MSc

The present study entitled
was undertaken with the objective of studying the physico-chemical,
phytochemical and antioxidant properties, anti-nutritional factors and bioactive compounds
of selected ornamental flowers viz., red hibiscus (both single and double), I. coccinea, I.
singaporensis, R. damascena, marigold (T. erecta and T. patula), N. nucifera, N. rubra and
C. sulphureus.
The physico-chemical properties such as moisture, protein, fat, fibre, vitamin C,
total ash and mineral contents (sodium, magnesium, calcium, iron, phosphorus and
potassium) of the selected flowers were ascertained. Moisture content ranged from 45.51
(C. sulphureus) to 87.53 per cent (N. rubra). Protein content ranged between 2.03 (I.
singaporensis) to 11.79 per cent (T. patula). Fat content of the ornamental flowers varied
from 0.77 (single typed red hibiscus) to 10.77 per cent (T. erecta). The mean fibre content
varied between 9.66 (single typed red hibiscus) to 20.00 (N. nucifera) per cent in the
flowers. Ascorbic acid content of the ornamental flowers was observed to be in the range
of 58.93 (T. patula) to 154.13 mg/100 g of DW (R. damascena). Total ash content of
ornamental flowers studied ranged from 2.83 (N. rubra and C. sulphureus) to 10.00 per
cent (N. nucifera). Sodium content of ornamental flowers ranged from 13.83 (double typed
red hibiscus) to 16.23 mg/100 g of dry weight (single typed red hibiscus). Magnesium
content varied from 5.61 (T. erecta) to 12.89 mg/100 g (single typed red hibiscus) in the
flowers studied. Calcium content was in the range of 6.84 (R. damascena) to 31.24 mg per
100 g of DW (N. nucifera). Iron content of flowers ranged from 0.43 (R. damascena) to
2.31 mg/100 g (T. patula). Phosphorus content of the ornamental flowers ranged from 7.80
(I. coccinea) to 22.40 mg/100 g DW (T. patula). The mean potassium content varied from
40.86 (R. damascena) to 104.66 mg/100 g (N. nucifera).
Phytochemicals in ornamental flowers such as carotenoids, anthocyanins, total
flavonoids and phenols were also estimated. Total carotenoid content of the ornamental
flowers ranged from 0.20 (R. damascena) to 8.13 mg per 100 g of DW (T. erecta).
Anthocyanin content of ornamental flowers was in the range of 6.56 (T. erecta) to 187.43
mg/100 g (R. damascena). Flavonoid content ranged between 33.33 (N. nucifera) to 104.16
mg/100 g of DW (T. erecta). Phenol content of the ornamental flowers varied between 6.52
(R. damascena) to 49.80 mg/100 g of DW (C. sulphureus).
Quantitative estimation of anti-nutritional factors such as tannin, oxalates and
nitrates were done in the selected ornamental flowers. Tannin content of ornamental
flowers ranged between 8.50 (N. nucifera) to 53.10 mg/100 g (R. damascena). Oxalate
content was found to vary from 23.23 (N. nucifera) to 687.30 mg per 100 g of DW (single
typed red hibiscus) of the flowers. Nitrate content varied between 6.30 (T. erecta) to 201.03
mg per 100 g DW (C. sulphureus) of the flowers.
Free radical scavenging activity of the ten ornamental flowers was studied using
DPPH and ABTS assays. Value of the DPPH assay ranged from 38.26 (R. damascena)
to 269.32 µg/ml (double typed red hibiscus). ABTS radical scavenging activity ranged from
47.92 (R. damascena) to 738.60 µg/ml (T. patula).
Estimation of physicochemical, phytochemical, anti-nutritional and antioxidant
properties and bioactive compounds of the selected ornamental flowers revealed that the
petals of N. nucifera recorded maximum fibre (20.00 %), total ash (10.00 %), magnesium
(11.49 mg), calcium (31.24 mg) and potassium (104.66 mg) contents per 100 g DW with
minimum anti-nutritional constituents such as tannins (8.50 mg) and oxalates (23.23 mg).
