鲨鱼软骨保健功能的研究

1983年美国科学家发现了鲨鱼软骨的抑制肿瘤作用,近年来关于这一天然动物资源的特殊人体保健功能的研究较多,但研究结果之间存在着较大的差异。本文通过对鲨鱼软骨三项人体保健功能的功能评价试验,验证鲨鱼软骨的抑制肿瘤等保健功能,并初步探讨各保健功能之间的联系。     

胰蛋白酶水解鲨鱼鳍软骨提取粘多糖的研究

对胰蛋白酶水鲨鱼鳍软骨提取粘多糖进行了系统的研究,研究了预加热处理对酶水解鲨鱼鳍软骨提取粘多糖的促进作用,考察了时间,温度,ｐＨ和酶添加量对酶解鲨鱼鳍软骨提取粘多糖和硫酸含量的影响。在单因素的实验的基础上,通过正交试验得出胰蛋白酶酶解鲨鱼鳍软骨的最佳工艺条件,比较了三氯乙酸,氯仿－丁醇以及氯仿－戊醇等蛋白沉淀剂除杂蛋白的效果,并对鲨鱼鳍软骨粘多糖进行了初步提纯。     

鲨鱼软骨粉综合监测方法探讨

采用气相色谱、氨基酸分析、红外光谱等方法检测鲨鱼软骨制品中有机物与无机物组成，尤其是对糖蛋白和蛋白多糖内中性糖成分、氨基酸含量特征的检验，可对市场上各种鲨鱼软骨制品的质量状况作出比较全面而准确的评价。     

鲨鱼软骨粉综合监测方法探讨

采用气相色谱、氨基酸分析、红外光谱等方法检测鲨鱼软骨制品中有机物与无机物组成,尤其是对糖蛋白和蛋白多糖内中性糖成分、氨基酸含量特征的检验,可对市场上各种鲨鱼软骨制品的质量状况作出比较全面而准确的评价。      

鲨鱼软骨粉综合监测方法探讨

采用气相色谱,氨基酸分析,红外光谱等方法检测鲨鱼软骨制品中有机物与无机物无机组组成,尤其是对糖蛋白和蛋白多糖内中性糖成分,特定氨基酸的检验,可对市场上各种鲨鱼软骨制品质量状况作出比较全面而准确的评价。     

鲨鱼软骨的溶解性及其差示扫描量热分析的研究

研究鲨鱼软骨在醋酸和氢氧化钠溶液中的溶解特性，并采用差示热扫描法分析经100℃热水、木瓜蛋白酶、醋酸和氢氧化钠溶液处理后鲨鱼软骨残留物的成分和热稳定性。结果表明：鲨鱼软骨较容易溶解在碱性溶液中；蒸气加压处理能提高鲨鱼软骨在醋酸溶液中的溶解度；鲨鱼软骨在40～132℃存在～个吸收峰，从230℃开始出现以360℃为峰高的放热峰．吸热峰可能主要由于胶原蛋白变性及其生物活性成分引起的，放热峰主要为糖蛋白分子断裂分解产生的。     

FINS方法鉴定鱼翅和鲨鱼软骨的鲨鱼种类

鱼翅一般来自于青鲨等常见鲨鱼,但少数不法分子也从濒危鲨鱼上采集鱼翅。为更好地保护濒危鲨鱼,建立了一种鲨鱼种类的基因鉴定方法——FINS法。根据基因库中虎鲨、条纹斑竹鲨、角鲨、猫鲨、白斑星鲨等线粒体细胞色素氧化酶亚基I(Cytochrome Oxidase subunit I,COI)序列设计合成了简并引物,采用Touchdown温度循环程序扩增COX I的5’端序列。PCR产物纯化后进行双向测序,将未知样品的COI基因序列与基因库中的鲨COI基因序列进行比对,根据相互间的遗传距离确定样品的种属。用FINS方法共对126份鱼翅和鲨鱼软骨样品进行了鉴定,结果发现供试样品大部分来自青鲨(82个样品),鼠鲨、尖吻鲭鲨、长鳍鲭鲨、加勒比斜锯牙鲨、尖吻斜锯牙鲨、澳洲半沙条鲨、舒氏星鲨、路氏双髻鲨以及犁头鳐、叶吻银鲛和兔银鲛等软骨鱼类,未发现来自受国际濒危动植物贸易公约保护的大白鲨、姥鲨、鲸鲨等鲨鱼的鱼翅和鱼骨。     

