共查询到20条相似文献,搜索用时 9 毫秒
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Lipase-Assisted Concentration of n-3 Polyunsaturated Fatty Acids from Viscera of Farmed Atlantic Salmon (Salmo salar L.) 总被引:1,自引:0,他引:1
ABSTRACT: In fish processing, viscera are generally considered waste products and often discarded. Our research objective was to use Atlantic salmon ( Salmo salar L.) viscera as a source of fish oil and to increase its concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by lipase-assisted hydrolysis. Lipids from fillets and viscera had similar fatty acid compositions. After the enzymatic hydrolysis, acylglycerols were isolated from free fatty acids, therefore increasing the concentrations of EPA and DHA in the acylglycerols. Among the 6 commercial lipases investigated, lipases from Pseudomonas cepacia and Candida rugosa were the most effective following incubation of viscera oil at 35 °C for 20 h. Salmon viscera were a good source for fish oil, and the concentration of DHA and EPA was doubled by using microbial lipases. 相似文献
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通过氨基酸分析法、超滤法、凝胶层析柱法、反相高效液相色谱法、超高分辨四极杆—飞行时间质谱法等,研究紫贻贝蛋白酶解过程中各种呈味物质的释放规律及呈味肽的结构。结果表明,酶解过程中,大分子肽逐渐降解为小分子肽,游离呈味氨基酸含量、三甲胺含量升高,肽基呈味氨基酸的含量先上升后下降,总糖含量变化不明显。pH较低时有利于低分子量肽的生成。总酸含量在酶解1h、酶解温度为50℃时最高。在50℃、pH 6.5条件下酶解2h后,紫贻贝酶解液中低分子量肽的比例较高,有机酸、糖和呈味氨基酸的释放较充分。紫贻贝酶解液中海鲜风味肽的分子量1kDa,其结构为Cys-Ser-Val-Gln-Asp-Gln或Gln-Ala-ValAsn-Phe-Thr,不同于任何已知序列的呈味肽,其呈味阈值为0.1mg/mL。 相似文献
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为探究不同状态下紫贻贝制品表面附着的微生物菌群组成情况。本实验以新鲜紫贻贝、冻藏紫贻贝、自制紫贻贝干,贮藏自制紫贻贝干和市售紫贻贝干为研究对象,通过对紫贻贝表面附着微生物提取及高通量测序分析,获得不同紫贻贝样品中微生物组成及变化情况。实验结果表明,各样本中有效序列范围为30066~40563条、Operational taxonomic unit(OTU)范围为28~128,其中市售紫贻贝干OTU数最低,而冻藏紫贻贝OTU数相对较高;新鲜紫贻贝和自制紫贻贝干中主要是嗜冷杆菌属和不动杆菌属,冻藏紫贻贝干中主要为嗜冷杆菌属,贮藏紫贻贝干中主要为假单胞菌属和嗜甲基菌属,而市售紫贻贝干中优势菌群为葡萄球菌属和肠球菌属。不同状态下的紫贻贝样品的菌群组成均存在着较大距离,表明紫贻贝状态、加工过程及贮藏销售环境等,均对贻贝产品菌群组成产生较大的影响。研究结果可为保障紫贻贝制品的质量与安全提供参考。 相似文献
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E. Fux D. Rode R. Bire P. Hess 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(8):1024-1032
Liquid chromatography coupled to mass spectrometry (LC-MS) is seen as an integral part of methods of choice for the replacement of animal tests in the determination of lipophilic shellfish toxins. However, these techniques are prone to matrix effects that need to be considered when developing and validating methods. The analysis of shellfish is a challenging task due to the complexity of the shellfish matrix and the number of shellfish species encountered in monitoring laboratories. Therefore, it is crucial that the cause and the extent of matrix effects is fully understood in order to apply corrective measures to the analytical method and to develop efficient sample clean-up steps. This paper presents different approaches to evaluate matrix effects associated with the analysis of okadaic acid (OA), azaspiracid-1 (AZA1) and pectenotoxin-2 (PTX2) in cooked and raw mussel flesh. Post-extraction addition and standard