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Ph.D.
(Science)
EXTRACTION, CHARACTERIZATION AND APPLICATIONS OF
PIGMENTS FROM DIFFERENT PLANTS AS BIOCOLOURS

Ph.D. Scholar : Patel Mrunali Rajendrakumar
Research Supervisor : Dr. Priti Patel

Regi. No.: 20276481002
Abstract :
Pigments are chemical compounds that absorb light in the wavelength range of the
visible region. Effluents containing synthetic pigments pose a significant threat to water
streams and the environment due to their synthetic origin and intricate molecular
compositions, which hinder their biodegradability. This emphasizes the need for exploring
alternative sources of environmentally safe pigments. The current situation focuses more
on the prodigious diversity of natural pigment supplies for use in food products,
pharmaceuticals, and textile materials rather than their synthetic counterparts to
preserve and prolong hu- man health. The stability of pigments is influenced by several
physicochemical factors, including the pH of the substance, light exposure, temperature
and complexation with other compounds in the matrix, which may cause loss or colour
variation. The present study was conducted to develop an eco-friendly biocolour with
effective stability. The Rubus fruticosus L., Bixa orellana L, Adhatoda vasica L. and Beta
vulgaris L. were selected for the extraction, purification and characterization of pigments
for effective application in a different field. Different solvent systems were used to extract
the selected plant, including Methanol, Acetone, Chloroform, Petroleum ether,
Dichloromethane, Ethyl acetate, Ethanol, Aqueous methanol, Aqueous ethanol and
Aqueous ace- tone. Preliminary phytochemical examination of all extracts revealed
positive results for major phytoconstituents such as phenol, flavonoid, alkaloid, and
tannin. The crude plant extracts were purified by flash column chromatogra- phy using
different solvents as mobile phase and alumina as adsorbent. The separation of pigment
was determined by thin-layer chromatography. The pigments were scanned in the
wavelength ranging from 200-800 nm using a UV spectrophotometer, and absorbance
value was used to quantify the pigment concentration using the Lambert beer law
equation. HPTLC fingerprinting was conducted to determine the presence of carotenoid,
anthocyanin, betalain and chlorophyll compounds. The functional groups of various plant
pigments were determined using FTIR. The molecular weight, structure, identity, and
quantity of specific components were determined through the analysis of LCMS.
Encapsulation, co-pigmentation and entrapment methods were used to increase the
stability of pigments. The antioxidant activity of pigments was performed by DPPH free
radical scavenging assay and also observed antibacterial activity by agar well diffusion

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