鲨鱼软骨粉对小鼠移植性肉瘤-180抑制作用的研究

为了观察鲨鱼软骨制品对小鼠移植性肉瘤 - 180 (S 180 )的抑制作用 ,分别经口灌胃给予昆明种小鼠 0 0 2～ 4 5g kgBW 的 11个品牌的鲨鱼软骨制品 ,每组单一性别 13～ 15只 ,连续给予 18d后 ,每只小鼠左腋下接种 0 2mL浓度为 5× 10 6～ 1× 10 7/mL的S 180细胞 ,继续给予受试物至接种12d后剖杀小鼠 ,取出瘤块 ,称体重、瘤重。同时分别经口灌胃给予Balb C小鼠 0 0 2～ 4 5g kgBW的 11个品牌的鲨鱼软骨制品 ,每组单一性别 13～ 15只 ,连续 30d后 ,测定小鼠免疫指标 (腹腔巨噬细胞吞噬鸡红细胞试验与NK细胞活性测定 )。结果显示 :(1)本实验中对照组小鼠的瘤重为 2 6 0± 0 17g (n =2 4 7只 ) ,受试物组的瘤重为 2 39± 0 15g (n =875只 ) ,抑瘤率仅为 8% ,经成组t检验统计 ,P =0 382 >0 0 5。即所使用的 11个品牌的鲨鱼软骨制品均没有抑制小鼠移植性肉瘤 -180的作用 ;(2 )NK活性实验结果表明 :鲨鱼软骨粉的剂量组与对照组相比 ,差异具有显著性 (P≤0 0 5 )并具有增强作用的占 36 4 % (4 11) ;(3)巨噬细胞吞噬实验结果表明 ,鲨鱼软骨粉剂量组与对照组吞噬率相比差异具有显著性 (P≤ 0 0 5 )并具有增强作用的占 18 2 % (2 11) ;(4 ) 2项免疫实验中至少 1项阳性的占 4 5 4 % (5 11)。 (5 )     

利用鲨鱼软骨制备钙螯合胶原肽及其性质的研究

以鲨鱼软骨为原料,通过单因素实验和正交实验优化胶原肽螯合钙的酶解制备工艺。结果发现,当酶解时间、酶添加量、底物浓度分别为1 h,0.25%,25 mg/m L时,制备的鲨鱼软骨胶原肽的钙螯合能力可达1087.01 mg/100 g蛋白。制备的钙螯合胶原肽小于5000 u的组分约占84%,天冬氨酸和谷氨酸占总氨基酸的比例为17.07%,疏水性氨基酸占总氨基酸的比例为41.24%,而必需氨基酸占总氨基酸的比例只有22.81%。根据红外光谱和扫描电镜结果,发现鲨鱼软骨胶原肽螯合钙的微观结构均匀致密,不仅具有胶原蛋白的特征,还含有硫酸软骨素的特征。      

软骨多糖对小鼠Ca761乳腺癌血管生成的影响

目的是研究软骨多糖对小鼠Ca761乳腺癌肺转移的抑制作用及其对血管生成的影响.方法是建立615近交系小鼠乳腺癌肺转移模型,设模型组和治疗组.检测软骨多糖肺转移抑制率、肺部石蜡切片HE染色观察肿瘤侵袭情况、免疫组化CD34观察瘤组织微血管密度(MVD)以及VEGF蛋白表达.结果表明,软骨多糖肺转移抑制率达44.4%;通过肺部HE染色发现治疗组转移情况明显低于模型组;免疫组化检测结果显示治疗组CD34蛋白标记的MVD、VEGF蛋白表达水平均低于模型组.可见软骨多糖能明显抑制小鼠Ca761乳腺癌的血管生成,从而抑制肿瘤转移,与软骨多糖能够下调瘤组织VEGF蛋白表达有关.     

