Effects of Fasting on Fatty Acid Composition of Muscle, Liver, and Abdominal Fat in Channel Catfish Ictalurus punctatus

Channel catfish Zctalurus punetatus were fasted for 20, 40, 60, and 80 d. Proximate and fatty acid composition of liver, abdominal fat, muscle, and viscera were determined. Percentage moisture, protein, and lipid of viscera showed little change during the period of fasting. Percentage protein in muscle decreased ( P < 0.05) after 20 d of fasting from time 0 (control), while percentage lipid increased ( P < 0.05). Fish fasted for 0, 40, 60, and 80 d were not different ( P > 0.05). In the liver, percentage lipid was higher in fish that were not fasted (0 d) than in fish fasted 20, 40, 60, and 80 d ( P < 0.05). while percentage moisture was lower in control fish compared to all other treatments ( P < 0.05). Fatty acid composition of muscle and liver indicated that docosahexaenoic acid (DHA), 22:6(n-3), was conserved in these tissues during fasting, while oleic acid, 18:1(n-9), concentration decreased during fasting. Fatty acid composition of abdominal fat indicated that a high percentage (>50%) of the total lipid was composed of oleic acid and there was little change in levels of individual fatty acids in abdominal fat during 80 d of fasting.     

大黄鱼鱼种阶段脂肪酸组成研究

对人工培育的90-180日龄的大黄鱼鱼种,用GC/MS法分析比较了其肌肉和肝脏的脂肪酸组成,肌肉和肝脏分别检出脂肪酸25种和42种.试验结果表明,7-10月,肌肉中的脂肪不断积累,而肝脏中则保持相对恒定,且是肌肉的1.7～3倍;2种组织中均以C16∶0(棕榈酸)含量最高,其次为C18∶1(油酸);肝脏中脂肪酸以饱和脂肪酸(SFA)为主,SFA的平均含量是多不饱和脂肪酸(PUFA)的4倍,而肌肉中的SFA平均含量则与PUFA基本相当;花生四烯酸(AA)、二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)及亚油酸(C18∶2)等n-3和n-6系列的PUFA在肌肉中含量更高;大黄鱼鱼种首先利用肌肉组织中以C16∶0为主的十八碳以下的SFA作为能量来源,而不轻易动用肝脏贮藏的能量.通过与幼鱼和成鱼比较可知,随着鱼体的成长,其脂肪酸种类不断丰富,组成也更趋合理.     

Fatty Acid Composition of Muscle,Liver, and Adipose Tissue of Freshwater Fish from Lake Victoria,Uganda

Fish oils may differ in fatty acid (FA) composition depending on diet. Oils extracted from muscle, liver, and adipose tissue of Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), silver fish (Rastrineobola argentea), lungfish (Protopterus aethiopicus), Victoria squeaker (Synodontis victoriae), and two catfishes (Clarias gariepinus and Bagrus docmac) from Lake Victoria, a tropical freshwater lake, were evaluated for FA composition. Oil contents of muscles, livers, and adipose tissues were in the range of 3.16 to 13.8%, 3.62 to 53.4%, and 28.8 to 42.4%, respectively. Omega-3 polyunsaturated FA, particularly alpha-linolenic (ALA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic (DHA) acids, were found to be in substantial amounts in oils from all seven fish species. Ratios of polyunsaturated FA to saturated FA (0.79 to 1.18) were in the range considered adequate for normal health. Overall, the results show that the fish species studied are a rich source of omega-3 polyunsaturated FA.     

Fat Soluble Vitamins,Cholesterol, and Fatty Acid Composition of Wild and Farmed Black Mussel (Mytilus galloprovincialis) Consumed in Bulgaria

