A comparative study on fatty acid content of main organs and lipid classes of land snails Assyriella Escheriana and Assyriella Guttata distributed in southeastern Anatolia

Abstract

In the present work, main organs (digestive gland, cephalopedal, gonad and mantle) and lipid classes (total, neutral and phospholipid) of land snails Assyriella escheriana and Assyriella gutta-ta from southeastern Anatolia were examined for their fatty acids. the major components detected in both of the species were c16:0, c18:0, c18:1ω9, c18:2ω6, c18:3ω3, c20:2ω6 and c20:4ω6. c18:2ω6 was identified as the primary fatty acid ranging from17.07% to 28.12% in A. guttata and 18.02% to 27.43% in A. escheriana. the proportions of c20:4ω6 modified to form prostaglandins that are directly involved in regulation of reproduction, ranged from10.01% to 20.30% in A. es-cheriana and 11.05 % to 16.58% in A. guttata. taking into consideration that ΣPUFA levels were always higher than ΣsFA and ΣMUFA levels in all treatments of both species. this was an expected finding for the snails collected during the breeding season because PUFA plays an important role as precursors for signal-transduction involved in the regulation of mating and reproduction. A significant amount of c20:2ω6 was concentrated in the cephalopedal of A. guttata (13.42%) and A. escheriana (14.93%). Probably, cephalopedal serves as a storage organ of this component. consequently , the findings revealed that the snail's fatty acid profiles were qualitatively similar, but quantitatively there were some differences. Most important of all, tissues of the snails were good source of essential fatty acids (c18:2ω6 and c18:3ω3) and PUFA, particularly omega 6 fatty acids.

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Ital. J. Food Sci., vol. 27 - 2015 1
- Keywords: Fatty acids, Assyriella escheriana, Assyriella guttata, organs, lipid classes -
A COMPARATIVE STUDY ON FATTY ACID CONTENT
OF MAIN ORGANS AND LIPID CLASSES
OF LAND SNAILS ASSYRIELLA ESCHERIANA
AND ASSYRIELLA GUTTATA DISTRIBUTED
IN SOUTHEASTERN ANATOLIA
I
.
. EKI
.
N
Sirnak University, Engineering Faculty, Department of Energy Systems Engineering, Sirnak,
Turkey
ekinihsan@gmail.com
ABSTRACT
In the present work, main organs (digestive gland, cephalopedal, gonad and mantle) and lipid
classes (total, neutral and phospholipid) of land snails Assyriella escheriana and Assyriella gutta-
ta from southeastern Anatolia were examined for their fatty acids. The major components detect-
ed in both of the species were C16:0, C18:0, C18:1ω9, C18:2ω6, C18:3ω3, C20:2ω6 and C20:4ω6.
C18:2ω6 was identified as the primary fatty acid ranging from17.07% to 28.12% in A. guttata and
18.02% to 27.43% in A. escheriana. The proportions of C20:4ω6 modified to form prostaglandins
that are directly involved in regulation of reproduction, ranged from10.01% to 20.30% in A. es-
cheriana and 11.05 % to 16.58% in A. guttata. Taking into consideration that ΣPUFA levels were
always higher than ΣSFA and ΣMUFA levels in all treatments of both species. This was an expect-
ed finding for the snails collected during the breeding season because PUFA plays an important
role as precursors for signal-transduction involved in the regulation of mating and reproduction.
A significant amount of C20:2ω6 was concentrated in the cephalopedal of A. guttata (13.42%) and
A. escheriana (14.93%). Probably, cephalopedal serves as a storage organ of this component. Con-
sequently, the findings revealed that the snail’s fatty acid profiles were qualitatively similar, but
quantitatively there were some differences. Most important of all, tissues of the snails were good
source of essential fatty acids (C18:2ω6 and C18:3ω3) and PUFA, particularly omega 6 fatty acids.

2 Ital. J. Food Sci., vol. 27 - 2015
INTRODUCTION
Assyriella escheriana and Assyriella gutta-
ta (endemic to southeastern Turkey and North
Iraq) species are common in moist and calcifer-
ous habitats of southeastern Turkey. Although
they are not eaten and commercially not export-
ed, they are big enough and fleshy as much as
edible relatives Helix lucorum, Eobania vermicu-
lata dwelling in the same region. The fatty acid
distribution of a large number of commercial-
ly important marine and freshwater molluscs
have been reported and reviewed in varying de-
grees of details (ACKMAN, 2000; KARAKOLTSID-
IS et al., 1995). Lipids from marine, freshwater
and edible land molluscs are more extensive-
ly studied (ÖZOĞUL et al., 2005; MILINSK et al.,
2006; MILETIC et al., 1991; RAKSHIT et al., 1997;
EKİN and BAŞHAN, 2010; EKİN et al., 2012, 2014)
than those from nonedible terrestrial members.
