鱼油精制的初步研究

本文着重研究了鱼油精制过程中的主要影响因素,以鱼油的粘度,气味,鱼泽,酸值,过氧化值作为鱼油的质量指标,通过试验确定了鱼油脱胶,脱酸,脱臭各工艺过程的工艺条件。     

草鱼内脏鱼油乙醇提取研究及其脂舫酸组成分析

对无水乙醇提取草鱼内脏鱼油工艺进行了研究,并分析了鱼油的基本理化性质和脂肪酸组成,主要研究了料液比对鱼油提取率的影响。无水乙醇提取草鱼内脏鱼油的工艺为:料液比(w:v)1:8,提取温度55℃,提取时间3小时。在此工艺条件下,粗鱼油提取率为87.6%。粗鱼油经85%磷酸脱胶、4%NaOH脱酸、活性白土脱色后,鱼油呈浅黄色透明状,酸价、过氧化值较低;经冬化处理后的鱼油中不饱和脂肪酸含量约为81.5%。     

鱼油在不同体系中的氧化稳定性

以过氧化植（ＰＯＶ）、共轭二烯型氢过氧化物含量和脂肪酸相对含量的变化为指标研究了鱼油在不同体系中的氧化稳定性。结果表明：在贮藏过程中以Ｎ２保护的鱼油氧化稳定性最高,而暴露于空气中的鱼油的氧化稳定性最差。将鱼油分散于水中形成Ｏ／Ｗ型的乳化体系能提高鱼油的氧化稳定性。在三种体系中高不饱和脂肪酸的含量均比低不饱和脂肪酸下降的更快。隔绝Ｏ２是防止鱼油氧化的重要措施。     

鳗鲡仔鱼微型胶囊饵料的初步研究

制备了囊心物为液态的，含脂溶性营养物（lipidic solubility nutriment,LSN)及水溶性营养物（water solubility,WSN)的明胶（GT）－羧甲基纤维素（CMC）微型胶囊饵料。制备方法为将WSN和LSN分别溶入适量水和鱼油中，再将水与鱼油制成W／O乳剂，最后以GT、CMC为囊材将乳滴包裹成微囊。平均囊径为41．2μm。对鳗鲡（Anguilla japonica)仔鳗的投喂实验表明，微囊饵料加上天然饵料可使仔鳗存活15d，而只投喂天然饵料的仔鳗只存活了8d。     

六、水产加工

941104 鱼油分离及纯化技术=Marine oilseparation purification technology[刊,英]/Chan J K,Nil//FSTA..—1993,25(7).—7R83作者研究认为,由于鱼体的成份不一,因此各种鱼油的性质也不相同。所以,处理方法各不同,但一般的加工方法是类似的。其鱼油的加工法一般都使用连续式蒸煮装置加热至95℃,以使蛋白质凝固及减少其溶解和粘度。     

喷雾干燥微胶囊化罗非鱼油的研究

对高包埋率的微胶囊化罗非鱼油的壁材组成及喷雾干燥参数进行了研究。以罗非鱼油微胶囊产品的包埋率为主要评价指标，对不同类别的壁材进行了筛选，得到适宜的壁材，并优化了壁材配比及喷雾干燥参数。结果表明，罗非鱼油微胶囊适宜的壁材为明胶、蔗糖及黄原胶，组成比例经优化后为明胶4．5％，蔗糖13．2％，黄原胶0．3％，鱼油7．0％；喷雾干燥参数为进风温度115℃，出风温度75％，喷雾压力100kPa。得到的罗非鱼油微胶囊经加速氧化15d后POV值仅为对照的1／2，抗氧化性得到明显提高。     

鱼油的提取与精制技术探讨

利用水产加工下脚料提取鱼油并进行精制.探讨了湿法工艺提取鱼油和精炼的工艺,比较了不同脱酸工艺对产品质量的影响,介绍了白土脱色和活性碳脱色工艺条件,并对冬化和脱臭工艺进行了研究.     