The most commercially important mollusk species from the Bulgarian Black Sea is the black mussel (Mytilus galloprovincialis). There is limited information about fat soluble vitamins, cholesterol, and fatty acid content of the Bulgarian Black Sea mussel. The aims of the present study are to determine and compare the fat soluble vitamin contents as well as relative daily intake of vitamins, cholesterol, fatty acid content, and lipid quality indices (atherogenic, thrombogenic) in the wild and farmed black mussels. Fat soluble vitamins and cholesterol were analyzed simultaneously using reverse phase high performance liquid chromatography. The fatty acid composition was analyzed by gas chromatography-mass spectrometry. In both mussels, fat soluble vitamins A and E were in high amounts, but they were a better source of vitamin D₃. Cholesterol contents were 67.54 ± 0.50 mg/100 g ww (wild) and 49.88 ± 0.30 mg/100 g ww (farmed). The fatty acid distributions of wild and farmed mussels are: saturated > polyunsaturated > monounsaturated fatty acid. The n3/n6 and polyunsaturated/saturated fatty acid ratios were greater than that recommended by the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO). A 100-g edible portion of both mussels contained from 0.252 g (wild) to 0.425 g (farmed) of eicosapentaenoic acid (EPA, C20:5n-3) + docosahexaenoic acid (DHA, 22:6n-3).     

微山湖四鼻须鲤养殖群体和野生群体肌肉营养成分分析

利用常规肌肉营养测定方法,分析了微山湖四鼻须鲤(Cyprinus carpio)野生群体和养殖群体各10尾的肌肉营养成分.结果显示,四鼻须鲤野生群体的粗蛋白(18.05%)和钙(0.69 mg/g)含量高于养殖群体的17.27%和0.49 mg/g,野生四鼻须鲤的粗脂肪含量(1.02%)低于养殖群体(1.86%),两者的水分、粗灰分和磷含量基本相同,肌肉中氨基酸组成基本一致,均含有18种氨基酸,4种呈味氨基酸总量分别为6.71%和6.08%(鲜样),必需氨基酸指数(EAAI)分别为73.35和67.44,其构成比例符合FAO/WHO的标准.     

微山湖四鼻须鲤养殖群体和野生群体肌肉营养成分分析

利用常规肌肉营养测定方法,分析了微山湖四鼻须鲤(Cyprinus carpio)野生群体和养殖群体各10尾的肌肉营养成分。结果显示,四鼻须鲤野生群体的粗蛋白(18.05%)和钙(0.69mg/g)含量高于养殖群体的17.27%和0.49mg/g,野生四鼻须鲤的粗脂肪含量(1.02%)低于养殖群体(1.86%),两者的水分、粗灰分和磷含量基本相同,肌肉中氨基酸组成基本一致,均含有18种氨基酸,4种呈味氨基酸总量分别为6.71%和6.08%(鲜样),必需氨基酸指数(EAAI)分别为73.35和67.44,其构成比例符合FAO/WHO的标准。     

Amino Acid and Fatty Acid Composition of Cultured Beluga (Huso huso) of Different Ages

The amino acids (AA) and fatty acids (FA) of Beluga (Huso huso) flesh at different ages were investigated as a source of AA and FA for human consumption. The analysis of Huso huso lipids (chloroform extracted) showed significant differences (p < .05) for specific FA with age. At all ages, the major saturated FA in Huso huso fillets was palmitic acid and the major unsaturated FA were oleic and docosahexanoic acid (DHA). Protein analysis indicated that the Huso huso muscle is well balanced with good levels of essential AA and appears to be a source of high quality protein (tryptophan was not measured) with methionine/cysteine as the first limiting AA. The major AA were glutamic acid, aspartic acid, and lysine. The results obtained from the present study show that Huso huso is an excellent protein and fat source when compared with other sturgeons.     

Proximate and Fatty Acid Compositions in Different Flesh Cuts of Cultured,Cultured Fasted,and Wild Pacific Bluefin Tuna (Thunnus orientalis)

