菊黄东方鲀鱼精蛋白提取工艺优化研究

为研究河鲀鱼精蛋白的制备工艺,以菊黄东方鲀(Takifugu Flavidus)精巢为原料,以鱼精蛋白提取率为指标,通过单因素试验研究NaCl溶液的pH、硫酸浓度、硫酸用量、提取温度、提取时间以及乙醇用量等单因素对鱼精蛋白提取率的影响,在此基础上,采用响应面法优化鱼精蛋白的提取工艺条件。结果显示,采用响应面法优化获得河鲀鱼精蛋白的最佳提取工艺条件为:NaCl溶液pH 8.5,硫酸浓度0.6 mol/L,硫酸用量4.0倍沉淀体积,提取温度45℃,提取时间2.4 h,乙醇用量4.0倍沉淀体积,此时鱼精蛋白提取率达到19.07%。研究表明,响应面法对河鲀鱼精蛋白提取条件的优化方案合理可行,可为河鲀精巢的开发利用提供参考依据。     

暗纹东方鲀鱼精蛋白的提取工艺优化研究

以暗纹东方鲀(Takifugu obscurus)精巢组织为原料,采用酸提法提取鱼精蛋白。以得率为指标,通过正交实验,确定了最佳的提取参数。结果显示,提取鱼精蛋白的影响因素重要性依次为：提取次数>硫酸用量>硫酸浓度>95%乙醇用量;最佳提取工艺条件：硫酸浓度为0.2 mol/L、硫酸用量为2.5倍、提取次数为2次、95%乙醇用量为2.5倍。在此工艺条件下,暗纹东方鲀鱼精蛋白的得率为3.82%,蛋白含量达89.01%。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳(Tricine-SDS-PAGE)可知,提取的粗鱼精蛋白有2个条带,分子量分别在25和20 kDa附近。分析其氨酸酸组成发现,暗纹东方鲀鱼精蛋白属于双鱼精蛋白,其中,精氨酸和丙氨酸含量相对较高,分别占31.40%和17.39%。本研究对暗纹东方鲀鱼精蛋白更好地应用在食品和医药领域具有重要意义。     

碱液浸提法制备硫酸软骨素的工艺优化

采用碱液浸提法对鱿鱼软骨中硫酸软骨素的提取工艺进行研究。以硫酸软骨素得率为评价指标,通过对影响硫酸软骨素得率的因素进行单因素试验和响应面优化试验确定最佳工艺参数。结果表明,碱液浸提的最佳工艺条件为：料液比1∶8( g/mL)、浸提温度50℃、浸提时间5．3 h, NaOH浓度3%。在此条件下,鱿鱼软骨中硫酸软骨素得率为62．89%。     

鲢鱼鱼精蛋白的提取

研究了鲢鱼鱼精蛋白的提取工艺。以淡水鱼鲢鱼鱼白为原料，以得率及抗菌活性为指标，通过正交试验，得出了较佳提取工艺：每克鱼白中加入5ml 10％的硫酸提取3h；每毫升提取液中再加入1.5ml 60％的三氯乙酸，沉淀0.5h。     

河豚鱼皮明胶提取工艺研究

研究从无毒河豚鱼皮下脚料中提取鱼明胶的最佳工艺。考察氢氧化钠浓度、硫酸浓度、预处理时间等因素对明胶提取率及性能的影响,确定最佳前处理工艺为分别以8倍0．2％氢氧化钠水溶液浸泡2h,洗净后以0．3％硫酸水溶液浸泡1h;考察河豚鱼皮明胶提取温度、提取时间、溶剂用量对鱼明胶强度及得率的影响,确定最佳的提取工艺为加4倍量水,在...     

鱿鱼加工副产物高值化综合利用综述

近年来,国内鱿鱼加工产业快速发展,其副产物占据着很大的比重,对这些副产物的加工和利用越来越引起关注。鱿鱼加工副产物包括鱿鱼皮、内脏、鱼眼、墨汁、精巢、软骨等,对鱿鱼加工过程中副产物进行回收利用,不仅提高鱿鱼的经济价值,还可以减少副产物引起的环境污染。本文分别介绍了鱿鱼皮、墨汁、精巢和软骨的组成特性、提取以及利用情况,总结了近年来国内外利用鱿鱼副产物为原料开发胶原蛋白、鱼精蛋白、软骨素等一系列生化制品的研发状况,并提出了以复合蛋白酶酶解鱿鱼皮制备小分子胶原寡肽和以酶水解-膜分离组合工艺生产软骨素、骨胶原蛋白的综合利用新工艺的技术特点,最后展望了鱿鱼加工副产物的高值化综合利用前景和发展趋势。     

