Food Science and Technology International http://fst.sagepub.com/
Fatty acid, cholesterol and fat-soluble vitamin composition of wild and captive freshwater crayfish ( Astacus leptodactylus) A. Gül Harlioglu, S. Aydin and Ö. Yilmaz Food Science and Technology International 2012 18: 93 DOI: 10.1177/1082013211414261 The online version of this article can be found at: http://fst.sagepub.com/content/18/1/93
Published by: http://www.sagepublications.com
On behalf of:
Consejo Superior de Investigaciones Científicas (Spanish Council for Scientific Research)
Additional services and information for Food Science and Technology International can be found at: Email Alerts: http://fst.sagepub.com/cgi/alerts Subscriptions: http://fst.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav
>> Version of Record - Feb 10, 2012 What is This?
Downloaded from fst.sagepub.com by guest on October 11, 2013
Article
Fatty acid, cholesterol and fat-soluble vitamin composition of wild and captive freshwater crayfish (Astacus leptodactylus) ¨ . Yilmaz2 ˘ lu1, S. Aydin2 and O A. Gu ¨ l Harliog
Abstract The proximate analysis (dry matter, protein, fat and ash), cholesterol, fatty acid and fat-soluble vitamin compositions of the tail muscle of wild caught and captive crayfish (Astacus leptodactylus) were investigated. Captive crayfish contained higher moisture and fat content than wild crayfish. In contrast, wild crayfish contained a higher level of crude protein, ash and n-3 polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) than captive crayfish. Arachidonic acid (C20:4 n-6) was the major n-6 PUFA in wild A. leptodactylus, and linoleic acid (C18:2 n-6) was the major n-6 PUFA in captive A. leptodactylus. The percentages of total saturated fatty acids (SFA), PUFA, and n-3/n-6 ratio were higher in wild crayfish and total monounsaturated fatty acids (MUFA) were lower. Although differences existed between wild and captive crayfish in vitamins A (p < 0.001), d-Tocopherol (p < 0.001), a-Tocopherol acetate (p < 0.05), no differences were found in vitamins D2, D3, a- Tocopherol and K (p > 0.05). The differences may be originated from the diet provided to captive crayfish. Since wild A. leptodactylus contained higher n-3/n-6 ratio than captive A. leptodactylus, crayfish farms can potentially produce a better quality of crayfish meat by increasing the PUFA n-3 (especially DHA and EPA) in the diets of A. leptodactylus.
Keywords Astacus leptodactylus, cholesterol, fat-soluble vitamin, fatty acids Date received: 20 November 2010; revised: 3 February 2011; accepted: 9 February 2011
INTRODUCTION Many decapod crustaceans are cultivated and harvested from the wild for human consumption. They are a popular luxury food which commands high prices (Holdich, 1993; Ackefors, 2000). Freshwater crayfish are a luxury food in many West European countries. Much of the production is obtained from introduced North American crayfish species such as the signal crayfish, Pacifastacus leniusculus and the red swamp crayfish, Procambarus clarkii which have become established in the wild or are cultured in crayfish farms (Harlıog˘lu and Holdich, 2001). In Scandinavian and other north European countries,
the native, noble crayfish, Astacus astacus is the preferred species, but this species is now more difficult to obtain, and consequently more expensive, due to the continuing impact of a fungal disease, crayfish plague, which has devastated populations since the last century (Holdich, 1999). In addition to these species, another native species of Europe, the narrow-clawed crayfish (popular name Turkish crayfish), Astacus leptodactylus, forms an important part of the market, either as imports or from introduced populations farms (Harlıog˘lu and Holdich, 2001).
