocados, apples, bananas, peaches, etc.

Question 33

what are the three things that enzymatic browning requires

Answer 33

1. Phenolic compounds (found w/in the cell)
2. Polyphenol oxidase (PPO)
3. Oxygen (enters cells when fruit is cut or bruised)

Question 34

what does PPO do to tannis

Answer 34

converts from clear to brown, but still safe to consume

Question 35

why does denaturing enzymes with heat help with enzymatic browning

Answer 35

because Blanching destroys polyphenol oxidase (PPO), but Can cause loss of fruit texture and flavor

Question 36

why does lowering pH help with enzymatic browning

Answer 36

because optimal pH for PPO activity is 7.0, which is why highly acidic fruits don’t brown

Question 37

why does lowering temp help with enzymatic browning

Answer 37

Cold temp slows reaction rate (doesn’t completely inhibit)

Question 38

why does coating with sugar or water help with enzymatic browning

Answer 38

Covering fruit with layer of sugar or syrup, or
submerging in water prevents exposure to oxygen

Question 39

why does adding antioxidants help with enzymatic browning

Answer 39

because Antioxidants use up available oxygen
ex: Commercially used (ex: golden raisins)

Question 40

why are fruits functional foods

Answer 40

rich in antioxidants, phytochemicals, polyphenols, vasocdialters

Question 41

what do polyphenols do

Answer 41

Associated with decreased risk of high blood pressure, heart disease, stroke, and dementia; high levels in pomegranates and berries