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1.
鱼品的脂肪氧化是冷藏鱼变质的主要因素之一。鱼肉脂肪中含有较多的高度不饱和脂肪酸,比其他肉类更容易发生氧化酸败,产生哈喇味。因此根据鱼类脂肪含量的不同,采取相应的预防措施,是冷藏管理的重要环节。一、鱼类脂肪构成的特征脂肪是甘油与脂肪酸形成的酯,又称真脂或中性脂肪。其他类似脂肪的物质,称之类脂,主要是磷脂、固醇和蜡等。  相似文献   

2.
3郾肝坏死病肝坏死病在整个养殖期均有发生。发病时,黄鳝体表粘液分泌过多,背部及两侧皮肤发黑,下颌部经常伴随有炎症,头盖骨表皮有时腐烂成一圆孔,并露出头骨。解剖发现,肝明显肿大、严重时甚至充满整个腹腔,肝颜色暗红,肠道无炎症,腹腔无腹水。病鳝一般游动无力,常游于水草之上。黄鳝肝坏死病主要是由于饲料脂肪氧化、酸败和变质以及B族维生素缺乏所引起肝中毒症状。目前,国内黄鳝饲料生产为降低成本,大量使用未脱脂鱼粉,这类鱼粉经高温加工和一段时间贮存后,其所含脂肪几乎全部氧化和酸败。油脂氧化后对黄鳝危害很大,可引起肝病变和肝组…  相似文献   

3.
氧化脂肪对鱼类危害的病理及防治   总被引:6,自引:1,他引:5  
脂类在鱼、虾类生命代谢过程中具有多种生理功能 ,是组织细胞的组成成分 ,为鱼虾类提供能量 ,有助于脂溶性维生素的吸收和运输 ,提供必需脂肪酸和某些激素、维生素的合成原料 ,提高饲料蛋白质利用率 ,节省蛋白质。脂肪氧化酸败是指油脂中不饱和脂肪酸的双键被空气中的氧所氧化或在微生物的作用下生成过氧化物或分子量较低的醛、酮、酸等复杂混合物的过程。氧化酸败油脂产生大量具有不良气味的醛、酮等低分子化合物和过氧化物 ,这些活性化合物与饲料中的蛋白质、维生素或其他脂类作用除引起饲料适口性下降 ,营养价值及消化率降低外 ,低分子醛…  相似文献   

4.
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。  相似文献   

5.
饲料中添加氧化鱼油对黑鲷幼鱼生长的影响   总被引:2,自引:1,他引:1  
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.  相似文献   

6.
盐干鱼油脂氧化酸败变质的问题,是水产加工技术上多年来没能很好解决的问题。油脂的氧化导致盐干鱼的酸败变质,必然急剧地降低制品的质量。随着国内外市场对盐干鱼品种和质量的要求日益提高,因此,更加迫切需要解决盐干鱼的“油烧”和“褐变”等长期存在的老问题。  相似文献   

7.
本文主要论述饲料卫生与安全对水产动物健康的影响,从抗营养因素、饲料霉菌污染、饲料脂肪酸败、饲料添加剂的使用不当对健康的影响四个方面进行论述.  相似文献   

8.
鱼类养殖与维生素日本的水面资源利用已相当充分,要提高养殖鱼类的产量和质量,只有改善饲料结构,发展配合饲料。而饲料业的发展,饲料脂肪用量的上升,必将增加维生素E(下面简称VE)的需求。1.氧化油脂的毒性与VEVE在鱼类方面的研究最早在酸败油脂引起虹的贫...  相似文献   