Simplified purification of chondroitin sulphate from scapular cartilage of shortfin mako shark (Isurus oxyrinchus)

Chondroitin sulphate (ChS) from the scapular cartilage of the shortfin mako shark (Isurus oxyrinchus) was purified by two‐stage enzymatic hydrolysis and a fractional precipitation process using isopropyl alcohol. Characteristics of the ChS fraction were investigated using cellulose acetate membrane electrophoresis and FT‐IR spectra. A maximum hydrolysis rate of 78.26% was achieved with 1.35% (w/w) Alcalase and 1.20% (w/w) Flavourzyme. A minimum nitrogen content of 2.89% was obtained with 1.43% (w/w) Alcalase and 1.33% (w/w) Flavourzyme, as determined by response surface methodology. The precipitation of ChS from the enzymatic hydrolysates was optimised at 40% (v/v) isopropyl alcohol, which contained 2% (w/v) NaCl to lower the nitrogen content. The precipitate was further purified via membrane filtration (molecular‐weight cut‐off, 3 kDa) to remove salt and low‐molecular‐weight materials. The ChS purified by enzymatic hydrolysis, isopropyl alcohol precipitation and membrane filtration was identified as ChS C by electrophoresis and FT‐IR spectra.     

Changes in functional properties of shark (Isurus oxyrinchus) cartilage gelatin produced by different drying methods

Fish gelatins extracted from shark ( Isurus oxyrinchus ) cartilage were dried by three different methods: freeze drying, hot-air drying and spray drying; and their functional properties were investigated. Freeze-dried gelatin was found to have the strongest gel strength, while gelatins made at high temperatures formed weaker gels. The 135-kPa gel strength of freeze-dried gelatin was relatively high. While foam formation ability of the freeze-dried gelatin was the highest, its foam stability was the lowest. In addition, spray-dried gelatin had the best emulsion capacities. Dynamic viscoelastic properties of shark cartilage gelatins prepared by these drying methods were closely correlated with their gel strength. Elasticity modulus ( G '; Pa) and loss modulus ( G ; Pa) of the freeze-dried gelatin had higher values than those prepared by hot-air drying and spray drying; viscoelastic properties of the freeze-dried gelatin were maintained longer than those of other drying methods.     

Isolation and characterization of collagen from the cartilages of brownbanded bamboo shark (Chiloscyllium punctatum) and blacktip shark (Carcharhinus limbatus)

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the cartilages of brownbanded bamboo shark (BBS; Chiloscyllium punctatum) and blacktip shark (BTS; Carcharhinus limbatus) were isolated and characterized. ASC and PSC extracted from BBS cartilage showed the yields of 1.27 and 9.59 g/100 g (Based on dry weight), respectively, while yields of ASC and PSC from BTS cartilage were 1.04 and 10.30 g/100 g (based on dry weight), respectively. All collagens had protein as a major constituent with the trace amount of ash and fat. They contained glycine as the major amino acid with high contents of alanine, proline and hydroxyproline. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoretic patterns and subunit compositions, all collagens more likely comprised 2 types of collagen, type I and II, and contained α- and β-chains as the major components. Peptide maps of those collagens from both species digested by V8-protease and lysyl endopeptidase were different and were completely different from those of type I collagen from calf skin. Thermal transition temperature of ASC from those collagens (36.28-36.73 °C) was slightly higher than their corresponding PSC (34.56-35.98 °C). From zeta potential analysis, isoelectric points (pI) of collagen from the cartilages of BBS and BTS were estimated to be from 6.53 to 7.03 and from 6.96 to 7.26, respectively. Fourier transform infrared (FTIR) spectra of both ASC and PSC were quite similar, suggesting that pepsin hydrolysis did not affect the secondary structure of collagen, especially triple-helical structure.     

鱼翅及其真伪鉴定技术研究进展

鱼翅是鲨鱼鳍软骨制品,是我国传统的名贵海珍品.由于不同鱼翅的价格悬殊,一些不法商贩通过以次充好、以假乱真和错误标识等手段谋取利益,损害消费者权益.另一方面,鲨鱼的捕捞加速了部分濒危鲨鱼物种数量的急剧减少,甚至造成物种灭绝,破坏了生态平衡.因此,国内外开展了对鱼翅真伪及其鉴定技术研究,对打击掺假制假行为和鲨鱼保护都具有重...     