This study was carried out to determine the differences in proximate and fatty acid (FA) compositions in different flesh cuts of the most valuable cephalic portion of cultured (full-cycle), cultured fasted (full-cycle), and wild Pacific bluefin tuna (PBT; Thunnus orientalis). Cultured fasted PBTs were fasted for 6 days to ensure empty stomachs during harvesting and to determine the influence of fasting on the lipid and FA composition in different flesh cuts. Significantly higher lipid contents were observed (p < 0.05) in the dorsal akami (lean part) and the ventral o-toro (very fatty part) flesh cuts in cultured and cultured fasted PBTs than in wild ones. However, monounsaturated fatty acid (MUFA) contents in all flesh cuts were significantly higher in cultured and cultured fasted PBTs than in wild PBT. Wild PBTs contained significantly higher (p < 0.05) polyunsaturated fatty acid (PUFA) contents than other cultured PBTs in all flesh cuts except for the dorsal akami and wakaremi (fatty part near dorsal fin) flesh parts, and contained higher n-3 FA content than other PBTs—especially docosahexaenoic acid (DHA, C22:6n-3)—in the lipid fraction from the dorsal chu-toro (medium fatty part), ventral akami, ventral chu-toro, o-toro, and in dark flesh cuts. The flesh quality of cultured or cultured fasted PBTs has the advantage of having a higher total amount of essential FAs than that of wild PBT.     

鲤野生和养殖群体遗传多样性分析中的微卫星(SSLP)分析

采用7个微卫星标记,研究了鲤(Cyprinus carpio)、高寒鲤和荷包红鲤抗寒品系(Cyprinus carpio var.wananensis)三个群体的遗传变异。结果显示,鲤野生群体、高寒鲤、荷包红鲤抗寒品系的平均杂合度分别为0.276、0.147、0.0952,平均无偏倚杂合度期望值为0.431、0.355、0.305。鲤野生群体的杂合度明显高于其他两个养殖品种,说明其较其他两个养殖品种的遗传多样性丰富。     

大鳍鳠产卵前后肌肉脂肪酸组成变化的研究

采用毛细管气相色谱法,对产卵前后大鳍鳠肌肉中的脂肪酸组成进行了测定。结果表明,大鳍鳠肌肉中脂肪酸种类丰富,含有22种脂肪酸,油酸(C18:1n-9)所占比例最高,其次为软脂酸(C16:0)、棕榈酸(C16:1n-7)、亚油酸(C18:2n-6),所占比例分别为22.38%~37.57%、18.86%~23.95%、7.00%~11.52%、7.46%~9.97%。EPA和DHA在大鳍鳠肌肉中占有较高的比例,EPA占总脂肪酸的5.39%,DHA占5.44%。在野生大鳍鳠产卵前后的22种脂肪酸中有8种饱和脂肪酸(SFA),6种单不饱和脂肪酸(MUFA)和8种多饱和脂肪酸(PUFA),大鳍鳠肌肉中脂肪酸在产卵前后表现出差异。     

Tissue Lipid Content and Fatty Acid Composition of Penaeus monodon Fabricius Broodstock from the Wild

Tissues (hepatopancreas, muscle, gonad) of wild Penacus mordon females with ovaries in different stages of development and males were analyzed for Upid content and fatty acid composition. Hepatopancreatic tissue had the highest mean levels of lipid at 15.72–25.20% in females and averaged 46.20 ± 1.53% in males. Levels of Lipid in the muscle were low with no marked variation throughout the maturation s-es. Ovarian lipid levels increased significantly at stage II (early maturing ovaries) and remained high through stage IV (fully mature ovaries). Peak lipid level was found at stage III (late maturing ovaries) and coincided with a decline in hepatopancreas lipid. Ovarian and hepatopancreatic lipids declined drastically in spent females. Profiles of fatty acid in the tissues consistently showed the presence of PUFA 204n-6, 20:5n-3 and 22611-3, with high levels in the polar lipid fraction of vitellogenic ovaries. These values were reflected in the male testis and spawned eggs. The finding suggest storage and utilization of lipids for maturation and spawning processes and that the phospholipids were mainly responsible for increases in ovarian lipids. The type of fatty acids present in maturing prawn ovaries is indicative of their importance in reproductive physiology.     