超声波辅助提取金枪鱼蒸煮液鱼油工艺研究及品质分析

为探索金枪鱼蒸煮液鱼油高值化开发利用技术,对超声辅助乙醇提取金枪鱼蒸煮液鱼油工艺进行优化,通过单因素试验研究液料比、温度、时间和功率对鱼油提取率的影响,在此基础上采用响应面法进一步优化工艺条件.试验结果表明,最优工艺条件为:提取温度34℃,提取时长60 min,超声功率154 W.该工艺条件下鱼油的提取率为91.32％...     

β-环糊精稳定南极磷虾油Pickering乳液的制备及其稳定性的研究

为了确定β-环糊精稳定南极磷虾油Pickering乳液的制备工艺并研究其稳定性,实验通过研究不同乳化方法(超声、高速剪切和高压微射流)、不同油相体积分数(30％、40％、50％、60％和70％)及不同β-环糊精添加量(1％、2％、3％、4％和5％,质量分数)对乳液特征指标(浊度、离心稳定性、粒径和ζ-电位)的影响,初步...     

鲣鱼加工废弃物中鱼油的提取及纯化的工艺研究

鱼油所含的不饱和脂肪酸既有助于脂的消化吸收、转运和形成,又是生物膜的重要结构物质.鲣鱼加工中产生大量的下脚料,如果用于提取鱼油,可以创造可观的经济效益.本文探讨了利用鲣鱼加工废弃物提取、精制、纯化鱼油的工艺条件,并且对从鲤鱼废弃物中提取鱼油并纯化出高不饱和脂肪酸的方法进行了研究,得到的鱼油中高不饱和脂肪酸占24%,其中...     

Development of diets for the intensive culture of Pacific lamprey

The Pacific lamprey Entosphenus tridentatus is an ancestral species of critical importance to the ecosystem and indigenous cultures in the Pacific Northwest. Conservation aquaculture has been proposed as a potential technique to restore Pacific lamprey populations. Intensive culture methods and diets for this species have not been developed. A sixteen week feeding trial tested the effects of seven diet treatments on the survival, growth, fatty acid profile and whole body lipid content of Pacific lamprey ammocoetes. Dietary treatments were: active dry yeast, yeast plus fish oil emulsion, micro‐algae, micro‐algae plus fish oil emulsion, yeast with micro‐algae, yeast with micro‐algae plus fish oil emulsion and yeast with larval fish diet. Each diet was offered to five replicate tanks stocked with 20 ammocoetes that were 51 days post hatch. Survival during the trial was not affected by diet. The greatest length and weight increases were in fish fed diets containing yeast. Growth decreased as the amount of algae in the diet was increased. Lipid retention was significantly higher in fish fed yeast with larval fish diet relative to the other treatments. Feed conversion ratio was lowest in fish fed diets containing yeast. Whole body fatty acid profiles tended to reflect the fatty acid profile of the diet. Percentages of 20:5n‐3 and 22:6n‐3 were significantly higher in fish fed diets containing fish oil emulsion. Overall, yeast with larval fish diet provided the best growth performance in larval Pacific lamprey.     

Pea and wheat starch possess different processing characteristics and affect physical quality and viscosity of extruded feed for Atlantic salmon

The aim of the study was to investigate the effect of starch source, retention time in the preconditioner and screw speed (RPM) on physical quality of extruded fish feeds. The experiment was arranged in a three by two by two factorial design using three carbohydrate sources [wheat starch (WS), pea starch (PS) or a combination (WS_PS)], two retention times in the preconditioner [long (120 s) or short (62 s)] and two RPM in the extruder [high (300) or low (220)]. Physical quality was assessed by hardness, diameter, expansion ratio, Holmen durability (HDI), DORIS value (DV), oil absorption capacity, oil leakage and pasting viscosity. The results showed that retention time in the preconditioner only affected HDI and oil leakage. Long retention time improved HDI but caused a greater leakage. Changing screw speed from 220 to 300 RPM gave a greater expansion ratio, improved HDI and oil absorption. PS resulted in higher pasting viscosity, HDI and DV, but a generally lower hardness than WS. To conclude, PS and WS have different processing characteristics, and the conditions need to be adjusted according to the starch source used when producing extruded fish feed.     

