Tissue distribution and elimination of deoxynivalenol and ochratoxin A in dietary-exposed Atlantic salmon (Salmo salar)

ABSTRACT

Post-smolt Atlantic salmon (Salmo salar) were fed standard feed with added 2 or 6 mg kg^–1 pure deoxynivalenol (DON), 0.8 or 2.4 mg kg^–1 pure ochratoxin A (OTA), or no added toxins for up to 8 weeks. The experiments were performed in duplicate tanks with 25 fish each per diet group, and the feed was given for three 2-h periods per day. After 3, 6 and 8 weeks, 10 fish from each diet group were sampled. In the following hours after the last feeding at 8 weeks, toxin elimination was studied by sampling three fish per diet group at five time points. Analysis of DON and OTA in fish tissues and plasma was conducted by liquid chromatography-mass spectrometry and high-pressure liquid chromatography with fluorescence detection, respectively. DON was distributed to the liver, kidney, plasma, muscle, skin and brain, and the concentrations in liver and muscle increased significantly from 3 to 8 weeks of exposure to the high-DON diet. After the last feeding at 8 weeks, DON concentration in liver reached a maximum at 1 h and decreased thereafter with a half-life (t_1/2) of 6.2 h. DON concentration in muscle reached a maximum at 6 h and was then eliminated with a t_1/2 = 16.5 h. OTA was mainly found in liver and kidney, and the concentration in liver decreased significantly from 3 to 8 weeks in the high-OTA group. OTA was eliminated faster than DON from various tissues. By using Norwegian food consumption data and kinetic findings in this study, we predicted the human exposure to DON and OTA from fish products through carryover from the feed. Following a comparison with tolerable daily intakes, we found the risk to human health from the consumption of salmon-fed diets containing maximum recommended levels of these toxins to be negligible.     

禾本红酵母M124产脂能力及其油脂脂肪酸组成分析

采用索氏提取法提取禾本红酵母M124(Rhodotorula graminis M124)的菌体油脂,测定了其产脂能力,并采用气相色谱-质谱联用法(GC-MS)测定了其脂肪酸组成.结果表明,禾本红酵母M124的产脂能力较强,油脂含量达菌体干重的53.64%,脂肪酸组成较为特殊,10-十八碳烯酸占脂肪酸总量的80.08%.     

The chemical composition of different edible locations (central and edge muscles) of flat fish (Lepidorhombus whiffiagonis)

The chemical composition of the different edible locations (central and edge muscles) of a flat fish (megrim, Lepidorhombus whiffiagonis) was comparatively analysed at both body sides. Higher moisture and lower lipid contents were obtained in central muscles than in edge ones. Edge sites showed higher triacylglycerols and sterols contents and lower mean phospholipids values than central muscles. A higher α‐tocopherol presence was observed in the lipid fraction of central muscles than in the edge ones. For both fish sides, fatty acid (FA) analysis showed lower monounsaturated FA and higher polyunsaturated FA contents and ω3/ω6 ratios in central muscles. Presence of essential elements (Co, Cu, Mn, Se, Zn) did not provide differences among sites considered. Concerning toxic elements, As content showed greater levels in central muscles than in their corresponding edge sites for both fish sides, upper zones showed higher mean scores in As, Cd, Cr, Hg, Ni, Pb and V.     

Lipid quality and filleting yield of reared meagre (Argyrosomus regius)

Reared meagre (Argyrosomus regius) of average weight 1278 g was evaluated for its filleting yield and fillet lipid quality. Filleting yield averaged 42.2%, while very low levels of muscle fat deposits were measured (1.06%). Analysis of lipid classes revealed a high proportion of polar lipids (48.3–59.1%) and low levels of neutral fatty acids (40.9–51.7%) when compared to corresponding values of other farmed fish species. Phosphatidyl‐choline (PC) was the dominant polar lipid (2.92 mg g^?1 muscle), while cholesterol the most abundant neutral lipid (1.68 mg g^?1 muscle). The fatty acid composition of meagre fillet generally reflects the dietary fatty acids. Among n‐3 fatty acids, eicosapentaenoic (4.58%) and docohexaenoic (15.0%) were measured to be the most abundant ones, and 18:2n‐6 (11.9%) was the most common n‐6 fatty acid. The fatty acid profiles of polar and neutral fractions differ, with monounsaturated fatty acids being predominant in the neutral and n‐3 polyunsaturates in the polar lipids. The high polar lipid contents and n‐3 fatty acids and the low atherogenic and thrombogenic indexes indicate a high quality of this species’ lipids.     