短期饥饿对大鳍鱯生化组成、氨基酸和脂肪酸组成的影响

在水温(21±1)℃条件下,研究了大鳍鱯(Mystus macropterus)在短期饥饿胁迫下生化组成、氨基酸和脂肪酸含量的变化。实验时间分别为饥饿0d(S0)、饥饿3d(S3)、饥饿6d(S6)、饥饿9d(S9)和饥饿12d(S12)。随着饥饿时间延长,水分显著升高(P<0.05),蛋白质、肝糖原和肌糖原显著降低(P<0.05),脂肪和灰分先显著降低(P<0.05),饥饿9d均出现回升(P<0.05)。氨基酸总量、必需氨基酸和非必需氨基酸含量均呈规则波动,饥饿12d均出现反弹现象,略高于实验起始值。饱和脂肪酸(SFA)呈先下降、后上升、再下降的趋势,单不饱和脂肪酸(MUFA)先上升后呈规则波动,多不饱和脂肪酸(PUFA)变化规律与饱和脂肪酸恰好相反,饥饿12d时仅高不饱和脂肪酸被保留,略高于实验起始值。双键位置不同的脂肪酸在饥饿过程中的损失速度也有差异,具体为∑n-9PUFA>∑n-3PUFA>∑n-6PUFA。     

短期饥饿对大鳍鱯生化组成、氨基酸和脂肪酸组成的影响

在水温(21±1)℃条件下,研究了大鳍鱯(Mystus macropterus)在短期饥饿胁迫下生化组成、氨基酸和脂肪酸含量的变化.实验时间分别为饥饿0 d(S0)、饥饿3 d(S3)、饥饿6 d(S6)、饥饿9 d(S9)和饥饿12 d(S12).随着饥饿时间延长,水分显著升高(P<0.05),蛋白质、肝糖原和肌糖原显著降低(P<0.05),脂肪和灰分先显著降低(P<0.05),饥饿9 d均出现回升(P<0.05).氨基酸总量、必需氨基酸和非必需氨基酸含量均呈规则波动,饥饿12 d均出现反弹现象,略高于实验起始值.饱和脂肪酸(SFA)呈先下降、后上升、再下降的趋势,单不饱和脂肪酸(MUFA)先上升后呈规则波动,多不饱和脂肪酸(PUFA)变化规律与饱和脂肪酸恰好相反,饥饿12 d时仅高不饱和脂肪酸被保留,略高于实验起始值.双键位置不同的脂肪酸在饥饿过程中的损失速度也有差异,具体为∑n-9PUFA＞∑n-3PUFA＞∑n-6PUFA.     

Effects of Frying-Chilling-Reheating on the Lipid Content and Fatty Acid Composition of Cultured Sturgeon (Huso huso,Beluga) Fillets

Slices of Huso huso were fried, chilled, and then reheated to evaluate for the changes in lipid characteristics. The total lipid content of raw sample was 3.09 g/100 g which consists of 29.1 g/100 g saturated fatty acids (SFAs), 42.554 g/100 g monounsaturated fatty acids (MUFAs), and 28.126 g/100 g polyunsaturated fatty acids (PUFAs). In fried samples, levels of C18 fatty acid groups, MUFAs, PUFAs, and n6/n3 ratio increased while SFAs, EPA, and DHA content decreased. Upon chill storage, C18:2 fatty acid and n6/n3 ratio decreased while n3 fatty acids increased slightly. Free fatty acid (FFA) decreased after frying, but peroxide value (PV) increased with subsequent decrease at chilled condition.     

人工养殖与野生鳙鱼肌肉营养成分的比较分析

本试验分析测定了贵州省人工养殖鳙鱼与贵州省红枫湖水库野生鳙鱼的含肉率及其肌肉的生化成分,比较分析了它们的含肉率、水分、粗蛋白、粗脂肪、灰分以及氨基酸。结果表明:人工养殖鳙鱼和野生鳙鱼含肉率、粗蛋白、粗脂肪、水分、灰分含量分别为57.73%和52.73%;18.06%和17.71%;0.70%和0.67%;80.03%和80.00%;1.21%和1.62%,肌肉中17种氨基酸(除色氨酸)总含量分别为14.642%和14.979%,其中7种必需氨基酸(除色氨酸)含量分别为5.957%和5.554%,必需氨基酸占总氨基酸的比值分别为40.684%和37.785%,4种鲜味氨基酸总量分别为5.266%和6.291%,占总氨基酸含量分别为35.965%和41.999%,必需氨基酸的指数分别为67.4和68.4;对鱼肉进行氨基酸评价,蛋氨酸、胱氨酸和缬氨酸为人工养殖鳙鱼的限制性氨基酸;而蛋氨酸、胱氨酸和亮氨酸为野生鳙鱼的限制性氨基酸。     