1
˘ , Turkey Fisheries Faculty, Fırat University, 23119, Elazıg Department of Biology, Faculty of Science, Fırat University, ˘ , Turkey 23169, Elazıg
2
Food Science and Technology International 18(1) 93–100 ! The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1082013211414261 fst.sagepub.com
Corresponding author: ˘ lu, Fisheries Faculty, Fırat University, 23119, Elazıg ˘, A. Gu ¨ l Harliog Turkey Email:
[email protected]
Food Science and Technology International 18(1) Turkey was the largest supplier of A. leptodactylus to Western Europe from 1970 (or possibly earlier) until 1986. Therefore, it constituted a major part of the European market (Ko¨ksal, 1988; Harlıog˘lu and Gu¨ner, 2007). As a result of the crayfish plague the harvest of A. leptodactylus was diminished severely in most populations in Turkey after 1985 (Ko¨ksal, 1988; Ackefors, 2000). The harvest was only 783 tonnes in 2008 (Anonymous, 2008). In Europe, the market demand for crayfish is not less than 10.000 tonnes per year. Scandinavia, Germany and France are the main consumers (Wickins and Lee, 2002). Thus, it is highly likely that there will be an increase in the demand for crayfish in Europe, mainly satisfied by imports, as most native crayfish species populations still need time and support in order to fully recover from the crayfish plague (Harlıog˘lu, 2008). At present, there is no crayfish aquaculture in Turkey. All production is obtained from wild harvest. However, it seems that A. leptodactylus may be of interest for crayfish aquaculture especially in Turkey and in some European countries in near future because of its rapid growth and high fecundity rate, wide temperature and dissolved oxygen tolerance, and non-burrowing behavior. In addition, it easily adapts to formulated food and it can be cultivated in extensive and semiintensive conditions. Furthermore, intensive aquaculture systems can be used in order to produce juveniles of this species (Harlıog˘lu, 2009). Nutritional value of aquatic species is the result of a complex set of characteristics involving factors such as chemical composition, vitamin and mineral content, texture and color, among others. According to Fuentes et al. (2010) these quality parameters are influenced by intrinsic (species, size and sexual maturity) and extrinsic factors (source of nutrients, season, water quality, temperature, etc.). They also stated that the nutritional value and organoleptic characteristics of aquatic species are especially affected by rearing conditions, so that composition and sensory parameters are expected to be different between wild and farmed aquatic species. The objective of this study is to investigate the differences in fatty acid composition, cholesterol and fat-soluble vitamins between wild caught and captive A. leptodactylus.
MATERIALS AND METHODS Materials Crayfish samples used in the present study were caught from Keban Dam Lake population of A. leptodactylus. Keban Dam Lake: 1097 m long and its crest is 207 m above the level of the river-bed 848 m above sea level and the surface area is 675 km2. 94
Methods Sample preparation. Twenty-one mature crayfish (average length and weight: 96.5 1.4 mm and 28.6 1.9 g, respectively, mean SD) were captived in the crayfish reproduction unit of Fisheries Faculty of Fırat University, Elazıg˘, Turkey between July 01, 2009 and November 01, 2009. Crayfish were stocked in a concrete tank (2 2 0.5 m3). Plastic pipes (20 cm in length and 7 cm in diameter) were placed in the tank to provide shelters for the crayfish. Crayfish were weighed and were fed 2% of their wet weight daily, divided into three separate feedings (Ackefors et al., 1992) with a commercial trout pellet (Manufactured by Pınar, Izmir, Turkey). There are no commercial crayfish pellets in Turkey at present. The commercial trout pellet used for the present study contained 7.81% moisture, 39.81% protein, 20.66% fat, 8.48% ash and 86.75 6.58 mg/100 g cholesterol content. The fatty acid percentage and the fat-soluble vitamins profile (mg/g) of the diet used in this study is in Table 1. Water flow was 0.2 L/s for the tank. Dissolved oxygen, pH and water temperature were measured daily. Ammonia, iron, copper, alkalinity, hardness, calcium and water flow were measured twice a week. Mean dissolved oxygen was 7.1 1.1 mg/L; mean ammonia, iron and copper concentrations were less than 0.001 mg/L (for each parameter), mean alkalinity was 224.8 1.9 mg/L as CaCO3; mean calcium was 42.4 2.3 mg/L; mean hardness was 350 30 mg/L as CaCO3; mean pH was 7.7 0.3 (AOAC, 1995). Mean water temperature ( C) was 19.45 0.7 in July, 21.8 0.6 in August, 20.1 0.4 in September and 16.2 0.2 in October. On November 01, 2009 (after 4 months), fifteen A. leptodactylus were collected randomly from the tank (average length and weight (mean standard error): 100 1.2 mm and 33 3.1 g, respectively). It appeared that the crayfish in captivity grew 3.5 mm in length (from 96.5 to 100 mm) and 4.4 g (from 28.6 to 33 g) in weight in 4 months. In addition, in the same week, for the comparative purpose 15 mature A. leptodactylus (average length and weight: 102 1.7 mm and 34.7 2.8 g, respectively) were caught from Keban Dam Lake population of A. leptodactylus. Tail muscle of wild caught and captive crayfish was dissected and was stored for approximately two weeks at 30 C until analyzed. Proximate analysis. Six wild caught and six captive A. leptodactylus were used to determine proximate analysis and cholesterol content of the tail muscles. Proximate analysis of triplicate samples were made as follows AOAC (1995): dry matter, after drying at 105 C for 24 h to constant weight in an oven; protein content