addition experiments were carried out and analysed using various LC-MS methods. Gradient and isocratic elution were compared and ultra-performance liquid chromatography (UPLC), using C8 and C18 Acquity BEH columns, was evaluated for the extent of matrix effects. When matrix effects were observed, OA and PTX2 were always prone to signal enhancement and AZA1 to signal suppression. For all the toxins studied, matrix effects were dependent on chromatographic conditions. UPLC separation using a C8 column significantly reduced matrix effects compared to the other conditions assessed. Furthermore, sample dilution has proven to be an efficient way of reducing matrix effects associated with OA analysis. 相似文献
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Kurt F. Schulbach Jodie V. Johnson Amarat H. Simonne Jeong‐Mok Kim Yoonhwa Jeong Yavuz Yagiz Maurice R. Marshall 《Journal of food science》2013,78(3):C425-C431
Enzymatic browning remains a problem for the fruit and vegetable industry, especially new emerging markets like pre‐cuts. A crude inhibitor from blue mussel (Mytilus edulis) showed broad inhibition for apple (58%), mushroom (32%), and potato (44%) polyphenol oxidase (PPO) and was further characterized. Inhibition increased as the concentration of inhibitor increased in the reaction mixture eventually leveling off at a maximum inhibition of 92% for apple PPO. The inhibitor was capable of bleaching the brown color formed in the reaction mixture with apple PPO. Identification of the inhibitor by mass spectrometry and high‐performance liquid chromatography revealed it to be hypotaurine (C2H7NO2S). Hypotaurine and other sulfinic acid analogs (methane and benzene sulfinic acids) showed very good inhibition for apple PPO at various concentrations with the highest inhibition occurring at 500 μM for hypotaurine (89%), methane sulfinic acid (100%), and benzene sulfinic acid (100%). Practical Application: An inhibitor found in the expressed liquid from blue mussel shows very good inhibition on enzymatic browning. Since this enzyme is responsible for losses to the fruit and vegetable industry, natural inhibitors that prevent browning would be valuable. Finding alternative chemistries that inhibit browning and understanding their mode of action would be beneficial to the fruit and vegetable industries and their segments such as pre‐cuts, juices, and so on. Inhibitors from products ingested by consumers are more acceptable as natural ingredients. 相似文献
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研究了俄罗斯鲟鱼加工副产物生殖腺的基本营养成分,蛋白质的氨基酸组成,脂肪酸组成,为鲟鱼生殖腺的高值化利用提供依据。结果显示,鲟鱼精巢的粗脂肪、粗蛋白及灰分含量(以湿基计)分别为75.20%、9.06%、0.10%,而鲟鱼卵巢的相应营养成分含量分别为42.00%、5.96%、0.20%。精巢蛋白中必需氨基酸占总氨基酸质量分数的36.80%,而卵巢蛋白的相应数值为35.00%。精巢脂质中二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)总量达到总脂肪酸的7.41%,而卵巢脂质的相应数值则为7.25%。综上,鲟鱼生殖腺富含脂质,可作为该副产物今后开发利用的主要目标。 相似文献
