罗非鱼鱼鳞胶制备降血压胶原肽的工艺及酶解物活性

以罗非鱼鱼鳞胶为原料,制备对血管紧张素转换酶(ACE)有抑制活性的降血压肽。以水解度(DH)及ACE抑制率为指标,筛选水解鱼鳞胶的最适酶种,并对其水解工艺条件进行优化;采用超滤技术对所制备的降血压肽进行分离纯化,比较不同组分的ACE抑制率,测定高ACE抑制率组分的氨基酸组成,并运用MALDI-TOF-MS法分析其分子质量分布。结果表明,复合蛋白酶是水解鱼鳞胶最适酶种,在50℃、pH7.5、料液质量体积比1∶5、酶与底物质量比(mE/mS)1.5%条件下,酶解6 h,酶解液的ACE抑制作用最强,其水解度DH 73%,ACE的抑制率76.15%。酶解液经超滤分离所获得的分子质量小于2 000 u的组分对ACE抑制率最高,达83.15%;该组分的氨基酸主要含有Gly和Pro,含量分别为22.04%和11.40%;该组分分子质量范围为1 300~2 000 u。     

几种鱼皮胶原蛋白的理化特性及其影响因素

利用水产加工废弃物研究了鳙鱼、鲈鱼、鲫鱼鱼皮胶原蛋白的氨基酸组成、粘度、凝胶强度、热变性温度(Td)等理化特性及其影响因素。结果表明,在0．1mol／L的乙酸溶液中鱼皮胶原蛋白溶液的粘度随着胶原蛋白浓度的增大而增大,随着温度的升高而下降。热水法提取鳙鱼、鲈鱼、鲫鱼鱼皮胶原蛋白的热变性温度分别为30℃,25℃,27℃。鱼皮胶原蛋白的凝胶强度则随着粘度、温度、pH值、外加介质等的变化而变化。     

Structural Changes and Rheological Properties of Dry Abalone Meat （Haliotis diversicolor） During the Process of Water Restoration

Changes in tissue structure, rheological property and water content of dry abalone meat in the process of water restora- tion were studied. The weight and volume of dry abalone meat increased with water restoration. When observed under a light micro- scope, structural change in myofibrils was obvious and a distinct network was found. When water restoration time increased from 24 h to 72 h, the instantaneous modulus E0 and viscosity η1 increased, whereas the rupture strength and relaxation time (τ1) were re- duced. There were no significant changes of rheological parameters (E0, η1, τ1, rupture strength) from 72 h to 96 h of water restoration. Therefore, the dry abalone meat was swollen enough at the time of 72 h. The rheological parameters were obviously influenced by the structural changes.     

两种不同海洋生物材料对大鼠急性创面修复效果的研究

为研究来源于海洋的鱼类胶原蛋白和海藻酸盐对创面的修复效果,建立大鼠皮肤急性创面模型,对两种材料的功效进行探索。研究采用临床常用创面敷料使用方法,将两种材料植入创面处,采用细胞生物学、病理学等方法进行观察评价。结果显示,鱼胶原蛋白和海藻酸盐均具有良好的生物相容性和诱导创面修复能力,但在诱导血管长入、材料降解融合以及整体创面修复状态等方面,鱼类胶原蛋白要优于海藻酸盐。结果证明,两种不同的海洋生物材料均可以创造良好的伤口愈合环境,有效促进创面的修复。     

The Antioxidant Effects of Complexes of Tilapia Fish Skin Collagen and Different Marme Oligosaccharides

An excess of reactive oxygen species(ROS)leads to a variety of chronic health problems.As potent antioxidants,marine bioactive extracts containing oligosaccharides and peptides have been extensively studied.Recently,there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries.However,only few studies are available on the antioxidant activities of such complexes,in terms of their ROS scavenging capability.In this study,we combined and superoxide radicals,and to evaluate the influences on the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and the level of malondialdehyde(MDA)in UV-induced photoaging models.The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components.Among the 11 complexes tested,two complexes,namely MA1000+CP and κ-ca3000+CP,turned out to be highly effective antioxidants.Although the detailed mechanisms of this improved scavenging ability are not fully understood,this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical,cosmetics and food industries.     

