J. Agr. Sci. Tech. (2011) Vol. 13: 553-566
Identification of Fatty Acid in Mackerel ( Scomberomorus commersoni) and Shark ( Carcharhinus dussumieri ) Fillets and Their Changes during Six Month of Frozen Storage at -18˚C
S. Nazemroaya 1, M. A. Sahari 2*, and M. Rezaei 1
ABSTRACT
Changes in the fatty acid composition and biochemical indices of mackerel (which has a substantial lipid content) and shark (which has negligible lipid content) fillets stored at - 18˚C for up to six months were measured. Lipid content was measured (6.35% and 1.38%) in mackerel and shark, respectively; however it decreased during frozen storage in both fish species. In analysis of fatty acids the amount of PUFA, especially ω-3 ones, was more predominant in mackerel than shark, nevertheless, fatty acid composition has changed in both species during frozen storage. The amount of saturated fatty acids in contrast with unsaturated fatty acids increased due to oxidation of PUFA. The decrease in PUFA compounds (40.1% and 23.94%) was as follows: ω-3 (48% and 42.83%), ω-3/ ω-6 ratio (41.36% and 50%), PUFA/SFA ratio (56% and 42.23%) and EPA+DHA/C16 ratio (55.55% and 46.66%) in mackerel and shark, respectively. For both species, tiobarbituric acid (TBA), peroxide (PV), free fatty acids (FFA) and total volatile base nitrogen (TVB-N) values were significantly (P< 0.05) increased with storage time. The results showed that, among these indices, changes in the PV and TBA in mackerel were significantly (P< 0.05) larger than in shark; but changes of FFA and TVB-N in shark were significantly (P< 0.05) higher than in mackerel. It means that oxidative and hydrolytic deterioration are promoter factors of biochemical changes in mackerel and shark, respectively.
Keywords: Biochemical changes, Carcharhinus dussumieri , Fish fillet, Frozen storage, Scomberomorus commersoni .
INTRODUCTION of fish. However, little attention has been paid to the composition of different species when selecting fish for the diet [3].
Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 Marine lipids have a high content of Degradation of PUFA by auto oxidation polyunsaturated fatty acids (PUFA), in during storage and processing of fish oils particular eicosapentaenoic (EPA, 20:5 ω-3) and fatty fish easily leads to the formation of and docosahexaenoic acids (DHA, 22:6 ω-3) volatiles associated with rancidity [1]. So, [1, 2]. There is strong evidence that freezing and frozen storage have largely consumption of fish containing high levels been employed to retain fish dietary and of these fatty acids (FAs) is favorable for nutritional properties [4]. Although frozen human health. When fish is suggested as a storage of fish can inhibit microbial means of improving health, both fat content spoilage, the muscle proteins undergo a and the PUFA composition must be number of changes which modify their considered. It is generally recognized that structural and functional properties [5]. PUFA composition may vary among species ______1 Department of Fisheries, College of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Islamic Republic of Iran. 2 Department of Food Technology, Collage of Agriculture, Tarbiat Modares University, P. O. Box: 14115- 336, Tehran, Islamic Republic of Iran. * Corresponding author, e-mail: [email protected]
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Autoxidation and hydrolytic degradation are have a direct sensory impact. However, the the main reasons for biochemical changes. relationship between lipolysis and lipid When oxygen comes into contact with fish oxidation is a matter of some debate. It is during frozen storage, the fats and oils turn generally accepted that FFAs oxidise more rancid, resulting in unpleasant flavors [6]. It readily than esterified FFAs. Increases in is the oxidation of lipids containing FFAs during frozen storage of Atlantic polyunsaturated fatty acids (PUFAs) that salmon at -10ºC, have been shown to have a causes the development of off-flavors and negative sensory impact that is directly aromas, often referred to as "rancidity". The related to the FFAs themselves and not the primary products of fatty acid oxidation oxidation products. This "hydrolytic (lipid hydroperoxides) are generally rancidity" was described in terms of considered not to have a flavor impact. The increasing train oil taste, bitterness and a compounds giving rise to rancid flavors and metallic taste [7]. So, the stability of ω-3 aromas are volatile secondary oxidation FAs during frozen storage of fish is an area products derived from the breakdown of of considerable uncertainty. these lipid hydroperoxides [7]. Narrow-barred Spanish mackerel ( S. The rate and degree of the reaction are commersoni ) and white cheek shark ( C. heavily dependent upon the fish species, the dussumieri ) are commercially important presence or absence of activators and fishes in the Persian Gulf, commonly inhibitors, and storage conditions [1]. processed as frozen fillets [11]. This study In some previous studies, the effect of was carried out to determine fatty acid freezing on the lipid composition of fishes or composition and its changes in mackerel and fish fillets has been investigated. In pre- and shark as a fatty and lean fish, and to postspawned hake, freezing and frozen compare biochemical changes in fillets storage affected polyenoics and ω-3 FAs. during frozen storage. The decrease in the contents of ω-3 FAs in fillets from postspawned hake was lower MATERIALS AND METHODS than that observed in fillets from prespawned fish. [8]. But in Atlantic salmon muscle, it was found that ω-3 FAs are Fish Fillet, Sampling and Processing relatively stable even under adverse storage conditions. Frozen storage of salmon fillets Narrow-barred Spanish mackerel ( S. for 3 months at -12°C showed very little loss commersoni ) and white cheek shark ( C. of triglyceride and no selective change in
Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 dussumieri ) specimens were caught by long triglyceride fatty acid composition, but an line near the West of the Qeshm Island increase in lysophospholipids (LPL) and in (Ram Chaah) in November 2005 (10 fish of free fatty acids [9]. The damage to the lipid each species; about 26 and 45 kg of the fraction of whole jack mackerel ( Trachurus mentioned fish, respectively). The length of symmetricus murphyi ) during frozen storage the specimens was in the 50-70 cm range showed that the lipid hydrolysis was the and the average weight of the specimens of major damage during 75 days’ frozen mackerel was 2.60 kg, while average weight storage. The normal oxidative rancidity in shark was 4.46 kg. The fish specimens (primary and secondary products) present in were beheaded and gutted on board and then fillets of different species was not observed transported in ice within 45 minutes of in the whole fish. Autolytic changes were landing. The fish were then filleted and predominant, because bacterial activity was frozen at -30˚C in order to minimize the low throughtout the entire storage time [10]. effects of biochemical changes during Progressive lipid hydrolysis is shown as transportation from sea to laboratory. Fillets free fatty acids (FFAs). FFAs are either were transported to the laboratory during the important from the point of view of 72 hours after capture. Upon arrival in the oxidation products or have been reported to laboratory, some of the fish fillets were
