Composition of total,neutral and phospholipids in wild and farmed tambaqui (Colossoma macropomum) in the Brazilian Amazon area

BACKGROUND: Fishing is a traditional extractive activity in the Amazonian region, representing an important factor in the economy of the area. The wet and dry cycles cause extreme changes in the chemical composition of the water. This study aimed to investigate the fatty acid composition of the total lipid (TL), neutral lipid (NL) and phospholipid (PL) fractions of the dorsal muscle, orbital cavity and abdominal cavity fat of farmed and wild tambaqui in the Amazon area captured in different seasons. RESULTS: Fatty acids were analyzed by high‐resolution gas chromatography/mass spectrometry. Sixty‐one fatty6 acids were detected in the TL, 67 in the NL and 58 in the PL. The main fatty acids found in the TL, NL and PL of farmed and wild fish were oleic, palmitic, stearic and linoleic acids. Higher levels of eicosapentaenoic and docosahexaenoic acids were observed in PL compared with NL. No distinctions in the quantity of these fractions between dorsal muscle and orbital cavity were found. CONCLUSION: The season had a significant influence on TL and fatty acid composition. Fish caught in the wild are considered superior for consumption. The seasonal characteristics of the Amazon influenced the composition of fatty acid composition in the species. Fish captured during the dry season showed a higher percentage of long‐chain polyunsaturated fatty acids. Copyright © 2008 Society of Chemical Industry     

LIPID CHANGES IN FROZEN STORED FILLETS FROM PRE- AND POSTSPAWNED HAKE (MERLUCCIUS HUBBSI MARINI)

The lipid composition of frozen stored fillets from pre‐ and postspawned hake was studied. The total lipid (TL) content in the chloroform/methanol extract from unfrozen postspawned hake was four times higher than that of prespawned fish. After freezing, the TL content of postspawning hake muscle remained unchanged whereas the TL extracted from prespawning fish muscle increased about 90%. The TL extractability of muscle from fish in both different gonadal conditions was not affected by frozen storage. Lipolysis in frozen stored fillets from prespawned hake occurs principally by hydrolytic action on phospholipids (PL), and phosphatidylcholine was the main PL hydrolyzed. Triacylglycerols were the main substrates hydrolyzed in frozen stored fillets from postspawned hake. Freezing and frozen storage affected polyenoics and n‐3 fatty acids (FA). The decrease in the contents of n‐3 FA in fillets from postspawned hake was lower than that observed in fillets from prespawned fish.     

鲤、鲫卵的脂质和脂肪酸特性

鲤(Cyprinus carpio)、鲫(Carassius auratus)卵总脂分别为干基的16.90%和10.19%。两者脂质和脂肪酸组成总体比较接近。总脂中含较高的甘油三酯和极性脂,并含一定量的固醇及其酯。极性脂约占总脂的30%,主要为PC和PE,并含一定的心磷脂。两种鱼卵主要含C14～C22的19种脂肪酸,16:0和18:1含量最高,DHA等n-3族多烯酸和20:4n-6也较高,而EPA较低,P/S>>0.5。总脂中饱和、单不饱和、多不饱和脂肪酸的比例接近1:1:1,中性脂中C18、C20酸较多,极性脂中C22酸(DHA)较多。鲫卵18:2n-6较高,使得多烯酸含量稍高,胆固醇、磷脂含量及PC/PE和n-3/n-6稍低于鲤卵。研究表明:两种淡水鱼卵与其鱼肉相比,磷脂和胆固醇明显高,磷脂以PC为主,其次为PE;多烯酸稍高,其中DHA高而EPA低,并含20:4n-6。鲫卵PL的乳化稳定性低于相同浓度大豆磷脂的。其独特的脂质具有较大的研究利用价值。     

Comparative assessment of proximate composition,physicochemical parameters,fatty acid profile and mineral content in farmed and wild rainbow trout (Oncorhynchus mykiss)