Nevertheless, nonedible land snails deserve spe-
cial attention from the point of their evolution-
al relationship, roles in food chain, nutritional
value, taxonomic and possible benefits in cos-
metic, medicine and biochemistry. Nutritional,
food chain and taxonomic studies are important
in understanding interrelationship in marine,
freshwater and terrestrial environment, how-
ever for the southeastern Anatolia; quite little
data were available in the literature on edible
and nonedible land snails.
A. escheriana and A. guttata species whose
edible relatives including Helix aspersa, H. as-
emnis, H. cincta and H. lucorum, Theba pisana,
Eobania vermiculata and Cantareus apertus, liv-
ing in Turkey (YILDIRIM, 2004), can deserve more
detailed studies. Many snail farms are being
established in some countries in order to pro-
duce good quality snails for consumption and
export. So, it seemed useful to make a compar-
ative study of similarity and differences in bio-
chemical and nutritional composition of edible
and nonedible snail species.
A comparative biochemical study on fatty acid
composition of snails belonging to same classes
but living in different habitats is hoped to pro-
vide an insight into the adaptive capabilities and
influence of the environment on their fatty acid
distribution. This paper discusses the fatty acid
distribution of main organs and lipid classes in
two same genus gastropods from southeastern
Anatolia, as data which is hoped to be basic to
further comparative biochemical, nutritional,
taxonomic and evolutionary studies.
MATERIALS AND METHODS
Sample collection and preparation
Fifteen adult A. escheriana species were col-
lected from a woodland near Tizyan (Elmabahçe)
village, 20 km north of Mardin (N 37° 49’ / E
40° 68’) at an altitude of 985 m and fifteen adult
endemic Assyriella guttata species were collect-
ed from stony and rocky region of Diyarbakır
city walls (N 37° 55.2’ / E 40° 13.8’) at an alti-
tude 675 m. Both species were collected in April
2012. Similar size (length: 4 ± 0.60 cm, wet flesh
weight: 13 ± 0.50 g) snail species were sampled
for lipid analyses. The snails’ shells were re-
moved and divided into seven groups (digestive
gland, cephalopedal, gonad, mantle, total lipid,
neutral lipid and phospholipid) and their organs
were dissected out. Then, tissues of each exper-
imental set were conditioned in polyethylene
bags and kept at -80°C until chemical analysis.
Extraction of fatty acids and GC analysis
Digestive gland, gonad, mantle, cephalopedal
and whole body samples were homogenized in
chloroform/ methanol (2:1, v/v) solution in order
to extract total body lipids (BLIGH and DYER,
1959). Organ’s lipid, total lipid, phospholipid and
neutral lipid fractions were obtained according
to the method of STANLEY-SAMUELSON and
DADD, 1983.
Fatty acids methyl esters (FAMEs) were pro-
vided by capillary gas chromatography (GC) us-
ing Hewlett Packard (Wilmington, DE) gas chro-
matograph (model 6890), a DB-23 capillary col-
umn (60 m × 0.25 mm i.d. × 0.250 m film thick-
ness and Bonded 50% cyanopropyl) (J & W Sci-
entific, Folsom, CA), a flame ionization detec-
tor, and Hewlett-Packard ChemStation software.
The injection port and the detector temperatures
were 270°C and 280°C, respectively. The split ra-
tio was 1:20. The flow rates of compressed air
and hydrogen were 300 ml/min, 30 ml/min,
respectively. Carrier gas was helium (2.8 ml/
min). The oven temperature was programmed
at a rate of 6.5°C/min from 130°C (1 min hold)
to 170°C, then increased at a rate of 2.75°C/
min to a 215°C, then again increased at a rate
of 40°C/min to 230°C, was held for 12 minutes.
Each tissue fatty acids percentages and spectra
of FAMEs are obtained by HP 3365 ChemSta-
tion computer program. FAMEs existence and
retention times were determined by comparing
the spectra of authentic standards (Sigma-Al-
drich Chemicals). Individual FAME was identi-
fied by comparisons with the chromatographic
behaviors of authentic standards.
Statistical analyses
The results were expressed as mean values
± SD (Standard Deviation). All analytical deter-
minations were performed in triplicate and the
mean values were reported. The analyses were
performed using a commercial statistical pro-
gram (SPSS 20). The percentages of fatty acid
were compared by ANOVA variance analysis with
5% significance level. TUKEY’s test was used for
cooperation of average values.

Ital. J. Food Sci., vol. 27 - 2015 3
RESULTS
In both snails, C16:0, C18:0, C18:1ω9,
C18:2ω6, C18:3ω3, C20:2ω6 and C20:4ω6 were
presented as predominant fatty acids. Of the de-
tected fatty acids, amount of C18:2ω6 was the
highest in all analyses from both A. escheriana
and A. guttata (Tables 1 and 2).