554 Identification of Fatty Acid in Mackerel and Shark ______
analyzed (start of storage as 0 month) and profile of mackerel and shark oils (% of total then other fillets packaged in individually fatty acids); this entailed using a fused-silica celled polyethylene bags for the freezing capillary column (BPX70; SGE, Melbourne, process. All fillets were stored at under - Australia) with 30 m×0.25 mm× 0.22 µm 18˚C. Analysis of frozen fish fillets was film thickness, a split injector (1.2 µL undertaken as fresh and after 1, 2, 3, 4, 5 and injections) at 240˚C and a FID at 250˚C. 6 months of storage at -18˚C. Triplicate Helium was used as the carrier gas (pressure samples (3 bags of each fish species) were of 50 psi ). The temperatures of the column drawn each month. The samples were and injection port were 190 and 300˚C, thawed in a refrigerator (at a temperature of respectively. The peaks were identified 4±1˚C) overnight, and analytical samples based on their retention times using fatty were drawn from different parts of the acids methyl esters standards and all thawed fillet pieces. All analyses were samples were run in triplicate. An internal carried out at the Department of Food standard method was used to calculate the Science and Technology of Tarbiat Modares fatty acid composition (the internal standard University (Tehran). was C15:0).
Moisture and Lipid Contents Determination of Total Volatile Base Nitrogen (TVB-N) Moisture was determined by weight difference of the homogenized muscle (1-2 The amount of TVB-N (mg 100 g-1 fish g) before and after 24 hours at 105˚C. Results were calculated as g water 100 g -1 flesh) was determined by the direct distillation method according to Goudlas and muscle [12]. Lipids were extracted from the Kontoinas [16]. homogenized white muscle by the Blight and Dyer method. Results were calculated as Statistical Analysis g lipids 100 g -1 wet muscle [13]. Data were presented as mean±standard Determination of Peroxide Value (PV), division (SD) and were subjected to analysis Thiobarbituric (TBA) and Free Fatty of variance (ANOVA). Significant means Acid (FFA) were compared by one-way procedure tests
Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 and T-test (for comparison of mackerel and -1 shark) at α= 0.05 level (n= 3). The PV (meq of O 2 kg lipid) of fillet lipid stored during frozen storage was determined periodically (on 0, 1, 2, 3, 4, 5 and 6 RESULTS AND DISCUSSION months) by the iodometric method according to the AOCS guidelines [14]. The thiobarbituric acid value (mg Moisture and Lipid Content malonaldehyde (MDA) kg -1 of fish flesh) was determined colorimetrically by the Moisture in mackerel and shark ranged Porkony and Dieffenbacher method [15]. between 73.32 and 75.05%, 76.33 and Free fatty acid (%) was determined by the 74.68% in all samples, respectively Kirk and Sawyer method [15]. (Figure1). Based on proximal analysis, water content in shark was significantly more than Fatty Acid Composition in mackerel. In both fishes no significant difference in moisture was obtained as a Gas liquid chromatography (Unicom result of temperature and time of storage model 4600) was used to determine the Fas between fresh and stored fillets up to 6
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SHARKShark MACKERELMackerel SHARKShark MACKERELMackerel 80 7 a a a a 78 6 a a a a a a 5 a 76 b b b a a b 4 b b b b 74 3 Moister, % 72 2 b b Lipid% Content, b b b b b 70 1 0 1 2 3 4 5 6 0 Time (month) 0 1 2 3 4 5 6 Time (month) Figure 1. Comparison of moisture between mackerel and shark during frozen storage Figure 2. Comparison of lipid content between (-18˚C). Data represent means and standard mackerel and shark during frozen storage deviations derived from three sampled fillets (-18˚C). Data represent means and standard for each sampling date. Different letters (bars) deviations derived from three sampled fillets indicate significant differences between for each sampling date. Different letters (bars) mackerel and shark in each time. indicate significant differences between mackerel and s hark in each time. months, and some insignificant difference in content analysis in mackerel were moisture is due to variations in individual significantly (P< 0.05) more than in shark, fish or might be as a result of permanent and showed that mackerel was a fatty fish bags. and shark a lean fish. Nevertheless, in both The levels of lipid in fish flesh vary fish significant (P< 0.05) decreases were depending on species, ranging from lean fish obtained on lipid content as a result of (< 2% total lipid) such as cod, haddock and frozen storage conditions (time and pollack, to high lipid species (8– 20% total temperature). Lipid deterioration is the main lipid) such as herring, mackerel and farmed cause of the low shelf life of fatty fish due to salmon. A total lipid level of 5% has been progressive oxidation and enzymatic suggested as a cut-off point between low and hydrolysis of unsaturated fatty acids in fish. medium fat fish. In addition to species variability, lipid levels vary with sex, diet, Fatty Acid Composition seasonal fluctuation and tissue [7, 17]. For example the dark muscle of Mackerel was Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 found to contain 20% lipid in comparison Susceptibility to rancidity depends not with 4% in the white muscle, while Atlantic only on the amount of lipid present, but also herring can have a seasonal variation of 1– the lipid composition and its location in the 25% total fat. It is well established that oily fish tissue. Fish contain high levels of highly fish are particularly susceptible to lipid unsaturated fatty acids and uniquely high oxidation and rancidity development levels of ω-3 fatty acids, for example, EPA because of the high content of PUFAs in and DPA. It is for this reason that they are their lipids, particularly the nutritionally susceptible to oxidative rancidity. important ω-3 Fas, EPA and DHA [7]. The fatty acid profile of fish varies quite Lipid content ranged in mackerel and considerably between and within species and shark between 6.35 to 3.89 and 1.38 to 0.75, are also influenced by the factors already on wet basis, respectively (Figure 2). It has mentioned [7]. been reported that low-fat fish have a higher The fatty acid composition of mackerel water content [3], as observed in this study; and shark over 6 months is summarized in shark also had higher moisture than Table 1. Except for months 1, 5 and 6 no mackerel. Also the initial amount of lipids, significant differences were observed among and the amount over every period of lipid
