浅谈鱼油的酸价与过氧化值

随着鱼粉加工业的发展及人们对鱼油中诸多不饱和脂肪酸医药性质的研究，开发和利用鱼油、生产优质鱼油已是水产加工企业的重要任务，而鱼油作为一种新的产品，将逐渐由鱼粉生产中的副产品转为主产品，其潜在的利用价值已逐渐超过鱼粉c在鱼油的加工、生产、储存过程中，生产者最难掌握的是酸价与过氧化值的含量，而此两项指标的高低又恰是评定鱼油质量的重要指标。那么问为酸价、过氧化值呢？酸价是指游离脂肪酸的含量；过氧化值是指油脂氧化过程中产生过氧化物的含量。鱼油因其富含高度不饱和脂肪酸而具重要价值，但所含的高度不饱和脂肪酸…     

一种来源于米根霉的低温脂肪酶催化鱼油酯交换反应及其氧化性质的研究

以一种来源于米根霉的低温脂肪酶为研究对象,研究其水解、酯化、酯交换特性并应用于制备高含量ω-3脂肪酸甘油三酯型(TG)鱼油。以酯交换产物TG中EPA和DHA的总含量为指标,分析温度、时间、加酶量、底物质量比对鱼油酯交换的影响,并通过核磁共振分析鱼油产物的氧化性质。结果显示:当低温脂肪酶的添加量为0.9%,底物质量比为1∶1,于30℃反应18 h,EPA和DHA总含量从鱼油原料的29.39%提高到44.83%。核磁共振分析表明,当酶法酯交换温度为30℃时,TG型鱼油产物氧化程度低;而使用酯交换温度为50℃的Novozyme 435反应时,TG型鱼油产物发生明显的氧化作用,氧化程度较高。因此,该低温脂肪酶的温度条件能够对鱼油品质有较好的保障。     

氧化鱼油对鲤抗应激能力的影响

在半纯化饲料中分别加入３％新鲜鱼油（ＰＯＶ１．２８ｍｅｑ／ｋｇ）和ＰＯＶ分别为５９．２８、１１８．７９和１８９．３７ｍｅｑ／ｋｇ的氧化鱼油,投喂体重１００ｇ左右２龄鱼种,１５周后进行抗应激试验,结果：氧化鱼油可导致鲁白细胞吞噬活性增强（Ｐ〈０．０５）,说明鲁非特异性的细胞免疫应答水平提高,处于应激状态,病原应激和运输应激实验结果证实,长期处于应激状态的鲤,其抗应激能力减弱。     

THE EFFECT OF FISH QUALITY ON THE COMPOSITION AND OXIDIZATION OF FISH OIL

本文以不同质量的鱼及生产出的鱼油为原料，研究了鱼体质量对鱼油组成及氧化特性的影响。氧化程度即鱼油的化学发光强度随鱼体质量下降而上升。化学发光强度与ＥＰＡ、ＤＨＡ含量无明显关系。随鱼体质量下降，鱼油颜色由浅而深，且共轭二烯系含量、游离脂肪酸和甘油二酯含量增加。鱼油中甘油三酯与鱼体总挥发性氨基氮呈负相关。由低质鱼生产的鱼油较易氧化。     

鱼体质量对鱼油组成及氧化特性的影响

本文以不同质量的鱼及生产出的鱼油为原料，研究了鱼体质量对鱼油组成及氧化特性的影响。氧化程度即鱼油的化学发光强度随鱼体质量下降而上升。化学发光强度与ＥＰＡ、ＤＨＡ含量无明显关系。随鱼体质量下降，鱼油颜色由浅而深，且共轭二烯系含量，游离脂肪酸和甘油二酯含量增加，鱼油中甘油三脂与鱼体总挥发性氨基氮呈负相关，由低质鱼生产的鱼油较易氧化。     

鲣鱼、金枪鱼眼窝内DHA含量高

近年,中上层鱼类中含量多的高度不饱和脂肪酸中的DHA生理活性高而引入关注,鲣鱼金枪鱼类的眼窝脂肪中的高度不饱和脂肪酸含量为30—40％,并含有丰富的DHA。尽管沙丁鱼、鲐鱼油中含有5—10％的DHA,但同时具有类似化学构造的EPA含量则为10—     

日本鲐鱼油在不同条件下的脂质氧化

粗制与精制日本鲐鱼油贮藏于以钨丝灯泡为光源或避光条件下，分析了光氧化对鲐鱼油精制前后的氧化稳定性以及丁基羟基茴香醚(BHA)和叔丁基对苯二酚(TBHQ)的抗氧化性，并观察其过氧化值(POV)和硫代巴比妥酸(TBA)值在5℃和40℃下18天内的变化。结果表明，可见光是加速鲐鱼油氧化的重要促进因素，抗氧化剂能明显延缓其氧化，其中TBHQ比BHA效果更好，其氧化速率的顺序光照＞光照+BHA＞避光＞光照+TBHQ＞避光+BHA＞避光+TBHQ；精制鲐鱼油的POV和TBA值较粗制鲐鱼油高；高温贮藏的精制鲐鱼油只在光照条件下氧化速度加快。     

