10/21

Question 1

milligrams of oxygen consumed per liter of sample during 5 days of incubation at 20C is _____

Answer 1

BOD (biological oxygen demand)

Question 2

increased BOD indicates

a) increased water pollution with organic matter
b) decreased water pollution with organic matter
c) increased microorganisms in water
d) decreased microorganisms in water
e) nothinw, we just do it for fun

Answer 2

a) increased water pollution with organic matter
the focus is not about microorganisms - you’d do a procedure with petri plates; it’s an indicator of the pollution of organic matter present in the water sample

Question 3

during yogurt making, lactic acid is produced as a result of the fermentation of ____ in milk (sugar)

Answer 3

lactose

Question 4

color and flavor are present in very small amounts like 0.1 mg/g. what’s this in ppm? how aout 10^2g/10^6g? or 10^-4/g? what about as a percentage?

Answer 4

100 ppm; 0.01%

Question 5

the _____ of visible light gives color to plants/animals

Answer 5

absorption

Question 6

factors that affect pigment stability

Answer 6

• pH
• reactions with O2
• other factor

Question 7

Changes in color are often detrimental to for _____ _____

Answer 7

food acceptability

Question 8

name the 5 categories of pigments that are gone over in this class

Answer 8

• chlorophylls
• anthocyanins
• carotenoids
• meat protein-based pigments (myoglobin)
• tannins

Question 9

chlorophylls are what color?

Answer 9

green

Question 10

how does chlorophyll get converted to pheophytin? what color is pheophytin?

Answer 10

loss of Mg ion (often due to processing w/heat); olive brown

Question 11

true or false: chlorophylls are affected by oxidation and change in pH

Answer 11

true

Question 12

anthocyanins are responsible for ______ color(s) in food

Answer 12

red/blue/violet

Question 13

the three-ring phenolic compound structure characterizes what group?

Answer 13

flavonoids

Question 14

anthocyanins are water _____

Answer 14

soluble

Question 15

true or false: anthocyanins can change color based on pH

Answer 15

true: anthocyanins tend to have stronger color in acidic pHs

Question 16

anthocyanins can be connected to a sugar molecule. what’s this process called?

Answer 16

glycosylation

Question 17

carotenoids are responsible for _____ color(s) in food

Answer 17

red, orange, yellow

Question 18

carotenes are _____ soluble

Answer 18

fat

Question 19

true or false: carotenes are saturated

Answer 19

false: they’re highly unsaturated

Question 20

b-carotene is considered a precursor of vit ____

Answer 20

A; it’s a symmetrical structure containing 2 units of vitamin A.

Question 21

what pigment is responsible for the red color in tomatoes and red carrots?

Answer 21

lycopene

Question 22

what is the pigment responsible for the darker yellow associated with egg yolks, but is also present in leafy greens

Answer 22

lutein (usually this is associated with egg’s being “organic”) - it can just be incorporated into the feed of the chicken to make it seem nice

Question 23

what class of pigments is responsible for the pinkish color in salmon, shrimp, and krill?

Answer 23

carotenoids

Question 24

why do farmed salmon have more grayish flesh?

Answer 24

they don’t eat as much shrimp and krill

Question 25

what color is used to color cheese? where does it come from?

Answer 25

annatto; extracted from seeds of a shrub that contains bixin and norbixin

Question 26

what pigment is found in the crocus stamen

Answer 26

saffron. it's $$$$$

Question 27

Beta carotene is a precursor for vitamin A. One mole of beta carotene produces _____moles of vitamin A

Answer 27

2

Question 28

phytochemicals serve as _____ in plants and protect plants from ___________ _____

Answer 28

antioxidants; light-induced damage

Question 29

why do pigments in groups A-C have such good antioxidant functionality?

Answer 29

they already have delocalized electrons as absorbers of light

Question 30

what's the metal center of myoglobin?

Answer 30

iron

Question 31

myoglobin is a _____ color in the Fe2+ state

Answer 31

bright red

Question 32

what oxidation state of myoglobin is associated with fresh meat?

Answer 32

Fe2+

Question 33

myoglobin is a _____ color in the Fe3+ state

Answer 33

purple

Question 34

if CO is bound to the iron center of myoglobin, the resulting color is; this keeps the meat color for how long?

Answer 34

cherry red; a year - but this is considered food fraud in canada, but not the states

Question 35

cured meats obtain its color due to the binding of _____

Answer 35

nitric oxide

Question 36

true or false: the color of meat is determined by the oxidative state of the iron atom within the heme group

Answer 36

true

Question 37

the structure of tannins can be described as

Answer 37

polyphenolic

Question 38

tannins are responsible for what color in food products

Answer 38

brownish

Question 39

what 5 tastes does our tongue have

Answer 39

sweet, salty, bitter, sour, and umami

Question 40

umami is due to the presence of receptors for _____ in the tongue

Answer 40

glutamate

Question 41

what type of volatile organic compound contribute to aroma?

Answer 41

- short-chain FAs - alcohols - aldehydes - ketones - sulfur-containing compounds

Question 42

what compound is the major contributor to aroma in bulb veggies?

Answer 42

sulfur-containing compounds

Question 43

what compound is responsible for the banana's aroma?

Answer 43

isopentyl acetate

Question 44

what compound is responsible vanilla's flavor?

Answer 44

vanillin

Question 45

essential oils are made up largely of _____ (class name)

Answer 45

terpenes

Question 46

essential oils are composed of _____, _____ molecules (physico chemical properties)

Answer 46

volatile hydrophobic

Question 47

examples of terpenes include

Answer 47

.... (look at slides)

Question 48

what lab method can be used to extract essential oils?

Answer 48

steam distillation

Question 49

what reactions are famous for producing flavors?

Answer 49

maillard, caramellization

Question 50

Limonene is the essential oil responsible for the flavor of a) lemon b) lime c) orange d) graperfruit

Answer 50

b) lime | lol