˘ lu et al. Gu ¨l Harliog Table 1. The fatty acid percentage and the fat-soluble vitamins profile of the diet of captive A. leptodactylus Fatty acid
Percentage or total fatty acids
14:0 14:1 15:0 16:0 16:1 n-7 16:1 n-9 17:0 17:1 18:0 18:1 n-7 18:1 n-9 18:2 n-6 18:3 n-6 18:3 n-3 20:0 20:1 n-9 20:2 n-6 20:3 n-6 20:4 n-6 20:5 n-3 21:0 22:0 22:1 n-9 22:5 n-6 22:5 n-3 22:6 n-3 24:1 Total SFA Total MUFA Total PUFA Total PUFA/SFA Total n-3 PUFA Total n-6 PUFA n-3/n-6 Fat-soluble vitamins (mg/g) A D2 D3 d-Tocopherol a-Tocopherol a-Tocopherol acetate K
4.48 0.21 0.34 0.01 0.26 0.00 10.27 1.86 4.60 0.17 0.93 0.01 0.48 0.01 1.19 0.00 4.49 0.15 1.26 0.20 23.56 0.13 7.43 0.07 0.81 0.01 2.70 0.04 3.14 0.01 7.62 0.09 1.43 0.01 0.13 0.00 0.33 0.00 8.71 0.05 0.16 0.00 3.67 0.19 0.93 0.01 1.12 0.00 1.56 0.01 7.57 0.05 0.76 0.01 0.76 0.01 26.95 41.19 31.79 1.17 20.54 11.25 1.82 10.36 1.36 0.71 0.04 2.03 0.17 4.12 0.56 1.74 0.47 1.33 0.09 0.70 0.10
Data are expressed as mean standard error.
was determined by Kjeldahl method (nitrogen 6.25); fat was determined by soxhlet apparatus with petroleum ether; ash content was determined by weighing after burning at 550 C. Fatty acid analysis and the fat-soluble vitamins. Ten wild caught and ten captive A. leptodactylus were used to carry out fatty acid and fat-soluble vitamins analysis. Extraction of lipids: lipid extraction of tissue samples were extracted with hexane-isopropanol (3:2 v/v) by the method of Hara and Radin (1978). One gram tissue sample was homogenized with 10 mL hexane-isopropanol mixture. The homogenate was centrifuged at 5000 rpm for 5 min at 4 C and parts of tissue remnants were precipitated. The supernatant part was used in the ADEK, cholesterol and fatty acid analysis. Preparation of fatty acid methyl esters: fatty acids in the lipid extracts were converted into methyl esters including 2% sulfuric acid (v/v) in methanol (Christie, 1992). The mixture was vortexed and then kept at 50 C for 12 h. Then, after being cooled to room temperature, 5 mL of 5% sodium chloride was added and then it was vortexed. Fatty acid methyl esters were extracted with 2 5 mL hexane. Fatty acid methyl esters were treated with 5 mL 2% KHCO3 solution and then the hexane phase was evaporated by the nitrogen flow and then by dissolving in 0.5 mL fresh hexane (Christie, 1992), they were taken to auto sampler vials. Gas chromatographic analysis of fatty acid methyl esters: methyl esters were analyzed with the Shimadzu GC-17 Ver. 3 gas chromatography (Kyoto, Japan). For this analysis, 25 m of long Machery-Nagel (Germany) capillary colon with an inner diameter of 0.25 mm and a thickness of 25 mm film was used. During the analysis, the colon temperature was kept at 120–220 C, injection temperature was kept at 240 C and the detector temperature was kept at 280 C. The nitrogen carrier gas flow was 1 mL/min. The methyl esters of fatty acids were identified by comparison with authentic external standard mixtures analyzed under the same conditions. After this process, the necessary programming was made and the necessary programming was made and the Class GC 10 software version 2.01 was used to process the data. HPLC analysis of ADEK vitamins: five mL supernatant was taken to 25 mL tubes with caps and 5% KOH solution was added and immediately vortexed for 20 s. The tubes were placed in a water bath at 85 C for 15 min. The tubes were then taken and cooled to room temperature and 5 mL of distilled water was added and mixed. Lypophlic molecules that did not saponify were extracted with 2 5 mL hexane. The hexane phase was evaporated with nitrogen flow. It was dissolved in 1 mL (50 þ 50%, v/v)
95
Food Science and Technology International 18(1) Table 2. Proximate analysis and cholesterol content of the tail muscle of wild caught and captive A. leptodactylus Component
Wild1
Captive1
a2
Moisture (%) Crude Protein (%) Crude fat (%) Ash (%) Cholesterol (mg/100 g)
78.19 0.31 14.61 0.40 0.57 0.02 1.39 0.03 81.51 4.33
81.77 0.34 12.88 0.25 0.71 0.01 1.27 0.02 75.88 2.95
*** ** ** * ns
1
Data are expressed as mean standard error, on a fresh weight basis, (n ¼ 6). Level of statistical significance (a): ns ¼ p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001.