鱿鱼加工副产物综合利用研究进展

综述了近年来国内外利用鱿鱼皮、内脏、软骨、墨汁、鱼眼、精巢等副产物为原料开发胶原蛋白、鱼油、核酸、酶、软骨素、透明质酸、鱼精蛋白等一系列生化制品的研发状况,展望了几种鱿鱼副产物的应用前景和发展趋势.     

鲟鱼硫酸软骨素的制备工艺研究

以史氏鲟鱼软骨为原料,按碱提-酶解-乙醇沉淀工艺流程进行提取硫酸软骨素的各主要工序工艺的研究.通过单因素试验及正交试验,得出最佳碱提工艺为以两倍量6%的NaOH为溶剂,于40℃的水浴中搅拌提取4 h.通过正交试验,得出最佳酶解工艺条件是先将浸提液调节pH至8.6,加入胰酶0.5%,50℃保温水解3 h;后降温至40℃,调pH至5.7,加入胃蛋白酶0.3%,保温水解2h.通过单因素试验,得出最佳的乙醇沉淀工艺条件是将滤液pH调为6.5,加入95%的乙醇至醇沉浓度为70%,静置过夜.制备的硫酸软骨素经检测符合WS1-C3-0030-2000(硫酸软骨素口服片)和WS-10001-(HD-0892)-2002(硫酸软骨素注射品)标准的要求.     

海带硫酸酯多糖的酶法提取工艺条件

实验研究了纤维素酶提取海带硫酸酯多糖的工艺条件,通过单因素实验和正交实验,确定了最佳提取工艺条件为:粒度80~100目,固液比1∶50,提取时间4h,酶加入量60g/kg,提取率为5.641%,是热水提取工艺的1.93倍。     

鱼精蛋白的提取纯化及应用研究进展

鱼精蛋白是一种存在于各种鱼类精巢组织中的多聚阳离子肽,富含精氨酸,呈碱性,具有促进细胞繁殖发育、增强肝功能、抑制肿瘤生长繁殖等功能,在医学和保健领域有着广泛的应用;此外还具有显著的抗菌活性,可以开发成一种天然防腐剂.本文从分析鱼精蛋白的基本特性入手,重点介绍了鱼精蛋白的提取和纯化工艺,并讨论了其在食品、医学上的应用及分...     

Characteristics and Functional Properties of Ovary from Squid Loligo Formosana

The characteristics and functional properties of the ovary from Loligo formosana were studied. Moisture (72.07 ± 0.24%) was dominant, followed by protein (18.64 ± 0.51%) and carbohydrate (7.44 ± 0.2%). Ash (1.39 ± 0.03%) and lipids (0.46 ± 0.5%) were found as the minor constituents. Albumin (79.02 ± 0.79%) was the major protein of the squid ovary, followed by glutelin-1 (8.31 ± 0.62%) and globulin (6.68 ± 0.08%). Nevertheless, prolamin and glutelin-2 constituted approximately 1% of the total proteins. Based on the electrophoretic studies, albumin had the largest band intensity. The squid ovary was rich in non-essential amino acids (52.26%) and high in hydrophobic amino acids (48.03%). It was also rich in polyunsaturated fatty acid (PUFA, 43.76 ± 0.84%), followed by saturated fatty acid (SFA, 39.36 ± 0.12%) and monounsaturated fatty acid (MUFA, 12.94 ± 0.55%). Ovary lipids had a high amount of docosahexaenoic acid (C22:6) (28.59%). At pH 3, the squid ovary powder (SOP) had the maximum solubility (96.39%), whereas the lowest solubility (38.33%) was observed at pH 9. The foaming capacity and stability of SOP were increased with increasing concentration up to 8% (p < 0.05). The globulin fraction showed the higher foaming capacity, as compared to albumin and glutelin-1 fractions. The squid ovary had good nutritional value and possessed excellent foaming properties. Therefore, the squid ovary could serve as a novel food additive or ingredient.     