Compared to the fatty acids of the species’
organs, in A. escheriana, highest level of C16:0
(11.81%) and C18:1ω9 (20.56%) were present-
ed in the gonad; C18:0 (15.18%) and C20:2ω6
(14.93%) were in the cephalopedal; C18:2ω6
(26.67%) and C18:3ω3 (7.36%) were in the di-
gestive gland and C20:4ω6 (17.86%) was in the
mantle (Table 1). In A. guttata highest level of
C16:0 (9.72%), C18:1ω9 (19.65%) and C18:3ω3
(4.76%) were found in the gonad; C18:0 (15.21%)
and C20:4ω6 (15.68%) were in the mantle;
C18:2ω6 (28.12%) was in the digestive gland and
C20:2ω6 (13.42%) was in the cephalopedal (Ta-
ble 2). On the other hand, the fatty acids from
lipid classes of the species showed some differ-
ences, in A. escheriana, highest level of C16:0
(10.16%) and C18:3ω3 (8.42%) were identi-
fied in the total lipid; C18:0 (11.21%), C18:1ω9
(13.33%) and C20:2ω6 (11.79%) were in the
neutral lipid; C18:2ω6 (27.43%) and C20:4ω6
(20.30%) were in the phospholipid (Table 1). In
A. guttata, highest level of C16:0 (9.61%) and
C20:4ω6 (16.58%) were presented in the total
lipid; C18:0 (13.01%), C20:2ω6 (10.99%) and
C18:1ω9 (16.03%) were in the neutral lipid;
C18:2ω6 (22.34%) and C18:3ω3 (10.70%) were
in the phospholipid (Table 2).
In all treatments, results showed that concen-
tration of ω6 (omega 6) always higher than con-
centration of ω3 (omega 3) family fatty acids. In
A. escheriana, the ratio of Σω6 / Σω3 was 4.86,
6.71, 5.44 and 7.66 in the digestive gland, ceph-
alopedal, gonad and mantle, respectively (Table
1). In A. guttata it was 5.13, 8.49, 5.29 and 4.84
in the digestive gland, cephalopedal, gonad and
mantle, respectively (Table 2). Additionally, Σω6
/ Σω3 ratio were 5.19 in the total lipid, 4.86 in
the neutral lipid and 6.59 in the phospholipid of
A. escheriana (Table 1). This ratio was observed
4.00 in the total lipid, 3.91 in the neutral lipid
Table 1 - Fatty acid profile of main organs total lipid and lipid classes from Assyriella escheriana.
Fatty acid compositions of total lipid Fatty acid compositions
from A. escheriana organs of lipid classes from A. escheriana
Fatty Acids Digestive gland Cephalopedal Gonad Mantle Total lipid Neutral lipid Phospholipid
(Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)**
C10:0 0.12±0.02a 0.05±0.01b 0.08±0.02ab - 0.02±0.01c 0.04±0.01b 0.10±0.02a
C12:0 0.03±0.01a 0.07±0.02b 0.04±0.01a 0.05±0.01ab 0.06±0.01ab 0.07±0.01b 0.09±0.02b
C13:0 0.08±0.01a - 0.09±0.02a 0.03±0.01b 0.10±0.02a - 0.05±0.01b
C14:0 1.31±0.11a 0.29±0.04b 0.49±0.06c 0.81±0.09d 0.58±0.07cd 0.73±0.08d 0.44±0.06c
C15:0 0.39±0.04a 0.19±0.03b 0.23±0.04b 0.30±0.04a 0.23±0.04b 0.68±0.06c 0.37±0.04a
C16:0 8.41±0.67a 9.33±0.83a 11.81±1.03b 9.72±0.80a 10.16±0.91ab 9.99±0.82a 7.05±0.61c
C17:0 1.63±0.14a 2.03±0.15b 0.87±0.09c 2.48±0.25b 1.60±0.14a 1.11±0.10d 1.08±0.09d
C18:0 10.66±0.84a 15.18±1.05b 10.11±0.79a 11.06±0.87a 10.30±0.73a 11.21±0.91a 9.67±0.69a
C14:1ω9 0.45±0.05a 0.90±0.10b 0.32±0.04a - 0.15±0.03c - 0.07±0.02c
C16:1ω7 0.88±0.09a 0.63±0.07b 1.07±0.09c 0.99±0.08c 1.80±0.16d 1.02±0.12c 0.98±0.09c