2
acetonitrile/methanol mixture and then was taken to autosampler vials and was analyzed. The analysis was made with the Shimadzu brand HPLC device. HPLC conditions were as follows: mobile phase 60:38:2 (v/v/v): acetonitrile/methanol/ water. The mobile phase flow rate was determined to be 1 mL. An UV detector was used for the analysis, and as a column the Supelcosil LC 18 (15 4.6 cm2 5mm; Sigma USA) column was used. For vitamin E and cholesterol 202 nm, retinol, 326 nm and for vitamin D and K, 265 nm was used (Katsanidis and Addis, 1999; Lo´pez-Cervantes et al., 2006). Data are presented as mean SD and subjected to independent-samples t-test for determining significant differences between treatment means.
RESULTS AND DISCUSSION Proximate analysis Proximate analysis (%) of the tail muscle of wild caught and captive A. leptodactylus are given in Table 2. Proximate composition differed significantly (p < 0.05 for ash, p < 0.01 for protein and fat, and p < 0.001 for moisture) between wild caught crayfish and captive crayfish. The wild caught crayfish had a higher protein, ash and cholesterol, but lower moisture and fat content than captive crayfish. However, the crayfish in captivity had a higher fat content than the crayfish caught from wild. This result could be due to a variety of factors including availability and type of food and dietary ingredients. D’Abramo and Robinson (1989) and Wickins and Lee (2002) also stated that commercial diets are usually high in fat content. USDA (2005) reported slightly higher moisture, protein, fat and lower ash contents (82.24%, 15.97%, 0.95% and 1.34%) for wild Procambarus spp. crayfish. Similarly, higher moisture, protein and fat and lower ash contents (84.05%, 14.85%, 0.97% and 1.0%) were reported for farmed crayfish by USDA (2005). The seasonal variations of the yield and proximate composition of A. leptodactylus caught from various lakes (Bıyıkali, Karacakılavız, Bayrams¸ ah, 96
Karaidemir and Karababa) in Tekirdag˘, Turkey a higher fat content (1.17%) and similar moisture (80.50%), protein and ash contents (14.60% and 1.42%) were found in the season of autumn by Erkan et al. (2009) in comparison to the findings of present study for wild caught crayfish. In another study on the meat content and chemical composition of A. leptodactylus caught from Bu¨yu¨kc¸ekmece Lake in Istanbul, Turkey. Ilhan and S¸ahin (2008) observed slightly higher moisture and fat contents (83.01% and 0.62%) and similar protein (14.17%) content in comparison to the present study. However, Huner et al. (1996) reported higher ash content (8.84%), similar fat content (0.79%), but lower moisture and protein content (73.6% and 10.37%) for A. astacus in compared to the findings of present study. The present study also showed that there was not a significant difference in the cholesterol content between wild caught A. leptodactylus and captive A. leptodactylus (p > 0.05) (Table 2). In comparison to the present study, Thompson et al. (2003) found slightly lower cholesterol content (68.40 mg/100 g) in the muscle of red claw crayfish Cherax quadricarinatus after an 8-week feeding trial conducted without lecithin and cholesterol. On the other hand, slightly higher cholesterol content was reported for wild caught crayfish meat (114 mg/ 100 g) in comparison to farmed crayfish (107 mg/ 100 g) by USDA (2005). In addition to these studies, cholesterol content (mg/100 g) was found to be 78 8.43 in wild caught blue crab (Callinectes sapidus), 152 2.73 in Penaeidae shrimp, 95 12.22 in lobster (Homarus americanus), 70 in spiny lobster (Jasus ssp) (USDA, 2005). Cahu et al. (2004) stated that cholesterol content of the farmed and wild caught fish was similar, and they concluded that cholesterol content of the farmed and wild caught fish apparently unrelated to their fat content and their protein content was the same. Statistical differences in the proximate analysis (%) and cholesterol content (mg/100 g) of the tail muscle of wild caught and captive A. leptodactylus (Table 2).