饲料中添加氧化鱼油对黑鲷幼鱼生长的影响

研究了饲料中添加氧化鱼油对黑鲷(Acanthopagrus schlegeli)生长性能、脂质过氧化及肝组织结构的影响.分别以新鲜鱼油(过氧化物值 POV,1.27 meq O2·kg-1油)与氧化酸败鱼油(POV,45 meq O2·kg-1油)为脂肪源配制等蛋等能的两种配合饲料,投喂平均体重18.9 g的黑鲷幼鱼9周.结果显示,氧化鱼油显著降低了黑鲷幼鱼的增重率(WG)、饲料效率(FE)及蛋白质效率(PER)(P＜0.05).饲料中添加氧化鱼油导致鱼体蛋白质含量极显著降低(P＜0.01)、肝脏与肌肉中脂肪含量显著升高(P＜0.05),而对鱼体、肝脏及肌肉中的水分及灰分含量无显著影响(P＞0.05).氧化鱼油组肝脏中脂质过氧化产物丙二醛(MDA)含量显著高于对照组,而维生素E含量则显著低于对照组(P＜0.05). 饲料中添加氧化鱼油显著影响黑鲷肝脏内主要抗氧化酶活性,氧化鱼油组肝脏中超氧化物歧化酶(SOD)与过氧化氢酶(CAT)活性显著高于对照组(P＜0.05);组织学结果显示氧化鱼油组肝脏出现明显病变,细胞核多集中在肝细胞边缘,肝细胞变大. 统计分析表明,氧化酸败油脂显著降低了黑鲷的生长性能,加重了组织中脂质过氧化的程度,并导致肝脏组织发生病变.     

从鱼糜下脚料中提取鱼油的研究

研究以金线鱼和长蛇鲻的混合鱼糜生产下脚料为材料,利用钾法提取鱼油。结果表明,钾法提取鱼油的工艺参数为水解pH为7.5,水解温度70℃,水解时间55min,硝酸钾用量4.5%,盐析时间30min,在该条件下鱼油的提取率达到64.5%。鱼油的理化性质达到了SC/T3502-2000标准粗鱼油的二级要求。鱼油中饱和脂肪酸的含量较高,占总量的48.59%;单不饱和脂肪酸和多不饱和脂肪酸的含量相当,分别为24.48%和24.49%,多不饱和脂肪酸主要是DHA和EPA,含量分别为11.18%和5.17%。     

饲料中添加氧化鱼油对黑鲷幼鱼生长的影响

研究了饲料中添加氧化鱼油对黑鲷（Acanthopagrus schlegeli）生长性能、脂质过氧化及肝组织结构的影响。分别以新鲜鱼油（过氧化物值POV，1．27meq O2·kg^-1油）与氧化酸败鱼油（POV，45meq O2·kg^-油）为脂肪源配制等蛋等能的两种配合饲料，投喂平均体重18．9g的黑鲷幼鱼9周。结果显示，氧化鱼油显著降低了黑鲷幼鱼的增重率（WG）、饲料效率（FE）及蛋白质效率（PER）（P〈0．05）。饲料中添加氧化鱼油导致鱼体蛋白质含量极显著降低（P〈0．01）、肝脏与肌肉中脂肪含量显著升高（P〈0．05），而对鱼体、肝脏及肌肉中的水分及灰分含量无显著影响（P〉0．05）。氧化鱼油组肝脏中脂质过氧化产物丙二醛（MDA）含量显著高于对照组，而维生素E含量则显著低于对照组（P〈0．05）。饲料中添加氧化鱼油显著影响黑鲷肝脏内主要抗氧化酶活性，氧化鱼油组肝脏中超氧化物歧化酶（SOD）与过氧化氢酶（CAT）活性显著高于对照组（P〈0．05）；组织学结果显示氧化鱼油组肝脏出现明显病变，细胞核多集中在肝细胞边缘，肝细胞变大。统计分析表明，氧化酸败油脂显著降低了黑鲷的生长性能，加重了组织中脂质过氧化的程度，并导致肝脏组织发生病变。     

The influence of a dietary lipid source on growth, muscle fatty acid composition and erythrocyte osmotic fragility of hybrid tilapia