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the SFA (saturated fatty acids) content compounds. Eicosapentaenoic (EPA) (C20:5 between mackerel and shark. Palmitic acid ω-3) and docosahexaenoic acids (DHA) (C16:0) was the major fatty acid among the (C22:6 ω-3) were major in total ω-3 SFAs and during the whole period. In the polyunsaturated fatty acids in both mackerel first month, the amount of palmitic acid and shark. The same results were found for (C16:0) in shark was significantly more than gilthead sea bream ( Sparus aurata ) and sea in mackerel; however, there were no bass ( Dicentrarchus labrax ) [18]. The lowest differences between the other months. Also amount of ω-3 compounds were found in C16:0 was the major fatty acid among all linolenic acid (C18:3 ω-3); however, in other fatty acids in both fish. The same mackerel it was significantly more than in result was obtained for Channa spp. [17]. shark. In both mackerel and shark, DHA The amount of myristic (C14:0) and content was more than EPA. The same margaric acids (C17:0) in mackerel were results were found for seal [20] and Channa more than in shark, whereas the amounts of spp. [17] but, in Atlantic mackerel [22], the stearic (C18:0), tricosaenoic (C23:0) and EPA content was more than DHA. lignoceric acid (C24:0) in shark were more Distribution of PUFA in mackerel is DHA> than in mackerel. Nonadecanoic (C19:0) and EPA> AA (arachidonic acid, C20:4 ω-6), arachidic acid (C20:0) were not detected in while in shark it is DHA> AA (C20:4)> shark. EPA. There was no significant difference among The level of ω-6 compounds in shark was the MUFA (monounsaturated fatty acids) significantly more than in mackerel. content between mackerel and shark during Linoleic acid (C18:2 ω-6 cis ), except in the 6 months. Oleic acid (C18:1 ω-9) was the first and third months, and also arachidonic major fatty acid among the MUFAs of each acid (C20:4 ω-6) in shark were significantly fish species. The same result was shown in higher than in mackerel. Linolelaidic acid Channa spp. [17], gilthead sea bream (C18:2 ω-6 trans ) was not detected in shark. (Sparus aurata ) and sea bass ( Dicentrarchus Statistical results showed that, during labrax ) [18]. The amount of palmitoleic frozen storage, changes of PUFA were (C16:1) and cis 10-heptadanoic acids (C17:1) significant, decreasing by 40.1% and in mackerel was more than in shark, while 23.94% especially ω-3 (48% and 42.83%) in the amount of oleic (C18:1 ω-9) and cis -11- mackerel and shark, respectively. The ecosenoic acids (C20:1) in shark were more differences in the fatty acid composition of than in mackerel. the fish species lipids had a decisive Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 In both mackerel and shark, unsaturated function in the formation of hydroperoxides. fatty acids were more than saturated fatty The oxidative changes in frozen fish lipids acids (SFA
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significant differences in this ratio between of storage TAG present in the muscle mackerel and shark during the whole period associated storage depots of oily fish. The of storage. The ω-3:ω-6 ratio in fresh fillets amount of phospholipids substrate available (4.16 and 2.02) and at the end of storage for oxidation by catalysts is proportional to (2.43 and 1.01) were in the recommended the surface area exposed to the aqueous ratio, but a decrease of 41.36% and 50%, phase. Potentially, phospholipids are more respectively, in mackerel and shark showed important in the initial onset of lipid that the nutritional value of these fish has oxidation. Phospholipids also tend to contain been lost during frozen storage. a higher proportion of unsaturated fatty The PUFA/ SFA (P/S) ratio reveals that acids than TAG. It is interesting to note that marine fish are a good source of PUFA it is generally accepted that lean white fish related to saturate fatty acids. In both such as cod are not prone to rancidity mackerel and shark this ratio obtained was development on storage even though they less than 1. Any decrease of PUFA relative contain highly unsaturated phospholipids. to SFA leads to a significant decrease of this These species contain virtually no TAG or ratio (56% and 42.23% in mackerel and myoglobin in the muscle tissue. This implies shark, respectively) during frozen storage; that one or both of these components have however, in mackerel it was significantly important implications for storage stability higher than in shark during 6 months. [7]. It has been suggested that the During storage of both fish, hydroperoxide EPA+DHA/C16:0 ratio is a good index for production was observed. In mackerel, the determining lipid oxidation [23]. Although PV was more significant than in shark, this ratio in mackerel was significantly more however the PV was not different in first than in shark, it has decreased (55.55% and month of storage (Figure 4); an important 46.66% in mackerel and shark, respectively) linear increase of PV was observed up to during frozen storage. The same result was month 6. In shark, a slower development of found for oyster [23]. The negative primary oxidation during storage was relationship between this ratio and storage detected (Figure 3). The increase in peroxide time showed that oxidation mechanisms are value (PV) from an initial value of 2.32 to -1 active during frozen storage. 15.41, and from 0.24 to 4.43 meq of O 2 kg lipid in mackerel and shark, respectively, Lipid Oxidation was significant during frozen storage and indicated oxidative deterioration. This Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 increase of PV in frozen fish in contrast with Within edible muscle tissues there are two fresh fish showed development of rancidity pools of lipids that may be involved in during frozen storage [24]. Development of oxidation reactions. These are storage triacyl an off-flavor is one of the major effects of glycerides (TAGs), which constitute the lipid oxidation [25] and, at the further stage majority of the total lipids in oily fish and of lipid peroxidation, changes in color and the fraction that accounts for the variability nutritional value are observed [22]. in fat content, and phospholipids present in Moreover, oxidized products of lipids the cellular membranes. This lipid fraction formed during storage of fishery products represents around 1% of the total weight of are known to influence the soluble proteins the flesh. The contribution of these lipid (sarcoplasmic and myofibrillar proteins) pools to rancidity development is a matter of [26]. In comparison with shark, mackerel some debate. Although present in much contributed to the more accelerated smaller amounts, the physical form of oxidative degradation of lipids. phospholipids in the membrane bilayer Secondary lipid oxidation was studied by present a large surface area for oxidation the TBA. The TBA number is a measure of reactions to occur compared with "droplets" MDA, a byproduct of lipid oxidation. TBA
