3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
P79 FATTy ACIDS DISTRIbuTION IN ThE LIPID
FRACTIONS OF CAleNDulA OffiCiNAlis L.
SEEDS OIL
ADeLA PInTEA, FRAnCISC VASILE DULF,
COnSTAnTIn BELE and SAnDA AnDREI
University of Agricultural Sciences and Veterinary Medicine,
Manastur 3–5, 400372, Cluj-Napoca, Romania,
apintea@usamvcluj.ro
Introduction
Plant oils are important renewable resources used as
food; feed or as industrial feedstocks 1 . The Calendula seeds
oil is currently considered a potential oilseed crop with industrial
or other functionalities. It is characterized by a high
content of the unusual conjugated octadecatrienoic acid –
calendic acid (18 : 3c 8t, 10t, 12c) and some other conjugated
isomers, which give special chemical and physical properties
2 . There is an increasing interest for conjugated fatty acids
since some of them were proved to have anticancer and lipidlowering
effects 3,4 . Calendic acids have inhibitory effect on
human colon cancer cells, decrease body fat content and have
hepatoprotective effect 5,6,7 . Here we present the fatty acids
distribution in the lipid fractions of Calendula seeds and the
fatty acids variation during seeds maturation.
Experimental
E x t r a c t i o n a n d L i p i d F r a c t i o n a t i o n
Total lipids were extracted using Folch method 8 . neutral
lipids were separated by TLC with a solvent mixture
of hexane: ethyl ether: acetic acid (95 : 15 : 1). Polar lipids
were scratched, extracted and separated according to Heape
method 9 .
Fatty Acids Analysis
The total lipid extract and the lipid fractions were transesterified
with BF3/methanol. The methyl esters of fatty
acids (FAME) were dissolved in hexane and injected for GC
analysis. A Shimadzu GC 17A with FID detector and a Crompack
Silica 25 MXO capillary column (25 m × 0.25 mm i.d.,
film thickness 0.25 µm) was used. The temperature program
was: 5 min at 70°C, 4 °C/min to 235 °C (hold 5 min). The
injector temperature was 260 °C and the detector temperature
– 260˚C. The carrier gas was helium.
S t e r o l s A n a l y s i s
A part of total lipid extract was saponified by refluxing
with 1M KOH ethanol/water (8 : 2, v/v) solution for 1 h. The
unsaponifiables, containing total sterols, were then extracted
first with petroleum ether and diethyl ether. The ether phases
were combined, washed and evaporated to dryness.
The sterols were derivatized trimethyl silyl ether
(TMS) derivatives and separated on fused silica capillary
column coated with 5% phenyl/95% dimethylpolysiloxane
(30 m × 0.25 mm i.d., film thickness 0.25 µm; Rtx-5; Restek
Corporation, Bellefonte, PA, USA) and using the same
s749
GC system mentioned above. The temperature program was:
5 min at 200 °C, 10 °C/min to 300 °C (hold 20 min).
FAME and sterols peaks were identified by comparison
of their retention times with those of commercially available
standards (Sigma). All extractions and GC-FID runs were
performed in triplicate and mean values were calculated.
Results
Calendula seeds were analyzed in different stages
during their maturation, seeds collected: immediately after
flower drops (0), one week after (1) and two weeks after
flower drops. (2). The fatty acids composition is presented
in Fig. 1. The calendic acid represents – 8.62 % at first stage,
it increased at 26.6 % one week after and reached the maximum
content of 53 % in the mature seeds. The increasing of
18 : 3c content occurs in the same time with the fast decreasing
of linoleic acid and a slow decrease of oleic acid, while
stearic and linolenic acid remain almost to the same values
during seeds maturation.
% of total fatty acids
60%
50%
40%
30%
20%
10%
0%
0
14:0
16:0
week 1
week 2
18:0
18:1 (9c)
18:1 (11c)
18:2
18:3
18:3c
Fatty acid
20:0
20:1
Triacylglycerols (TAG) contain the highest amount
of conjugated fatty acids (33 %), while in diacylglycerols
(DAG) and monoacylglycerols (MAG) contain less than
10 % (data not shown). The polar lipid (PL) fraction is highly
unsaturated, with more than 65 % of linoleic acid. Conjugated
acids are present in polar lipids fraction fact which can
22:0
Fig. 1. Fatty acids variation during seeds maturation
Table I
Fatty acids distribution in lipid fractions
Fatty acid TAG SE PL
Miristic 14 : 0 0.75 1.58 0.34
Palmitic 16 : 0 6.41 21.25 12.88
Stearic 18 : 0 2.47 2.65 2.84
Oleic 18 : 1 (9c) 7.33 10.02 7.21
Linoleic 18 : 2 (9c, 12c) 47.2 47.8 65.56
α-linolenic 18 : 3
(9c, 12c, 15c)
1.17 3.15 3.13
Conjugated acids 18 : 3c 33.33 11.5 6.56
Arachidic 20 : 0 0.65 2.25 0.31
Gadoleic 20 : 1 (9c) 0.49 0.65 0.30