Evaluation of chondroitin sulfate in shark cartilage powder as a dietary supplement: Raw materials and finished products

We evaluated the content and biochemical properties of chondroitin sulfate (CS) in shark cartilage powders being used as nutraceutical supplements. The quantities of CS in shark cartilage products (SCPs) and finished products containing shark cartilage powder were determined by analyzing unsaturated disaccharides after treatment with chondroitinase ABC, and the results were compared with the specifications on the product labels. This method was validated and good linearity (r ? 0.999) was obtained. The recovery ranged from 95.27% to 102.39% with precision from 2.27% to 3.95%. Furthermore, the average molecular weights (MW) and the origins of CS in SCPs and finished products were evaluated by agarose gel-electrophoresis and assessment of disaccharide compositional patterns, respectively. Quantitative and compositional analysis of disaccharides after enzymatic depolymerization showed that the amount of CS in the samples of SCPs ranged from 0% to 28.92 ± 0.03%. All of the SCP samples except for SCP D had ΔDi-2,6diS and had more ΔDi-6S than ΔDi-4S, indicating that they originated from shark cartilage. In the finished products, the amount of CS ranged from 0.58 ± 0.01% to 21.30 ± 0.08%. With the exception of SCP D and two finished products (F and D), which contained CS with lower MWs, the average MW of CS in the SCPs and finished products was approximately 40 kDa or higher than that of MW standard (40 kDa) of CS. These analyses contribute to the evaluation of the quantity and quality of CS in SCPs and finished products containing CS, which is necessary for the manufacture of high-grade nutraceuticals.     

鲨鱼肉猫用食品的试制

主要研究了鲨鱼肉猫用食品制作工艺,通过多种试验确定了最佳生产工艺和配方,并对产品烘干和添加剂的选择进行了讨论。     

鲨鱼肌肉与鱼翅营养价值的比较

为全面、客观地评价鲨鱼肌肉和鱼翅的营养差异,以镰状真鲨（Carcharhinus falciformis）和大青鲨（Prionace glauca）为研究对象,比较分析了2 种鲨鱼肌肉、鱼翅（包括全翅和翅针,下同）的各种营养成分。结果显示：鲨鱼的肌肉和鱼翅蛋白质量分数均很高（24.34%～37.03%）,其中同一鲨鱼的鱼翅蛋白质量分数高于肌肉;2 种鲨鱼肌肉和鱼翅的粗脂肪质量分数都非常低,均小于0.50%;鲨鱼全翅因其鱼皮表面有砂质导致灰分质量分数特别高（6.18%～7.09%）,但肌肉的灰分质量分数（1.23%～1.63%）仅略高于翅针（0.86%～0.90%）。鲨鱼的肌肉和鱼翅中氨基酸种类齐全,总体上鱼翅中氨基酸总量（total amino acid,TAA）高于肌肉,但肌肉的必需氨基酸（essential amino acid,EAA）质量分数（41.94%～42.42%）高于鱼翅（17.93%～22.61%）,且只有肌肉满足联合国粮食及农业组织/世界卫生组织提出的氨基酸模式标准（EAA/TAA≥40%且EAA/非必需氨基酸≥60%）,因此,鲨鱼肌肉的氨基酸营养价值远高于鱼翅,是一种优质蛋白源,而鱼翅并非优质蛋白源。通过氨基酸评分（amino acid score,AAS）、化学评分（chemical sore,CS）和必需氨基酸指数（essential amino acid index,EAAI）3 种氨基酸评分发现：鲨鱼肌肉的AAS、CS以及EAAI值均显著高于鱼翅,约为鱼翅的2 倍,说明鲨鱼肌肉的氨基酸营养价值高于鱼翅。蛋氨酸＋半胱氨酸是鲨鱼肌肉的第一限制性氨基酸;亮氨酸（根据AAS结果）或蛋氨酸＋半胱氨酸（根据CS结果）为鱼翅的第一限制性氨基酸。鲨鱼肌肉中共检出13 种脂肪酸,且饱和脂肪酸（saturated fatty acid,SFA）质量分数＞多不饱和脂肪酸（polyunsaturated fatty acids,PUFA）质量分数＞单不饱和脂肪酸（monounsaturated fatty acid,MUFA）质量分数;鱼翅中共检出16 种脂肪酸,且SFA质量分数＞MUFA质量分数＞PUFA质量分数。鲨鱼肌肉和鱼翅中均含有丰富的油酸、二十二碳六烯酸和花生四烯酸等具有重要生理活性的不饱和脂肪酸,且均符合理想脂肪酸的标准（PUFA/SFA＞0.4）,但肌肉的PUFA/SFA明显高于鱼翅。鲨鱼肌肉和鱼翅中均含有丰富的胶原蛋白,且鱼翅中胶原蛋白质量分数（7.61%～11.99%）明显高于肌肉（0.27%～0.41%）。鲨鱼肌肉和鱼翅中还含有一定的硫酸软骨素,其中全翅中硫酸软骨素含量非常高（镰状真鲨和大青鲨分别为2.67 mg/g和10.87 mg/g）,而肌肉和翅针中含量较少（质量分数低于1.2%）。     

