特基拉芽孢杆菌液态发酵制备菜籽多肽的工艺研究

以菜籽粕为原料,通过特基拉芽孢杆菌液态发酵生产菜籽肽,以多肽得率为筛选指标,先通过单因素试验对发酵基质的料水比、磷酸二氢钾添加量、葡萄糖添加量、初始pH进行优化,再通过单因素和正交实验对发酵的温度、菌种接种量、发酵时间、转速等条件进行优化,确定最佳发酵工艺。对发酵工艺进行验证,测定发酵上清液中的多肽和氨基酸含量以及发酵上清液的抗氧化能力。结果表明,发酵基质优化后的配方为料水比1∶25,初始pH 8;发酵条件为接种量0.35 mL/g发酵基质,37℃、240 r/min发酵42 h。优化后菜籽多肽得率为21.4%,较对照组提高了9.3倍。发酵上清液的氨基酸含量为373.27 mg/100 mL,较对照组显著提高9.55倍,其中异亮氨酸、赖氨酸和组氨酸含量分别提高了18.24、20.46、30.98倍。发酵上清液体外抗氧化活性显著提高,50%DPPH自由基清除率为0.053 mg/mL,50%ATBS自由基清除率为0.087 mg/mL,发酵上清液稀释20倍后的铁总抗氧化活性FRAR值为0.25±0.01。     

利用正交实验优化豆清液的发酵条件

实验以湘式休闲豆干生产中的豆清液为主要研究原料,利用发酵培养确定最适的豆清液发酵时间、发酵温度、种子液添加量。通过对单因素实验的探讨,选取发酵温度、发酵时间、种子液添加量三因素的三水平进行L_9(3~3)正交实验,并通过测总酸含量(以乳酸计)和pH,得出结论:湘式休闲豆干生产中各因素的优水平为发酵温度37℃、种子液接种量20%、培养时间48h;豆清液发酵在最佳工艺条件下的pH值为4.32,产酸量为18.26mL/dL。     

牛骨蛋白分步酶解制取胶原多肽螯合钙的研究

以富含胶原蛋白和有机钙的新鲜牛骨为原料,在采用正交试验确定胃蛋白酶(pepsin)适宜水解条件的基础上,通过添加A1398中性蛋白酶(neutral protease)结合三因素二次旋转试验方法对水解牛骨蛋白制备胶原多肽钙的工艺进行优化。结果表明:先用胃蛋白酶在pH1.5,料液比1∶30,E/S5∶000U/g(蛋白质),温度37℃,酶解3h,再调节pH值至7.5,E/S3000U/g(蛋白质),温度50℃,酶解40min,螯合率最高可达98.36%。     

混菌发酵菜籽粕制备多肽技术的研究

以发酵产物中多肽含量为指标,研究白地霉和枯草芽孢杆菌混菌发酵菜籽粕生产多肽的工艺条件。采用Plackett-Berman实验得出影响多肽含量的显著因素有是否灭菌、发酵温度和发酵时间。通过单因素实验和响应面实验,得到预测发酵产物中多肽含量的数学模型为:Y=154.90+7.64X4-1.10X5+4.75X3-1.52X4X5-5.84X42-11.56X52-5.42X32,X3为发酵时间(d),X4为发酵温度(℃),X5为接种量(%),发酵温度和接种量对多肽含量的影响有显著的交互作用。研究得出多肽的最优发酵条件为:发酵温度35.68℃,接种量18.68%,发酵时间4.25d,此时所得发酵产品中多肽含量为157.79mg/g。     

辅料及发酵条件对食醋酒精发酵工艺影响研究

以高粱为主要原料,大曲和蜂蜜为辅助原料,利用单因素实验方法,以酒精度和还原糖含量为指标,确定了食醋酒精发酵阶段的最佳工艺参数。结果表明,大曲添加量为60%,蜂蜜添加量为10%;发酵时间为7d,发酵温度25℃~30℃,酵母接种量为2×107个/g,初始pH值为4.5最佳发酵参数,经验证试验,最终得到的酒精度为7.38%vol。     

黑曲霉发酵核桃粕生产核桃多肽工艺优化

以核桃粕为原料,以核桃多肽含量为考察指标,黑曲霉发酵产核桃多肽.通过单因素和响应面分析法确定黑曲霉发酵核桃粕产核桃多肽的最优发酵条件.结果表明,最优发酵条件为:发酵温度为30℃,发酵时间为48h、摇床转速为200r/min、核桃粕浓度7％、pH=6、接种量11％,在此最佳发酵条件下核桃多肽含量为22.33Lg/mL.     

