Natural Pigments

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Total cards: 24•Content version: v4•Public deck•Updated: 8/1/2026

Card preview (24)

Front (Question)

Food quality attributes of natural pigments

Back (Answer)

• Flavor (taste/smell) • Texture • Nutritive value • Microbial load • Color / appearance

Front (Question)

Natural Food Pigments (8)

Back (Answer)

• Chlorophyll • Myoglobin & Hemoglobin • Carotenoids • Anthocyanins • Flavonoids • Tannins • Quinones & Xanthones • Melanins & Betalains

Front (Question)

Chlorophyll

Back (Answer)

• Plant pigment (main sources are green vegetables, root vegetables, fruits) o Mg in the center o Fat soluble o Can be destroyed by heat o Sensitive to acids and alkali o Green color o Plant sources, algae

Front (Question)

Chlorophyll structure

Back (Answer)

tetrapyrrole

Front (Question)

Major chlorophylls are ____

Back (Answer)

‘a’ & ‘b’ (3:1)

Front (Question)

The proportion of a and b chlorophylls is

Back (Answer)

3:1

Front (Question)

What colour is alpha chlorophyll

Back (Answer)

green-bluish colour

Front (Question)

What colour is beta chlorophyll

Back (Answer)

dull green colour

Front (Question)

Is chlorophyll water soluble or fat soluble?

Back (Answer)

fat soluble

#10

Front (Question)

Heme pigments are ____ and ____

Back (Answer)

hemoglobin and myoglobin

#11

Front (Question)

Heme pigments general features

Back (Answer)

• Responsible for red color of muscle foods; • Complex molecule with a protein part (globin), and an essential non-protein part (heme); • Both Mb and Hb are tetrapyrrole compounds.

#12

Front (Question)

Mb and Hb structure

Back (Answer)

tetrapyrrole compounds.

#13

Front (Question)

Is heme fat or water soluble

Back (Answer)

water soluble

#14

Front (Question)

What are the major food sources that contain heme

Back (Answer)

meats (beef, pork, chicken, fish) o The pigment in the muscle is due to myoglobin, and the intensity of the color depends on the myoglobin content

#15

Front (Question)

Myoglobin structure

Back (Answer)

• Single polypeptide chain • 4 N’s in the 4 pyrole molecules , covalently linked to central Fe atom • Fe also covalently linked to N in a histidine residue in globin (protein); • Fe can bind electron pair donors (e.g., O2, CO, CO2, CN, etc).

#16

Front (Question)

Oxymyoglobin

Back (Answer)

• Bright red color of fresh meats • Fe present as ferrous (Fe2+) form • Mb + O2 <==> MbO2 • Mb (purple color; Fe2+) • MbO2 (bright red; Fe2+)

#17

Front (Question)

What is the compound that gives the fresh color to meat?

Back (Answer)

oxymyoglobin

#18

Front (Question)

Metmyoglobin (Met-Mb)

Back (Answer)

• Brownish color (Fe3+) • MbO2 <==> Mb ==> Met-Mb • MbO2 (bright red) • Mb (purple) • Met-Mb (brown)

#19

Front (Question)

What is the compound that gives the brown color to meat?

Back (Answer)

metmyoglobin

#20

Front (Question)

Chlorophyll a vs. Chlorophyll b

Back (Answer)

One of the pyrroles have a methyl group = chlorophyll A Formyl group –CHO = Chlorophyll B

#21

Front (Question)

What makes chlorophyll fat soluble molecule?

Back (Answer)

Fat soluble bc of the presence of the C20 carbon molecule that is attached to the chlorophyll molecule. 20C unit known as PHYTOL (300g/mol) Phytol side chain is a hydrocarbon and highly hydrophobic, and this accounts to its insolubility in H2O, but highly solubility in lipids. – wax

#22

Front (Question)

What happens when the phytol group is removed form chlorophyll?

Back (Answer)

If we remove the phytol group, the molecule left behind is water soluble

#23

Front (Question)

How can we obtain chlorophyllide from chlorophyll and how does the color change?

Back (Answer)

loss of phytol by chlorophyllase very bright color

#24

Front (Question)

How can we obtain pheophytin from chlorophyll and how does the color change?

Back (Answer)

expose it to acid and heat loss of Mg atom blue color