动物皮的利用方式及其发展前景

概述了动物皮及其水解产物以皮、胶原、明胶、水溶性明胶、多肽、短肽及氨基酸的多种存在状态及其性质,以及它们在工业、医疗等方面的应用,同时对其发展前景进行了展望。     

动物皮在生物医学材料中的应用

对动物皮本体及其水解产物皮胶原、明胶、水溶性明胶及多肽在生物医学材料各个方面的应用进行了综述.重点介绍皮胶原在止血方面、药物释放载体材料、组织工程、美容矫形方面的应用,并指出利用动物皮制造生物医学材料具有广阔的发展前景.     

动物皮在生物医学材料中的应用

对动物皮本体及其水解产物皮胶原、明胶、水溶性明胶及多肽在生物医学材料各个方面的应用进行了综述。重点介绍皮胶原在止血方面、药物释放载体材料、组织工程、美容矫形方面的应用,并指出利用动物皮制造生物医学材料具有广阔的发展前景。     

大鲵皮明胶提取及其性质分析

为有效利用大鲵加工副产物鲵皮,研究了从鲵皮中提取明胶的工艺条件及其部分性质。鲵皮经碱酸预处理后,以提取率为指标,通过单因素试验和正交试验优化了明胶提取的工艺参数。结果表明:鲵皮明胶最适提取条件为温度60℃,超声功率400 W、提取时间7 h,料液比1∶9(g∶m L),明胶提取率可达13.76%。鲵皮明胶中甘氨酸、脯氨酸、谷氨酸和丙氨酸含量相对较高,约占总氨基酸的50%,该明胶在234 nm处有最大紫外吸收,黏度为3.3 m Pa·s,凝冻强度Bloom值为216 g。     

罗非鱼皮明胶的过氧化氢法提取工艺

考察了过氧化氢的添加及其浓度、提取温度、提取时间等因素对罗非鱼皮明胶的提取率和明胶黏度的影响。采用响应面实验设计优化显著影响明胶提取率和明胶黏度的工艺参数,确定最佳提取工艺条件。实验优化结果为过氧化氢浓度0.07 mmol/g、提取温度53℃、提取时间4.6 h,此条件下明胶提取率达87.71%,黏度达8.90(mpa·s)。     

大目金枪鱼皮明胶的理化性质及结构分析

以大目金枪鱼皮为原料制备明胶,对所得明胶的凝胶强度、胶凝温度、熔化温度、氨基酸组成、十二烷基硫酸钠-聚丙烯酰氨凝胶电泳（sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE）、光谱学特性等理化性质及结构特性进行研究,并与猪皮明胶进行比较。结果表明,金枪鱼皮明胶的凝胶强度为403?g,胶凝温度和熔化温度分别为21.5?℃和28.8?℃,略低于猪皮明胶;氨基酸分析结果表明,金枪鱼皮明胶中亚氨基酸质量分数为19.09%,低于猪皮明胶的22.82%,可以解释金枪鱼皮明胶凝胶特性、胶凝温度和熔化温度低于猪皮明胶的原因。SDS-PAGE电泳结果显示,金枪鱼皮明胶的小分子组分质量分数仅为6.67%,说明预处理及热水提胶过程并没有破坏明胶中亚基的完整性。金枪鱼皮明胶的紫外光谱与红外光谱谱图均与猪皮明胶相似,进一步说明实验所制得的产物为高质量明胶。     

狭鳕鱼皮明胶提取工艺的研究

为了充分利用水产品加工废弃物狭鳕鱼皮,优化狭鳕鱼皮明胶提取工艺,通过单因素试验和响应曲面法对鱼皮明胶提取工艺进行优化。结果表明：狭鳕鱼皮明胶提取的最佳工艺条件为：氢氧化钠浓度0.10%、硫酸浓度0.21%、浸提时间12.1h,此条件下明胶的提取率为17.52%。     