˘ lu et al. Gu ¨l Harliog Table 3. Fatty acids in the tail muscle of wild caught and captive A. leptodactylus (% of total fatty acids) Fatty acid
Wild
Captive
a2
14:0 14:1 15:0 16:0 16:1 n-7 16:1 n-9 17:0 17:1 18:0 18:1 n-7 18:1 n-9 18:2 n-6 18:3 n-3 20:0 20:1 n-9 20:2 n-6 20:4 n-6 20:5 n-3 21:0 22:1 n-9 22:5 n-6 22:5 n-3 22:6 n-3 SFA MUFA PUFA PUFA/SFA n-3 PUFA n-6 PUFA n-3/n-6
0.60 0.13 nd 0.44 0.01 15.46 0.46 5.47 0.37 1.14 0.06 0.63 0.04 0.68 0.04 7.50 0.37 4.17 0.26 15.10 1.07 3.67 0.44 1.04 0.10 0.45 0.03 1.61 0.02 0.82 0.03 7.53 0.23 23.10 0.30 0.48 0.08 nd 1.21 0.06 0.83 0.03 7.77 0.12 25.56 0.58 28.17 1.77 45.97 0.60 1.79 0.05 32.74 0.35 13.23 0.56 2.47 0.11
1.75 0.11 0.10 0.02 nd 13.84 0.17 4.63 0.24 1.23 0.05 0.67 0.02 0.67 0.03 6.10 0.31 4.29 0.17 22.51 0.47 8.84 0.23 1.78 0.02 0.59 0.02 6.98 0.03 0.99 0.03 2.94 0.10 13.51 0.20 nd 0.56 0.03 1.15 0.05 0.76 0.02 6.02 0.11 22.95 0.37 40.97 0.93 35.99 0.48 1.56 0.05 22.07 0.25 13.92 0.36 1.58 0.04
***
** ns ns ns ns * ns *** *** *** ** *** ** *** ***
ns ns *** * *** *** *** *** ns ***
1
Data are expressed as mean standard error, on a fresh weight basis, (n ¼ 10); nd: not detected. Level of statistical significance (a): ns ¼ p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001.
2
Fatty acids The fatty acid profiles of wild caught and captive A. leptodactylus examined in the present study are listed in Table 3. The percentage of SFAs and PUFAs in wild caught A. leptodactylus was higher than those of captive A. leptodactylus. On the other hand, captive A. leptodactylus contained a higher content of MUFAs than wild caught A. leptodactylus. This is probably due to the high content of MUFAs in the diet of the captive crayfish. In addition, the results revealed that captive A. leptodactylus contained significantly higher proportions of 20:0, 20:2 n–6 (p < 0.01) and significantly higher proportions of 14:0, 18:1 n-9, 18:2 n-6, 18:3 n-3, 20:1 n-9 (p < 0.001), but significantly lower proportions of 18:0
(p < 0.05), 16:0 (p < 0.01) and 20:4 n-6, 20:5 n-3, 22:6 n-3 (p < 0.001) than wild caught A. leptodactylus. According to Wickins and Lee (2002) the fatty acid composition in crustaceans varies with habitats and readily reflects the composition of the diet. It was also reported that assimilation pattern of dietary fatty acids in fish muscle reflect the content of the dietary lipid sources (Ackefors et al., 1997; Wickins and Lee, 2002). In the present study it was determined that the total SFA content of lipids was 25.56% in wild caught A. leptodactylus and 22.95% in captive A. leptodactylus. In addition, palmitic acid (C16:0) was the major SFA in both wild caught and captive A. leptodactylus, followed by stearic acid (C18:0). These contents were also found higher in some wild caught fish species (Chen et al., 1995; Fuentes et al., 2010). 97
Food Science and Technology International 18(1) Table 4. The fat-soluble vitamins in the tail muscle of wild caught and captive A. leptodactylus Fat-soluble vitamins
Wild1
Captive1
a2
A D2 D3 d-Tocopherol a-Tocopherol a-Tocopherol acetate K
0.43 0.02 0.54 0.03 0.26 0.03 0.15 0.02 1.19 0.06 0.70 0.04 0.76 0.10
0.66 0.01 0.62 0.02 0.29 0.04 1.04 0.01 1.11 0.04 0.82 0.03 0.56 0.07
*** ns ns *** ns * ns
1
Data are expressed as mean standard error (n ¼ 10). Level of statistical significance (a): ns ¼ p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001.
