Trout Muscle Research Articles

Anti-obesity effects of Lipid Extract from Sea-reared of Rainbow Trout (Oncorhynchus mykiss) Fed with Sea Squirt (Halocynthia roretzi) Tunic's Carotenoids and CLA

Purpose: In order to produce new functional seafood, rainbow trout were acclimation in seawater and fed with inclusion of CLA and carotenoid extract from sea squirt tunic. Lipid extract from the sea-reared rainbow trout muscle (RME) and viscera (RVE) were administered to rats simultaneously with normal or high fat diet for six weeks. We evaluated the effects of the dietary supplementation with CLA, carotenoids, and n-3 HUFA by the beneficial effects of anti-obesity activities. Materials and method: Sea-reared rainbow trout (800 ± 20.5 g; 40.0 ± 1.7 cm) were fed with basal feed which supplemented with 10 mg/kg sea squirt tunic’s carotenoids and 3% CLA (w/w) for three months. Lipid was extracted from rainbow trout muscle and viscera using chloroform/methanol (2/1). Forty eight male Sprague Dawley rats (400 ± 2.0 g) were randomly divided into six groups (n=8). Two types of diets, normal types (SN, RVN, RMN) and 45% of high fat research diets (SHF, RVHF, RMHF) were used. The excised liver and epididymal adipose tissues were fixed in 3% formaldehyde solution, embedded in paraffin. Organs sections were stained with hematoxylin-esosin. Histological examination on liver and adipose tissues sections were carried out with a light microscope. Results: Sea farming and inclusion of CLA and carotenoids pigment extracted from the tunic of sea squirt, the content of C18:1n-9 was reduced to 32.5% in the muscle’s lipid and 35.8% in the viscera’s lipid. Serum lipid and liver enzymes activity in blood serum showed that RME and RVE have the liver protective ability. Conclusion: RME and RVE have potency as weight reducer through fat burner routes as well as liver protective ability. Hence, it could be considered as anti-obesity supplement for the long period of administration.

Effects of anthocyanidins on myogenic differentiation and antioxidant defense in primary myogenic cells isolated from rainbow trout (Oncorhynchus mykiss)

There is increasing interest in using plant-derived extracts to promote growth and health in finfish species in recent years. Elucidating the effects of plant secondary metabolites on skeletal muscle growth signaling will contribute to an improved understanding of the effects of feeding carnivorous fish diets supplemented with plant extracts on fish somatic growth. Dietary intake of anthocyanins, a type of flavonoid widely distributed in plants, has long been associated with beneficial effects in both human and animal health; however, their effects in finfish are largely unknown. We conducted an experiment to test the effect of three doses (treatments A, B and C; 1×, 2.5× and 10×, respectively) of a mixture of three types of anthocyanidins (peonidin, cyanidin and pelargonidin chloride) on the expression of several genes in primary myogenic cells isolated from the skeletal muscle of rainbow trout (Oncorhynchus mykiss) after 24h of treatment. The genes of interest analyzed are involved in myogenic programing (pax7, myoD and myogenin), Notch signaling (her6 and hey2) and antioxidant enzymes (sod1, cat and gpx1). Significantly greater expression of pax7 in cells under treatment B compared with the untreated cells was detected. Although no differences in expression of myogenic regulatory factors, myoD and myogenin between test groups or the control were detected, a trend toward significantly lower expression in all groups tested compared with the control group was observed. Moreover, significantly higher expression levels of her6 and hey2 in cells under treatments A and B compared with untreated cells were detected. Although no significant differences in the expression of cat and sod1, significantly greater expression in gpx1 in all treated groups compared with the control group was detected. Collectively, we demonstrated that anthocyanidins enhance the expression of gpx1 in primary myogenic cells, thereby contributing to skeletal muscle tissue defense against oxidative stress in finfish species. Further, anthocyanidins appear to delay myogenic differentiation in primary myogenic cells by up-regulating the expression of pax7 while decreasing myogenic regulatory factors in a Notch signaling-dependent interaction. Whether this effect results a reduced growth performance and/or an increase in feed conversion ratio in fish fed diets supplemented with plant extracts rich in anthocyanins or anthocyanidins needs further study, and the need to better define the potential effects of different polyphenol classes in myogenic differentiation on primary myogenic cells from carnivorous fish is warranted. Statement of relevanceThe study contributes to increase our understanding regarding the effect of plant-derived secondary metabolites such as anthocyanidins on myogenic program and antioxidant enzyme defense in differentiating myogenic cells from carnivorous fish. We have demonstrated that anthocyanidins may delay the progress of the myogenic differentiation process and promote antioxidant defense expression in myogenic cells.