鳕鱼皮明胶肽硒复合物的制备及结构表征

以新西兰鳕鱼皮为原料，提取鳕鱼皮明胶并酶解获得鳕鱼皮明胶肽，以亚硒酸钠为硒源，制备并筛选出硒结合量较高的肽硒复合物，对其进行结构表征。结果显示，鳕鱼皮明胶胃蛋白酶酶解物的硒结合含量最高（13.61 μg/mg），因此将其用于制备鳕鱼皮明胶肽硒复合物；鳕鱼皮明胶肽与硒结合后，紫外光谱吸收峰强度增大且红移，荧光光谱吸收峰由波长311 nm迁移到355 nm且荧光强度减弱，表明鳕鱼皮明胶肽与硒结合产生新的物质；基于粒径分布、原子力显微镜、扫描电子显微镜、X射线衍射分析，鳕鱼皮明胶肽硒复合物呈现为纳米晶体结构，主要是由于鳕鱼皮明胶肽上的羧基和氨基与硒发生了结合反应，使得β-折叠结构转变为α-螺旋结构和β-转角结构，从而使得结构更加紧凑有序。本研究制备了一种新型的肽硒复合物，为实现鱼皮高值化利用提供了新途径。     

牛蛙皮明胶提取工艺优化及其性质分析

以牛蛙皮为原料,在单因素试验基础上,通过正交试验探讨了料液比、胃蛋白酶添加量、胃蛋白酶处理时间、提取温度和熬胶时间对牛蛙皮明胶提取率的影响,并对其性质作了初步分析。优化的牛蛙皮明胶提取条件为:料液比1︰8(g/m L)、胃蛋白酶添加量15 U/g、胃蛋白酶处理时间3 h、提取温度50℃、熬胶时间16 h;明胶提取率最高,达12.78%。牛蛙皮明胶色泽洁白,黏度和凝冻强度分别为3.85 m Pa·s和223 g,等电点为5.78。此外,牛蛙皮明胶的氨基酸组成中,脯氨酸和羟脯氨酸总含量为18.25%。优化的牛蛙皮明胶提取工艺合理、可行,提取率较高,且符合食用明胶标准。     

明胶水晶冻及果冻粉的研制

明胶是以动物皮、骨、软骨、韧带、肌膜等含有的胶原蛋白,经部分水解后得到的高分子多肽的高聚合物、容易被人体消化、吸收。明胶水晶冻及其果冻粉是众多明胶食品中的一种,以蔗糖、明胶为主要原料,配以果汁、咖啡、奶粉、可可等各种辅料精制而成。加入上述的任一种辅料,可具     

Gelation, oxygen permeability, and mechanical properties of mammalian and fish gelatin films

The objective of this study was to evaluate the gelation, thermal, mechanical, and oxygen permeability properties of different mammalian, warm- and cold-water fish gelatin solutions and films. Mammalian gelatin solutions had the highest gel set temperatures, followed by warm-water fish and then cold-water fish gelatin solutions. These differences were related to concentrations of imino acids present in each gelatin, with mammalian gelatin having the highest and cold-water fish gelatin having the lowest concentrations. Mammalian and warm-water fish gelatin films contained helical structures, whereas cold-water fish gelatin films were amorphous. This was due to the films being dried at room temperature (23 °C), which was below or near the gelation temperatures of mammalian and warm-water fish gelatin solutions and well above the gelation temperature of cold-water fish gelatin solutions. Tensile strength, percent elongation, and puncture deformation were highest in mammalian gelatin films, followed by warm-water fish gelatin film and then by cold-water fish gelatin films. Oxygen permeability values of cold-water fish gelatin films were significantly lower than those for mammalian gelatin films. These differences were most likely due to higher moisture sorption in mammalian gelatin films, leading to higher oxygen diffusivity.     