An 8-week feeding trial was conducted to determine the effects of various dietary lipids on the growth, tissue proximate composition, muscle fatty acid composition and erythrocyte osmotic fragility of red hybrid tilapia, Oreochromis sp. Five isonitrogenous and isoenergetic semipurified diets were supplemented with 10% of either cod liver oil (CLO), sunflower oil (SFO), crude palm oil (CPO), crude palm kernel oil (CPKO), or a combination of 5% CLO with 5% palm fatty acid distillates (PFAD), respectively. There were no significant effects (P > 0.05) of diet on growth but fish fed the CLO diet showed a significantly (P< 0.05) poorer feed efficiency ratio compared to fish fed the CPO diet. Lipid deposition in fish muscle was mostly similar among fish fed the various diets but bone ash was significantly higher in fish fed the CPO and CPKO diets. Muscle lipids of fish fed palm oil-based diets did not increase in saturated fatty acids content but showed significantly lower polyunsaturated fatty acid (PUFA) concentrations compared to fish fed the CLO diet. The concentrations of individual PUFA in muscle lipids were strongly influenced by dietary PUFA concentrations. Dietary lipids did not markedly affect the structural integrity of erythrocyte membranes but the erythrocytes of tilapia fed the CPO diet were slightly more resistant to osmotic lysis. It was concluded that palm oil products, especially CPO, could be successfully used in the diet of hybrid tilapia based on its availability, cheaper costs and its potential ability to enhance oxidative stability due to its low PUFA content and high natural concentrations of antioxidants.     

Oxidative stability of salmon and herring roe lipids and their dietary effect on plasma cholesterol levels of rats

ABSTRACT:   The oxidative stability of lipids from salmon roe and herring roe was compared with those of commercial fish oils originated from sardine and tuna. Both fish roe lipids contained high amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Total EPA and DHA was more than 35% of total fatty acids in both roe lipids. On the basis of oxygen consumption, fish roe lipids showed the higher oxidative stability than both fish oils. This tendency in oxidative stabilities was also confirmed by the determination of propanal formation during oxidation. Analyses of lipid compositions suggested that the higher oxidative stabilities of fish roe lipids would be mainly due to the presence of phospholipids in them. Dietary effects of salmon and herring roe lipids were also determined. Little increase in total cholesterol level was observed in plasma lipids in rats fed salmon and herring roe lipids, although cholesterol content in fish roe lipids were 6.3% and 9.7% of total lipids for salmon roe and herring roe.     

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.     

日粮中添加鱼溶浆粉和鱼油对草鱼生长、肝脏脂肪含量和血清理化指标的影响

本实验探讨以猪肉粉为动物蛋白源的草鱼日粮中添加鱼溶浆粉和鱼油以补充鱼类所需的部分生长因子,对草鱼生长、肝脏脂肪含量和血清理化指标的影响,以期达到节约鱼粉的目的。在实用配方模式下,设计6种等氮等能饲料,分别是添加6%猪肉粉(6P)、3%猪肉粉+3%鱼溶浆粉(3P3SW)、6%鱼溶浆粉(6SW)、3%猪肉粉+3%鱼溶浆粉+2%鱼油(3P3SW2O)、6%鱼溶浆粉+2%鱼油(6SW2O)和6%鱼粉(6F,对照)。在池塘网箱中饲喂(80.0±2.0)g的草鱼72 d。结果表明,6P和6F在SGR、FCR、PRR、ERR和HSI方面均无显著差异(P>0.05)。添加鱼溶浆粉后,3P3SW、6SW与6F相比,SGR提高了9.1%～9.6%,FCR下降了8.5%～11.2%,差异显著(P<0.05),但3P3SW和6SW无显著差异(P>0.05),同时,在PRR、FRR和ERR方面,3P3SW、6SW均有一定程度提高。添加鱼油后,3P3SW2O、6SW2O和3P3SW、6SW比,SGR分别下降了9.7%、15.4%,FCR分别上升了6.9%、31.1%,除3P3SW2O和3P3SW的FCR之外,其余差异显著(P<0.05);在PRR和ERR方面,3P3SW2O、6SW2O均有一定程度下降;同时,3P3SW2O、6SW2O的FRR和肝脏粗脂肪含量都出现不同程度增高,HSI增大,血清TBA、CHOL、HDL和LDL与肝脏粗脂肪呈现出相同趋势,且上述指标均是6SW2O组最高,与其余各组均存在显著差异(P<0.05)。此外,在对饲料中游离氨基酸和生物胺与FCR和SGR的相关性分析中,发现游离Lys、Tau和Put与FCR和SGR的Pearsion相关系数都大于0.8,且符合二次函数关系。因此,鱼溶浆粉对草鱼的促生长作用优于鱼粉,在无鱼粉日粮中添加少量的鱼溶浆粉能满足草鱼需求,节约鱼粉用量,这种促生长作用与饲料中游离Lys、Tau和Put的关系密切;由于鱼油促使脂肪在体内和肝脏沉积,加重肝脏脂质代谢负担,加上其易氧化变质特性,限制了它在水产饲料中的使用。     

