International Journal of Horticulture, 2017, Vol.7, No. 4, 26-32
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antioxidant measurement, is based on the absorbance measurement of the Cu (I) - neucoproine (Nc) chelate
formed as a result of the redox reaction of chain breaking antioxidants with the CUPRAC reagent, Cu (II) Nc
where absorbance is recorded at the maximal light absorption wavelength of 450 nm; thus this is an electron
transfer (ET) based method. The method described by Apak et al. 2006 was followed with minor modifications.
For CUPRAC analysis, 100 µl samples were mixed with 4ml of CUPRAC reagent (1 ml of neucoproine; 1 ml
ammonium acetate; 1 ml copper chloride and 1 ml distilled water; pH 7.4). Then the absorbance was recorded at
450 nm in spectrophotometer.
Similarly, FRAP (Ferric Reducing Ability of Plasma) was performed based on the procedure described by Benzie
and Strain (1999) with slight modifications. For this, 100 µl of the distilled sample was added to 3 ml of the FRAP
reagent and the reaction was monitored after 4 mins at 593 nm. The results were expressed as µmol Fe (II)/g fresh
weight of the sample.
Total phenolic contents were determined with Folin–Cicalteau method (Singleton and Rossi, 1965). Modifications
were done accordingly for the amount of sample present. Briefly, 0.50 ml extract was mixed with 2.5 ml of 1:10
diluted Folin–Cicalteau reagent. After 4 min, 2 ml of saturated sodium carbonate solution was added. The mixture
was incubated in dark for 2 h at room temperature. The resulting complex was measured at 760 nm at the
spectrophotometer for absorbance. Gallic acid was used as a standard for the calibration, and the results were
expressed as mg of Gallic acid equivalents (mg GAE) per 100 g fresh weight (FW) of sample.
2.3 Plant pigment content
Lycopene:
it is an important phytonutrient and consumers are becoming increasingly aware of the health benefits
of its consumption. For determination of Lycopene content 5 g of sample was taken and crushed with Acetone
until the residue becomes colourless. Filtrate was transferred in the separating funnel containing 20 ml of
petroleum ether. 2-3 drops of Sodium sulphate was added in separating funnel. Then 20 ml of petroleum ether was
added to make 2 separate phases. Lower phase was re extracted with additional petroleum ether till it became
colourless. Final volume was made up to 50 ml and absorbance was taken at 503 nm and 452 nm using petroleum
ether as blank.
Absorbance (1 unit) = 3.1206 µg Lycopene/ml
Statistical Analysis:
Statistical analyses were conducted using OP Stat software and SPSS. The variability estimates were worked out
through Analysis of Variance (ANOVA) in a completely randomized Design, while correlation coefficients were
determined by co variance and variance between the traits.
3 Results and Discussion
Phenolic compounds are widely distributed in fruits, vegetables and cereals. Plants vary widely both in their
phenolic composition and content which are controlled both genetically and environmentally (Awika and Rooney,
2004). These components have received considerable attention due to their antioxidant activities and free radical
scavenging capacity, which potentially have beneficial implications in human health (Imeh and Khokar, 2002).
The Analysis of Variance revealed highly significant difference amongst the flower species for all the
Phytochemicals under study, almost all the species contained good amount of antioxidants, Phenol content
ranging CUPRAC 4.98→32.33 µM trolox/ g and FRAP 0.22→2.07 µM trolox/ g, while TPC varied from 973.59
→ 2282.54 µg Gallic acid/ gfw. Vinca Red flower exhibited highest antioxidant capacity viz. CUPRAC 32.33
µmol trolox/g followed by Vinca Pink 30.46 while, least was observed in Gomphrina.4.983 µmol while its
1000
Sample
of
Weight
100
dilution
made
Volume
nm 503 at OD
3.1206
sample)
g 100 in
(mg
Lycopene
1000
Sample
of
Weight
100 410 9.31 nm 452 at OD
g)
/100 μg(
Carotene
-β