9.
养殖大黄鱼和天然大黄鱼的理化指标比较   总被引:2,自引:0,他引:2  
通过对养殖和天然大黄鱼的理化指标及其变化规律的研究,为养殖大黄鱼的肉质改善提供理论依据。养殖和天然大黄鱼的体长、体质量以及水分、脂肪等指标的测定采用常规分析法,并对大黄鱼的肥满度进行分析。养殖大黄鱼体长和体质量的自然对数值成正比;无论是养殖还是天然大黄鱼,其肌肉中水分含量和脂肪含量成反比;肥满度的大小与脂肪含量成正比,但两者的变化范围以及变化速率都不尽相同。养殖和天然大黄鱼的主要差别在于其脂肪的变化,养殖大黄鱼的肉质改善重点在控制其脂肪含量上。  相似文献   

10.
国内测定鱼粉中脂肪含量的方法,常用索氏脂肪抽提法,其缺点是测定速度慢,效率低,且鱼粉需要在高温下干燥,以致脂肪中的不饱和脂肪酸很容易氧化,使测定数据的精确程度受到一定影响。用ZYF-80型比重法快速测定仪测定脂肪含量,操作简便、测定速度快、精度高、劳动强度低。  相似文献   

11.
Abstract.— Bioelectric impedance analysis (BIA) was evaluated as a method for predicting carcass yield, fat, and moisture in live channel catfish, Ictalurus punctatus (N = 20), and fat and moisture in fillets from channel catfish ( N = 20) and channel catfish female × blue catfish male, I. furcatus , hybrids ( N = 20). Fish were cultured in ponds, fed a commercial catfish diet (28% protein), and harvested at market weight (450 g-900 g, ∼19 months post-hatch). Live channel catfish were tranquilized, weighed, and sexed. Resistance and reactance were measured with a four-terminal impedance analyzer. Fish were then deheaded, eviscerated, weighed, and carcass yield was calculated. Fillets from channel catfish and channel catfish × blue catfish hybrids were measured for weight, resistance, and reactance. Carcasses and fillets were ground and fat and moisture were determined by chemical analysis. Regression models including total weight, resistance, and reactance as independent variables explained 71%, 75%, and 65% of the variation in carcass yield, fat, and moisture, respectively, in live fish. Regression models with fillet weight, resistance, and reactance as independent variables explained 62% and 41% of the variation in fillet fat and moisture, respectively, in channel catfish, and 53% and 58% of the variation in fillet fat and moisture, respectively, in channel catfish × blue catfish hybrids. Models including resistance and reactance explained significantly more variation in the traits measured than did models containing only whole weight as an independent variable. Improvements in prediction accuracy will be needed to make BIA a useful tool for predicting carcass yield, carcass composition, and fillet composition in farm-raised catfish.  相似文献   

12.
Abstract

A pond trial was conducted to compare growth, feed efficiency, survival, processing yield, and body composition of the NWAC103 strain of channel catfish, Ictalurus punctatus and the F1 channel X blue catfish hybrid (CB hybrid), I. punctatus X I. furcatus. Each genotype was stocked into five 0.4-ha earthen ponds at a rate of 14,820 fish/ha. Initial weights were 24.9 and 31.8 g/fish for the NWAC103 strain of channel catfish and the CB hybrid, respectively. Fish were fed a commercial, 28% protein diet once daily to satiation for 160 days. Compared to NWAC103 channel catfish, the CB hybrid consumed more diet, gained more weight, converted diet more efficiently, and had higher net production, survival, carcass yield, nugget yield, visceral fat, fillet moisture and protein, and a lower level of fillet fat. There were no differences in fillet yield and fillet ash concentration between the channel X blue catfish hybrid and the channel catfish. These results suggest that the CB hybrid possesses superior production traits compared with the NWAC103 channel catfish. However, problems of producing a large number of hybrid fingerlings in a cost-effective manner remain to be resolved before the hybrid catfish can be commercially farmed.  相似文献   