Effects of Dietary Energy: Protein Ratio and Stocking Density on Growth and Survival of the Common Snapping Turtle Chelydra serpentinal1

Although the common snapping turtle Chelydra serpentina is cultured commercially in the United States, little information is available on nutritional and culture requirements. This study was conducted to evaluate the effects of dietary energy: protein ratio and stocking density on survival, growth, feed consumption, feed conversion, liposomatic index, dress-out percentage, and productive protein value of cultured, common snapping turtles. Hatchling turtles were stocked at 29 and 58 animals/m² and fed one of seven prepared diets. Six diets contained 30, 35, or 40% protein at two digestible energy (DE) levels (7 or 9 kcal DE/g protein); the seventh was a reference diet (66% protein and 5 kcal DE/g protein) formulated to equal or exceed the whole-body essential amino acid composition of wild, common snapping turtles. Turtles stocked at 58/m² exhibited greater mortality, lower weight gain, higher feed consumption, less-efficient feed conversion, lower liposomatic index, and lower productive protein value than turtles stocked at 29/m² (P < 0.05). The reference diet produced the greatest weight gain (P < 0.001). The superior performance of turtles fed the reference diet suggests that: 1) the protein (amino acid) content and/or energy: protein ratio of the reference diet was superior to that of the other diets tested; 2) improvements in growth parameters can be made with dietary manipulation; and 3) high levels of plant protein can be used in prepared, snapping turtle diets.     

Modification in Body Fat Content and Fatty Acid Profile of Wild Yellow Shortfin Eel,Anguilla australis,through Short‐term Fattening

Wild‐catch eels with low fat content are either not accepted at all or accepted as a lower‐quality and less valuable product in the global eel market. This study was undertaken with the goal of increasing the fat content of yellow shortfin eel, Anguilla australis (104 ± 11 g initial weight), captured in the wild and kept in captivity for a short period, as well as assessing their rate of growth. An 86‐d feeding trial was conducted indoors in a recirculation aquaculture system, at 25.5 ± 1.6 C. Two commercial extruded dry feeds were tested; one formulated for European eel and one not specifically intended for use on eels. Good values of specific growth rate (1.10 and 1.12%/d) and feed conversion ratio (1.01 and 1.10) were achieved with both tested feeds. At the end of the trial, eels achieved 20–22% total fat, starting from wild fish with 7% fat content. Fat quality of the fattened eel was appreciably superior (higher proportion of omega‐3 fatty acids) than the fat of eels captured in the wild. The results of this study are encouraging for the prospect of fattening yellow shortfin eels and obtaining a market‐oriented eel product.     

Comparison of Proximate Composition and Fatty Acid Profile of On-Growing and Wild Mediterranean Horse Mackerel (Trachurus mediterraneus)

ABSTRACT

On-growing of horse mackerel is not known in the world. Recently, we have initiated on-growing of the Mediterranean horse mackerel in the Black Sea. Therefore, we aim to compare proximate composition and fatty acid profile of on-growing and wild horse mackerels to evaluate the effect on their nutritional value. Captured horse mackerels less than 13 cm were kept on-growing in sea cages and fed sea bass feed for a year in the southern Turkish Black Sea. Results showed seasonal variations in the proximate contents and fatty acid profile of both on-growing and wild fish groups (p < 0.05). Protein contents of the wild horse mackerel group were significantly higher than the on-growing mackerel group, while the opposite situation was observed for lipid contents (p < 0.05). Despite higher eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels (as fatty acid methyl esters %) of wild horse mackerel in comparison with on-growing group, much higher EPA + DHA contents were accounted for in on-growing fish in the edible portion resulting from higher lipid contents of these samples. The results suggest that lower amounts of fish meat, 50–90 g, from on-growing mackerel would cover the daily suggested value of EPA + DHA; this level is calculated as 51–150 g for wild fish meat.