天然鱼翅翅针中氨基酸和脂肪酸组成分析与评价

为客观评价天然鱼翅的营养价值,为消费者做出指导,分析和评价了天然鱼翅的关键食用部位——翅针中的氨基酸和脂肪酸组成。氨基酸测定结果显示:镰状真鲨和大青鲨鱼翅翅针中共检出16种氨基酸,种类齐全,其中包含7种必需氨基酸(EAA);其氨基酸总量(TAA)分别为24.76%和23.32%,高于常见经济鱼类肌肉中TAA含量,但其EAA含量远低于常见经济鱼类肌肉中EAA含量,均为4.44%。氨基酸评分(AAS)结果显示:两种翅针除苯丙氨酸+酪氨酸的AAS评分是FAO/WHO评分标准的1.10和1.25倍之外,其余氨基酸的AAS评分均介于0.3~0.6之间,远低于评分标准;亮氨酸为两种翅针的第一限制性氨基酸。化学评分(CS)结果显示:两种翅针的CS评分均介于0.1~0.5之间,远低于标准蛋白(全鸡蛋蛋白)营养价值,亮氨酸或蛋氨酸+胱氨酸为第一限制性氨基酸;必需氨基酸指数(EAAI)评分结果显示:两种翅针的EAAI评分与标准蛋白(全鸡蛋蛋白)相距甚远,且低于几种常见经济鱼类肌肉的EAAI值。综合AAS、CS和EAAI分析结果认为:镰状真鲨和大青鲨翅针的氨基酸营养价值偏低,非优质蛋白质源,其主要限制性氨基酸为亮氨酸和蛋氨酸+胱氨酸。脂肪酸测定结果显示:两种天然鱼翅翅针中共检出4种饱和脂肪酸(SFA)、5种单不饱和脂肪酸(MUFA)和7种多不饱和脂肪酸(PUFA);其不饱和脂肪酸的含量(MUFA+PUFA)高于饱和脂肪酸(SFA)的含量,且富含花生四烯酸(ARA,分别为9.8%和9.2%)和二十二碳六烯酸(DHA,分别为4.2%和5.9%);两种天然翅针的ΣPUFA(n-3)/ΣPUFA(n-6)比值均明显高于FAO/WHO推荐比值(0.1~0.2),说明两种天然鱼翅翅针的脂肪酸营养价值较高。结论:镰状真鲨与大青鲨鱼翅翅针中氨基酸营养价值偏低,并非优质蛋白质来源;但富含人体必需的不饱和脂肪酸,其脂肪酸营养价值较高。     

食品中鲨鱼源性成分真实性PCR鉴别研究

建立食品中真实性鲨鱼源性成分PCR鉴别方法,该方法特异性强,灵敏度高。运用普通PCR技术对9种鲨鱼及42种常见非鲨鱼类动植物样品进行检测,9种鲨鱼中出现180bp的特异性扩增条带,其他非鲨鱼样品中均未出现扩增条带,实验表明,本检测方法具有特异性,检测限为0.1ng/μL鲨鱼DNA和0.1%(W/W)鲨鱼肉粉。运用建立的方法对20种常见的鲨鱼产品进行PCR检测,除仿鱼翅和鲨鱼肝油外,所有产品中均能检测出鲨鱼成分。该检测方法能够用于食品中鲨鱼源性成分的真实性鉴别。