13.
A comparative study was conducted on growth and protein requirements of channel catfish, Ictalurus punctatus, and blue catfish, Ictalurus furcatus. Four diets containing 24, 28, 32, or 36% protein were fed to both channel (initial weight 6.9 g/fish) and blue (6.6 g/fish) catfish for two growing seasons. There were significant interactions between dietary protein and fish species for weight gain and feed conversion ratio (FCR). No significant differences were observed in weight gain of channel catfish fed various protein diets, whereas higher protein diets (32 and 36%) resulted in better weight gain in blue catfish than lower protein diets (24 and 28%). No consistent differences were observed in the FCR of channel catfish fed various levels of dietary protein, whereas significantly higher FCRs were noted in blue catfish fed the 24 and 28% protein diets compared with fish fed 32 and 36% protein diets. Regardless of dietary protein levels, blue catfish had higher carcass, nugget, and total meat yield, and higher fillet moisture and protein, but lower fillet yield and fillet fat. Regardless of fish species, fish fed the 36% protein diet had higher carcass, fillet, and total meat yield than fish fed the 28 and 32% protein diets, which in turn had higher yields than fish fed the 24% protein diet. It appears that blue catfish can be successfully cultured by feeding a 32% protein diet.  相似文献   

14.
Abstract. Semi-purified casein/gelatin diets containing two levels of lipid (5 or 10%) and three levels of reduced glutathione (0,0·1 or 1·0%) in a factorial arrangement were fed to fingerling channel catfish, Ictalurus punctatus (Rafinesque), in aquaria for 10 weeks. Factorial analysis of variance indicated that dietary lipid had significant ( P < 0·05) effects on growth, feed efficiency and body composition of channel catfish. Diets containing 10% lipid generally produced higher weight gain and feed efficiency values as well as higher intraperitoneal fat. The higher level of dietary lipid also produced lower moisture and higher lipid (on a wet-weight basis) levels in whole-body and fillet tissues. Stability of fillet samples was estimated by 2-thiobarbituric acid (TBA) analysis which revealed that 10% dietary lipid significantly elevated fillet TBA values while glutathione did not have any effect. Therefore, dietary lipid level altered growth and body composition of channel catfish as well as oxidative stability of fillet samples while dietary glutathione was generally ineffective.  相似文献   

15.
The use of polyphosphates as a partial replacement of salt in different meat products to improve water holding capacity yield and retard oxidative rancidity has been noticed for many years. Therefore, in this study, effects of polyphosphates dip treatment in 5% solution with three different compounds of phosphate—including tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP), and a mixture of them on kutum (Rutilus frisii kutum) fillets stored in ice was investigated for 18 days. Phosphate pretreatments showed desirable modal effects on fillets. In particular, the use of TSPP and the mixture of TSPP and STPP solutions were found to delay the fish fillet color changes and improved textural characteristics. An increase in water holding capacity accompanied with a decrease in hardness was observed in samples pretreated with polyphosphates. In total, the results indicated that dipping kutum fillets in polyphosphates solution was the most effective method to improve the quality properties of fillets during ice storage when compared with other phosphate-treated groups.  相似文献   

16.
Fat content and fatty acid profile of two pike yearling groups grown on two different diets were compared. The groups originated from culture on artificial feed. One group (cultured pike fed first pellet then prey‐fish (PF)) was fed with natural food, live prey‐fish, while the other one (cultured pike fed exclusively pellet (PP)) by trout feed through a 3‐month experimental period. Growth of pike was lower with PP than with PF. The trout feed resulted in an increase of the fat content of fillet and the formation of abdominal fat depots. Feeding of natural food decreased the fat content. The proportion of the saturated fatty acids in fillet was higher in the (PF) group. The n‐6 fatty acids (arachidonic C20:4n‐6 and docosatetraenic C22:4n‐6 acids) were lowest in PP‐fed pike. Regarding total n‐3 fatty acids ratio there was no significant difference between the groups, but the level of α‐linolenic (C:18:3n‐3) acid showed significant difference among groups.  相似文献   