This study was conducted to determine differences between farmed and wild rainbow trout in terms of proximate and fatty acid composition, physicochemical parameters and mineral content. Fat content of farmed fish fillets was higher, while moisture content was lower than wild fish. However, wild fish had higher pH value and water‐holding capacity comparing to farmed fish. The muscle lipids of farmed fish contained higher proportions of 20:0, 18:1n‐9 and 20:1n‐9; and lower proportions of 18:2n‐6, 20:2cis, 18:3n‐3, 20:3n‐6, 20:4n‐6, 20:5n‐3 and 22:6n‐3 fatty acids than wild fish. The percentage of total saturated fatty acids (SFAs) was similar in both fish. Total polyunsaturated fatty acids (PUFAs), n‐3 PUFAs and n‐3/n‐6 PUFAs ratio were higher in the wild fish comparing to farmed fish, whereas its total monounsaturated fatty acids (MUFAs) and n‐6 PUFAs contents were lower. Among the seventeen minerals analysed in fish flesh, differences existed between farmed and wild rainbow trout in Ca and Fe contents. Moreover, toxic trace minerals (As, Cd, Pb and Hg) were all present in amounts below their toxic levels. The differences observed between farmed and wild fish may be attributed to the diet constituents and environmental conditions of the fish.     

Distribution of lipids and trace minerals in different muscle sites of farmed and wild turbot (Psetta maxima)

Lipid and trace mineral composition were studied in different sites of the edible flesh of farmed and wild turbot (Psetta maxima). Lipid matter (total content, sterols, tocopherols) showed to accumulate in the edge zone (EZ), except for phospholipid (PL), which provided a distribution that was found to be independent from the kind of turbot and the zone considered. Fatty acid composition of total lipids showed a non‐homogeneous distribution, as the EZ exhibited a different fatty acid group composition (higher monounsaturated and lower polyunsaturated and ω3/ω6 ratio values) than the other zones considered; fewer differences were observed by considering the PL fatty acid composition. Most minerals (Ca, Cu, Fe, Mn and Se) studied showed to be homogeneously distributed along the muscle sites of the wild fish, while more differences were obtained when considering the farmed one. For both kinds of turbots, the most important difference was obtained in the case of Zn, as a largely higher content in the EZ than in the other zones was detected. A close relationship between Zn and total lipid contents (r² = 0.90 and 0.76 for farmed and wild turbots, respectively) was observed.     

Changes in fatty acid composition in muscle and adipose tissue of farmed rainbow trout (Oncorhynchus mykiss) in relation to ration and age

To evaluate the importance of age and feed ration level (RL) on the composition of tissue fatty acid (FA) in rainbow trout (Oncorhynchus mykiss), fish were fed rations ranging from appreciable underfeeding to gross overfeeding in a longitudinal experiment lasting from start of feeding to onset of sexual maturation 2.4 years later. In order to study the effects of compensatory growth and reduced feed availability, fish were moved from high to low ration and vice versa. Changes of individual FA of total lipid (TL), triacylglycerols (TAG) and total phospholipids (PL) were studied in white and red muscle, as well as in three major adipose tissues. The effect of saltwater transfer on FA composition was also examined. A strong interdependence was found between the relative proportion of PL and TAG with changes in TL content. This was most prominent in white muscle. In parallel with this change in relative lipid class composition, a major effect was seen on FA in the TL fraction. The most marked effect of RL was an inverse relationship between 22:6 n-3 of the PUFA n-3 series and 16:1 and 18:1 of the MUFA series. This was seen in all tissues studied. It is suggested that the most important factor governing FA composition in muscle, pending changes in feed intake, is the TL content, affecting the relative level of PL and TAG. In adipose tissue, consisting mainly of TAG, more subtle changes were observed. The FA compositions of PL and TAG were not affected to any major extent by RL, except at extreme reductions. Significant changes in FA of PL and TAG were observed as an effect of saltwater transfer.     

Fatty acids in muscles and liver of Tunisian wild and farmed gilthead sea bream, Sparus aurata

The total fat content and the fatty acids profile were analysed in the dorsal and ventral muscles and in the liver from wild and farmed gilthead sea bream (Sparus aurata). The amount of fish lipid was higher in farmed than in wild fish in all studied samples and the highest level of all was observed in liver. It was noted that, among all the samples studied for saturated fatty acids (SFA) and Monounsaturated fatty acids (MUFA), whether farmed or wild, palmitic (C16:0) and oleic (C18:1 n − 9) acids were the principal saturated and monounsaturated fatty acids. The results showed that farmed fish contained a higher level of n − 3 polyunsaturated fatty acids (PUFA), particularly docosahexaenoic acids (DHA) and eicosapentaenoic acids (EPA), whereas wild fish contained a higher level of n − 6 PUFA. Arachidonic acid (C20:4 n − 6) was the primary n − 6 PUFA in wild fish whereas in farmed fish, linoleic acid (C18:2 n − 6) was the major n − 6 PUFA. Farmed fish were characterized by higher n − 3/n − 6 ratio for all samples studied, due to the abundance of n − 3 PUFA, particularly DHA.     