2
In the present study it was also determined that oleic acid (C18:1 n-9) was the primary MUFA in wild caught and captive A. leptodactylus. Furthermore, the oleic acid content of captive A. leptodactylus (22.51 0.47) was significantly (p < 0.001) higher than that of wild caught A. leptodactylus (15.10 1.07) (Table 3). In the present study, the oleic acid content of experimental diet was 23.56%. Similar to the findings of present study, the oleic acid content of farmed and wild caught sea bass (Dicentrarchus labrax) by Fuentes et al. (2010) in a study on the comparison of wild and farmed sea bass meat quality (Table 5). Fuentes et al. (2010) concluded that the higher amount of oleic acid in cultured fish could be due to its dominance in its commercial diet. The oleic acid content of experimental diet in Fuentes et al. (2010)’s study was 17.9%. Linoleic (C18:2 n-6), linolenic (C18:3 n-3), eicosapentaenoic (EPA; C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) are particularly important dietary ingredients for crustaceans (Wickins and Lee, 2002). In the present study, among n-3 series of the fatty acids, the percentages of EPA and DHA in wild caught A. leptodactylus lipids were significantly higher than those of captive A. leptodactylus (p < 0.001), which is in good agreement with those previously reported for some wild fish species (Rueda et al., 1997; Fuentes et al., 2010). The results of this study revealed that among n-6 series of the fatty acids, the primary fatty acid was arachidonic (C20:4 n-6) for wild caught A. leptodactylus, and linoleic acid (C18:2 n-6) for captive A. leptodactylus. Linoleic acid was also found in high amounts in the diet used for captive A. leptodactylus in the present study. Therefore, it is thought that wild caught crayfish contained less amounts of linoleic acid than captive crayfish. Similar results (Table 5) were found for some fish species by O’Leary and Matthews (1990), Rueda et al. (1997) and Mnari et al. (2007). On the other hand, wild caught crayfish had higher levels of arachidonic acid in agreement with the findings of Gonzalez et al. (2006). They reported that higher 98
concentrations of arachidonic acid in wild fish (yelllow perch, Perca flavescens) when compared to the farmed fish. It was concluded that the high amount of arachidonic acid in wild caught crayfish was due probably to the diet of wild caught crayfish being rich in this fatty acid. However, in captive crayfish, levels of arachidonic acid were low because the diet used contained minimal amounts (0.33%) of this fatty acid. The ratio of n-3 to n-6 fatty acids was significantly (p < 0.001) higher in wild caught crayfish than captive crayfish which shows that there is a reduction in the nutritional quality in the lipid components of captive crayfish. The lower proportion of n-3 PUFA in captive crayfish may reduce the nutritional quality of their lipid components. Alasalvar et al. (2002) found same results in a study on the differentiation of cultured (2.88) and wild sea bass (3.02; Dicentrarchus labrax). D’Abramo and Robinson (1989) reported that the fatty acid composition of the tissue reflected the fatty acid composition of the diet, but other factors may also influence their fatty acid composition. Environmental factors such as the relative abundance of food sources, temperature, tissue, life cycle and moult stage and reproductive performance can affect fatty acid composition of freshwater and marine crustaceans (Eversole et al., 1999; Wickins and Lee, 2002). As regarding PUFA/SFA, it was found to be 1.79 and 1.56 for wild caught and captive crayfish. According to the nutritional guidelines of the Department of Health (1994) of the UK, a ratio of 0.45 or more is recommended as a balanced fatty acid intake on healthy diet. Therefore, it can be concluded that the findings of present study show that wild caught crayfish and captive crayfish can be considered as appropriate for human diet (Table 3). The fat-soluble vitamins The results showed that the vitamin A, D2, D3, d-Tocopherol, a-Tocopherol acetate contents were high in captive crayfish. There was a significant
˘ lu et al. Gu ¨l Harliog Table 5. Oleic, arachidonic, linoleic and palmitic acids of A. leptodactylus and some wild and reared fish species (percentage of total fatty acids) Wild species
Oleic acid (%)
Arachidonic acid (%)
A. leptodactylus Dicentrarchus labrax Penaeus monodon
15.10 16.47 8.4
7.53 5.37 12.9
3.67 2.73 1.9
15.46 24.57 13.0
Pagrus pagrus Sparus aurata Perca flavescens Reared species A. leptodactylus Dicentrarchus labrax Penaeus monodon
9.7 15.12 7.27
9.3 11.82 7.37
1.2 3.0 4.61
22.9 19.39 17.5
22.51 28.27 –
2.94 0.33 4.9
8.84 13.56 9.8
13.84 21.50 –
Pagrus pagrus Sparus aurata Perca flavescens
18.0 15.33 7.51
1.0 1.63 2.61
5.0 4.92 4.43
20.0 15.83 20.9
difference in the a-Tocopherol acetate (p < 0.05), vitamin A and d-Tocopherol (p < 0.001) between wild caught crayfish and captive crayfish (Table 4). The fat-soluble vitamins have been reported to show wide range of variations among fish and crustaceans species (D’Abramo and Conklin, 1995; Dias et al., 2003; USDA, 2005). For example, vitamin A content (mg/100 g) was found to be 16 and 15 in wild crayfish and farmed crayfish, 2 in wild blue crab (C. sapidus), 54 in Penaeidae shrimp, 21 in lobster (H. americanus), 5 in spiny lobster (Jasus ssp) by USDA (2005). In addition, vitamin E (a-Tocopherol) content (mg/100 g) was found to be 2.85 in wild caught crayfish, 1.10 in Penaeidae shrimp, 1.47 in lobster (H. americanus) and vitamin K (mg/100 g) was found to be 0.1 in wild caught crayfish and 0.1 lobsters (H. americanus) (USDA, 2005). In addition to this study, Dias et al. (2003) investigated the vitamin contents of fish and fish products consumed in Portugal. They found that vitamin A, D and E contents of mackerel meat were 64 mg/100 g, 9.3 mg/100 g and 1.5 mg/100 g, respectively. Those of salmon were found to be 33 mg/100 g, 11 mg/100 g and 4.0 mg/100 g, and those of rainbow trout were 8.8 mg/ 100 g, 19 mg/100 g and 0.13 mg/100 g, respectively (Dias et al., 2003).