T. patula recorded highest protein (11.79 %), fat (10.43 mg), sodium (15.30 mg),
magnesium (10.61 mg), iron (2.31 mg), phosphorus (22.40 mg), potassium (79.40 mg) and
flavonoid (101.00 mg) contents per 100 g DW but with lowest antioxidant properties in
DPPH (257.57 µg/ml) ABTS (738.60 µg/ml) assay. Highest content of fat (10.77 mg),
sodium (15.86 mg), carotenoids (8.13 mg) and flavonoids (104.16 mg) with lowest nitrate
(6.30 mg) values per 100 g DW were noticed in T. erecta. R. damascena registered
maximum sodium (15.23 mg), vitamin C (154.13 mg), anthocyanins (187.43 mg/100 g
DW) and antioxidant properties in DPPH (38.26 µg/ml) as well as ABTS (47.92 µg/ml)
assay, but having high tannin content (53.10 mg) per 100 g DW. H. rosa-sinensis (single)
showed highest quantity of sodium (16.23 mg), magnesium (12.89 mg) and anthocyanins
(184.82 mg) but with maximum oxalate content (687.30 mg) per 100 g DW. H. rosasinensis (double) showed highest quantity of magnesium (11.30 mg) and anthocyanins
(186.63 mg) per 100 g DW but with least antioxidant property (269.32 µg/ml) as revealed
in the DPPH assay. Petals of N. rubra registered maximum moisture content (87.53 %) and
antioxidant properties in DPPH assay (47.04 µg/ml) with lowest nitrate (7.73 g) content
per 100 g of DW. Cosmos recorded highest quantity of sodium (14.80 mg), iron (1.85 mg)
and phenols (49.80 mg) but with maximum quantity nitrates (201.03 mg) per 100 g DW.
I. coccinea recorded maximum sodium content (15.43 mg/100 g DW) among the
ornamental flowers tested.
GC-MS analysis of ten ornamental flowers revealed the various compounds present
in its methanol extracts. Flowers of I. singaporensis contained more compounds (18)
compared to rest of the flowers. The most abundant compound in I. singaporensis was (1R,
3R, 4R, 5R)-(-)-Quinic acid (70.60 %) whereas in I. coccinea, it was stigmast-5-en-3-ol,
3.beta (45.33 %). The most abundant compound in C. sulphureus was benzene, 1-chloro4-methoxy- (34.22 %) while in T. erecta -amyrin (42.37 %). Damask rose and red
water lily contained eight compounds each. The most prevalent compound in Damask rose
was 1, 2-benzenedicarboxylic acid (37.74 %) whereas in red water lily, it was heptacosane
(44.27 %). Flowers of both single and double petalled hibiscus were found to contain seven
-amyrin (83.41 %) was found in single petalled
red hibiscus while 9-octadecenoic acid, 12-(acetyloxy) (25.56 %) and 9-octadecadienoic
acid (25.51 %) were the most abundant in double petalled red hibiscus. Six different
compounds were found in methanol extracts of both sacred lotus and T. patula. Most
abundant compounds in the flower extracts of lotus were 9, 12, octadecadien-1-ol (34.74
%) and 9-octadecenoic acid, 12-(acetyloxy)-, methyl ester, [r-(z)]- (22.70 %). The
predominant compound in T. patula was vitamin E (59.67 %).
The present study revealed that the selected ornamental flowers are having
nutritional value with high antioxidant properties and low anti-nutritional contents. The
GC-MS analysis of ornamental flowers showed that they contained a variety of beneficial
compounds that can act as nematicide, pesticide, anti-cancerous, antimicrobial, antifungal,
antioxidant and anti-inflammatory agents. Some compounds identified in this study were
reported to have anti-xanthine oxidase and anti-tyrosinase potentials. The compounds
identified in the flowers could be used for the development of novel drugs also.