560 Identification of Fatty Acid in Mackerel and Shark ______
SHARKShark MACKERELMackerel SHARKShark MACKERELMackerel 18 a a 16 a 0.12 a a 14 0.1 a 12 b a a 0.08 b 10 a a 8 a 0.06 a b b b b b a PeroxideValue, 6 b 0.04 kg fish of flesh) (meq O2/ kg lipid) (meq O2/ 4 a a b b b b 0.02
2 b TBA, (mg malonaldehyde/ 0 0 0 1 2 3 4 5 6 0 1 2 3 4 5 6 Time (month) Time (month)
Figure 3. Comparison of peroxide value Figure 4. Comparison of TBA between between mackerel and shark during frozen mackerel and shark during frozen storage (- storage (-18˚C). Data represent means and 18˚C). Data represent means and standard standard deviations derived from three sampled deviations derived from three sampled fillets fillets for each sampling date. Different letters for each sampling date. Different letters (bars) (bars) indicate significant differences between indicate significant differences between mackerel and shark in each time. mackerel and shark in each time. a result of consumption of MDA in another records revealed an increased rate of lipid reaction. As it was shown in Figure 5, at the oxidation during the frozen storage of the end of the frozen storage the amount of TBA fish species examined. The significant in shark decreased. It might be as a result of increase in TBA from an initial value of consumption of MDA in another reaction 0.043 to 0.104, and from 0.038 to 0.068 mg [28]. of MDA kg -1 of fish flesh in the mackerel and shark, respectively, was revealed during Lipid Hydrolysis frozen storage and indicated oxidative deterioration (Figure 4). The higher increase in TBA value was obtained significantly for An increase in free fatty acid (FFA) mackerel but in the fresh fillets, there was (lipolysis) is a well established post-mortem not any significant difference between feature in fish tissue resulting from the mackerel and shark. Significant differences enzymatic hydrolysis of esterified lipids. in the mackerel and shark indicated a high The build up of FFA can be quite substantial Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 rate of lipid oxidation, and this could be due [7]. to the fact that mackerel is a fatty fish as The development of progressive lipid shown by its lipid content. It is also hydrolysis was observed during frozen important to note that TBA records may not storage of both mackerel and shark. FFA (of reveal the actual rate of lipid oxidation, total lipid as oleic acid) increased since MDA can interact with other significantly (P≤ 0.05) from 3.2 to 5.66, and compounds of fish body such as amines, from 1.06 to 8.37, in mackerel and shark, nucleosides and nucleic acid, proteins, respectively, indicating extensive hydrolysis amino acids of phospholipids, or other of lipids (Figure 5). There were significant aldehydes that are the end product of lipid differences between mackerel and shark oxidation; and this interaction may vary during frozen storage. As has been shown in greatly, with species of fish [17, 26-27]. In Figure 3, FFA in the two first months of this study, generally the TBA values frozen storage in mackerel was more than in recorded were extremely low (< 0.4 mg shark, while it was higher in shark than MDA kg -1 of fish flesh) in both stored fish. mackerel for the other months. These results This, however, does not confirm control of corroborate previous works describing lipid oxidation, since the low TBA could be notable rates of lipid hydrolysis mechanisms
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SHARKShark MACKERELMackerel SHARKShark MACKERELMackerel 45 a a 12 a a a 40 b a a 10 a a 35 a b b b 8 b 30 b b a b b 25 6 b b a a 20 a a FFA, % 4 b 15 b
2 TVBN,100 (mg/ flesh)g 10 5 0 0 0 1 2 3 4 5 6 Time(month) 0 1 2 3 4 5 6 Time (month) Figure 5. Comparison of FFA between Figure 6. Comparison of TVBN between mackerel and shark during frozen storage (- mackerel and shark during frozen storage 18˚C). Data represent means and standard (-18˚C). Data represent means and standard deviations derived from three sampled fillets deviations derived from three sampled for each sampling date. Different letters (bars) fillets for each sampling date. Different indicate significant differences between letters (bars) indicate significant mackerel and shark in each time. differences between mackerel and shark in
in different types of fish during their frozen lipid constituent are phospholipids and are storage [4, 29-31]. generally accepted not to have a rancidity The lipid origin of FFA has been debated. problem [7]. In the work done on hake mince during In comparison with mackerel, shark frozen storage, it has been shown that the contributed to the more accelerated FFA formed originated from both hydrolytical degradation of the fish lipids. phospholipids and neutral lipid fractions Changes in mackerel were consistently [32]. Dekoning and Theodora carried out lower than those observed for shark. After more detailed follow-up work with the same the third month, the FFA content in shark system in which they calculated the rates of stabilized; this could have been due to a enzymatic hydrolysis of phospholipids and depletion of substrate or oxidation of the neutral lipids over a range of temperatures. FFA [28]. The decrease in the rate of FFA formation While the formation of FFA itself does not with decreasing temperature was greater for lead to nutritional losses, its assessment is the phospholipids than for neutral lipids deemed important when an effect of FFA on Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 [33]. Tsukuda also found that FFA was lipid matter is proposed, and explained on derived from both phospholipids and TAG the basis of a catalytic effect of the carboxyl in frozen stored skipjack tuna. In the dark group on the hydro peroxides. Moreover, muscle the majority of FFA was formed being relatively small sized molecules, FFA from TAG but, in the light tissue, FFA was have been shown to undergo a faster mainly due to phospholipids hydrolysis. oxidation rate than bigger lipid classes of Mackerel lipid hydrolysis on frozen storage triglycerides and phospholipids; this showed an increase in FFA consistent with significantly affects the dietary quality of hydrolysis of the phospholipids fraction aquatic food products [31]. It is generally [34]. Similar findings were obtained when accepted that FFAs phospho more readily studying lipid hydrolysis in the flesh of ten than esterified FA, especially when enzymes species of Chinese fresh water fish. The such as lipoxygenase (LOX) can be involved increase in FFA in silver carp was attributed in tissue [7]. to the hydrolysis of phospholipids [35]. During frozen storage a negative Much of the work on the mechanism of correlation between FFA formation and fish muscle lipolysis has been conducted on protein extractability has been observed lean fish such as cod in which the primary [36]. Regardless of the source, FFA may be