服用多烯鱼油对母乳中DHA含量的动态研究

为研究国产鱼油制品对母乳中二十二碳六烯酸（ＤＨＡ）含量的影响,随机抽取１２名哺乳母亲为受试者,以气相色谱法测定母乳样本。测试结果表明,有８３．３％的受试者服用鱼油后的第２天乳汁中ＤＨＡ含量开始升高,所有受试者在服用鱼油的第８天乳汁中ＤＨＡ含量均高于服用鱼油前。证明哺乳期妇女服用高含量ＤＨＡ鱼油制品是提高母乳中ＤＨＡ含量的最直接有效的途径。     

Oxidative Stability of a Cod-Canola Oil Model System

ABSTRACT

The oxidative stability of a cod muscle-canola oil model system as affected by the order of tocopherol and canola oil addition to the cod muscle was studied. Oxidation was monitored by the measurement of TBARS and sensory score. The addition oftocopherol to the cod muscle before oil addition significantly (p < 0.01) increased the oxidative stability of the model system compared to the reverse order of addition. Irrespective of the order of tocopherol and canola oil addition, 300 ppm tocopherol significantly increased (p < 0.01) the oxidative stability of the model system compared to 100 ppm tocopherol.     

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).     

Oxidative Stability of Spray-Dried Microencapsulated Fish Oils with Different Wall Materials

Multilayer microencapsulation of fish oil was evaluated by using fish gelatin (treated with or without microbial transglutaminase [MTGase]), chitosan, and maltodextrin for its ability to control lipid oxidation. This study showed that a mixture containing gelatin and maltodextrin obtained the highest percentage of core release. The oxidative stability of the formulated mixtures and the bulk oils was investigated during a period of 60 days. The peroxide value (PV) was assessed as a parameter for primary oxidation products, and p-anisidine (p-AV) and thiobarbituric acid reactive sub-stances (TBARS) was used to analyze secondary oxidation compounds. Observation of oxidation products showed that combinations of gelatin and maltodextrin made by adding MTGase and a mixture of gelatin and chitosan were able to increase the oxidative stability, and increases in PV and p-AV and TBARS were found for all oils.     

Changes in the Quality of Refined Fish Oil in an Accelerated Storage Study

ABSTRACT

The aim of this study was to prepare the refined oil derived from Sardinella longiceps by a step-wise procedure of degumming, bleaching, and deodorization. The refined sardine oil showed greater susceptibility toward oxidation than the crude oil, but the addition of ethyl acetate fractions of the red seaweeds Hypnea musciformis, Kappaphycus alvarezii, and Jania rubens with great antioxidant potential significantly increased the oxidative stability of the refined oil. The refined oil supplemented with the ethyl acetate fraction of these seaweeds indicated more noteworthy oxidative stability indices (≥ 0. 51 h) than α-tocopherol. The induction time was greater for refined oil added with H. musciformis (1.26 h) than butylated hydroxytoluene (1.04 h) and α-tocopherol (0.4 h). No traces of aromatic (δ 6.7–7.5 ppm), hydroperoxides, and aldehydes (δ 9–10 ppm) in the ¹H-NMR spectra of the refined oil supplemented with seaweed extracts at the baseline and after the accelerated storage study demonstrated that the seaweed extracts were able to prevent the formation of secondary oxidation products in the unsaturated system during storage. This study demonstrated the potential of seaweeds as natural alternatives to the synthetic antioxidants to prevent the rancidity of the refined fish for use in food and pharmaceutical industries.     

Effect of dietary oxidized fish oil and vitamin C supplementation on growth performance and reduction of oxidative stress in Red Sea Bream Pagrus major

A 50‐day feeding trial was conducted to determine the effects of dietary oxidized fish oil (OFO) and vitamin C (VC) on growth and oxidative stress in juvenile red sea bream. Test diets were formulated with 2 degrees of peroxide value (23 and 29 meq kg^?1) combined with 3 levels of VC (0, 400 and 800 ppm). No significant difference was found on growth performance between fish fed OFO with 400 or 800 mg VC and the control group that fed a diet with fresh fish oil after 50 days. However, fish fed OFO without VC supplement indicated significantly poor growth than the control group. Liver and muscle thiobarbituric acid reactive substances were reduced by increased VC intake of fish. Fish fed diets containing low OFO with 400 and 800 mg VC, high OFO with 800 mg VC, and fresh fish oil are allocated in the zone of high resistance against oxidative stress together with low oxidative stress condition. On the other hand, no VC supplemented group was under the highest oxidative stress condition. In conclusion, dietary oxidized lipid increased the oxidative stress condition of fish, but more than 400 mg VC kg^?1 of dietary supplement improved growth and health of juvenile red sea bream.