Changes in water holding capacity and drip loss of Atlantic salmon (Salmo salar) muscle during superchilled storage

Changes in water holding capacity and drip loss of Atlantic salmon (Salmo salar) fillets during superchilled storage were studied. Due to the significant differences in ice crystal sizes observed in our previous study, the liquid loss (LL) was analysed separately, at the surface and centre of the superchilled samples. No significant differences were found in LL between surface and centre parts of the superchilled samples. No significant difference in the LL was observed from surface samples between 1 and 14 days of storage. There was a significant difference in the LL at day 1 of the centre samples, but no significant differences were observed between 3 and 14 days of storage. In contrast, the LL was significantly decreased at day 21 both at the centre and the surface of the superchilled samples. No significant difference (p < 0.05) was found in drip loss between 1 and 14 days of storage for the superchilled samples. A significant increase in drip loss for the superchilled samples was observed at day 21. These findings are significant for the industry because it provides valuable information on the quality of food in relation to ice crystallisation/recrystallisation during superchilled storage.     

The effects of natural antioxidants and lighting conditions on the quality of salmon (Salmo salar) fillets packaged in modified atmosphere

The effect of lighting conditions (darkness, a low‐UV colour‐balanced lamp and supermarket fluorescents), along with the application of natural antioxidants (rosemary extract and ascorbic acid) on shelf‐life of salmon (Salmo salar) fillets packaged in modified atmosphere and stored at 1 ± 1 °C was studied. Darkness and lighting with low‐UV colour‐balanced lamps led to an extension of shelf‐life compared with conventional light, as assessed by a* values, lipid oxidation (TBARS value) and sensory evaluation. The application of natural antioxidants on the surface of MAP salmon fillets gave rise to a delay of lipid oxidation as well as an improvement of the sensory quality, mainly in the case of conventional lighting conditions. Copyright © 2005 Society of Chemical Industry     

Lipid and protein deterioration during the chilled storage of minced sea salmon (Pseudopercis semifasciata)

Sea salmon is a very appreciated seafood. The aim of this work was to analyze changes in lipid and protein fractions of minced muscle during chilled storage (1 ± 1 °C). Lipid oxidation was important during the first 6 days of storage according to 2‐thiobarbituric acid (TBA) values determined, decreasing mainly ω3 22:6 fatty acid content. Lipid hydrolysis was evident after 9 days of storage. Interaction compounds between oxidation products and other cellular components were analyzed by fluorescence measurements. The results obtained showed evidence of the formation of interaction products involved, mainly polar components such as proteins. Decreases in myosin and actin thermal stability and myosin denaturation were recorded by differential scanning calorimetry. Solubility of total and myofibrillar proteins decreased after 6 days of storage. The electrophoretic profile of soluble fractions showed an increase in the intensity of bands corresponding to low‐molecular‐weight polypeptides and a decrease in high‐molecular‐weight species. Available lysine content did not change during chilled storage. Copyright © 2007 Society of Chemical Industry     

Influence of feeding state and frozen storage temperature on the lipid stability of Atlantic mackerel (Scomber scombrus)

Lipid deterioration of mackerel caught in Icelandic waters was studied, as affected by different frozen storage temperatures (?18 °C vs. ?25 °C) and seasonal variation (August vs. September). The lipid stability was investigated by analyses of hydroperoxide value (PV), thiobarbituric acid reactive substances (TBARS), free fatty acids, as well as changes in fatty acid composition. Results showed significant lipid deterioration with extended storage time, where the lower storage temperature showed significantly more protective effects. Furthermore, a higher lipid oxidation level was recorded for fish caught in September than in August, although lipid hydrolysis occurred to be greater for fish in August than in September. Moreover, results indicated a rather stable level of omega‐3 fatty acid during the whole frozen storage period. The analysis indicated that both lipid oxidation and hydrolysis were affected by the frozen storage temperature and the stability differed with regard to season of catch.     

Protein,fat and fatty acid composition of Celosia species

The seeds of 13 lines of Celosia referable to four species were analysed for protein, fat and fatty acid composition. The protein contents varied from 101 to 170 g kg^?1 and fat contents from 56 to 109 g kg^?1. The fatty acid composition was of the simple palmitic-oleic-linoleic type.     

松籽油脂肪酸组成及分布特征分析

通过气相色谱法分析了松仁油的总脂肪酸组成及其上位置分布特点。结果表明,松仁油主要含有亚油酸（46.29%）、油酸（26.68%）和松籽油酸（13.84%）。sn2位置上的亚油酸（66.84%）和油酸（28.33%）含量高于sn1,3上的含量,但是Δ5系列多不饱和脂肪酸（Δ5-PUFA）主要分布在sn1,3位置上。Δ5-PUFA的存在和它们选择性地分布在sn1,3位等特点是包括红松籽油在内主要松属植物果实油脂的特点。松籽油主要由12种甘油三酯组成,其中含量比较多的是LLPi（24.13%）,OLL/LOL（17.87%）和LOPi（14.32%）。我们还对植物甾醇和维生素进行分析,结果显示松籽油含有141.64mg/100g的总植物甾醇和23.63mg/100g的总生育酚。      