C18:1ω9 19.50±1.41a 15.20±1.30b 20.56±1.52a 14.53±1.21b 12.68±1.10c 13.33±1.11c 13.04±1.10c
C20:1ω9 0.60±0.05a 0.75±0.07a 0.76±0.06a 0.46±0.04b 0.34±0.04b 0.64±0.05a 0.96±0.08c
C22:1ω9 0.03±0.01a 0.05±0.01a 0.12±0.03b 0.14±0.03b - 0.06±0.01a 0.18±0.03b
C18:2ω6 26.67±1.72a 18.02±1.41b 24.42±1.55c 22.32±1.49d 20.45±1.39e 19.77±1.43e 27.43±1.66a
C18:3ω3 7.36±0.69a 1.74±0.15b 5.66±0.44c 3.96±0.29d 8.42±0.71a 8.00±0.70a 6.60±0.51e
C20:2ω6 7.35±0.68a 14.93±1.26b 8.51±0.75a 10.91±0.96c 10.72±0.94c 11.79±1.01d 7.25±0.64a
C20:3ω6 1.41±0.12a 0.66±0.05b 1.42±0.13a 0.88±0.07b 0.73±0.06b 0.88±0.09b 1.30±0.10a
C20:4ω6 11.14±1.04a 14.37±1.12b 10.01±0.94a 17.86±1.27c 19.51±1.39d 17.12±1.25c 20.30±1.44d
C20:5ω3 1.07±0.09a 4.11±0.31b 1.90±0.13a 1.91±0.15a 1.03±0.14a 1.75±0.15a 1.00±0.09a
C22:2ω6 0.09±0.02a 0.22±0.03b - 0.06±0.01a - - 0.05±0.01a
C22:5ω6 0.21±0.03a 0.45±0.04b 1.05±0.08c 0.73±0.05d 0.89±0.08d 0.78±0.06d 1.02±0.10c
C22:6ω3 1.22±0.12a 1.40±0.13a 0.78±0.06b 1.02±0.09a 0.63±0.05b 0.60±0.05b 1.10±0.10a
Σω6 / Σω3 4.86 6.71 5.44 7.66 5.19 4.86 6.59
ΣSFA 22.63±1.50a 27.14±1.63b 23.72±1.56a 24.45±1.58c 23.05±1.49a 23.83±1.51a 18.85±1.41d
ΣMUFA 21.46±1.47a 17.53±1.25b 22.83±1.44a 16.12±1.23b 14.97±1.17c 15.05±1.19c 15.23±1.18c
ΣPUFA 56.52±2.28a 55.90±2.27a 53.75±2.20b 59.65±2.48c 62.38±2.55d 60.69±2.52c 66.05±2.61e
Results expressed as percentage of total fatty acids methyl esters.
*Values are means ± S.D (Standard Deviation) for three samples of triplicate analysis.
**Means followed by different letters in the same line are signicantly different (P < 0.05) by Tukey’s test.
SFA: Saturated Fatty Acids, MUFA: Monounsaturated Fatty Acids, PUFA: Polyunsaturated Fatty Acids,
Σω
6: Total of omega 6 fatty acids,
Σω
3: Total of ome-
ga 3 fatty acid.

4 Ital. J. Food Sci., vol. 27 - 2015
and 2.28 in the phospholipid of A. guttata (Ta-
ble 2). These high levels of Σω6/Σω3 were mostly
on account of higher concentration of C18:2ω6
and C20:4ω6.
The most notable result was significantly high
level of ΣPUFA (total polyunsaturated fatty ac-
ids) and low level of ΣSFA (total saturated fatty
acids) and ΣMUFA (total monounsaturated fat-
ty acids) in all organs and lipid classes. Among
the organs, the maximum level of ΣPUFA was ob-
tained in the mantle (59.65%) of A. escheriana
(Table 1) and in the digestive gland (60.17%) of
A. guttata (Table 2). On the other hand, maxi-
mum level of ΣSFA was detected in the cephalo-
pedal (27.14%) of A. escheriana (Table 1) and in
the mantle (28.76%) of A. guttata (Table 2). The
level of ΣMUFA in all treatments was found sig-
nificantly lower than ΣPUFA and ΣSFA. It ranged
from 16.12% to 21.46% in A. escheriana and
16.44% to 21.63% in A. guttata. It was notewor-
thy that, the amount of ΣPUFA was significant-
ly high; 66.05% in the phospholipid, 62.38% in
the total lipid and 60.69% in the neutral lipid of
A. escheriana (Table 1) and 66.23% in the phos-
Table 2 - Fatty acid profile of main organs total lipid and lipid classes from Assyriella guttata.