562 Identification of Fatty Acid in Mackerel and Shark ______
directly responsible for off-flavors, the organs of sea fish and invertebrates [38, 40], destruction of some vitamins and amino and it is believed that they use it to increase acids, changes in texture, and changes in osmotic concentration and thus depress the water holding capacity. The latter two freezing point of body fluids [40]. Freezing results are particularly important in frozen and frozen storage do not destroy the fish and are related to the propensity of fatty activity of TMAO demethylase. The rate of acids to bind, denature and cross-link enzymatic cleavage of TMAO to myofibrillar proteins [7]. FFAs attach formaldehyde (FA) and dimethylamin themselves hydrophobically or (DMA) depends on the substrate and FA hydrophilically to the appropriate sites on [40]. In cod (Gadus morhua ) and other the protein surface, creating a hydrophobic gadoid fish, TMA constitutes most of the so- environment which results in a decrease in called total volatile bases until spoilage. protein solubility [26]. Besides, TVB-N levels still rise due to There is circumstantial evidence that formation of NH 3 and other volatile amines. products of lipid hydrolysis promote protein In some fish that do not contain TMAO, or denaturation, especially in lean fish species where spoilage is due to a non-TMAO [36, 37]. According to the lipid content of reducing flora, a slow rise in TVB-N is seen shark, it is a lean fish species; hence, FFA during storage, probably resulting from the might have affected protein denaturation of deamination of amino-acids [38]. The initial shark in comparison to mackerel [36]. amount of TVB-N in both fishes showed freshness, and this is in agreement with the Total Volatile Base Nitrogen (TVB-N) initial measured amount of TVB-N for chub mackerel and hake [16, 40], salmon, whiting and mackerel [36]. TVB-N levels vary from TVB-N content of both mackerel and species to species and in each species it shark during frozen storage are shown in varies based on age, sex, environment and Figure 6. In fresh fillets, the TVB-N values season. In frozen conditions in which the -1 were 14.83 and 13.86 mg 100 g flesh for bacterial count and activity are gradually mackerel and shark, respectively. At the first decreased, factors like texture enzymes are month of storage, the TVB-N values showed effective to produce TVB-N. Also, an an increasing trend up to 35.58 and 41.73 increase in TVB-N during storage can be -1 mg 100 g of flesh for mackerel and shark, due to an increase of ammonia released from respectively, and reached their maximum amination of adenosine mono phosphate or Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 level. After that they decreased, although histamine. their level was more than in fresh fillets; In this study, the abrupt increase of TVB- during the last month of storage, they N in the first month of storage may be due to showed an increasing pattern in both fish TMAO degradation and, after it decreases, again. The amount of TVB-N did not differ the degradation process and TVB-N amount significantly between mackerel and shark at has decreased. But, from the third month to the beginning of storage, however their the end of frozen storage, the increase in amount in shark was significantly more than TVB-N level may be a result of ammonia mackerel during the other months. liberation and other volatile amines from Although TVB-N level is a poor indicator muscular damaged tissue. Shark contains a of fish freshness [38], it has been commonly great deal of urea in its blood and muscles, used to evaluate fish muscle spoilage [39]. which helps it in osmo-regulation in the sea For several fish species, TVB-N values were water. Although bacteria are inactive under reported to increase curvilinearly or linearly –8˚C, their enzymes are active. Presence of with time [39]. Trimethylamine N-oxide urea in shark muscle can help increase (TMAO) is a natural characteristic ammonia as a result of degradation by component of muscle tissues and visceral bacterial enzymes.
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CONCLUSSIONS Fish Lipids and Frozen Fish Muscle. Food Chem., 92 : 547-557. 2. Bayir, A., Haliloglu, H. İ., Sirkecioglu, A. Frozen fish may develop a dry, stringy N. and Aras, N. M. 2006. Fatty Acid texture during frozen storage. The process is Composition in Some Selected Marine Fish mainly due to the denaturation and Species Living in Turkish Waters. J. Sci aggregation of myofibrillar proteins and, Food Agric ., 86 : 163-168. perhaps, collagen [41]. Enzymes appear to 3. Osman, H., Suriah, A. R. and Law, E. C. contribute to this quality defect in several 2001. Fatty Acid Composition and ways. Free fatty acids resulting from lipid or Cholesterol Content of Selected Marine Fish in Malaysian Waters. Food Chem., 73 : 55- phospholipid hydrolysis can bind to 60. myofibrillar proteins causing denaturation 4. Lugasi, A., Losada, V., Hovari, J., Lebovisc, and aggregation. Products of lipid oxidation, V., Jakoczi, I. and Aubourg, S. P. 2007. such as malonaldehyde, can react with Effect of Pre-soaking Whole Pelagic Fish in protein to form cross-linked proteins. a Plant Extract on Sensory and Biochemical TMAO demethylase forms formaldehyde Changes during Subsequent Frozen Storage. (with dimethylamine) in fish and the LWT, 40 : 930-936. presence of formaldehyde is related to 5. Badii, F. and Howell, N. K. 2002. Changes texture deterioration by formation of the in the Texture and Structure of Cod and cross-linking agents during frozen storage Haddock Fillets during Frozen Storage. Food Hydrocolloids, 16 : 313-319. [7]. 6. Gunderson, J. 1984. Fixin' Fish: A Guide to In the present study PV, TBA, FFA and Handling, Buying, Preserving, and TVBN increased significantly (P< 0.05) Preparing Fish. 2nd Edition, University of during frozen storage. Comparison of results Minnesota Press, Minneapolis, 56 PP. between each of the species studied has led 7. Bremner, H. A. 2002. Safety and Quality to some marked differences in lipid Issues in Fish Processing. Woodhead oxidation and hydrolytic development. Publishing Limited, Food Science and Increase in lipid oxidation which shown as Technology , Cambridge, 519 PP.