高效液相色谱-高分辨率质谱联用技术鉴定阿胶块中不同胶类的特征性多肽

为研究阿胶块中不同明胶的来源,本文以4种品牌的阿胶块为原料,向其中分别加入低含量(1 mg/mL)的牛明胶和猪明胶,采用高效液相色谱-质谱联用技术(high-performance liquid chromatography-mass spectrometry,HPLC-MS/MS)分别鉴定阿胶、牛明胶和猪明胶的特征性...     

单宁酸交联处理对明胶性质的影响

采用单宁酸作交联剂对明胶进行交联改性处理,对其凝胶性、降解性进行分析,制备VB1 微胶囊并确定芯材的释放性能。结果表明,与原料明胶相比,交联明胶形成凝胶的最低浓度基本未发生改变,仍为0.6 % 左右,但是在相同浓度下交联明胶的凝胶强度明显降低。体外降解实验表明,原料明胶和交联明胶在模拟胃液中几乎不发生降解,但在模拟肠液中都发生降解,且交联明胶的降解速度更慢。交联明胶为壁材制备的微胶囊,其芯材在模拟胃液和模拟肠液中有一定的缓释效果。     

Preparation and characterisation of chicken skin gelatin as an alternative to mammalian gelatin

The aims of this study were to report for the first time, the extraction and physico-chemical properties of chicken skin gelatin compared to bovine gelatin. Extracted chicken skin gelatin 6.67% (w/v) had a higher bloom value (355 ± 1.48 g) than bovine gelatin (259 ± 0.71 g). The dynamic viscoelastic profile of chicken gelatin exhibited higher viscous and elastic modulus values compared to bovine gelatin for a range of concentrations and frequencies. Thermal properties studied by differential scanning calorimetry (DSC) showed that the melting temperature of 6.67%, chicken skin gelatin was significantly greater (p < 0.05) than that of bovine gelatin, indicating lower stability of bovine gelatin compared to chicken skin gelatin. Results obtained in this study showed that Gly (33.70%), Pro (13.42%), H.Pro (12.13%) and Ala (10.08%) were the most dominant amino acids in chicken skin gelatin which contributed to the higher gel strength and stability. Raman spectra of chicken skin and bovine gelatin were similar and displayed typical protein spectra. Chicken gelatin showed strong hydrogen bonding compared to bovine gelatin as the tyrosine doublet ratio (I₈₅₅/I₈₃₀) of chicken gelatin was significantly lower than that of bovine gelatin. Significantly, the alpha helix and β-sheet type structures were higher for chicken skin gelatin compared with bovine gelatin. The average molecular weight of chicken gelatin was 285,000 Da. These findings, obtained for the first time for chicken skin gelatin, show that it has high potential for application as an alternative to commercial gelatin.     

加热方式和加热时间对鱼类明胶理化性质的影响

为探究加热方式和加热时间对鱼类明胶理化性质的影响,对加热明胶溶液的蛋白组成、粘度、流变性质和热稳定性,以及明胶凝胶的强度、质构（texture profile analysis,TPA）参数和微观结构进行分析和比较。结果显示,鱼类明胶溶液的粘度、流变性质及热稳定性随加热时间的增加而明显降低,但间歇加热明胶中这些性质的变化幅度均低于连续加热明胶。连续加热明胶至48 h时电泳图谱中β条带消失,96 h时α₁和α₂亚基明显降解,而当间歇加热明胶至96 h时β条带才消失。鱼类明胶形成的凝胶其强度和TPA参数随热处理时间的延长逐渐减小,但间歇加热明胶的凝胶形成能力优于连续加热明胶。扫描电子显微镜结果显示,连续加热的凝胶表面光滑平整,而间歇加热凝胶的结构更加粗糙且多孔隙。研究结果表明,间歇加热及加热时间小于12 h有利于减少明胶热降解。     