Fatty acid compositions Fatty acid compositions
of total lipid from A. guttata organs of lipid classes from A. guttata
Fatty Acids Digestive gland Cephalopedal Gonad Mantle Total lipid Neutral lipid Phospholipid
(Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)** (Mean*±S.D.)**
C10:0 - 0.09±0.02a 0.12±0.03b 0.08±0.02a 0.07±0.02a 0.24±0.04c -
C12:0 0.70±0.08a - 0.87±0.10b 0.95±0.10b 0.60±0.07a 0.77±0.08ab -
C13:0 1.35±0.13a 1.16±0.12a 1.09±0.10a 1.30±0.12a 1.11±0.12a 1.05±0.11a 0.09±0.02b
C14:0 2.22±0.21a 1.47±0.16b 1.10±0.12a 1.78±0.19ab 1.85±0.20ab 2.03±0.21a 0.64±0.08c
C15:0 0.99±0.10a 1.02±0.11a 1.32±0.14a 1.44±0.15a 1.32±0.14a 1.82±0.20b 0.47±0.07c
C16:0 7.01±0.64a 9.01±0.72b 9.72±0.78b 7.82±0.66ab 9.61±0.73b 7.78±0.58ab 5.92±0.41c
C17:0 0.13±0.03a 0.33±0.06b 0.16±0.03a 0.18±0.04a 0.06±0.02c 0.09±0.02ac 0.08±0.02ac
C18:0 8.62±0.64a 13.58±0.91b 10.11±0.74c 15.21±1.04d 12.33±0.86bc 13.01±0.94b 8.76±0.59a
C14:1ω9 0.35 ±0.05a 0.21±0.04a 0.23 ±0.04a - 0.25±0.04a - 0.67±0.06b
C16:1ω7 1.34±0.12a 0.77±0.09b 0.87±0.10b 0.89±0.16b 0.40±0.03c 0.44±0.03c 0.68±0.07bc
C18:1ω9 17.42±1.32a 16.32±1.25a 19.65±1.49b 15.35±1.21c 15.06±1.21c 16.03±1.30a 16.02±1.29a
C20:1ω9 0.60±0.07a 0.75±0.08a 0.67±0.06a 0.16±0.03b 0.43±0.05c 0.31±0.05c 0.69±0.08a
C22:1ω9 - - 0.21±0.04a 0.04±0.01b - 0.09±0.02b 0.08±0.02b
C18:2ω6 28.12±1.75a 21.60±1.48b 24.24±1.55c 20.23±1.45b 18.54±1.38d 17.07±1.35d 22.34±1.65a
C18:3ω3 4.06±0.31a 2.43±0.19b 4.76±0.44a 2.90±0.32a 6.24±0.51c 7.01±0.57c 10.70±0.41ac
C20:2ω6 6.14±0.53a 13.42±1.16b 9.15±1.02c 8.81±0.96c 9.22±1.04c 10.99±1.16bc 8.52±0.84c
C20:3ω6 0.71±0.62a 0.61±0.56a 0.24±0.03b 0.19±0.03b 0.13±0.03c 0.08±0.02c 0.80±0.09a
C20:4ω6 15.09±1.29a 13.73±1.12b 11.05±1.10c 15.68±1.25a 16.58±1.30d 15.71±1.28a 16.13±1.33ad
C20:5ω3 4.53±0.39a 2.16±0.21b 2.45±0.23b 4.85±0.35c 3.75±0.38c 3.54±0.34c 4.76±0.41a
C22:2ω6 0.14±0.03a 0.02±0.01b 0.04±0.01b - - 0.59 ±0.05c 0.08±0.02ab
C22:5ω6 0.15±0.03a 0.13±0.03a 0.55±0.06b 0.37±0.04c 0.98±0.10d 0.67±0.08b 0.82±0.09d
C22:6ω3 1.23±0.13a 1.24±0.12a 1.38±0.14a 1.60±0.16a 1.36±0.15a 1.00±0.10a 2.08±0.24b
Σω6 / Σω3 5.13 8.49 5.29 4.84 4.00 3.91 2.28
ΣSFA 21.02±1.51a 26.66±1.62b 24.49±1.56ab 28.76±1.74c 26.95±1.67b 26.79±1.59b 15.96±1.32c
ΣMUFA 19.71±1.37a 18.05±1.33a 21.63±1.42b 16.44±1.28c 16.14±1.22c 16.87±1.30c 18.14±1.33a
ΣPUFA 60.17±2.49a 55.34±2.25b 53.86±2.15c 54.63±2.18b 56.80±2.39d 56.66±2.36d 66.23±2.51e
Results expressed as percentage of total fatty acids methyl esters.
*Values are means ± S.D (Standard Deviation) for three samples of triplicate analysis.