PV and TBA were significantly more in 8. Roldán, H. A., Roura, S. I., Montecchia, C. ĕ mackerel than shark. Lipid deterioration is L., P rez Borla, O and Crupkin. M. 2005. Lipid Changes in Frozen Stored Fillets from the main cause of the low shelf life of fatty Pre and Postspawned Hake ( Merlccius fish due to progressive oxidation and hubbsi Marini ). J. Food Biochem., 29 : 187- enzymatic hydrolysis of unsaturated fatty 204. acids in fish. Although the lipid content in 9. Polvi, M. Sh., Ackman, R. G., Lall, S. P. and shark was less than in mackerel, Saunders, R. L. 2007. Stability of Lipids and Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 development of lipid hydrolysis described as Omega-3 Fatty Acids during Frozen Storage FFA in shark was significantly more than in of Atlantic Salmon. J. Food Processing and mackerel and promotes quality loss during Preservation, 15 : 167-181.
frozen storage in this lean fish. On the other 10. Aranda, M., Mendoza, N. and Villegas, R. hand, the more TVBN is present in shark, 2006. Lipid Damage during Frozen Storage of Whole Jack Mackerel ( Trakhurus the greater the formation of the cross-linking symmetricus murphyi ). J. Food Lipid, 13 : agent formaldehyde occurs during frozen 155-166. storage. It means that oxidative and 11. Fishery Statistics. 2004 . Scientific Statistical hydrolytic deterioration are promoter factors Committee of Fishery . State Institute of of biochemical changes in mackerel and Fishery, Tehran (2005). shark, respectively. 12. AOAC, 1990. Association of Official Analytical Chemists . 15 th Edition ., Procedure REFERENCES 984. 13. Bligh, E. G. and Dyer, W. J. 1959. A Rapid Method of Total Lipid Extraction and
1. Pasoz, M., Gallardo, J. M., Torres, J. L. and Purification. Can. J. Biochem. Physiol., 37: Medina, I. 2005. Activity of Grape 911-917. Polyphones as Inhibitors of the Oxidation of
564 Identification of Fatty Acid in Mackerel and Shark ______
14. AOCS, 1989. Official Methods and 25. Fagan, J. D., Gormley, R. T. and Recommended Practices of the American Mhuircheartaigh, M. 2003. Effect of Freeze- Oil Chemists Society. 4th Edition, AOCS, Chilling, in Comparison with Fresh, Chilling Champaign. and Freezing, on some Quality Parameters 15. Kirk, R. S. and Sawyer, R.1991. Pearson’s of Raw Whiting, Mackerel and Salmon Composition and Analysis of Foods . 9th Portion. LWT, 36: 647-655. Edition, Longman Scientific and Technical, 26. Sarma, J., Vidyasagar Reddy, G. and Srikar, London, PP. 634-648. L.N. 2000. Effect of Frozen Storage on 16. Goudlas, A. E. and Kontaminas, M.G. 2005. Lipids and Functional Properties of Proteins Effect of Salting and Smoking-Method on of Dressed Indian Oil Sardine ( Sardinella the Keeping Quality of Chub Mackerel longiceps ). Food Research International, 33 : (Scomber japonicus ): Biochemical and 815-820. Sensory Attributes. Food Chem., 93: 511- 27. Simeonidou, S., Govaris, A. and Vareltzis, 520. K. 1998. Quality Assessment of Seven 17. Zuraini, A., Somchit, M. N., Solihah, M. H., Mediterranean Fish Species during Storage Goh, Y. M., Arifah, A. K., Zakaria, M. S., on