Effect of cold temperature on the composition of different lipid classes of the foodborne pathogen Listeria monocytogenes: focus on neutral lipids

In this work a thorough consideration of the membrane lipid composition of Listeria monocytogenes together with DSC analysis is described in order to estimate the biological importance of lipid changes during low-temperature adaptation. Furthermore, these studies provide comparative data for fatty acid changes for neutral, NL and polar lipids, PL separately. The cold adaptation (5 degrees C) response of L. monocytogenes showed (i) an increase in the level of NL content (30%) among the total lipids, TL and (ii) that the increase (7-fold) in the anteiso-15:0/anteiso-17:0 fatty acid ratio, FAr, for cold NL was at variance with the ratio for TL and PL (about 10-fold). We correlated our findings with DSC studies on phase transition temperature (Tc), enthalpy difference (DeltaH) and peak range of the transition for TL, PL, NL (from cultures at 30 and 5 degrees C); The decrease of Tc (10.5 degrees C) and DeltaH (51%) for TL is a reflection of the decrease of Tc (11.5 degrees C) and DeltaH (56%) for PL. This large decrease is interpreted by the high (10-fold) increase of a-15:0/a-17:0 FAr of PL5 degrees C. In NL the decrease of Tc (3 degrees C) and of DeltaH (42%) is interpreted by both adaptation mechanisms: the (lower) 7-fold increase of anteiso-15:0/anteiso-17:0 FAr and the NL percentage calculated from increased mass values. The peak range of TL5 degrees C (from -15 to 25 degrees C) is a reflection of the peak range of NL5 degrees C, which is unchanged, as is the peak range of NL30 degrees C.     

Lipid Changes of Freeze-Dried Spinach by Various Kinds of Oxidation

: Lipid changes in freeze‐dried spinach by various oxidations were studied by using thin‐layer chromatography and gas chromatography. There were no characteristic changes in lipids by the oxidation except decrease in esterified sterols in NL and phosphatidic acid and phosphatidylcholine in PL. Stability of the freeze‐dried spinach lipid to the oxidation was higher when it was in the form of total lipid than when separated into NL, GL, or PL. Autoxidation and enzyme‐catalyzed oxidation resulted in the highest fatty‐acid composition change in NL. However, photooxidation showed the biggest change in PL and GL. C₁₆ fatty acids tended to be more stable than C₁₈ fatty acids to the oxidation.     

Fillet proximate composition,lipid quality,yields, and organoleptic quality of Mediterranean-farmed marine fish: A review with emphasis on new species

Species diversification in Mediterranean mariculture involves various important fish that contribute to the diet of many human populations. These include meagres (Sciaenidae), flatfishes, mullets, and various sparids. Their quality aspects (yields, fillet proximate composition, and lipid quality) are discussed in this review. Their filleting yield is mostly 40–45%. The viscerosomatic index ranges from 1.5% to 14%, depending on species. Low muscle fat contents of flatfishes and meagres differentiate them from the rest of the farmed species. Farmed fish contain high n-3 polyunsaturates fatty acids (PUFA; 12.3–36.3% vs. 5.48–37.2% in the wild) and have higher muscle fat and n-6 PUFA contents (mainly 18:2 n-6) than their wild counterparts. The aquaculture management, diet, and season can affect fillet composition and fatty acids, while season (i.e. food availability and maturation) largely affects lipid quality in wild fish. Data on the sensory quality of Mediterranean-farmed species are mainly limited to whether specific management differentiates the sensory quality; thus, further development of tools for sensory analysis is required. Observations on the quality features in farmed Mediterranean fish indicate that species diversification can also provide product diversification based on different commercial weights and fillet quality specifications.     

Analysis of lipid classes and the fatty acid composition of the salted fish roe food products,Ikura, Tarako,Tobiko and Kazunoko

This study was designed to clarify the content of lipid classes and the fatty acid composition of total lipids (TL), sterol esters (SE), triacylglycerols (TG), phospholipids (PL), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) of the Japanese fish roe products, Ikura, Tarako, Tobiko and Kazunoko. The TL, total cholesterol, TG, and PL content of Ikura were higher than those of Tarako, Tobiko and Kazunoko. Kazunoko had the lowest cholesterol content among these roe products. PC was the main component in the PL class of each fish roe product. The main fatty acids of all roe products were 16:0, 18:1n−9, 20:5n−3, and 22:6n−3. Docosahexaenoic acid (22:6n−3) was rich in the TL, SE, TG, PL, PC and PE fractions of all roe products. In particulars the 22:6n−3 percentage of PC and PE fractions in Tobiko were higher than those of Ikura, Tarako and Kazunoko. These results indicate that the lipid from fish roe products may be a useful food source for maintaining human health.     