**Means followed by different letters in the same line are signicantly different (P < 0.05) by Tukey’s test.
SFA: Saturated Fatty Acids, MUFA: Monounsaturated Fatty Acids, PUFA: Polyunsaturated Fatty Acids, Σω6: Total of omega 6 fatty acids, Σω3: Total of ome-
ga 3 fatty acids.
pholipid, 56.80% in the total lipid and 56.66%
in the neutral lipid of A. guttata (Table 2).
DISCUSSION
The significance of fatty acids drives from their
role as fuel to provide metabolic energy, their
usage for storage products, eicosanoids, physi-
ological activities, structural components such
as membrane lipids particularly phospholipids
and sterol esters. Most importantly, they fulfill a
structural role and are also very important inter-
mediates in cell physiology, formation of prosta-
glandins and other eicosanoids from ω3 and ω6
fatty acids (STANLEY-SAMUELSON, 1994). The im-
portance of specific fatty acids as dilatory com-
pounds for animals is partly because of almost
all animals to introduce second or third double
bond into fatty acids to synthesize polyunsat-
urated fatty acids (BEENAKKERS et al., 1985).
The seriousness of fatty acids was mostly em-
phasized for freshwater molluscs. However, li-
pid data correlated with nutritional, physiologi-

Ital. J. Food Sci., vol. 27 - 2015 5
cal, structural and environmental factors in ter-
restrial snails is notably limited in literatures
and relatively little is known about terrestrial
snails’ fatty acid composition, particularly on
their organs. There are only a few studies re-
garding of fatty acids of edible, nonedible snails
and land slugs such as H. aspersa (ÇAĞILTAY et
al., 2011), H. aspersa maxima (MILINSK et al.,
2006), H. pomatia (ÖZOĞUL et al., 2005), E. ver-
miculata (STAVRAKAKIS et al., 1989), Helix sp.,
Haplotrema sportella, Vespericola columbiana,
Arion ater, Limax maximus, Prophysaon ander-
soni (ZHU et al., 1994). Furthermore, only few
studies are present on fatty acid distribution of
mollusc organs and tissues. Macoma balthica
(WENNE and POLAK, 1989), Telescopium telesco-
pium (RAKSHIT et al., 1997), Argopecten purpu-
ratus (CAERS et al., 1999), Bellamya bengalen-
sis, Pila globosa (MISRA et al., 2002), Unio elon-
gatulus (EKİN and BAŞHAN, 2010), Corbicula flu-
minalis (EKİN, 2012), H. lucorum (EKİN 2014) are
some of known mollusc species, tissue and or-
gans studied.
Qualitatively, fatty acid profiles of two species
were similar. Similarity of the fatty acid content
of both species is not surprising. Because they
are close relatives and derived from the same or-
igin. However, quantitative differences in the fat-
ty acid profile were likely due to environmental,
nutritional and physiological effects.
Generally, molluscs are well known to con-
tain C16:0, C18:0, C18:1ω9, C18:2ω6, C18:3ω3
and C20:4ω6 as major fatty acids. These fatty
acids have previously reported in most of the
mollusc species and explored for their potential
use in food chain studies. They were identified
as predominant components in Theodoxus jor-
dani, Melanoides tuberculata, Pyrigula barroisi,
Melanopsis praemorsum freshwater snails (GO
et al., 2002); in Helix sp. H. sportella, V. colum-
biana (ZHU et al., 1994), H. aspersa (ÇAĞILTAY
et al., 2011), H. pomatia (ÖZOĞUL et al., 2004),
H. lucorum (EKİN, 2014) land snails; in T. tele-
scopium marine snail (RAKSHIT et al., 1997); in
U. elongatulus (EKİN and BAŞHAN, 2010), C. flu-
minalis (EKİN, 2012), B. bengalensis, P. globo-
sa (MISRA et al., 2002), A. purpuratus mussels
(CAERS et al., 1999); in P. andersoni, A. ater, L.
maximus (ZHU et al., 1994) slugs. As highlight-
ed above, A. escheriana and A. guttata also con-
tained high amount of C16:0, C18:0, C18:1ω9,
C18:2ω6, C18:3ω3 and C20:4ω6, concentrated
in the organs and fractions. In previous stud-
ies, it was stated that C20:4ω6 is more charac-
teristic of sea urchins and starfish, C20:5ω3 is
characteristic of invertebrates that feed on sin-
gle-celled algae and occurs in almost all class-
es, additionaly C22:6ω3 is more characteristic of
fish and crustacea (SINANOGLOU and MINIADIS-
MEIMAROGLOU, 1998). Notably, C16:0, C18:0
and C18:1ω9 can be found in most of the ani-
mal tissues and very common among fatty acids.