CONCLUSIONS Wild caught and captive A. leptodactylus may be differentiated using proximate composition, fatty acid proportions and the fat-soluble vitamins. The total saturated, polyunsaturated fatty acids and the n-3/n-6
Linoleic acid (%)
Palmitic acid (%)
Source This study Fuentes et al. (2010) O’Leary and Matthews, (1990) Rueda et al. (1997) Mnari et al. (2007) Gonzalez et al. (2006) This study Fuentes et al. (2010) O’Leary and Matthews (1990) Rueda et al. (1997) Mnari et al. (2007) Gonzalez et al. (2006)
ratios were higher in wild caught crayfish than captive crayfish. These differences may be attributed to the diet constituents of the crayfish. However, it can be concluded that in order to have higher n-3/n-6 ratios, to meet fatty acid requirement of A. leptodactylus and to have a better quality of A. leptodactylus meat PUFA n3 (especially DHA and EPA) content in the diet of A. leptodactylus should be increased.
References Ackefors H, Castell J and O¨rde-O¨stro¨m IL. (1997). Preliminary results on the fatty acid composition of freshwater crayfish, Astacus astacus and Pacifastacus lenisculus, held in captivity. Journal of the World Aquaculture Society 28(1): 97–105. Ackefors H. (2000). Freshwater crayfish farming technology in the 1990s: a European and global perspective. Fish and Fisheries 1(4): 337–359. Ackefors H, Castell JD, Boston LD, Raty P and Svensson M. (1992). Standard experimental diets for crustacean nutrition research. II. Growth and survival of juvenile crayfish Astacus astacus (Linne) fed diets containing various amounts of protein, carbohydrate and lipid. Aquaculture 104(3-4): 341–356. Alasalvar C, Taylor KDA, Zubcov E, Shahidi F and Alexis M. (2002). Differentiation of cultured and wild sea bass (Dicentrarchus labrax): total lipid content, fatty acid and trace mineral composition. Food Chemistry 79(2): 145–150. Anonymous (2008). Yearly Fishery Statistics. Ankara, Turkey: Turkish Statistical Institute (TURKSTAT). AOAC, (1995). Official Methods of Analysis of the Association of Official Analytical Chemists (AOAC).
99
Food Science and Technology International 18(1) Association of Official Analytical Chemists, 16th edn. Arlington, VA, USA. Cahu C, Salen P and Lorgeril M. (2004). Farmed and wild fish in the prevention of cardiovascular diseases: assessing possible differences in lipid nutritional values. Nutrition, Metabolism and Cardiovascular Diseases 14(1): 34–41. Chen I, Chapman FA, Wei I, Portier KM and O’Keefe SF. (1995). Differentiation of cultured and wild sturgeon (Acipenser oxyrinchus desotoi) based on fatty acid composition. Journal of Food Science 60(3): 631–635. Christie WW (1992). Gas Chromatography and Lipids. Glaskow: The Oil Pres, p. 302. D’Abramo LR and Robinson EH. (1989). Nutrition of crayfish. Aquatic Sciences 1(4): 711–728. D’Abramo LR and Conklin DE. (1995). New developments in the understanding of the nutrition of Penaeid and Caridean species of shrimp. In: Browdy CL and Hopkins JS (eds) Proceedings Swimming thorough Troubled Water. Baton Rouge, Louisiana: World Aquaculture Society, 95–107. Department of Health (1994). Nutritional Aspects of Cardiovascular Disease. Report on Health and Social Subject No: 46. London: Her Majesty’s Stationery Office. Dias MG, Sanchez MV, Bartolo H and Oliveira L. (2003). Vitamin content of fish and fish products consumed in Portugal. Electronic Journal of Environmental, Agricultural and Food Chemistry 2(4): 510–513. Erkan N, Mol S, Tosun SY and Alakavuk DU¨. (2009). Seasonol variations of the yield and proximate composition of freshwater crayfish, Astacus leptodactylus (Eschscholtz, 1823). Advanced Food Science 31(1): 41–44. Eversole AG, Turker H and Kempton CJ. (1999). Lipid content of Procambarus acutus acutus (Girard). Freshwater Crayfish 12: 194–204. Fuentes A, Fernandez-Segovia