الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
In the early nineteenth century the only colouring materials
available for dyeing were natural products. Many of the early
researches were directed to an understanding of these natural dyes.
When SYnthetic dyes were produced, interest in natural pigments
declined, although it never disappeared. During the past thirty
years there had been a tremendous interest in biochemistry and a
great variety of problems were studied vigorously.
This study was carried out to investigate the methods for
extraction and identification of natural pigments from some plants;
carotenoids from carrot (Daucus carota L.), anthocyanins from red
beet (Beta vulgaris), and lycopene from tomato (Solanum
tycopersicum, Mill). The effect of food processing on the stability
of these pigments was also studied.
The results obtained. can be summarized as follows :-
I- The Anthocyanins II-
The most efficient solvent in extracting red beet pigments was
water followed by methanol, ethanol and acetone, the yield of
pigments was 141.38,20.21, 19.65 and 0.51 mg/loo g sample
on dry weight basis, respectively.
2- The intense absorption of red beet pigments exhibited in the
visible region between 520 md S40 nm, maximum absorbance
was at 533 nm.
3- The pigment content of fresh, dehydrated and the of sulphited
before dehydration for red beet was 201.951’ 62.33 and 58.53
mg/loo g sample on dry -sis, respectively. The 10IIes of
pigment was 69.13 and 71.01, respectively.
4- The percentage of pigment retention after heated at 95°C for 15,
30, 45 and 60 min. at pH values of3, 5, 7 and 9 was : 56.36,
52.72, 18.18 and 21.81% at pH 3~52.84, 29.91, 20.93 and
18.940/0at pH 5~ 51.51,31.31,27.27 and 25.25% at pH 7 and
41.66,32.14,26.19 and 26.19% at pH 9, respectively.
5- A concentration of 0.01% L-ascorbic acid was most effective in
stabilizing red beet pigments, where the samples retained
98.58, 96.490/0 of the pigments after 5, 10 days of storage at
SoC in the dark, respectively, compared with the control where
was 98.00.and 61.18%.
6- No shifts in the absorption maximum of red beet juice were
noted between pH 3 - 7, below pH 4 and above pH 7 the
intensity of the absorbance decreased.
11-The Carotenoids:-
1- Acetone was the most efficient solvent in extracting of
carotenoids from carrot and tomato processing waste. The yield
of pigments was 0.52 and 0.34 mg/g sample on dry weight
using acetone for carotenoids from carrot and tomato
processing waste, respectively.
2- The intense absorption, of carotenoids from carrot exhibitin, in the
visible region between 420 and 480 om, maximum absorbance
was at 447 nm, The intense absorption of carotenoids, from
tomato exhibitin, in the visible region ~ 472 and 477 DID,
maximum absorbance was at 474 DDl.
3- The ~-carotene content of fiesh C8I’f0t,residue, blanched before
dehydrated, dehydration juice and sulphited, before dehydration
was 48.86, 44.85,26.50,20.70 and 14.53 mg/IOO g sample on
dry weight, respectively.
4- The lycopene 13-carotene contents of fresh fruit of tomato, juice
concentrated to 19.1% TSS at atmosphere pressure extracted by
CBM, juice concentrated to 19.5% TSS under vacuum
extracted by CBM, juice concentrated to 19.1% ISS at
atmosphere pressure extracted by IlBM, juice concentrated to
18.6% ISS under vacuum extracted by HBM, residue after
extraction by CBM and residue after extraction by HBM were
(21.35, 5.82); (12.98, 4.71); (17.01, 5.43); (65.41, 9.32);
(38.76, 8.62); (23.44, 4.62) and (54.54, 11.34) mg/IOO g
sample on dry weight, respectively.
5- The higher carotene was found in residue of carrot after
extraction of the juice where it was 86.46 mg/IOO g sample on
dry weight followed by blanched before dehydration.
dehydrated, juice and sulphited with dehydrated where was
75.32, 63.80, 45.87 and 43.80 mg/loo g sample on dry weight,
respectively, compared with the fresh carrot 104.24mg/l00 g
sample on dry weight.
6- The higher lycopene was found in the concentrated juice to
19.1% TSS at atmosphere pressure extracted by HBM followed
by residue after extraetillg the juice by HBM, juice
concentrated to 18.6% TSS extracted by HBM ueder vacuum,
residue after extraction the juice by CUM, juice concentrated to
19.5% TSS under vacuum extracted by CBM, residue after
extraction by CBM and juice ~ to 19.1%TSSat
atmosphere pressure extmeted by CBM.
III-Utilization of Natural Pigments as foodcolourants
1- the crude pigments extrract from red beet and yellow carrot were
added to artificial syrup fostrawberry and orange The results of
organoleptic evaluation was acceptable .
2- by study the stability of these pigments during storage the syrup at the
room tempreture, was found increasing in the absorbance during the frist
third week after that decrease in the absorbarce was found.
The carotenoids pigments was mor stable than red beet pigments at
room tempreture so the red beet pigments could be used in foods having
short shelf-life.