PUFAs may be further modified to form pros-
taglandins that are directly involved in regula-
tion of reproduction, renal function, ion regula-
tion as known from mollusc species, (STANLEY-
SAMUELSON, 1987). It is stated that egg pro-
duction in freshwater snail Helisoma durgi was
stimulated by prostaglandins (KUNIGELIS and
SALEUDDIN, 1986). C20:4ω6 precursors of pros-
taglandins was found to be 15.09% in the diges-
tive gland, 13.73% in the cephalopedal, 11.05%
in the gonad, 15.68% in the mantle of A. gutta-
ta and 11.14% in the digestive gland, 14.37% in
the cephalopedal, 10.01% in the gonad, 17.86%
in the mantle of A. escheriana. Probably, this
high value is related to reproduction and oth-
er physiological activities of the snails. In ani-
mal cells prostaglandins precursor C20:4ω6 is
mostly obtained from phospholipid main source
of PUFA. To remember, the phospholipids of the
snails contained high level of C20:4ω6, 20.30%
in A. escheriana and 16.13% in A. guttata. As a
matter of fact, ΣPUFA levels in the phospholip-
id were detected much higher than other lipid
fractions and organs both in A. escheriana and
A. guttata. In the phospholipid of A. escheriana
and A. guttata, ΣPUFA levels were presented to
be 66.05% and 66.23%, respectively. Recogniz-
ing that snail species in this study are herbi-
vores, therefore containing high proportion of
PUFA was expected result. Because plant based
diet is containing much more PUFA than flesh
based diet.
In the present study, ΣPUFA levels were al-
ways found to be higher than ΣSFA and ΣMUFA.
This finding was in agreement with garden snail
H. aspersa stating that PUFA was most abun-
dant fatty acids (ÇAĞILTAY et al., 2011). It was
also declared that C18:2ω6, C20:4ω6, C18:3ω3
and C20:5ω3 were the dominant fatty acids.
Snails frequently feed on decaying plant mate-
rials to avoid high concentration of deterrent or
toxic plant metabolites (SPEISER et al., 1992).
Aging of plant material results in a decrease of
its PUFA content (KIS et al., 1998), suggesting
that snails eating old plant material may suf-
fer from a shortage of PUFA. Therefore, it can
be said that natural food sources vary season-
ally in the composition of ingredients (WACK-
ER, 2005). In the present study, the snails were
collected in spring season and they mostly fed
on fresh plant materials. Maximization of PUFA
levels in all organs and fractions were probably
because of fresh plant diets. The snails’ mating
activities are significantly reduced when snails
were fed the PUFA-deficient diet. It is stated that
PUFA played important role in reproductive al-
location (WACKER, 2005).
A. escheriana species were collected from
woodland, whereas A. guttata species were col-
lected from stony and rocky region of city walls
which is containing decaying organic matter,
garbage, sediments, grass, shrubs and etc. De-
caying organic matter containing places mostly
shelters bacteria, protozoa, mold, invertebrates

6 Ital. J. Food Sci., vol. 27 - 2015
and other microorganisms. C13:0, C14:0, C15:0,
C17:0 and other short-chain saturated fatty ac-
ids are common in bacteria (WACKER, 2005). In
the analyses, it was observed that A. guttata con-
tained slightly higher amount of short-chain fat-
ty acids than A. escheriana. C14:0 ranged from
1.10% to 2.22% in A. guttata organs and 0.49%
to 1.31% in A. escheriana organs. C15:0 var-
ied from 0.99% to 1.44% in A. guttata and from
0.19% to 0.39% in A. escheriana. Probably, it
was stem from habitats of A. guttata which is
suitable for living for microorganisms.
In all fractions and organs, C18:2ω6 essen-
tial fatty acid was the main components fol-
lowed by C18:1ω9 and C20:4ω6. The highest
concentration of the fatty acid was found to be
28.12% and 26.67% in the digestive gland of A.
guttata and A. escheriana, respectively. Among
the snails’ lipid fractions, the phospholipid con-
tained 27.43% in A. escheriana and 22.34% in
A. guttata of C18:2ω6 (Table 1, 2). On the con-
trary, this fatty acid was found in low level in T.
telescopium freshwater snail’s organs; 2.5% in
the digestive gland, 4.3% in mantle and 4.95%
in the cephalopedal (RAKSHIT et al., 1997). On
the other hand, in edible snail H. aspersa max-
ima, C18:2ω6 was found rather a lot, between
44.79%-51.19% (MILINSK et al., 2006) and this
fatty acid was also found good amount in edible
snail H. lucorum (EKİN, 2014). Most likely, these
different data stem from the requirement of the
fatty acid for snail species. This essential fat-
ty acid plays central role in production of oth-
er PUFA and most animals cannot synthesize it,
for this reason they are dependent on taking it
from their diets.