Identification and intracellular localization of carbonic anhydrase I in gills, heart, muscle, and intestine of rainbow trout, Oncorhynchus mykiss

Carbonic anhydrases (CAs) play a key role in physiological functions such as pH homeostasis, calcification, photosynthesis, and ionic regulations. Among CA isozymes, CA I is a specific marker for the cytoplasm or apical cell membranes of colonic epithelial cells, and it is related to enterocyte proliferation in mammals. The major aim of the present study was to investigate the regional, cellular, and subcellular localization of CA I in a fish, rainbow trout, Oncorhynchus mykiss. The CA I was identified in the gills, heart, and intestine of the rainbow trout. CA I protein detected in the tissues of the rainbow trout was similar to a CA III with a molecular weight of 29 kDa. Immunohistochemical results demonstrated that CA I was localized in the various cells of gills, heart, muscle, and intestine of the rainbow trout.

The Quality of Rainbow Trout (Oncorhynchus Mykiss) Cultured in Various Polish Regions

Abstract There is a lack of regulations regarding labeling of the place of cultivation of freshwater fish, even though some research indicates that environmental factors can influence the quality of rainbow trout meat. The purpose of this study was to assess the necessity of such regulations and to determine the meat quality of rainbow trout cultivated in different regions of Poland. The analysis of color measurement, fatty acid profile, sensory evaluation and microbiological analysis of trout muscle were performed to assess the influence of cultivation region on the quality of trout meat. The place of cultivation did not influence the redness (a*) and yellowness (b*) of fillet, but had impact on lightness (L*). The microbiological analysis showed no pathogenic microorganisms on the fish surface. The fatty acids composition differed highly significantly (P<0.01) depending on the place of cultivation. Since there are significant differences in quality and nutritional value between studied samples, the necessity of labeling the place of cultivation of rainbow trout for the final consumer should be implemented.

Changes of Electrophoretic Protein Profiles of Smoked and Marinated Rainbow Trout (Oncorhynchus mykiss) During Refrigerated Storage

In this study, we aimed to determine the changes of electrophoretic protein profiles of smoked and marinated rainbow trout (Oncorhynchus mykiss) during refrigerated storage. Changes in muscle proteins during 9 weeks refrigerated storage of raw, smoked and marinated trout samples have been examined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE and densitometric analysis revealed that intensity and the number of some protein bands were reduced while the bands of actin didn’t change significantly during marination and smoking of rainbow trout muscle. Myosin heavy chain (MHC) band with molecular weight of 205 kDa disappeared in the 9th week of smoking and marinating process. Subsequently, there were significant weekly changes in the protein percentages of samples caused by smoking and marinating processes (P<0.01). Protein percentages of the raw, smoked and marinated samples were determined as 18.34-18.82%, 23.83-24.70% and 16.29-17.76%, respectively

Molecular characterization of CD9 and CD63, two tetraspanin family members expressed in trout B lymphocytes