Effect of Dietary Inclusion of N-Acetyl Cysteine on Mucus Viscosity and Susceptibility of Rainbow Trout, Oncorhynchus mykiss, and Atlantic Salmon, Salmo salar, to Amoebic Gill Disease

The treatment of amoebic gill disease (AGD) in cultured Atlantic salmon, Salmo salar L., using mucolytic agents has been previously reported. The agent L‐cysteine ethyl ester reduces salmonid mucus viscosity and potentially increases the flushing of the gill. In the present study, the effects of the mucolytic agent N‐acetyl cysteine (NAC) were assessed. Cutaneous mucus from rainbow trout, Oncorhynchus mykiss Walbaum, and Atlantic salmon was shown to have reduced viscosity when mixed in vitro with 100 or 200 μg/mL NAC. Saltwater‐acclimated rainbow trout and Atlantic salmon were fed an oil‐incorporated, NAC‐medicated diet (8 g NAC/kg diet) for up to 24 d and challenged with inoculation of 300 cells/L Neoparamoeba spp., the etiological agent of AGD. Control fish were fed normal oil‐coated pellets and received no NAC. NAC medication failed to reduce the severity of gill lesions associated with AGD even though the mucus viscosity from medicated fish was less than that of controls. Oral NAC medication does not appear to be an effective method for controlling AGD in salmonids despite reducing cutaneous mucus viscosity.     

HUFA content and DHA/EPA improvements of Artemia sp. with commercial oils during different enrichment periods

Several commercial oils of plant and animal origin were tested in order to improve the HUFA content and the DHA:EPA ratio of Artemia sp. metanauplii. The relationship between the n-3 and n-6 fatty acid series, and more recently, the DHA:EPA ratio seem to be indicators for better survival and growth of marine fish larvae. The tested plant oils were derived from linseed, peanut and sunflower, and the animal oils came from squid, sardine, cod liver and Selco emulsion. For each oil emulsion tested, four different enrichment periods (9, 24, 33 and 48 h) were evaluated in the same Artemia sp. strain (Artemia EG from Artemia Systems Inc., Baasrode, Belgium). The results show that oil emulsions of plant origin give very poor results in relation to either HUFA content or DHA:EPA ratio. All the oil emulsions from animal origin resulted in HUFA incorporation. Sardine oil was the poorest and squid oil the best. The HUFA content and the DHA:EPA ratio increased with enrichment periods up to 33 h, followed by a negligible variation up to the final 48 h.     

Examination of the Interaction of Chitosan and Oil-in-Water Emulsions Under Conditions Simulating the Digestive System Using Confocal Microscopy

ABSTRACT

Chitosan is a cationic biopolymer that has been used extensively in dietary supplements to reduce fat absorption in the fight against obesity. The mechanism of fat binding of chitosan is still not fully understood and has been the subject of controversy. This study was designed to improve the understanding of the underlying mechanism by investigating the interaction of chitosan with oil-in-water emulsion droplets. Our results indicated that (0.1% w/w) chitosan adsorbed to a 20% w/w phosphatidylcholine-stabilized anionic primary emulsion to form a secondary cationic emulsion by electrostatic attraction forces under conditions resembling the stomach (pH 2). Bile salts (6 mM) were added to simulate secretion in the small intestine and pH increase. Bile salts adsorbed to the chitosan secondary emulsion, which resulted in aggregation of oil droplets followed by coalescence due to close packing of droplets. Increased viscosity (267–2531 cp) and increased degree of deacetylation (40–92% DDA) of chitosan enhanced emulsion breakdown. Increasing the pH to 7.5 without addition of bile salts yielded little aggregation. Pronounced aggregation is thought to decrease the accessibility of lipase to the oil resulting in lower bioavailability and reduced caloric intake. Understanding how chitosan interacts with oil droplets in the digestive tract is vital to developing a comprehensive model of the influence of chitosan on the bioavailability of dietary lipids. The information gained in this study may be useful for the interpretation and experimental design of animal and human feeding studies and for the rational design of chitosan-based functional foods for fat reduction.     

Fatty Acid Composition and Oxidative Stability of Fish Oil Products in Turkish Retail Market

The fatty acid composition and oxidative stability of fish oil and syrups available in the Turkish retail market were examined in this study. The major saturated fatty acids in capsules and syrups were palmitic acid (16:0) and stearic acid (18:0). The monounsaturated fatty acid contents of fish oil products have very different results (10.71–50.46%). The results show that the label claims for total omega-3, eicosapentaenoic acid, and docosahexaenoic acid presented a reasonable accuracy for the examined products, but it was noted that some of the results showed a considerable difference with the labels.