An interesting fact was that snails had
C20:2ω6 with high concentrations varying from
6.14% to 13.42% in A. guttata and from 7.25%
to 14.93% in A. escheriana. In particular, the
highest level of the fatty acid was detected in
the cephalopedal of both species. In some stud-
ies, it is stated that snail cephalopedal served
as a storage organ (JOHNS et al., 1979), prob-
ably, the cephalopedal stored this fatty acid for
further metabolic activities.
In comparison with A. escheriana and A. gut-
tata, it was observed some strange results in T.
telescopium snail, for instance C18:3ω3 was not
detected in the digestive gland and mantle, but it
was found 10.7% in the cephalopedal tissue as
well as C16:1ω7 was found to be 11.3% in the
digestive gland, 6.1% in the mantle, 4.9% in the
cephalopedal (RAKSHIT et al., 1997). In A. gutta-
ta and A. escheriana, C16:1ω7 was found at low
concentrations, did not exceed 1.80%. However,
C18:3ω3 was presented 7.36% in the digestive
gland, 3.96% in the mantle of A. escheriana and
4.06% in the digestive gland, 2.90% in the man-
tle of A. guttata. For A. escheriana, the highest
proportion of C18:3ω3 was found to be 8.42% in
the total lipid in comparison with 10.70% in the
phospholipid of A. guttata. C18:3ω3 was another
essential fatty acid and its content was expect-
ed to be high in the phospholipid fractions, be-
cause phospholipid contains much more PUFA
than MUFA and SFA. It is also noteworthy that,
the content of fatty acids may differ from year to
year, season to season, and depend on the nu-
trition of organism. Above all, the distribution of
an organism is mostly influenced by many fac-
tors including temperature, reproduction sea-
son, growth, nutrient availability, genetic, phys-
iology and etc.
In the treatments, neutral lipid and total lipid
fatty acid distribution are more similar to each
other than phospholipids. In particular, ΣSFA,
ΣMUFA and ΣPUFA contents in neutral lipid and
total lipid were detected so close to each other in
both species. This kind of determination is very
normal, because neutral lipids and total lipids
are structurally and contently similar.
Both ω3 and ω6 fatty acids are important com-
ponents of biomembranes and are precursors to
many other substances in organisms. Research-
es indicate that omega fatty acids especially ω3
fatty acids reduce inflammation and may help
lower risk of chronic diseases such as heart dis-
ease, cancer, and arthritis. The ratio of Σω6/Σω3
is usually received to be useful indicator for com-
paring nutritional values of the samples. In A.
escheriana, the highest value of Σω6/Σω3 was in
the phospholipid (6.59), whereas the lowest val-
ue was in the neutral lipid and digestive gland
(4.86). On the other hand, in A. guttata the high-
est value of Σω6/Σω3 was in the cephalopedal
(8.49), the lowest value was in the phospholipid
(2.28). This wide difference between snails’ phos-
pholipids fractions was due to the high propor-
tion of C18:2ω6 in A. escheriana. In agreement
with our findings, Σω6/Σω3 ratio was also found
to be high in A. ater, L. maximus, P. andersoni,
slugs and V. columbiana, H. sp. H. sportella (ZHU
et al., 1994) and in H. lucorum land snails (EKİN,
2014). But, in marine molluscs, percentage of
Σω6 was found to be lower than Σω3 (ABAD et
al., 1995; PAZOS et al., 2003).
Eventually, the results showed that species
were rich in PUFA, totally always over 50% in
all analyses and maximization of C16:0, C18:0,
C18:1ω9, C18:2ω6, C18:3ω3, C20:2ω6 and
C20:4ω6 were observed. Particularly, the organs
and lipid fractions of both snails contained good
amount of essential fatty acid, C18:2ω6 taking
role in the synthesis of other fatty acids. More-
over, Σω6/Σω3 and ΣPUFA/ΣSFA+ ΣMUFA ra-
tios were found in good range. Herewith, the re-
sults can be important guide for further investi-
gation on nutritional, physiological, biochemical
and taxonomic studies of molluscs. Commercial-
ly some important edible snails Cryptomphalus
aspersus (H. aspersa), H. asemnis, H. cincta, H.
lucorum, T. pisana, E. vermiculata and C. aper-
tus dwell in Turkish territories (YILDIRIM, 2004).
Although A. escheriana and A. guttata are not
edible snails; however they are very common in

Ital. J. Food Sci., vol. 27 - 2015 7
the southeastern Anatolia region. It should not
be forgotten, snails collected from the wild en-
vironment may accommodate poisonous chem-
icals, heavy metals, drugs, alkaloids and agri-
cultural chemicals. Perhaps, A. escheriana and
A. guttata land snails will be used as edible af-
ter the pathological and biochemical detailed
studies in the future; however we can offer no
adequate explanation about edibility at present.
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Paper Received April 24, 2014 Accepted June 23, 2014