紫海胆黄油微胶囊制备工艺的研究

为开发品质较好的紫海胆(Anthocidaris crassispina)黄油微胶囊,以辛烯基琥珀酸酯化淀粉(HICAP100)和β-环糊精为壁材,通过喷雾干燥制备紫海胆黄油微胶囊,以乳化液稳定性及包埋率为指标,通过单因素试验,研究紫海胆黄油微胶囊的壁材比例、乳化液浓度及油脂添加量对微胶囊的影响。以单因素试验的结果为基础,采用正交实验得出紫海胆黄油微胶囊化的最优制备工艺,并检测其理化性质和卫生指标。结果显示,最优制备工艺为:壁材比例为4∶2(HI-CAP100∶β-环糊精),乳化液质量浓度为17%,油脂添加量为15%。经过分散机乳化30 min,利用料理机均质5 min,在进风温度180℃、出风温度80℃、进样速度500 mL/h下进行喷雾干燥时,得到的包埋率和乳化液稳定性分别为95.7%和96.8%,紫海胆黄油微胶囊的水分含量为2.82%,溶解度为71.94%,自流角为22.05°,菌落总数为480 CFU/g,大肠菌群数30 MPN/100 g,霉菌和酵母10 CFU/g,金黄色葡萄球菌、沙门氏菌、志贺氏菌皆未检出。紫海胆黄微胶囊的理化性质及安全卫生指标皆符合行业标准。     

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。     

冷冻干燥法制备壳聚糖微胶囊

壳聚糖作为一种天然的阳离子聚合物,生物相容性好,是理想的微胶囊壁材材料之一;而鱼油是一种易氧化的材料,低温有利于鱼油加工,采用冻干技术可以缓解鱼油的氧化作用。实验以壳聚糖为壁材,金枪鱼油为芯材,采用冷冻干燥法制备鱼油微胶囊,并运用响应面分析法优化制备工艺参数。结果表明:以包埋率为评价指标,在单因素试验的基础上根据Box-Behnken中心组合试验设计原理,结合实际生产情况,最终确定最优的微胶囊制备工艺参数为壁材质量浓度2.1%、壁芯比1.9∶1、乳化剂Tween80和Span80比为2∶1、乳化剂添加量0.9%,在此条件下鱼油微胶囊理论包埋率为79.67%,实际平均值为79.45%,所制得微胶囊理化指标符合行业标准。研究结果不仅对冷冻干燥法制备鱼油微胶囊具有一定的实践参考意义,也为壳聚糖微胶囊的制备提供一定的实验理论基础。     

南极磷虾虾青素微胶囊制备工艺优化及其理化性质研究

为减缓虾青素的氧化速度,提高虾青素的储藏稳定性,以麦芽糊精、羟丙基-β-环糊精(HP-β-CD)为壁材,采用喷雾干燥法对南极磷虾(Euphausia superba)虾青素进行微胶囊化包埋,并对微胶囊化后产品的理化性质进行研究。结果显示,麦芽糊精与HP-β-CD壁材质量比为1∶3、虾青素添加质量分数为4.76%、聚山梨酯-80添加质量分数为0.87%、固形物浓度为0.20 g/ml时,虾青素微胶囊包埋率为98.77%。制备的虾青素微胶囊水分含量为(3.11±0.11)%,溶解度为(94.32±0.08)%,休止角为(34.16±0.24)°。稳定性实验表明,与未微胶囊化的虾青素晶体相比,虾青素微胶囊在高温条件、自然光条件与有氧条件下,虾青素的保留率分别由28.72%、45.27%与20.76%提高到了78.32%、84.88%和74.97%。可见微胶囊化可明显改善虾青素溶解性和稳定性,为虾青素微胶囊化产品制备提供技术支持。     

酶解法提取鱿鱼肝油的生产工艺研究

以鱿鱼肝脏为原料,采用AS.1398中性蛋白酶水解提取肝油,选用提取率为指标,通过单因素试验和响应面试验法确定最佳的酶解工艺;并从其肝油的提取率、品质、脂肪酸组成方面与传统水提法进行比较.试验结果表明,最佳酶解工艺参数为:料液比1∶1,酶解pH值6,加酶量1 340 U/g,酶解温度55℃,酶解时间4h;酶提法提取率高于水提法,且过氧化值较低,鱼油品质较好.     

复合抗氧化剂在鱿鱼肝油中的应用研究

以Schall烘箱加速氧化法研究茶多酚、天然生育酚和抗坏血酸棕榈酸酯在鱿鱼肝油中的抗氧化效果,选取响应面法确定最佳复合抗氧化剂配方,并将单一抗氧化剂与复合抗氧化剂对鱿鱼肝油抗氧化效果进行对比.结果显示复合抗氧化剂配方为茶多酚添加量0.28‰,抗坏血酸棕榈酸酯0.14‰,天然生育酚0.18‰时,鱿鱼肝油的过氧化值为7.93 meq/kg;而通过添加复合抗氧化剂,鱿鱼肝油贮藏期由48 d延长至96 d,说明复合抗氧化剂具有良好的抗氧化效果.     