Lipolytic and oxidative changes in Iberian dry-cured loin

This study was conducted using 61 Iberian pigs from four different genetic lines fattened under two different rearing systems. Fatty acid composition of neutral lipids (NL), polar lipids (PL) and free fatty acids (FFA) of the 61 fresh loins and their corresponding dry-cured loins and indices of lipid oxidation (hexanal, TBARS and rancid flavour) of the dry-cured loins were analyzed. Although the total amount of fatty acids from PL decreased most (89.77%), the fatty acid profile of FFA from dry-cured loin was more similar to that of NL from fresh loins. Monounsaturated fatty acids (MUFA) were the most abundant FFA type (260mg/100g muscle dry matter) followed by saturated fatty acid (SFA) (256mg/100g muscle dry matter) and polyunsaturated fatty acids (PUFA) (148mg/100g muscle dry matter). Neither genetic line nor rearing system showed any significant (P>0.05) effect on the decrease of fatty acids in the lipid fractions studied. The important decrease in PUFA from NL (43.70%) and PL (89%) was not reflected in higher oxidative indices in dry-cured loin. Neither PCA nor Pearson's correlation showed any clear relationships between lipolytic changes and oxidative indices.     

Fatty Acids of Neutral and Phospholipids, Rancidity Scores and TBA Values as Influenced by Packaging and Storage

The fatty acid (FA) of neutral lipids (NL) and phospholipids (PL) and this composition's relationship to rancidity score and TBA values of cooked beef patties, during frozen storage at times up to 4½ months under vacuum and nonpackaged conditions were studied. The predominant FA in the NL was C_18:1 (46.0%), followed by C_16:0 at 29.2%. However, the PL fraction gave a more balanced distribution of FA. In the neutral lipid fractions, reduction in the C_16:1 and C_18:2 fatty acids made significant contributions to increased rancidity scores and TBA values but in the phospholipid fraction, changes in the C_18:3 and C_20:4 were of greatest importance. After 3 months of frozen storage a regression model containing the neutral lipid fatty acids C_18:1 and C_18:2 and the phospholipid fatty acids C_18:3 and C_20:4 accounted for 88% and 85% of the variation in rancidity score and TBA value.     

Comparison of two different methods for the separation of lipid classes and fatty acid methylation in reindeer and fish muscle

In the present study different methods for the separation of lipid classes and methylation were compared and evaluated for method optimisation in muscle tissue. Fish and reindeer muscle were tested as fish represents a high proportion of polyunsaturated FA (PUFA) and reindeer a moderate amount of PUFA. Lipids were separated either by solid phase extraction (SPE) into neutral (NL) and polar lipids (PL) or by thin layer chromatography into triacylglycerols (TAG) and phospholipids. All fractions were methylated with or without boron trifluoride (BF₃). The two different separation methods showed differences between PL and phospholipids, while TAG and NL were largely similar. Methylation method did not lead to important differences when comparing within the different separation methods, though methylation with BF₃ generally resulted in similar or higher values of methylated FA, indicating a more complete methylation. The content of PUFA in the muscle tissue did not affect these outcomes. Separation of lipids by SPE, followed by methylation with BF₃ was judged to be the best overall method, though not suitable for analysis of samples with labile fatty acids.     

Lipid Changes in Sea Urchin Gonads during Storage

In lipids of salted sea urchin gonads, the changes in contents of neutral lipids (NL), glycolipids (GL) and phospholipids (PL), in peroxide and carbonyl values, in lipid class compositions of NL and PL, and in fatty acid composition were investigated as a function of storage time. NL increased while GL and PL decreased by autolysis during 180 days storage. The increase of NL resulted from free fatty acids (FFA) [plus fatty acid ethyl esters (FAEE)] generated enzymatically by hydrolysis of PL and GL. Triglycerides were stable throughout a period of storage. In heat-treated and salted gonads, NL, GL and PL remained nearly unchanged during storage, and FFA and FAEE could not be detected. The oxidation of lipids was not detected during 180 days storage, although salted gonads had high content of polyunsaturated fatty acids.     