阿胶制品中典型明胶特征性多肽的鉴定

为了研究不同类型阿胶制品中典型明胶的来源,本文选取9种市面上常见的阿胶制品（阿胶糕、阿胶口服液和阿胶颗粒各3种）为研究对象,分别添加质量分数为1%的牛明胶和猪明胶,采用高效液相色谱-高分辨率质谱联用技术（high-performance liquid chromatography-mass spectrometry,HPLC-MS/MS）鉴定这9种阿胶制品中典型明胶的特征性多肽。结果表明,不同数量的典型明胶特征性多肽被检出于9种阿胶制品。进一步分析发现,所有阿胶制品共有的阿胶、牛明胶、猪明胶的特征性多肽分别为25、3、14条,其中,未经修饰的特征性多肽依次为7、2、3条。在上述共有特征性多肽中,源自α1链的分别有22、2、5条,源自α2链的分别为3、1、9条。这些共有特征性多肽可作为HPLC-MS/MS鉴定复杂体系中明胶源的依据,对不同阿胶制品中明胶来源的鉴定具有指导意义。     

Preparation of gelatin microparticles using water-in-water (w/w) emulsification technique

Gelatin microparticles were prepared using water-in-water (w/w) emulsification technique, in which aqueous solutions of gelatin and polypropylene glycol (PEG) were employed as dispersed phase and continuous phase, respectively. The effect of gelatin and PEG concentrations on the size of gelatin microparticles were evaluated. The size of the gelatin microparticles decreased with the increase in PEG concentration and increased with the increase in gelatin concentration. The gelatin microparticles obtained through this process were nearly perfect spheres with smooth surface. The gelatin microparticles, both un-crosslinked and crosslinked, were found to be fully amorphous in nature. The un-crosslinked gelatin microparticles were found to swell instantaneously (within 10 s) whereas the crosslinked ones were quite resistant to water uptake.     

Improved microstructure and properties of the gelatin film produced through prior cross‐linking induced by horseradish peroxidase,glucose oxidase and glucose

The effects of prior enzymatic cross‐linking of bovine gelatin via horseradish peroxidase, glucose oxidase and glucose on microstructure and properties of the target film (cross‐linked gelatin film) were assessed. The cross‐linked gelatin film exhibited similar film thickness and moisture content, lower water solubility and higher opacity than the gelatin film directly prepared with bovine gelatin. The cross‐linked gelatin film also demonstrated improved thermal stability and mechanical properties, characterised by higher melting point and glass transition temperature, enhanced tensile strength and elongation at break and greater storage modulus. Prior gelatin cross‐linking resulted in 30.2% and 68.6% reductions in water vapour and CO₂ permeability of the cross‐linked gelatin film, respectively, but did not affect oil permeability. Furthermore, the cross‐linked gelatin film possessed smaller cross‐sectional voids (diameter 100?360 nm vs. 200?595 nm) than the bovine gelatin film. This study shows that cross‐linking can efficiently improve film microstructure and properties of the gelatin‐like products.     

兔皮明胶功能特性及其影响因素

为研究兔皮明胶的功能特性,对兔皮明胶的流体特性、全质构特性等进行测定。结果表明兔皮明胶对剪切速率的敏感性较小,其硬度、胶着性、咀嚼性和弹性高于猪皮明胶,在耐咀嚼的糖果类食品、肉制品生产中具有应用优势。色差检测结果表明兔皮明胶对产品的外观颜色影响较小,在实际应用中可替代猪皮明胶。不同质量浓度和pH值条件下,兔皮明胶和猪皮明胶加工特性的测定结果表明,兔皮明胶的黏度、起泡性总体均高于猪皮明胶;兔皮明胶的黏度随质量浓度的增加而增大,当质量浓度为4 g/100 mL时达到最大,当pH值靠近等电点时,其黏度减小;兔皮明胶的起泡性随质量浓度增加呈上升趋势,在质量浓度为3 g/100 mL时达到最佳。兔皮明胶的乳化稳定性随质量浓度和pH值的增大呈现先升高后降低的趋势,当质量浓度和pH值分别为3 g/100 mL和4.0时乳化稳定性达到最佳,且均高于猪皮明胶。