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%。     

复凝聚法制备焦酚缓释微囊工艺优化

用复凝聚法制备以壳聚糖和海藻酸钠为囊壁、以焦酚为囊芯的缓释微囊,研究微囊形态、色泽及包埋率等指标来探究囊壁配比、囊芯浓度(1、2、3、4、5 mg/mL)和DMSO含量(17%、29%、38%、44%、50%)对焦酚缓释微囊制备的影响,以优化焦酚缓释微囊制备工艺。结果显示,壳聚糖与海藻酸钠复凝聚反应最佳含量比例为1:2;囊芯浓度为3 mg/mL焦酚缓释微囊呈球形,大小均匀,包埋率为51.56%,当助溶剂DMSO含量为17%时,包埋率达到93.35%,微囊大小均匀呈球形,色泽晶莹透亮。     

喷雾干燥与冷冻干燥对鱼油微胶囊品质的影响

为深度开发金枪鱼加工副产物,充分利用金枪鱼油所含营养成分,以壳聚糖为壁材,金枪鱼油为芯材,分别采用喷雾干燥法和冷冻干燥法制备鱼油微胶囊,比较两种制备方法对制得微胶囊品质的影响。结果显示:喷干鱼油微胶囊和冻干鱼油微胶囊的包埋率分别为77.26%、63.86%,但后者对鱼油脂肪酸保护更好;前者挥发性成分共有43种,其中酮类物质相对含量最高,占33.01%;而后者的挥发性成分仅有24种,以酯类为主,占52.29%,且没有检测到典型的腥味物质,这可能是由于冻干过程温度较低,抑制了多不饱和脂肪酸的氧化,更能掩盖鱼油不良风味。贮藏试验显示,两种鱼油微胶囊与鱼油相比,过氧化值的增长速度均显著降低(P<0.05);贮存7d后,两种胶囊的二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)保留率分别为82.22%和85.25%,两种制备方法对DHA和EPA保留率的影响不大(P>0.05)。研究表明,两种鱼油微胶囊制备方法对延缓鱼油氧化和掩蔽不良风味有一定作用,对制备鱼油微胶囊具有一定的参考意义。     

中华绒螯蟹嗜水气单胞菌微胶囊口服疫苗制备工艺及特性研究

以福尔马林灭活的中华绒螯蟹(Eriocheir sinensis)腹水病及抖抖病并发病病原菌嗜水气单胞菌(Aeromonas hydrophila)CL99920菌株为芯材和海藻酸钠为壁材,采用乳化法制备嗜水气单胞菌微胶囊口服疫苗.通过单因素试验和正交试验,研究了海藻酸钠浓度、乳化时间、搅拌速度和菌胶比例对嗜水气单胞菌...     

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.     

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.     

Essentiality of Dietary n-3 Highly Unsaturated Fatty Acids in Juvenile Japanese Flounder Paralichthys olivaceus

This study was conducted to confirm the essentiality of dietary n-3 highly unsaturated fatty acids (n-3 HUFA) and to investigate the effects of dietary lipid sources on growth performance, liver, and blood chemistry in juvenile Japanese flounder. Three replicate groups of fish (average weighing 3.0 g) were fed experimental diets containing lauric acid ethyl ester, soybean oil, soybean and linseed oils mixture, and squid liver oil as lipid sources for 13 wk. No significant difference was observed in survival among all groups ( P >0.05). Weight gain, feed efficiency and protein efficiency ratio of fish fed the squid liver oil diet containing high n-3 HUFA level were significantly higher than those of fish fed the other diets ( P 0.05). Saturated and monounsaturated fatty acids of liver polar and neutral lipid fractions in fish fed the diet containing lauric acid tended to increase compared to those of the other groups. Fish fed the diets containing soybean and/or linseed oils, which contained high contents of 18:2n-6 and 18:3n-3, respectively, showed the highest contents of 18:2n-6 and 18:3n-3 in both lipid fractions of the liver ( P 0.05). Significantly higher content of n-3 HUFA was observed in both lipid fractions of the liver from fish fed the diet containing squid liver oil than for fish fed the other diets ( P 0.05). Total cholesterol, glucose, and glutamic-oxaloacetic acid transaminase in plasma were significantly affected by dietary lipids ( P 0.05). Histologically, the liver of fish fed the diet containing squid liver oil had a clear distinction between nuclear and cytoplasm membranes; however, cytoplasm of fish fed the diets containing lauric acid and soybean oil was shrunken, and the hepatic cell outline was indistinguishable. It is concluded that the dietary n-3 HUFA is essential for normal growth, and that the dietary lipid sources affect growth performance, liver cell property, and blood chemistry in juvenile Japanese flounder.     