东太平洋不同海区茎柔鱼肌肉脂肪酸组成分析与比较

茎柔鱼(Dosidicus gigas)是一种广泛分布在东太平洋的大洋性头足类,具有重要的经济价值。本研究以捕获自3个作业海区的茎柔鱼为研究对象,对其肌肉脂肪酸含量进行测定、分析和比较。结果显示,各海区茎柔鱼肌肉脂肪酸种类和组成存在显著差异。秘鲁外海样品所含脂肪酸种类最多(共28种),中东太平洋赤道海域样品含有脂肪酸27种,而智利外海样品所含脂肪酸种类最少,只检测出24种。脂肪酸均以多不饱和脂肪酸为主(59.68%~69.28%),其次是饱和脂肪酸(20.71%~27.28%)和单不饱和脂肪酸(10.01%~13.04%)。各海区茎柔鱼肌肉中C16:0、C18:0、C20:1n9、C18:2n6、EPA和DHA含量较高,均占脂肪酸总含量的81%以上。脂肪酸组成的空间异质性主要是由各海区C16:0、C18:2n6、C20:4n6和DHA的含量不同造成的,这种差异可能与各海区海洋环境、食物来源和个体能量需求的差别有关。本研究说明了脂肪酸分析在茎柔鱼食性研究中的潜在作用,对分析不同海区茎柔鱼营养成分和资源合理利用有一定的应用价值。     

Amino acids composition and protein quality evaluation of marine species and meals for feed formulations in cephalopods

The amino acid composition and protein levels of three species of cephalopods (Octopus vulgaris, Loligo gahi and Todarodes sagittatus), the natural diets of common octopus (O. vulgaris) and different kinds of meals were determined in order to optimise the content of these nutrients in artificial feeds. Arginine, leucine and lysine were the most abundant essential amino acids in cephalopods, while glutamate and aspartate represented the main non-essential amino acids. Arginine and leucine were the limiting amino acid in most samples, with maximum Chemical Score values for mussel (79–98 %), squid (84 %) and crustaceans (65–91 %); medium for fish (41–70 %); and minimum for meals (29–64 %). Mussel, squid, crustaceans and fish showed a high essential amino acid index according to Oser (OI: 88–99 %) suggesting a suitable amino acid balance. The protein from animal meals (fish and krill) covered all the essential amino acids except arginine and lysine in fish meal. The vegetable meal presented the worst amino acid balance (OI: 74–89 %) with several deficiencies in essential amino acids, including arginine, threonine, lysine and methionine. Supplementation with arginine or leucine and protein complementation of crustaceans and bivalves with fish or animal meal are proposed as alternatives for improving the performance of protein in feed for cephalopods.     

Physicochemical and Structural Properties of Recovered Elastin from Jumbo Squid (Dosidicus gigas) By-Products

Physicochemical and structural properties of soluble jumbo squid (Dosidicus gigas) elastin recovered from skin by-products were evaluated. The molecular weight of isolated elastin was ~40 kDa with an isoelectric point (pI) between 9 and 10. Aspartic, glutamic, arginine, proline, glycine, and lysine amino acids were the most abundant in squid elastin, whereas the hydroxyproline absence, ~0.7% cysteine content, and the calculated 0.35 isoleucine/leucine ratio were used as purity index. Total and reactive sulfhydryl contents were similar (247.0 ± 5.1 vs 242.0 ± 7.5 μmol mg^?1 of protein, P ≥ 0.05) in purified squid elastin but surprisingly higher than previously reported in other elastins. On the other hand, the secondary structures of squid elastin analyzed by Fourier transform infrared spectroscopy (FTIR) were ~45% β-sheets, ~15% α-helices, ~10% β-turns, and ~30% undefined structures. In addition, squid elastin experienced glass transition at 82.01 ± 0.01ºC, denaturation temperature at 110.45 ± 0.64ºC, and aggregation at 197.5 ± 0.23ºC. In conclusion, the prevalence of charged amino acids and pI of squid elastin can facilitate its solubilization in hydrophilic systems, whereas the secondary structure profile and thermostability are desirable features in proteins used for biopolymer designs such as food biofilms or barrier systems.     

Apparent digestibility coefficients of feed ingredients and their predictability in compound diets for gilthead seabream, Sparus aurata L.

