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7/31/2019 Pigments Found in Vegetables and Its Extraction Technique
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PIGMENTS FOUND INVEGETABLES AND ITS
EXTRACTION TECHNIQUE
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INTRODUCTION
The pigments found in plants playimportant roles in plant metabolismand visual attraction in nature. Theyare also important for humans,attracting our attention andproviding us with nutrients. Major
plant pigments include carotenoids,anthocyanins and other flavonoids,betalains, and chlorophylls.
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CAROTENOIDS
Carotenoids pigments are yellow, orangeor red, and play pivotal roles inphotosynthesis. Carotenoids are organicpigments that are naturally occurring in
chromoplasts of plants and some otherorganisms like algae, fungus and bacteria.There are over 600 known carotenoids.They absorb blue light. Carotenoids servetwo key roles in plants and algae: they
absorb light energy for use inphotosynthesis, and they protectchlorophyll from photo damage photo-oxidation and are accessory, light-harvesting pigments and photoreceptors.
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EXTRACTION OF CAROTENOIDS
Carotenoids are extracted fromplant matter by mixing the plantmatter and water to obtain amixture of no greater than 10 Bx,crushing the mixture to obtain apulp and a serum, and extracting
the pulp to obtain a carotenoidscontaining plant oleoresin.
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Carotenoids are found in
vegetables
Zeaxanthin, a powerful carotenoids
antioxidant
CAROTENOIDS
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CHLOROPHYLL
Chlorophyll are green pigments. Theyoccur in all green plants and are localizedin plastids. Chlorophylls capture light
energy and convert it into chemical energy.They rarely occur outside of photosynthetictissue. Chlorophyll absorbs light moststrongly in the blue and red but poorly in
the green portions of the electromagneticspectrum, hence the green color ofchlorophyll-containing tissues such as plantleaves.
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EXTRACTION OF CHLOROPHYLL
Chlorophylls and carotenes do not dissolvevery well in water, but they dissolve like inhexane. The other compounds do not dissolvewell in hexane, but dissolve well in water.Water and hexane do not mix. If you mixthem together, the hexane will form a layer ontop of the water because hexane is less densethan water. The differences in compound
solubility in water and hexane, and the factthat water and hexane form layers, and wecan separate the chlorophylls and carotenesfrom the water-soluble compounds. Aftervigorous shaking to mix the layers
temporarily, you will allow them to separate.
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CHLOROPHYLL
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ANTHOCYANINS
Anthocyanins are water-soluble flavonoidspigments that appear red to blue, according topH. They occur in all tissues of higher plants,providing color in leaves, stems, roots,flowers, and fruits, though not always insufficient quantities to be noticeable.Anthocyanins are most visible in the petals offlowers, where they may make up as much as
30% of the dry weight of the tissue. In plantslike Tradescantia zebrina; the anthocyanincatches light that has passed through the leafand reflects it back towards regions bearingchlorophyll, in order to maximize the use of
available light.
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EXTRACTION OF ANTHOCYANINS
The undesirable materials contained inanthocyanin extracts are removed bysubjecting the extracts to ultra filtrationor dialysis to remove low molecular
weight components from the extracts.The extracts are also subjected to ionexchange to remove additional of theseundesirable constituents..
They are also enhanced with oxidative
stability and photo stability. Suchprocessed anthocyanin extracts may havehigher tinctoral powers, and thus theymay be suitable for coloring various foodproducts.
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The purple color of flower is due to the presence of anthocyanins.
ANTHOCYANINS
http://en.wikipedia.org/wiki/File:Orange_violet_pansies.jpg7/31/2019 Pigments Found in Vegetables and Its Extraction Technique
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BETALAINS
Betalains are a class of red and yellowin dole-derived pigments found in plantsof the Caryophyllales. They are mostoften noticeable in the petals of flowers,
but may color the fruits, leaves, stems,and roots of plants that contain them. Thedeep red color of beets, bougainvillea,amaranth, and many cacti results fromthe presence of betalain pigments.
Betalains may occur in any part of theplant, including the petals of flowers,fruits, leaves, stems, and roots.
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Betalains are
found in beetFlowers containingbetalains
BETALAINS
http://en.wikipedia.org/wiki/File:Cactus_in_Bloom_01.jpg7/31/2019 Pigments Found in Vegetables and Its Extraction Technique
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