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为探讨海藻糖和褐藻胶寡糖的低温保护活性,以紫贻贝为对象,评价了海藻糖和褐藻胶寡糖处理对冻藏紫贻贝肉品质特性的影响。结果发现,在6周冻藏过程中,相比于蒸馏水和空白组,海藻糖和褐藻胶寡糖显著(p0.05)降低了紫贻贝肉解冻损失率,褐藻胶寡糖组解冻损失率低至14.28%,并维持了较好的弹性和咀嚼性等特性,同时有效抑制了紫贻贝肉中菌落总数的快速增加。此外,两种糖类浸泡处理维持了较好的肌原纤维蛋白Ca~(2+)-ATPase活力,肌原纤维蛋白Ca~(2+)-ATPase活力在0.019~0.021U/mgprot范围内,三个处理组之间并无显著性差异(p0.05)。微观观察发现,海藻糖和褐藻胶寡糖处理紫贻贝,组织结构相对较为完整、致密,细胞间隙冰晶颗粒面积较小,其组织结构保护作用明显优于焦磷酸钠处理效果。海藻糖和褐藻胶寡糖可作为一种高效的低温保护剂,用于保持紫贻贝及其制品品质及延长冻藏产品货架期。 相似文献
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对深海杂鱼粗鱼油精炼工艺进行优化,考察了磷酸体积分数、超量碱和活性白土添加量对鱼油酸值、回收率和感官品质的影响,并对精炼鱼油的理化指标及脂肪酸组成进行分析。结果表明:适宜的精炼条件为采用占鱼油质量1%、体积分数80%的磷酸脱胶,脱胶油中加入占鱼油质量1.5%的超量碱和理论碱量的Na OH(4 mol/L)脱酸,脱色选用添加占鱼油质量20%的活性白土;精炼鱼油的理化指标均达到我国水产行业精制鱼油的一级标准(SC/T 3502—2000),酸值(KOH)由(5.52±0.12)mg/g下降到(0.29±0.11)mg/g;精炼工艺对鱼油脂肪酸组成的影响较小,其中二十碳五烯酸和二十二碳六烯酸的总量约占总脂肪酸含量的38%,且分别占多不饱和脂肪酸含量的35.99%和51.59%,品质较优。 相似文献
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基于脂肪酸特征指标的鳕鱼肝油掺假鉴定 总被引:1,自引:0,他引:1
通过分析鳕鱼肝油中各脂肪酸的相对含量及特征指标变化规律,建立鳕鱼肝油掺假鱼油的鉴定方法。鳕鱼肝油中所含脂肪酸经柱前衍生转化为甲酯后进行气相色谱测定,采用面积归一化法计算各脂肪酸相对总脂肪酸的相对含量。根据多样本脂肪酸相对含量分析结果,找出能有效识别掺假的特征性指标二十二碳六烯酸(docosahexaenoic acid,DHA)/二十碳五烯酸(eicosapentaenoic acid,EPA)值和鲸蜡烯酸相对含量,并确定其限度范围,DHA/EPA值为1.40~1.68,鲸蜡烯酸相对含量为7.0%~9.4%。当鳕鱼肝油样品中测得的DHA/EPA值和(或)鲸蜡烯酸相对含量超过此限度时,可初步判定该样品掺假鱼油。为进一步有效识别掺假水平,本研究探索建立一种以DHA/EPA值和鲸蜡烯酸相对含量为坐标的掺假模型,并绘制不同掺假水平的识别分析图,46 批样品经鉴定,有2 批样品疑似掺假25%的鱼油。该鉴定方法准确可靠、直观简便,可用于鳕鱼肝油中掺假鱼油的快速鉴定。 相似文献
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贻贝蛋白的酶解及其酶解物的抗氧化活性研究 总被引:3,自引:0,他引:3
比较了6种不同的蛋白酶(胰蛋白酶、风味蛋白酶、中性蛋白酶、木瓜蛋白酶、复合蛋白酶、碱性蛋白酶)对贻贝粗蛋白的酶解效果,确定碱性蛋白酶为最适用酶。用此酶制备不同水解度(DH 6%、DH 11.5%、DH16%、DH 20%、DH 25%)的贻贝蛋白酶解物,考察不同DH酶解产物的抗氧化活性。试验结果表明:贻贝酶解产物具有较强的抗氧化活性,并呈一定的量效关系;当DH为25%时,贻贝酶解物对DPPH自由基、超氧自由基、羟基自由基的清除率最高,分别为77.4%、75.2%、43.4%,同时具有最强的金属螯合率(64.7%);而DH为16%时,酶解物对亚油酸的过氧化抑制作用较还原型谷胱甘肽强,达65.6%。DH对酶解产物的抗氧化活性有一定的影响,但在不同的抗氧化体系中,影响趋势不一致。 相似文献
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Stephen L. Pahl David M. Lewis Feng Chen Keith D. King 《Journal of Bioscience and Bioengineering》2010,109(3):235-239
To investigate the nutritional value of the diatom Cyclotella cryptica (Reimann, Lewin, and Guillard) as an alternative feed for use in the aquaculture industry, the heterotrophic growth characteristics and resultant fatty acid profile of the microalga were studied when cultivated under a variety of controlled salinity and temperature conditions. In addition, the effects of pH on the growth characteristics were also studied. The maximum specific growth rate was affected by initial pH and cultivation temperature, but not by salinity. The optimal pH and temperature ranges for growth were 7.2 to 8.1 and 22.5 to 25.0 °C, respectively. Lipid accumulation and the fatty acid composition were also affected by cultivation temperature and salinity. The optimal temperature range and salinity level for lipid accumulation were 18.0 to 25.0 °C and 11.2 psu, respectively. In all cases the fatty acid distribution was similar, with the most abundant fatty acids being palmitic acid (16:0), palmitoleic acid (16:1 n-7), stearidonic acid (18:4 n-3, SDA), eicosapentaenoic acid (20:5 n-3, EPA), and decosahexaenoic acid (22:6 n-3, DHA). 相似文献