Apparent digestibility of crude protein, amino acids, lipid, carbohydrate and energy was measured for a range of feed ingredients fed to gilthead seabream, Sparus aurata L. — fish meal, poultry meal, meat meal, blood meal, squid meal, extracted soyabean and wheat flour. Chromic oxide was used as a non-absorbed reference substance and faeces were collected by stripping. Diets compounded from mixtures of these ingredients were then used to examine the possibility of predicting the digestibility of formulated diets.
Apparent digestibility of crude protein ranged from 79% to 90%, lipids from 83% to 95% and energy from 72% to 88% in the different ingredients. Apparent digestibility of carbohydrates was lower and ranged from 49% to 77%. Apparent digestibility of amino acids was higher than that of crude protein and differences were found among digestibilities of individual amino acids.
Tests conducted using five compound diets indicated that ingredient digestibility was additive for protein, amino acids, lipids and energy, whereas the digestibility of carbohydrates in the compound feeds was slightly lower than predicted.
Diets for Sparus aurata may thus be formulated on the basis of digestibility of individual ingredients.     

Comparison of extractive components in muscle and liver of three Loliginidae squids with those of one Ommastrephidae species

Extractive components were determined for the mantle muscle and liver of three species of Loliginidae squid, Sepioteuthis lessoniana, Loligo bleekeri, and L. edulis, and one species of Ommastrephidae, Todarodes pacificus, as a control. Total free amino acid levels and the major free amino acids in muscle, taurine, proline, glycine, alanine, and arginine, were significantly higher in Loliginidae squids than in T. pacificus. The main nucleotide was adenosine 5′-monophosphate, which did not differ significantly between species. Malate was the organic acid found in muscle in highest concentrations. The muscle of these species contained a large amount of trimethylamine oxide. A large amount of glycine betaine was also detected in the muscle, but showed no large species difference. From these results, the muscle of Loliginidae species is considered to have a much sweeter taste than that of T. pacificus. Compared with muscle, squid liver was characteristic with high contents of taurine, glutamate, bitter amino acids, succinate, propionate, trimethylamine, and glycine betaine, and with low contents of sweet amino acids, arginine, nucleotides, malate, and trimethylamine oxide. These results suggest that squid liver is characterized by a complicated taste containing umami, bitterness, sourness, fishy flavor, and less sweetness.     

Use of White Fat as a Replacement for Squid Liver Oil in Practical Diets for Surubim Pseudoplatystoma coruscans

The effect of dietary lipid on culture performance, fatty acid composition of carcass, and the liver polar lipid of surubim fingerlings Pseudoplatystoma coruscans was investigated. Five isonitrogenous (46.5% crude protein) and isolipidic (19% crude lipid) diets were formulated with squid liver oil (SLO) and white fat (pig lard-PL) as lipid sources. Diet 1 was supplemented with 12% SLO, diet 2 with 8% SLO and 4% PL, diet 3 with 6% SLO and 6% PL, diet 4 with 4% SLO and 8% PL, and diet 5 with 12% PL. Fish were fed to apparent satiation over a 64-d feeding trial. No statistically significant difference ( P >0.05) was observed in growth performance of fish. In contrast, fatty acid profile of fish carcass and liver polar lipid fraction was affected ( P 0.05) by dietary fatty acid composition. Palmitic (16:O) and the oleic (18:1n-9) acids were the major saturated and monoene fatty acids respectively found in fish carcass, independent of the lipid source in the diets. The total amount of saturated and monoene fatty acids was significantly higher ( P 0.05) in the carcass of the fish fed diets 4 and 5, than in the other fish. The concentration ( P 0.05) of eicosapentaenoic and docosahexaenoic acids and the n-3/n-6 ratio in fish carcass and in polar lipid fraction of liver increased in direct proportion to the level of squid liver oil in diet. Results of this experiment clearly demonstrated that both squid liver oil and pig lard have a positive nutritive value for surubim and that it is possible to increase the n-3 to n-6 ratio in favor of n-3, without loss in the growth performance, feeding fish with a diet containing a lipid source rich in this fatty acid.     

鱼精蛋白的抑菌机理

鱼精蛋白对细菌呼吸系统能产生微弱的抑制作用，但这并不是其抑菌活性的主要途径；鱼精蛋白主要是以分子中多聚精氨酸或多聚精氨酸与其它少数几个氨基酸以某一种结构或形式和细菌细胞壁结合，破坏细胞壁的形成，从而达到其抑菌效果。