17.
The morphological characters, fillet texture, and nutrient contents of the F3 generation of Barbless carp (Cyprinus pellegrini,BC) female × Heilongjiang carp (Cyprinus carpio,HLC, geographical population of common carp) male hybrid, which were named as High‐quality carp F3 (HQC F3), were studied. The main morphological characteristics of HQC F3 were between BC and HLC, but closer to the BC. The fillet amino acids and crude protein showed significant differences between HQC F3 and BC. But, only fillet crude fat showed significant differences between HQC F3 and HLC. HQC F3's fillet had significantly different with BC's on the contents of myristic acid, linolenic acid, and stearic acid, and with HLC's on the contents of linoleic acid, linolenic acid, EPA, palm oleic acid, and 20 carbon‐dilute acid. HQC F3 broodstocks were selected with high intramuscular fat and effective population size. HQC F4 were bred and showed improved intramuscular fat content compared to F3. The intramuscular fat of 2‐year‐old HLC F4 was significantly (p < 0.05) correlated with body weight/standard length. Intramuscular fat is a stable trait that can be continuously passed on to the next generation. This study will lay a foundation for further carp selective breeding study to improve fillet quality.  相似文献   

18.
Tissue (fillet, viscera and carcass) distributions of fat were examined in Atlantic salmon, Salmo salar L. (740→1400→2000 g) to test the hypothesis that the fillet becomes increasingly important as a fat depot when fish increase in size. The salmon were fed for 11 weeks on either a high‐fat feed (H: 39% fat) or a low‐fat feed (L: 28% fat), and half of the fish were then subjected to a dietary switch to create four feed treatments (HH, HL, LL and LH). Fillet fat concentration increased with the passage of time, and the fillet also represented an increasing percentage of the body mass (48.5→55→58.5%) as the fish increased in size. As a consequence, the fillet became increasingly important as a fat depot, containing ≈30% of the body fat in the small fish at the start of the experiment, and 50% in the fish sampled at the end of the trial. The proportion of fat localised in the viscera was little influenced by either fish size or feeding treatment, and was within the range of 19–25%, whereas the carcass held a decreasing percentage of the body fat stores as fish size increased. There was a highly significant negative correlation between the percentages of body fat found within the carcass (C) and fillet (F): F = 73.589–0.9285C (R2 = 0.973; n = 13). Although the fillet became more important as a fat depot as fish increased in size, the percentage of the body fat reserves found within this tissue appeared to plateau at 50–55%.  相似文献   

19.
The fillet fatty acids (FAs) and volatile compounds (VCs) of gilthead sea bream, fed either fish oil‐based diet (FO) or plant oils (PO), were studied in dorsal and ventral fillet parts over a 12‐day ice storage. Fillet FA reflected the FA composition of the respective diets. Monounsaturated FAs were reduced with storage, while no FA differentiations occurred between fillet parts. VCs varied between diet treatments, with food chain‐transported compounds (α‐pinene and dimethylsulphide) showing higher abundance in the FO group. VCs proposed as fish spoilage indicators (trimethylamine, pentanal, propanal, 3‐methylbutanal and 1‐penten‐3‐ol) increased with storage, while concentration of carbon disulphide associated with fresh fish aroma decreased during the same period. VCs varied between fillet parts, with ventral part exhibiting higher concentrations in fat‐soluble (terpenes, aromatic hydrocarbons) and spoilage‐associated VCs. Sensory analysis revealed no significant differences between diet groups with the exception of fattiness, which was found significantly higher in the plant oil group.  相似文献   

20.
ABSTRACT:   The purpose of this study was to determine the growth and reproductive characteristics of round scad Decapterus maruadsi in the East China Sea. The characteristics regarding growth and reproduction of round scad based on otolith reading and gonad histology, respectively, were estimated. The von Bertalanffy's growth model for round scad was estimated as follows:
FL t  = 342[1 − exp{−0.55( t  + 0.58)}], (1 <  t  < 7)
where FL t is fork length (mm) at age in years t . The maturation stage of the ovary was observed by histological techniques. June was the main spawning period; the maturation and migratory nucleus stage of the oocyte was observed when the gonad somatic index value was approximately greater than 4.  相似文献   

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