I, Serra JA and Barat JM. (2010). Comparison of wild and cultured sea bass (Dicentrarchus labrax) quality. Food Chemistry 119(4): 1514–1518. Gonzalez S, Flick GJ, O’Keefe SF, Duncan SE, McLean E and Craig SR. (2006). Composition of farmed and wild yelllow perch (Perca flavescens). Journal of Food Composition and Analysis 19(6–7): 720–726. Hara A and Radin NS. (1978). Lipid extraction of tissues with low- toxicity. Analytical Biochemistry 90(1): 420–426. Harlıog˘lu MM. (2008). The harvest of the freshwater crayfish Astacus leptodactylus Eschscholtz in Turkey: harvest history, impact of crayfish plague, and present distribution of harvested populations. Aquaculture International 16: 351–360. Harlıog˘lu MM. (2009). A comparison of the growth and survival of two freshwater crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana) under different temperature and density regimes. Aquaculture International 17(1): 31–43. Harlıog˘lu MM and Holdich DM. (2001). Meat yields in the introduced crayfish, Pacifastacus leniusculus and Astacus
100
leptodactylus, from British waters. Aquaculture Research 32(5): 411–417. Harlıog˘lu M.M. and Guner U. (2007). A new record of recently discovered crayfish, Austropotamobius torrentium (Shrank, 1803), in Turkey. Bulletin Franc¸ais de la Peˆche et de la Pisciculture - Connaıssance Et Gestıon Du Patrımoıne Aquatıque 387: 1–5. Holdich DM. (1999). The negative effects of estabilished crayfish introductions. In: Gherardi F and Holdich DM (eds) Crayfish in Europe as Alien Species- How to Make the best of a bad situation?. Rotterdam: Brookfield, 31–47. Holdich DM. (1993). A review of astaciculture: Freshwater crayfish farming. Aquatic Living Reseurces 6(4): 307–317. Huner JV, Ko¨no¨nen H, Henttonen P, Lindqvist OV and Jussila J. (1996). Proximate analyses of freshwater crayfishes and selected tissues with emphasis on cambarids. Freshwater Crayfish 11: 227–234. Ilhan RE and S¸ahin SK (2008). The effect of reproduction period on the flesh yield and chemical composition of crayfish (in Turkish with English abstract). Research Bulletin pp. 45–48. Katsanidis E and Addis PB. (1999). Novel HPLC analysis of tocopherols and cholesterol in tissue. Free Radical Biology and Medicine 27(11–12): 1137–1140. Ko¨ksal G. (1988). Astacus leptodactylus in Europe. In: Holdich DM and Lowery RS (eds) Freshwater Crayfish: Biology, Management and Exploitation. London: Timber Press, Oregon, 365–400. Lo´pez-Cervantes G, Sa´nchez-Machado DI and Rı´ os-Va´zquez NJ. (2006). High performance liquid chromatography method for the simultaneous quantification of retinol, tocopherol and cholesterol in shrimp waste hydrolysate. Journal of Chromatography A 1105: 135–139. Mnari A, Bouhlel I, Chraief I, Hammami M, Romdhane MS, Cafsi ME, et al. (2007). Fatty acids in muscles and liver of Tunisian wild and farmed gilthead sea bream, Sparus aurata. Food Chemistry 100: 1393–1397. O’Leary CD and Matthews AD. (1990). Lipid class distribution and fatty acid composition of wild and farmed prawn, Penaeus monodon (Fabricus). Aquaculture 89(1): 65–81. Rueda FM, Lopez JA, Martinez F, Zamora S, Divanach P and Kentouri M. (1997). Fatty acids in muscle of wild and farmed red porgy, Pagrus pagrus. Aquaculture Nutrition 3: 161–165. Thompson KR, Muzinic LA, Christian TD and Webster CD. (2003). Effect on growth, survival, and fatty acid composition of Australian red claw crayfish Cherax quadricarinatus fed practical diets with and without supplemental lecithin and/or cholesterol. Journal of World Aquaculture Society 34(1): 1–10. SDA (2005). National nutrient database for standard. Available at http://www.nal.usda.gov/fnic/foodcomp/cgibin/list_nut_edit.pl (accessed 9 April 2010). Wickins JF and Lee DOC. (2002). Crustacean Farming Ranching and Culture. Oxford: Blackwell Science, 446.