Lipid composition and contaminants in farmed and wild salmon

Levels of omega-3 (n-3) and omega-6 (n-6) fatty acids and lipid-adjusted concentrations of polychlorinated biphenyls (PCBs), dioxins, toxaphene, and dieldrin were determined in 459 farmed Atlantic salmon, 135 wild Pacific salmon, and 144 supermarket farmed Atlantic salmon fillets purchased in 16 cities in North America and Europe. These were the same fish previously used for measurement of organohalogen contaminants. Farmed salmon had greater levels of total lipid (average 16.6%) than wild salmon (average 6.4%). The n-3 to n-6 ratio was about 10 in wild salmon and 3-4 in farmed salmon. The supermarket samples were similar to the farmed salmon from the same region. Lipid-adjusted contaminant levels were significantly higher in farmed Atlantic salmon than those in wild Pacific salmon (F = 7.27, P = 0.0089 for toxaphene; F = 15.39, P = 0.0002 for dioxin; F > or = 21.31, P < 0.0001 for dieldrin and PCBs, with df = (1.64) for all). Levels of total lipid were in the range of 30-40% in the fish oil/fish meal that is fed to farmed salmon. Salmon, especially farmed salmon, are a good source of healthy n-3 fatty acids, but they also contain high concentrations of organochlorine compounds such as PCBs, dioxins, and chlorinated pesticides. The presence of these contaminants may reduce the net health benefits derived from the consumption of farmed salmon, despite the presence of the high level of n-3 fatty acids in these fish.     

Influence of finishing diet on fatty acid profiles of intramuscular lipids, triglycerides and phospholipids in muscles of the Iberian pig

Thirty Iberian × Duroc pigs allotted in groups of ten animals were fed in three traditional different management systems ('Montanera' (MO), fed on acorns; 'Recebo' (RE), fed on acorns and a commercial diet; and 'Cebo' (CE), fed on a commercial diet). Masseter muscle was obtained to evaluate the influence of management system on fatty acid (FA) composition of lean. The FA composition of the intramuscular total lipids, triglyceride (TG) and phospholipid (PL) fractions was evaluated. Muscle from MO pigs had greater quantities of monounsaturated fatty acids (MUFA) in the total lipids, triglyceride and phospholipid fractions than the other feedings. The percentage of saturated fatty acids (SFA) of i.m. total lipids and TGs increased (P < .05) with duration of feeding on RE and CE, from 35.13-35.10% in MO pigs to 37.47-37.84% in RE pigs and 39.98-41.11% in CE pigs. PLs from RE and CE pigs contained more C(18:2) and C(20:4) and less C(18:1) than MO pigs.     

Fatty acids of neutral and phospholipids of three endangered trout: Salmo trutta caspius Kessler, Salmo trutta labrax Pallas and Salmo trutta macrostigma Dumeril

Total (TL), neutral (NL) and phospholipid (PL) amounts and fatty acid (FA) composition of female Salmo trutta caspius, Salmo trutta labrax and Salmo trutta macrostigma were investigated during one year. Twenty-three FAs were identified in both NLs and PLs. The principal FAs of both fractions were palmitic acid in saturated fatty acid, oleic acid in monounsaturated fatty acid, docosahexaenoic acid (DHA) in n-3 polyunsaturated fatty acids (n-3 PUFAs) and linoleic acid in n-6 PUFAs. The highest values for TLs, NLs and PLs were found in winter. As a general trend, the highest n-3/n-6 ratios and eicosapentaenoic acid (EPA) + DHA amounts were found in the winter and this coincided with the lowest gonado-somatic index.     

Lipid composition of retailed organic, free-range and conventional chicken breasts

Lipid fractions of 20 retailed chicken breasts were correlated with production system: organic, corn‐fed, free‐range and conventional. Neutral lipid (NL), phospholipid (PL) and free fatty acids (FFA) were examined separately. Influence of production systems was found more pronounced in PL composition than NLs. Corn‐fed and free‐range NLs had higher contents of nutritionally beneficial eicosapentanoic acid (C20:5 n‐3) and docosahexanoic acid (C22:6 n‐3) than organic and conventional. Lower polyunsaturated fatty acids in organic and free‐range PLs could be beneficial for tissue stability. Principal component product space for PLs showed clear clustering related to product category. In contrast, this was not observed with FFA except in the partial least square regression product space suggesting influences on NLs and PLs and FFA. PLs had lower contents of arachidonic acid than in earlier studies. Advantages were observed in lipid fractionation using advanced sorbent extraction matrices.