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