骨胶原蛋白的酶解工艺条件

采用胰蛋白酶酶解骨胶原蛋白制备胶原多肽,通过单因素和响应面试验,以水解度为指标,确定胰蛋白酶酶解胶原蛋白的最佳工艺条件。结果表明：最优工艺条件为pH6.91、反应温度60℃、酶添加量200mg/g 胶原蛋白、底物水平0.1/61.5(g/mL)、水解时间为4h;此条件下的胶原蛋白水解度达到29.36%。酶解后胶原蛋白的溶解性及乳化性均显著提高。     

牛骨胶原蛋白酶解工艺优化及结构特性分析

为研究前期纯化的特异性降解牛骨胶原蛋白的胶原蛋白酶(BSC)对牛骨胶原蛋白的酶解工艺,以水解度为响应值,在单因素试验基础上通过五元二次正交旋转组合试验,确定最佳酶解工艺为:反应温度46℃、牛骨胶原蛋白添加量5.14g/100mL、BSC添加量0.42g/100 mL、反应时间6h、pH 6.5,该工艺条件下水解度为34.98%。采用紫外光谱(UV)、荧光光谱(FS)、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)对牛骨胶原蛋白及其产物进行结构特性分析。通过UV分析表明BSC酶的降解作用破坏了牛骨胶原蛋白的三股螺旋结构,游离出大量的氨基酸;FS分析表明牛骨胶原蛋白分子表面C═O、CONH_2、COOH逐步增多,胶原蛋白肽中生色基团分布也随之发生变化;FT-IR分析可知牛骨胶原蛋白经降解后的胶原蛋白肽的肽链上—NH_2~+—排斥作用逐渐减弱,主要以β-转角为主;SEM表明酶破坏了牛骨胶原蛋白的表面分子结构,使其变得疏松。     

发酵法制备大豆肽的工艺优化及其抗氧化能力

主要研究了枯草芽孢杆菌1398发酵制备大豆肽的工艺条件。以大豆肽含量和平均肽链长度为指标,通过对蔗糖添加量、水分添加量、接种量、发酵温度、发酵时间的单因素实验和正交实验,确定了发酵法制备大豆肽的最优工艺条件:蔗糖添加量0.5%,水分添加量70%,接种量2.0%,32℃条件下发酵32 h。此条件下测得短肽含量为252.95 mg/g。初步提纯后,粗肽的DPPH.,O2-.和.OH清除能力较市售肽分别提高了119.53%,26.02%,65.56%。实验结果表明,发酵工艺能够显著提高产物的大豆肽含量及抗氧化能力。     

响应面分析法优化山杏仁多肽发酵制备工艺条件

以山杏仁饼为原料,经脱脂后通过黑曲霉发酵制备山杏仁多肽,对发酵工艺条件进行了优化.在单因素实验的基础上,采用四因素三水平的响应面法对影响山杏仁多肽含量的4个主要因素,即液料比、初始pH、接种量和发酵温度进行分析优化.结果表明,山杏仁多肽发酵制备工艺的最佳条件为:初始pH6.4,液料比12∶1,接种量10.5％,发酵温度30℃.在此条件下,测得山杏仁多肽含量为4.768 mg/mL,与理论预测值的相对误差为1.058％.     

Bovine collagen. II. Electrophoresis of collagen fractions

Summary. Vertical starch gel electrophoresis was used to separate components of neutral salt soluble (NSS) and acid soluble (AS) collagens, and of eucollagens, from muscle, skin and tendon of bovines of different age. The relative proportions of the separated components were assessed spectrophotometrically.
The electrophoretograms indicated that the greater difficulties of extraction which distinguish AS from NSS collagen reflect a greater measure of cross-bonding between the α chains of the former.
They also indicated that there was a marked increase in the proportion of components having intra molecular cross bonds, in both NSS and AS collagens and in the three tissues studied, between the 5th and 9th month of gestation. In older animals there were also indications of an enhanced degree of inter molecular cross bonding.
Such changes help explain the increased toughness of the meat from older bovines despite a lower percentage of collagen.     

胶原蛋白酸解为胶原多肽的动力学研究

通过全波长扫描和凝胶渗透色谱,对水解过程动态及其多肽分子质量的变化进行了研究,考察了水解温度、酸用量等因素对水解动态的影响,并对酸法水解的过程动力学进行了分析。结果说明:鸭掌胶原蛋白酸法水解得到的多肽分子质量分布不均匀,分子质量大小随反应时间的增大而减小;增大酸用量和提高温度可使水解反应更彻底,水解过程可用一级反应动力学方程进行描述。     

Physicochemical characterization of collagen fibers and collagen powder for self-composite film production

The purpose of this work was to determine some physicochemical characteristics of collagen fibers and collagen powder obtained from bovine hides as potential raw materials for production of films with improved mechanical properties. These materials are collagen in its crude form, without the hydrolysis reaction that leads to gelatin production. The following analyses were carried out: proximate composition, amino acid composition, solubility in water, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), size distribution and moisture sorption isotherms. The collagen fibers and collagen powder showed practically the same protein content, and the only differences between them, apart from the particle shape and size, were in their solubility in water, which was probably partly due to differences in particle size. Due to their similar composition but different physical properties, collagen fibers and collagen powder were shown to be suitable for the production of biocomposite films where the powder is the basis of the film matrix and the fibers act as filler, exerting a reinforcement effect. Films with the protein content supplied by 50% collagen powder and 50% collagen fibers could be produced with the film thickness fixed at 180 μm and subjective evaluations suggested that the fibers remained completely involved in the filmogenic matrix.     