The free fatty acid level in fish oil products was generally low (0.13–1.95% of oleic acid). Peroxide value of all examined products was below the limit of 10 meq kg^?1 oils for edible oil as indicated in Codex (1999). It was detected that the p-Anisidine value of fish oil capsules (5.36–8.90) was considerably lower than for fish oil syrups (21.86–26.74). According to our results, the totox value of fish oil capsules evaluated in this study (7.08–17.35) was within acceptable limits. However, fish oil syrups (34.72–38.06) highly exceeded the upper tolerable limit (26).     

Microencapsulation of Fish Oil Using Fish Protein Hydrolysate,Maltodextrin, and Gum Arabic: Effect on Structural and Oxidative Stability

ABSTRACT

Microencapsulated fish oil was prepared by spray drying using fish protein hydrolysate, sodium caseinate, maltodextrin, and gum Arabic as wall material. Fish protein hydrolysate was prepared from pink perch meat, and its physical and functional properties were studied. Microencapsulates prepared with a combination of sodium caseinate, maltodextrin, and gum Arabic were kept as control. The encapsulation efficiency and oil release behavior of microencapsulates was evaluated. Surface morphology and thermal properties of microencapsulates were determined by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) analysis, respectively. Fourier-transformed infrared spectroscopy analysis indicated that the spectral pattern of microencapsulates showed a similar structural pattern with a minor band shift for both control and fish protein hydrolysate containing microencapsulates. Oxidative stability of fish oil microencapsulates indicated that the sample stored under was 4°C was more stable than microencapsulates stored under 60°C and 28 ± 2°C temperature conditions. Moreover, microencapsulates containing fish protein hydrolysate had a lower thiobarbituric acid value. Results suggest that the incorporation of fish protein hydrolysate along with other wall material could improve the oxidative stability of microcapsules during storage.     

激素缓释制剂诱导海水养殖鱼类性腺发育成熟与生殖行为的研究进展

综述促性腺素释放激素类似物（GnRH-a)缓释制剂（SRDS），人绒毛膜促性腺激素（HCG）SRDS，类固醇激素SRDS；雄烯二酮（ADSD）和17a-甲基睾丸酮（MT），以及鲤垂体匀浆（CPE）混合SRDS诱导海水养殖鱼类性腺发育成熟和生殖行为的效果，认为采用GnRH-a SRDS处理性腺发育良好的鲈形目鱼类和鲆鲽鱼类，可以显著提高血液促性腺激素（GtH)水平，且持续时间长，诱导排卵成功，HCG乳胶SRDS可诱导日本鳗鲡（Anguila japonicus)血液GtH持续 升高，性成熟系数明显升高并且性腺发育成熟；HCG和CPE水／油／水（W／O／W）复乳SRDS对日本鳗鲡的催熟效果显著，采用ADSD和MT SRDS SRDS可成功诱导日本鳗鲡性腺成熟与排卵。     

Production of High Quality Fish Oil by Thermal Treatment and Enzymatic Protein Hydrolysis from Fresh Norwegian Spring Spawning Herring By-Products

There is an increasing demand for omega-3 containing fish oils. By-products from fish fillet production can be utilized for the production of fish oils and be a valuable source of omega-3 for human consumption. The aim of this work was to evaluate industrial processes for production of quality oil for human consumption made from Norwegian spring spawning herring by-products. A mobile production plant was used to compare two industrial processes, thermal treatment (wet rendering) and enzymatic protein hydrolysis, for production of oil from herring by-products immediately after filleting. Results show that high quality herring oil can be produced from fresh by-products. The use of by-products immediately after filleting resulted in a low amount of free fatty acids for all the produced oils (below 0.4%). Thermal treatment at 70°C resulted in an oil with lower oxidation status and higher stability compared to the oils produced by enzymatic protein hydrolysis. Nevertheless, both processing methods gave a crude oil of high quality compared to crude oils on the market.