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Food Chem 2 > Food Pigments > Flashcards

Food Pigments Flashcards

1
Q

Where can we find chlorophyll in foods

A

Green vegatvles, root vegetables and fruits

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2
Q

What is the structure of chlorophyll

A

Tetrapyrrole

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3
Q

What is the difference between chlorophyll a and b

A

The absorbance of the wavelength
Chlorophyll b has a 475 nm
Chlorophyll a is at 670 nm and because of this difference they have different colors chlorophyll a is darker and it is the most present

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4
Q

Chlorophyll
- colour
- solubility

A

Green and water insoluble

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5
Q

If chlorophyll lost a photos what molecule would form

A

Chlorophyllide

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6
Q

Chlorophyllide
- colour
- solubility

A

Water soluble and green

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7
Q

If chlorophyll loss Mg what molecule would form

A

Pheophytin

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8
Q

Pheophytin
Color
Solubility

A

Dark brown colour and water insoluble

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9
Q

If Pheophytin loss payroll what it would form

A

Pheophorbide

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10
Q

Pheophorbide
Color
Solubility

A

Soluble and brown Color

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11
Q

True or false
Chlorophyll is a fat soluble

A

True

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12
Q

How can you destroy chlorophyll

A
  • By heating under acidic condition
  • It is degraded by various enzymes such as chlorophylase and lipoxidase
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13
Q

Give 2 examples of heme pigments

A

Myoglobin and hemoglobin

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14
Q

What is heme pigments responsible for

A

Red colors of muscle

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15
Q

Major food sources of heme pigments

A

Meats and fish

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16
Q

Myoglobin structure

A

4 N’s in the 4 purple molecules covalently linked to central iron atom

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17
Q

True or false
4 myoglobins form 1 hemoglobin

A

True

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18
Q

What is oxymyoglobin

A

Bright red colour of fresh meats and the iron is present as ferrous form

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19
Q

What happens when you heat oxymyoglobin

A

Change te texture and color

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20
Q

What is the advantage and disadvantage with rare vs well done meat

A

Rare meat has more iron and so it is easily absorbed compared to well done meat. However, well done meat is better for energy because rate meat is difficult to digest

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21
Q

What colour is metmyoglobin

A

Brownish colour

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22
Q

What happens when we storage a meat

A

Gradual oxidation forming dark brain color

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23
Q

What happens when we cook meat

A

Denatures proteins
Oxidation of Fe2+ to Fe3+
Formation of dark color

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24
Q

Hemoglobin and myoblobin are what type of compound

A

Tetrapyrrole

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25
Where is found carotenoid pigments
Plants, animals and Microorganisms
26
What color is carotenoid
Yellow, orange and red orange colors in plants and animals
27
Give examples of carotenoids foods from fruits and vegetables
Carrots Peppers Cantaloupe Watermelon Oranges
28
Give animal source examples of carotenoids
Milk fat, egg yolk, butter, salmonid, crustacean
29
How animals can have a carotenoid part
The pigment will deposit of the fat and it will give the color
30
Give an microbial source example of caratenoid
Fungi, yeast, algae
31
Why the microorganisms Phaffia is used as a feed supplement for farmed animals
1) rich in pigment 2) easier to cultivate 4) don’t cause environmental concern
32
In which form ( cis or trans) are carotenoid found in the most? And what happens when you heat trans form
Trans form is the most found and when you heat it will go from trans to via and it will have a change of color
33
What is the structure of carotenoids
5C compound - isoprene
34
Can carotenoid be cyclic
Yes
35
What are the 3 sources of carotenoids
1) extraction from natural sources 2) chemicals synthesis 3) biosynthesis/ microbial fermentation
36
Explain for caratenoids are available from extraction from natural sources
Extraction entails adding the source material to a solvent such as acetone which is able to extract both water soluble and fat soluble components. After the acetone step the non polar carotenoids are extracted further with non polar solvents such as petroleum either to leave behind the water soluble proteins peptides, amino acids and surfaces
37
How much carbon does a carotenoid gas
40 carbons
38
What isopentenyl 5 pyrophosphate can do
Grows or polymerize to form the various carotenoid compounds we find in nature
39
How is beta carotene formed
Retinal + beta retinyltriohenykphospjonium chloride
40
What is the difference of beta and alpha carotene
Is the double bond on one of the cyclic form
41
What happens if we do the hydrolysis ( couper) of beta carotene
We obtain 2 molecules of vitamin A
42
We know that beta carotene can make 2 vitamins A. How much vitamin A can the alpha carotene make
1 vitamin a because the alpha carotene is not symmetrical
43
Where is lycopene found
Major pigments in tomatoes and apricots
44
What is the molecular structure of lycopene
It is symmetrical but the ring structures are open so it cannot do vit A
45
Can lycopene has vit A activity
No
46
True or false Lycopene is a potent antioxidants
True
47
What is the chemical structure of lutein
Symmetrical It has an OH in the cyclic group
48
Lutein can make vit a true or false
False because lutein has a OH on its cyclic group so we cannot form vit A
49
Is lutein more a potent antioxidants than beta carotene
True because it has the oxygen which makes more potent
50
Give some examples of oxy carotenoids
Lutein Canthaxanthin Astaxanthin Cruptoxanthin Zeaxanthin
51
What is the source of lutein
Green leaves and egg yolk
52
Where is canthaxanthin found
Plants, microorganisms, animals
53
How is canthaxanthin used
As a feed supplement for cultured salmonidé and imitation of seafood products
54
Does canthaxanthin has vit A act
No
55
Where au is astaxanthin found
Salmonids, crustaceans
56
Does astaxanthin has a vitamin a activity
No
57
If we give animals canthaxanthin and another group of animals astaxanthin which of the group will have a more intense color
Astaxanthin - more stable
58
Where can you find cryptoxanthin
Peaches, yellow corn and egg yolk
59
How is the chemical structure of cryotoxanthin
Similar to carotene but it has an OH function on one of the cyclic carbons
60
True or false Cryptoxanthin cannot make vitamin a activity
False it can make one vitamin A
61
Where is found zeaxanthin
Yellow corn, egg gold wifely distributed in nature
62
How is the chemical structure of zeaxanthin- can it make vitamin A
It has an OH in the cyclic carbons so it cannot make vitamin a
63
What are some of the application of carotenoids
1) food colorant : put on oats, margarine 2) forticagion 3) biochemical/ pharmaceutical : treat cancers 4) cosmetics
64
What is the major cause of distraction of carotenoids
- oxygen and light - dehydration
65
True or false Is carotenoids lost by cooking water
False it is NOT lost

Food Chem 2 (5 decks)

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