Bovine collagen. I. Changes in collagen solubility with animal age

Summary. The changes with animal age in the concentrations of five forms of collagen of differing solubility characteristics were followed in bovine l. dorsi, skin and tendon. Those forms which were extractable in neutral salt and dilute acid were found to increase swiftly during the gestation period and fall to low levels between birth and 1–2 years of age in the three tissues. After birth there was a rapid rise in the concentrations of the more insoluble forms of collagen and these greatly predominated by 1–2 years of age in each tissue. The relative time relations of the changes were compatible with a transformation of the easily extractable forms into the more insoluble ones with increasing age.
In muscular tissue only, after about 2 years of age, there was some diminution in total collagen and also in the proportion of the latter which resisted extraction. Possible reasons were discussed.     

胶原的生物学性质

胶原作为一种天然蛋白质材料 ,可应用于生物医学领域。简述了与此应用相关的胶原的生物学性质。     

胶原的生理作用

胶原存在于人体内的各处器官 ,本文简要介绍了人体各主要器官中的胶原成分所起的生理作用     

一种胶原蛋白寡肽促进皮肤胶原蛋白与透明质酸合成的研究

研究罗非鱼鱼鳞胶原蛋白寡肽对人皮肤成纤维细胞透明质酸分泌以及对小鼠真皮中胶原蛋白合成的影响.采用WST-8法测定了该胶原蛋白寡肽对人皮肤成纤维细胞增殖的影响,ELISA法检测了胶原蛋白寡肽对人皮肤成纤维细胞透明质酸分泌的影响;以D-半乳糖衰老模型小鼠为实验对象,考察胶原蛋白寡肽对小鼠真皮中胶原蛋白合成的影响.结果表明,胶原蛋白寡肽能促进人皮肤成纤维细胞增殖(p＜0.01),能促进人皮肤成纤维细胞透明质酸和小鼠真皮中胶原蛋白的合成(p＜0.05)说明该胶原蛋白寡肽能有效促进透明质酸和胶原蛋白的合成.     

Pyridinoline in ovine intramuscular collagen

Pyridinoline, a mature crosslink of collagen, was measured in intramuscular connective tissue isolated from ovine semimembranosus, a muscle noted for its highly insoluble collagen. Concentration ranged between 0·25 and 0·59 mol/mol of collagen, on the high side of concentrations reported in the literature for this and other muscles in various species. Pyridinoline concentration was inversely related to collagen solubility in muscle homogenates (P < 0·0). In a comparison between semimembranosus, biceps femoris and gluteus medius, pyridinoline concentration was again inversely related to collage solubility. For all these muscles, pyridinoline remained insoluble in a heat-dependent solubility test, but it is argued that pyridinoline does not explain all the solubility properties of ovine intramuscular collagen. Pyridinoline concentration was not significantly correlated with sensory or shear properties of cooked semimembranosus, confirming the importance of other heat-stable crosslinks.     

人造胶原肠衣的研究进展

肠衣作为食品包装材料,对维持肉制品的品质、延长货架期具有重要作用。随着肠衣需求量的增加,天然肠衣市场供不应求,为人造肠衣的出现和发展提供了机会。其中人造肠衣包括塑料肠衣、纤维素肠衣和胶原肠衣。在加工过程中每种肠衣都体现出各自的特点同时存在不同的亟待解决的问题。人造胶原肠衣在可食性、收缩性、黏着性等性能方面与天然肠衣相似,在资源稳定性和食品安全性等方面优于天然肠衣。胶原肠衣兼有天然肠衣和人造肠衣两者的优点,因此具有非常大的市场前景。本文在综述了肠衣类型的基础上,对比了国内外胶原肠衣的研究进展,总结了胶原肠衣的制备方法,并对胶原肠衣尤其是水产胶原肠衣的发展前景进行了展望,以期对胶原肠衣的研究提供理论基础。     

Interaction of malonaldehyde with collagen

Summary The studied derivatives of malonaldehyde had measurable crosslinking properties, even though much less pronounced than malonaldehyde. The optimum conditions for the reaction of these compounds were in the same pH range, around pH 4. It was shown that the substitution of malonaldehyde entailed a considerable decrease of its initially high reactivity. The polar effects of substituents influenced the electron acceptor function of malonaldehyde in accordance with established mechanism of aldolization.

---

Zusammenfassung Die verwendeten Derivate des Malonaldehydes vernetzen das Kollagen, wenn auch in viel kleinerem Ausmaß. Das Optimum der Reaktion liegt im gleichen Bereich bei pH um 4. Es hat rich gezeigt, daß durch die Substitution des Malonaldehydes dessen große Aktivität gestört wird. Polare Effekte der Malonaldehyd-Substituenten beeinflussen die Elektronacceptor-Fähigkeit des Malonaldehydes im Einklang mit dem allgemein gültigen Mechanismus der Aldolisation.