Ice. Food Research International, 30: Somchit, N., Rajion, M. A., Zakaria, Z. A. 479-484. and Mat Jais, A.M. 2006. Fatty Acid and 28. Namulema, A., Muyonga, J. H. and Kaaya Amino Acid Composition of Three Local N. A. 1999. Quality Deterioration in Frozen Malaysian Channa spp. Fish. Food Chem., Nile Perch ( Lates niloticus ) Stored at -13 97: 674-678. and -27°C. Food Research International, 32: 18. Saglik, S., Alpaslan, M., Gezgin, T., 151-156. Getinturk, K., Tekinary, A. and Guven, K. 29. Aubourg, P. S. 1999. Lipid Damage C. 2003. Fatty Acid Composition of Wild Detection during the Frozen Storage of an and Cultivated Gilthead Sea Bream ( Sparus Underutilized Fish Species. Food Research aurata ) and Sea Bass ( Dicentrarchus International, 32 : 497-502. labrax ). European J. Lipid Sci. Technol., 30. Losada, V., Pineiro, C., Barros-Velazques, J. 105 : 104-107. And Aubourg, S. P. 2005. Inhibition of 19. Silva, J. L. and Ammerman, G. R. 1993. Chemical Changes Related to Freshness Composition, Lipid Change and Sensory Loss during Storage of Horse Mackerel Evaluation of Two Sizes of Channel Catfish (Trachurus trachurus ) in Slurry Ice. Food during Frozen Storage. J. Applied Chem ., 93 : 619-625. Aquaculture, 2: 39-49. 31. Losada, V., Barros-Velazques, J. and 20. Shahidi, F., Synowiecki, J., Amarowies, R. Aubourg, S. P. 2007. Rancidity and Wanasundara, U. 1994. Omega-3 Fatty Development in Frozen Fish: Influence of Acid Composition and Stability of Seal Slurry Ice as Preliminary Chilling Lipids. Lipid in Food Flavors, 16: 233-243. Treatment. LWT, 40: 991-999. 21. Arrayed, F. H., Maskati, H. A. and 32. Dekoning, A. J., Milkovitch, S. and Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 Abdullah, F.1999. N3-Polyunsaturated Fatty Theodora, H. M. 1987. The Origin of Free Acid Content of Some Edible Fishes from Fatty Acids Formed in Frozen Cape Hake Bahrain Waters. Estuarine, Costal and Shelf Mince during Cold Storage at -18ºC. J. Sci. Science, 4: 109-114. Food Agric. , 39 : 79–84. 22. Dragoev, S. G., Kiosev, D. D., Danchev, S. 33. Dekoning, A. J. and Theodora, H. M. 1990. A., Ioncheva, N. I. and Genov, N. S. 1998. Rates of Free Fatty Acid Formation from Study on the Oxidative Processes in Frozen Phospholipids and Neutral Lipids in Frozen Fish. Bulgarian J. Agric. Sci., 4: 55-65. Cape Hake Mince at Various Temperatures . 23. Jeong, B. Y., Oshima, T., Koizumi, C. and J. Sci. Food Agric. , 50 : 391–8. Kanou, Y. 1990. Lipid Deterioration and its 34. Tsukada, N. 1976. Changes in the Lipids of Inhibition of Japanese Oyster ( Crasostrea Skipjack during Frozen Storage. Bull. Tokai gigas ) during Frozen Storage. Nippon Suisan Reg. Fish. Res. Lab. , 84 : 31–41. Gakkaishi, 56: 2083-2091. 35. Kaneniwa, M., Miao, S., Yuan. C. H., Iida, 24. Ben-Gigirey, B., Desousa, J. M., Villa, T. G. H. and Fukuda, Y. 2000. Lipid Components and Barros-Velazqez, J. 1999. Chemical and Enzymatic Hydrolysis of Lipids in Changes and Visual Appearance of Albacore Muscle of Chinese Freshwater Fish. J. Amer. Tuna as Related to Frozen Storage. J. Food Oil Chem. Soc., 77 : 825–30. Sci., 64 : 20-24. 36. Sikorski, Z. E. and Kolakowska, A. 1994. Changes in Protein Frozen Stored Fish, In:
565 ______Nazemroaya et al.
"Seafood Protein ", Sikorski S. E., Pan B.S. 39. Mazorra-Manzano, M. A., Pacheco-Aguilar, and Shahidi, F (Eds.). Chapman and Hall R., Diaz-Rojaz, E. I. and Lugo-Sanchez, M. Inc, New York, PP. 99-112. E. 2000. Postmortem Changes in Black 37. Natseba, A., Lwalinda, I., Kakura, E., Skipjack Muscle during Storage in Ice. J. Muyanja, C. K. and Muyonga, J. H. 2005. Food Sci., 65: 774-779. Effect of Pre-Freezing Icing duration on 40. Sikorski, Z. E. and Kostuch, S. 2003. Quality Changes in Frozen Nile perch ( Lates Trimethylamin N-oxide Demethylase: Its niloticus ). Food Research International , 38 : Occurrence, Properties, and Role in 469-474. Technological Changes in Frozen Fish. 38. Castro, P., Carlos Penedo Padron, J., LWT, 3: 213-219. Caballero Cansino, M., Sanjuan Velazques, 41. Haard, N.F. 1994. Protein Hydrolysis in E. And Millan de Larriva, R. 2006. Total Seafood, In: " Seafoods: Chemistry, Volatile Base Nitrogen and its Use to Assess Processing Technology and Quality ", Freshness in European Sea Bass Stored in Shahidi, F. and Botta, R. (Eds.). Chapman Ice. Food Control, 17: 245-248. and Hall, London, PP. 10–33.
ﺷﻨﺎﺳﺎﻳﻲ اﺳﻴﺪﻫﺎي ﭼﺮب در ﻓﻴﻠﻪ ﻣﺎﻫﻴﺎن ﺷﻴﺮ ( Scomberomorus commersoni) و ﻛﻮﺳﻪ ﭼﺎﻧﻪ ﺳﻔﻴﺪ ( Carcharhinus dussumieri) و ﺗﻐﻴﻴﺮات آن ﻃﻲ ﺷﺶ ﻣﺎه ﻧﮕﻬﺪاري ﺑﻪ ﺣﺎﻟﺖ اﻧﺠﻤﺎد در C° 18- 18-
س . ﻧﺎﻇﻢ رﻋﺎﻳﺎ، م ع. . ﺳﺤﺮي و م . رﺿﺎﻳﻲ
ﭼﻜﻴﺪه
ﺗﻐﻴﻴﺮات ﺗﺮﻛﻴﺐ اﺳﻴﺪﻫﺎي ﭼﺮب و ﺷﺎﺧﺺ ﻫﺎي ﺑﻴﻮﺷﻴﻤﻴﺎﻳﻲ ﻓﻴﻠﻪ در ﻣﺎﻫﻴﺎن ﺷﻴﺮ ( ﺑﺎ ﻣﻘﺪار زﻳﺎدي ﭼﺮﺑﻲ ) و ﻛﻮﺳﻪ ﭼﺎﻧﻪ ﺳﻔﻴﺪ (ﺑﺎ ﻣﻘﺪار اﻧﺪك ﭼﺮﺑﻲ ) ﺧﻠﻴﺞ ﻓﺎرس ﺣﻴﻦ ﻧﮕﻬﺪاري ﺑﻪ ﺣﺎﻟﺖ اﻧﺠﻤﺎد ( C° -18 ) ﺗﺎ ﻣﺪت ﺷﺶ ﻣﺎه اﻧﺪازه ﮔﻴﺮي ﮔﺮدﻳﺪ . در آﻧﺎﻟﻴﺰ ﺗﻘﺮﻳﺒﻲ ﻣﺤﺘﻮاي ﭼﺮﺑﻲ در ﻣﺎﻫﻲ ﺷﻴﺮ و ﻛﻮﺳﻪ ﺑﻪ ﺗﺮﺗﻴﺐ (% 6/35 %و 1/38 ) اﻧﺪازه ﮔﻴﺮي ﺷﺪ، ﻫﺮﭼﻨﺪ در ﺣﻴﻦ ﻧﮕﻬﺪاري ﺑﻪ ﺣﺎﻟﺖ اﻧﺠﻤﺎد ﻣﻘﺪار آن ﻛﺎﻫﺶ ﻣﻌﻨﻲ داري (% /65 45 و % /74 38 ﺑﻪ ﺗﺮﺗﻴﺐ در ﺷﻴﺮ و Downloaded from jast.modares.ac.ir at 13:36 IRST on Thursday October 7th 2021 ﻛﻮﺳﻪ ) ﻧﺸﺎن داد . در ﺑﺮرﺳﻲ اﺳﻴﺪﻫﺎي ﭼﺮب، ﻣﻘﺪار PUFA ﺧﺼﻮﺻﺎً اﻧﻮاع اﻣﮕﺎ 3- در ﻣﺎﻫﻲ ﺷﻴﺮ ﻧﺴﺒﺖ ﺑﻪ ﻛﻮﺳﻪ ﺑﻴﺸﺘﺮ ﺑﻮد . ﺑﺎ اﻳﻦ وﺟﻮد، ﻣﺤﺘﻮاي اﺳﻴﺪﻫﺎي ﭼﺮ ب در ﻫﺮ دو ﻣﺎﻫﻲ ﺣﻴﻦ ﻧﮕﻬﺪاري ﺑﻪ ﺣﺎﻟﺖ اﻧﺠﻤﺎد ﺗﻐﻴﻴﺮ ﭘﻴﺪا ﻛﺮد . ﻣﻘﺪار اﺳﻴﺪﻫﺎي ﭼﺮب اﺷﺒﺎع در ﺑﺮاﺑﺮ اﺳﻴﺪﻫﺎي ﭼﺮب ﻏﻴﺮ اﺷﺒﺎع اﻓﺰاﻳﺶ ﻧﺸﺎن داد . ﻛﺎﻫﺶ ﺗﺮﻛﻴﺒﺎت PUFA (% /1 40 40 و % /94 23 ) ﺑﻪ ﺗﺮﺗﻴﺐ در ﺷﻴﺮ و ﻛﻮﺳﻪ ﺑﻪ ﺻﻮرت زﻳﺮ ﻣﻲ ﺑﺎﺷﺪ : اﻣﮕﺎ 3- (% 48 و % /83 )42 ، ﻧﺴﺒﺖ اﻣﮕﺎ 3- ﺑﻪ اﻣﮕﺎ -6 -6 (% /36 41 و % )50 ، ﻧﺴﺒﺖ PUFA/ SFA ( % 56 و % /23 42 ) و ﻧﺴﺒﺖ EPA+DHA/C16 %( /55 55 و % /66 ).46 در ﻫﺮ دو ﻣﺎﻫﻲ ﺷﺎﺧﺺ ﻫﺎي ﺗﻴﻮﺑﺎرﺑﻴﺘﻮرﻳﻚ اﺳﻴﺪ (TBA) ، ﭘﺮاﻛﺴﻴﺪ (PV) ، اﺳﻴﺪﻫﺎي ﭼﺮب آزاد ( FFA) و ﻛﻞ ﺑﺎزﻫﺎي ازﺗﻪ ﻓﺮار ( TVBN ) ﺑﻪ ﻃﻮر ﻣﻌﻨﻲ داري (p<0.05) در ﻃﻮل زﻣﺎن اﻓﺰاﻳﺶ ﻳﺎﻓﺖ . ﻧﺘﺎﻳﺞ ﻧﺸﺎن داد ﻛﻪ در ﻣﻴﺎن اﻳﻦ ﺷﺎﺧﺺ ﻫﺎ، ﺗﻐﻴﻴﺮات ﭘﺮاﻛﺴﻴﺪ و ﺗﻴﻮﺑﺎرﺑﻴﺘﻮرﻳﻚ اﺳﻴﺪ در ﻣﺎﻫﻲ ﺷﻴﺮ ﺑﻪ ﻃﻮر ﻣﻌﻨﻲ داري (p<0.05) ﺑﻴﺸﺘﺮ از ﻛﻮﺳﻪ ﺑﻮد اﻣﺎ، ﺗﻐﻴﻴﺮات اﺳﻴﺪﻫﺎي ﭼﺮب آزاد و ﻛﻞ ﺑﺎزﻫﺎي ازﺗﻪ ﻓﺮار در ﻣﺎﻫﻲ ﻛﻮﺳﻪ ﺑﻪ ﻃﻮر ﻣﻌﻨﻲ داري (p<0.05) ﺑﻴﺸﺘﺮ از ﻣﺎﻫﻲ ﺷﻴﺮ ﺑﻮد . اﻳﻦ ﻣﻮﺿﻮع ﻧﺸﺎن دﻫﻨﺪه آن اﺳﺖ ﻛﻪ ﺗﻐﻴﻴﺮات اﻛﺴﻴﺪاﺳﻴﻮﻧﻲ و ﺗﻐﻴﻴﺮات ﻫﻴﺪ روﻟﻴﺘﻴﻜﻲ ﺑﻪ ﺗﺮﺗﻴﺐ در ﻣﺎﻫﻴﺎن ﺷﻴﺮ و ﻛﻮﺳﻪ ﭘﻴﺶ ﺑﺮﻧﺪه ﺗﻐﻴﻴﺮات ﺑﻴﻮﺷﻴﻤﻴﺎﻳﻲ در ﺣﻴﻦ اﻧﺠﻤﺎد ﻫﺴﺘﻨﺪ .
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