Proline with or without Hydroxyproline Influences Collagen Concentration and Regulates Prolyl 4-Hydroxylase α(I) Gene Expression in Juvenile Turbot(Scophthalmus maximus L.)

This study was conducted to investigate the effect of dietary proline(Pro), and Pro and hydroxyproline(Hyp) in combination on the growth performance, total Hyp and collagen concentrations of tissues, and prolyl 4-hydroxylase α(I)(P4H α(I)) gene expression in juvenile turbot feeding high plant protein diets. A diet containing 50% crude protein and 12% crude lipid was formulated as the basal and control, on which other two protein and lipid contents identical experimental diets were formulated by supplementing the basal with either 0.75% Pro(Pro-0.75) or 0.75% Pro and 0.75% Hyp(Pro+Hyp). Four groups of fish in indoor seawater recirculating systems, 35 individuals each, were fed twice a day to apparent satiation for 10 weeks. The results showed that dietary Pro and Hyp supplementation had no significant effect on growth performance and feed utilization of juvenile turbot(P 0.05). Total Hyp and collagen concentrations in muscle were significantly increased when dietary Pro and Hyp increased(P 0.05), and fish fed diet Pro+Hyp showed significantly higher free Hyp content in plasma than those fed other diets(P 0.05). The expression of P4 H α(I) gene in liver and muscle was significantly up regulated in fish fed diet Pro-0.75 in comparison with control(P 0.05); however the gene was significantly down regulated in fish fed diet Pro+Hyp in muscle in comparison with fish fed diet Pro-0.75(P 0.05). It can be concluded that supplement of crystal L-Pro and L-Hyp to high plant protein diets did not show positive effects on growth performance of juvenile turbot, but enhanced total collagen concentrations in muscle.     

绿鳍马面鲀(Navodon septentrionalis)鱼头酸溶性与酶溶性胶原蛋白的分离纯化及理化性质研究

利用酸溶法和酶溶法制备马面鲀鱼头酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC),并对所制备的ASC和PSC的氨基酸组成、SDS-PAGE、红外光谱、黏度和热变性温度,以及溶解度等性质进行分析。结果表明:马面鲀鱼头中ASC和PSC的提取率分别为0.94%±0.07%和3.91%±0.14%。Gly(265.0和251.8残基/1000残基)、Ala(111.0和107.6残基/1000残基)和Pro(87.0和83.1残基/1000残基)含量较高,而His和Tyr的含量较少,且未检测到Cys。ASC和PSC中亚氨基酸(Pro和Hyp)含量为169.3和160.6残基/1000残基。氨基酸组成分析、SDS-PAGE和红外光谱(FTIR)证实ASC和PSC均属于I型胶原蛋白,热变性温度分别为17.6°C和16.5°C。在酸性p H值范围内,ASC和PSC的溶解度较高;当Na Cl溶液浓度高于2%,ASC和PSC的溶解度会显著降低。综上,相对于哺乳动物类胶原蛋白,马面鲀鱼头ASC和PSC的亚氨基酸含量和热变性温度较低,结构稳定性差,易于降解,可作为胶原蛋白肽的制备原料进行开发。     

水产动物源胶原蛋白医学应用研究进展

胶原蛋白具有免疫原性低,生物相容性较好等优点,同时还具有可降解、止血和促进细胞生长增殖的特性。其中水产源胶原蛋白在提取工艺、安全性方面具有更大优势,因此在医学应用方面得到了广泛的研究与应用。本文探讨了水产动物源胶原蛋白在医学应用方面的研究进展,为后续的研究工作提供依据。     

Amino acid composition and functional properties of giant red sea cucumber (Parastichopus californicus) collagen hydrolysates

Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.