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.     

微粒化固体鱼油加工新工艺——喷雾定型固化法

本文介绍了微粒化固体鱼油加工新工艺——喷雾定型固化法的主要操作要点和注意事项,该工艺以食用褐藻酸钠作为鱼油的壁囊材料,用氯化钙溶液作为定型液,将均质的鱼油褐藻酸钠混合液用喷雾法喷入氯化钙溶液中定型,经水洗、烘干后得到微粒化固体鱼油。     

Influence of lipid level and supplemental lecithin in diet on growth,feed utilization and body composition of juvenile flounder (Paralichthys olivaceus) in suboptimal water temperatures

This study was conducted to investigate the influence of dietary lipid level and supplemental soy lecithin on growth, feed utilization and body composition of juvenile flounder reared at two suboptimal water temperatures, 12 and 17 °C. Three isonitrogenous (CP 50%) diets containing 1% squid liver oil (S7), 7% squid liver oil (S14), and a mixture of 2% soy lecithin and 5% squid liver oil (SL14) were formulated to obtain 7% and 14% of crude lipid. Triplicate groups of fish (6.3 ± 0.2 g) were fed to apparent satiation twice a day for 60 days. Weight gain, daily feed intake, feed efficiency and protein efficiency ratio were significantly higher for fish reared at 17 °C than at 12 °C. Daily feed intake was significantly decreased with the increase of dietary lipid level at the same water temperature, but weight gain was not affected by dietary lipid composition. At 12 °C, feed efficiency and protein efficiency ratio were significantly higher for fish fed the S14 and SL14 diets than those of fish fed the S7 diet, while at 17 °C feed efficiency and protein efficiency ratio of fish fed the S14 diet, which were not significantly different from those of fish fed the SL14 diet, were significantly higher than those of fish fed the S7 diet. There were no significant effects of dietary lipid composition or temperature range on the whole body contents of moisture, crude protein, lipid or ash. Dietary lipid composition and temperature affected the fatty acid content of the polar lipid from the liver; and the n-3HUFA contents such as 20:5n-3 and 20:6n-3 were higher at 12 °C than at 17 °C. The results of this study indicate that an increase of dietary lipid level from 7% to 14% has beneficial effects on feed utilization of flounder when reared in suboptimal water temperatures. The increase of water temperature from 12 to 17 °C improved growth and feed utilization, but 2% soy lecithin had no substantial effect on growth and feed efficiency of juvenile flounder.     

轻量化神经网络在远洋鱿钓检测技术中的应用

中国远洋鱿鱼捕捞技术比较单一,智能化的鱿鱼捕捞技术对远洋渔业资源统计至关重要。在智能化鱿鱼捕捞作业过程中,以YOLOV3算法检测时,其特征提取网络Darknet53模型参数量较大,模型输出权重存储量较高,降低了检测速度。为此,建立轻量化MobileNetV3网络作为特征提取网络,进行初步有效特征提取,再设计CSP瓶颈层作为逆瓶颈结构,提高特征提取能力;最后通过CIoU模型建立网络模型的损失函数。在实验室环境下,使用Squid数据集验证轻量化网络模型的有效性,并对其主干网络与损失函数的性能进行分析。通过训练目标数据集,将轻量型网络模型与YOLOV3网络模型结构做消融试验,验证轻量化网络应用在远洋捕捞技术上的准确性以及实用性。结果显示,轻量化网络结构的性能明显优于YOLOV3网络模型结构,可以大幅度降低参数量,提高检测速度,缩短检测时间,提高检测率,提高了鱿鱼实时检测的工作效率。本研究成果为远洋渔业资源调查提供重要依据。     

轻量化神经网络在远洋鱿钓检测技术中的应用

中国远洋鱿鱼捕捞技术比较单一,智能化的鱿鱼捕捞技术对远洋渔业资源统计至关重要。在智能化鱿鱼捕捞作业过程中,以YOLOV3算法检测时,其特征提取网络Darknet53模型参数量较大,模型输出权重存储量较高,降低了检测速度。为此,建立轻量化MobileNetV3网络作为特征提取网络,进行初步有效特征提取,再设计CSP瓶颈层作为逆瓶颈结构,提高特征提取能力;最后通过CIoU模型建立网络模型的损失函数。在实验室环境下,使用Squid数据集验证轻量化网络模型的有效性,并对其主干网络与损失函数的性能进行分析。通过训练目标数据集,将轻量型网络模型与YOLOV3网络模型结构做消融试验,验证轻量化网络应用在远洋捕捞技术上的准确性以及实用性。结果显示,轻量化网络结构的性能明显优于YOLOV3网络模型结构,可以大幅度降低参数量,提高检测速度,缩短检测时间,提高检测率,提高了鱿鱼实时检测的工作效率。本研究成果为远洋渔业资源调查提供重要依据。