Natural pigments second midterm Flashcards
Carotenoids have a lot of ___ since they derive from ____ unit
conjugated double bonds isoprene
name a few carotenoids sources ?
- animal sources (crustaceans, milk fat, egg yolk, butter, salmonds, trouts) 2. vegetables like carrots 3. tomatoes 4. microbial (yeasts, mushrooms, algea) 5. vegetable oils
Draw the isoprene unit
true or false : some carotenoids can be found without double bonds
false, they all derive from isoprene units which contain double bonds so impossible
what will determine the extent at which the carotenoid is an antioxidant?
the lenght of the molecule (more double bonds)
what are the various hydrocarbon carotenoids seen
b-carotene
alpha-carotene
lycopene
when cleaved, alpha carotene yields ___ vitamin A
B-carotene yields ___ vitamin A
alpha carotene = 1
beta carotene = 2
Which molecule is this
alpha carotene
which molecule is this
beta-carotene
which molecule is this
lycopene
which molecule is this
vitamin A
lutein is a ____ carotenoid
oxycarotenoid
which molecule is this
lutein
what is the only difference between b-carotene and lutein
the presence of OH on the ring
does lutein has a vitamin A activity
no because of the presence of the OH on the ring
why does a-cartone yields only one vitamin A upon cleavage
because the position of the double bond on one of the ring is shifted
lycopene:- major pigment in ___ and ___
tomatoes & apricots
what is the difference between lycopene and b-and a-carotene
the ring in the lycopene is open (acyclic hydrocarbon caretnoid)
is lycopene symmetrical?
yes
what are the common oxy-carotenoids we saw in class?
- lutein
- canthaxanthin
- astaxanthin
- cryptoxanthin
- zeaxanthin
is lutein symmetrical
yes
what are the food sources of lutein
egg yolk, green leaves
which molecule is this
canthaxanthin (a la cantine on a des rigolos)
what is the difference between b-carotene and canthaxhantin
there is a =O on each rings
name food sources of canthaxanthin?
- microorganisms : mushroom
- plants and animal : red pepper, flamingo, shrimps
which one of the carotenoids can be commercially produce by chemical synthesis?
canthaxanthin
does canthaxanthin as a vitamin A activity?
no
which are the carotenoids with vitamin A activity?
alpha and beta-carotenoid
cryptoxanthin
what is the major carotenoid in salmonids and crustaceans?
astaxanthin
does astaxanthin as a vitamin A activity
no
which molecule is this
Astaxanthin (asteur qu’on a des rigolo ya aussi des hoe)
what is the difference between astaxanthin and b-carotene?
presence of OH and =O
is astaxanthin symetrical?
yes
what is the major carotenoid pigment in peaches, yellow corn and egg yolk?
cryptoxanthin
which molecule is this?
cryptoxanthin (OH tu t’es acheter une ring avec ta crypto?)
what is the difference between cryptoxanthin and b-carotene?
presence of OH on one ring
what is the difference between lutein and cryptoxanthin?
crypto as only one OH on one ring while lutein has 2
does cryptoxanthin as vitamin A activity?
YESSS!!!
what is the difference between b-carotene and zeaxanthin?
the zeaxanthin as 1 OH on each ring
which pigment is this?
zeaxanthin (hoho zea aime leo)
what are the major source of destruction of carotenoids?
-dehydration (lipooxygenase)
-oxygen
-light
heat
is beta-carotene lost to cooking water?
not it is liposoluble
what is this pigment?
anthoxcyanin
anthocyanins are ___soluble
water
what is the basic structure of anthocyanins?
the flavilium
what is the color of anthocyanin?
blue, red, violet
In nature, the anthoxyanins can have a maximum of ___ sugars attached to them
three
why does anthocyanins exhibits different color?
because of the level of hydroxylation and sugars
•Increasing ____ content increases redness.
methoxy (-OCH3)
•Increasing hydroxy (-OH) content increases ___color
blue
At acidic pH you get more ___ on anthocyanins and you favor ___ color
OH
red color
At basic pH you get more ___ on anthocyanins and you favor ___ color
OCH3 (glycosid bonds)
blue color
___ and __ enzymes remove the sugars from anthocyanins, thus destabilizing the molecule and causing loss of color
•Glucosidases or anthocyanases
flavonoids are ___ soluble
water
what is the difference in the basic structures between flavonoids and anthocyanins?
what are the different class of flavonoids we saw in class?
- flavones
- isoflavones
- Flavonols
- flavonones
- Flavanonols
which class of flavonoids is this
flavones (double bond from 2-3)
which class of flavonoids is this
isoflavones (benzene ring is at C3)
which class of flavonoids is this
flavonol (OH at position 3)
which class of flavonoids is this
flavonones (like flavones but none double bond at C2-3)
which class of flavonoids is this
flavonones (like flavonol byt without the double bond at C2-3).
depending ____ and depending on ____, we can distinguish 5 type of flavonoids
where the ring A is attached to ring B
the nature of the bond between the C2 and C3
which pigment is this : yellow in color, found in many fruits & vegetables (celery), and in chamomile tea. Has pleasant smell, and a bitter, astringent taste. Has calming effect and reduces anxiety in some people
apigenin (flavonoid)
which pigment is this : colorless, found in many fruits. Vegetables, legumes (soy, alfalfa, peas). Has bitter taste and estrogenic effects. Protects against osteoporosis and menopause symptoms (hot flashes)
genistein
which pigment is this : •yellow / brown in color. Ubiquitous; found in fruits, vegetables (onion), leaves & grains. Bitter / astringent taste (immature apples)
quercetin
which pigment is this : colorless, found in many plant materials. Very bitter – responsible for bitter taste in grapefruits;
naringenin
which pigment (flavonoids) is this : colorless and found mostly in leaves. Has bitter & astringent taste.
xeractinol
betalaine are ___ soluble
water
what are the two main colors of betalaine?
red and yellow
how is called the red pigment of betalaine
betacyanin (betanin)
how is called the yellow pigment of betalaine?
betaxanthin (vulgaxanthin)
what is the major difference between betalaines and flavonoids and anthocyanins?
the difference from the anthocyanins and flavonoids is the presence of the nitrogen.
Which pigment is this : solubility is based on the size
tannins
what group of pigment is this pigment from?
quinone
which class of pigment are we referring to : •Plant pigments with structural resemblance to flavonoids & quinones, i.e., glycosides;
xanthones