泡酒肥肉浸制过程中脂肪氧化和脂肪酸组成的变化

泡酒肥肉是豉香型白酒(玉冰烧)生产过程\     

鲟鱼卵脂质的提取及脂肪酸组成分析

以西伯利亚鲟鱼卵为原料,比较不同提取方法对鲟鱼卵脂质提取率、脂肪酸及脂质组成的影响。采用索氏提取、酶辅助有机溶剂和超临界CO2三种不同的方法提取鲟鱼卵中的脂质,并分析鲟鱼卵脂肪酸组成及脂质组成。结果显示,不同提取方法对所得到的鲟鱼卵脂质的提取率和脂肪酸的相对含量有显著的影响（P＜0.05）,对鲟鱼卵脂质的脂肪酸种类和脂质组成没有显著影响（P＞0.05）。索氏提取法的提取率为（23.71±1.82）%,中性蛋白酶酶解辅助有机溶剂法的提取率为（15.47±1.21）%,超临界CO2萃取法的提取率为（10.43±2.16）%。鲟鱼卵脂质中含有17 种脂肪酸,包括6 种饱和脂肪酸,4 种单不饱和脂肪酸,7 种多不饱和脂肪酸,其中总不饱和脂肪酸含量达到70%以上,多不饱和脂肪酸含量达到17%以上。不同提取方法提取鲟鱼卵脂质中均含有甘油三酯、胆固醇、极性脂质,其中甘油三酯相对含量达到89%以上。     

Total lipid,fatty acid composition and lipid oxidation of Indian white shrimp (Fenneropenaeus indicus) fed diets containing different lipid sources

BACKGROUND: Seafood is an important constituent of the human diet. In Iran, Indian white shrimp (Fenneropenaeus indicus) is the major cultured shrimp species as a result of market demand, local availability and growth rate. It is mainly reared using commercial feed. The purpose of this study was to evaluate the effects of replacing 50% of the fish oil by vegetable oils in shrimp feed on total lipid, fatty acid composition and lipid oxidation of shrimp muscle. RESULTS: No significant differences in total lipid content (6.1–7.3 g kg^?1) were found between edible tissues of shrimp fed different diets. The major fatty acids in shrimp muscle were palmitic, oleic, lionoleic, stearic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Higher levels of EPA and DHA were observed in muscle of shrimp fed a diet containing fish oil. Oxidative rancidity, measured as thiobarbituric acid reactive substances, for all shrimps did not exceed 0.2 mg malonaldehyde kg^?1 muscle tissue, which was low and acceptable. CONCLUSION: This study had shown that the fatty acid composition of feed directly affects the fatty acid composition of Indian white shrimp muscle. Farmed Indian white shrimp can be considered as a species of low fat and shrimp muscle was quite stable to oxidation during storage. Copyright © 2009 Society of Chemical Industry     

肌内脂肪与背最长肌肉质、脂肪酸组成的关系

研究肌内脂肪（IMF）含量与肉质以及脂肪酸含量和组成比例之间的关系。以北京黑猪背最长肌（n=20）为实验材料,测定肌内脂肪含量、肉质以及脂肪酸含量和组成。结果显示,肌内脂肪含量与滴水损失呈显著正相关（p<0.05）,与蒸煮损失、剪切力、肉色的相关性不显著（p>0.05）。随着肌内脂肪含量升高,除长链多不饱和脂肪酸(C_20:3n6、C_20:4n6)以外的大多数脂肪酸含量增加,相对比例也上升;多不饱和脂肪酸的含量增加,但是相对比例下降;长链多不饱和脂肪酸的含量和相对比例都降低。随着肌内脂肪含量的升高,饱和脂肪酸（SFA）和单不饱和脂肪酸（MUFA）的含量升高,回归方程斜率分别为197.3和248.31,多不饱和脂肪酸（PUFA）增加的幅度不大,回归方程的斜率为11.43。结果提示:肌内脂肪含量较低时（本实验平均值2.86%）,对肉质的影响不显著。随着肌内脂肪含量升高,总脂肪酸含量（TFA）增加,主要归因于SFA和MUFA含量的增加。PUFA的含量相对稳定,受肌内脂肪含量变化的影响较小。      

人初乳脂肪酸组成及sn-2位脂肪酸分布的研究

选择广州市健康产妇20例,用超声法快速萃取乳中脂肪,采用DM-FFAP毛细管柱气相色谱对人初乳脂中总脂肪酸组成及sn-2位脂肪酸进行了测定,并采用SPSS13.0软件对测定数据进行统计分析。结果表明:总脂肪酸组成中饱和脂肪酸(主要为棕榈酸)含量低,为36.47%,不饱和脂肪酸含量高(主要为油酸和亚油酸),为63.9%;sn-2位脂肪酸组成中饱和脂肪酸含量为61.48%,不饱和脂肪酸含量为37.95%;棕榈酸多分布在sn-2位(72.08%),油酸和亚油酸多分布在sn-1,3位。初乳中脂肪酸的组成和分布具有独特的特点,对婴儿生长发育具有非常重要意义,本文对开发人乳脂替代品具有理论指导意义。     

铝(Ⅲ)配合物溶液组成及组份分布研究综述

介绍了单纯从配位化学的角度及从制革化学的角度对铝 ( )配合物溶液的组成及组份分布进行研究的方法及已取得的成果。