Tetraspanins are a family of membrane-organizing proteins, characterized by the presence of four highly conserved transmembrane regions that mediate diverse physiological functions. In the current study, we have identified two novel tetraspanin members in rainbow trout (Oncorhynchus mykiss), homologs to mammalian CD9 and CD63. Both genes were expressed in muscle, skin, gills, hindgut, gonad, liver, spleen, head kidney, thymus and peripheral blood leukocytes. Throughout the early life cycle stages, CD9 mRNA levels significantly increased after first feeding, whereas CD63 transcription remained constant during all the developmental stages analyzed. In response to an experimental bath infection with viral hemorrhagic septicemia virus (VHSV), CD9 transcription was down-regulated in the gills, while CD63 mRNA levels were down-regulated in the head kidney. Instead, when the virus was intraperitoneally injected, the transcription of both genes was significantly up-regulated in peritoneal cells at several days post-infection. Additionally, both genes were transcriptionally up-regulated in the muscle of trout injected with a VHSV DNA vaccine. To gain insight on the relation of these tetraspanins with B cell activity we determined their constitutive expression in naive IgM+ populations from different sources and observed that both molecules were being transcribed by IgM+ cells in different tissues. Furthermore, CD9 transcription was significantly down-regulated in splenic IgM+ cells in response to in vitro VHSV exposure. Our results provide insights on the potential role of these tetraspanins on teleost B cell and antiviral immunity.

Depletion of metronidazole in brook trout (Salvelinus fontinalis)

Metronidazole (MNZ), which is effective in the treatment of intestinal infections in fish, is also a suspected carcinogen and has been banned in numerous jurisdictions for use in any food-producing animal, including fish. Few reports have been published on the depletion of MNZ in fish. A depletion study was therefore undertaken using MNZ in feed provided to trout under controlled conditions. The water was maintained at 17.5 ± 0.9°C throughout the medication and depletion periods in the study. Following a 20-day acclimatisation period in the holding tanks, the trout (approximately 150–200 g bodyweight at the start of the study) were subjected to two separate medication and withdrawal periods: (A) 5 day medication/5 day withdrawal and (B) 5 day medication/16 day withdrawal. This simulated a potential multiple dosing in an aquaculture setting. In both medication periods, the trout were dosed with medicated feed containing 3 g MNZ kg–1 fish. Fish were sacrificed in accordance with accepted animal care protocols and tissue samples were analysed by UPLC-MS/MS. Analyte concentrations in trout muscle ranged from a high of 27 000 ± 10 000 ng g–1 for MNZ and 830 ± 570 ng g–1 for MNZ-OH on day 1 of withdrawal period A to a low of 1.8 ± 2.3 ng g–1 for MNZ and < 0.4 ng g–1 for MNZ-OH on day 16 of withdrawal period B. The results demonstrate that when using the UPLC-MS/MS method, residues of MNZ may be detected in fish treated with MNZ after 16 days of withdrawal.

Antibiotic residuals in some farmed rainbow trout(Oncorhynchusmykiss) of market size in Iran

To assess the hygienic conditions of market rainbow trout (Oncorhynchusmykiss ), the residuals of three antibiotics consisting of oxytetracycline (OTC), enrofloxacin (EN) and erythromycin (ET) were measured in the muscles of freshly caught fish obtained from 17 trout farming in Charmahal-va-Bakhteyari (CVB) province using high performance liquid chromatography. Totally 266 fish samples were randomly obtained and 798 muscle samples were used for detection of the above antibiotics. The obtained results showed that OTC was detected in one fish farm (5.8%) having a residual of 0.75 to 7.13 µgg-1. EN was detected in 6 fish farms (35%) with a residual of 0.5- 0.73 µgg-1. Also, the lowest and highest residuals of ET were 23.38 and 181.38 µgg-1, respectively in 5 fish farms (29.4%). The obtained results showed that the residual of these antibiotics in trout muscles of some fish farms were higher than the acceptable levels and therefore, requires a serious attention of both the environment and the consumer health care. Also, the detection limit of 0.05 µgg-1used for these antibiotics shows that application ofhigh performance liquid chromatography method used here in this study is a useful tool for a routine screening of these antibiotics in trout farming.

해수산 무지개송어(Oncorhynchus mykiss) 가공부산물(프레임육)의 식품학적 품질 특성 조사

This study compared the meat quality of sea rainbow trout Oncorhynchus mykiss frame muscle (S-FR-TY) and fillet (S-FI-TY) with the frame muscle of freshwater rainbow trout (F-FR). There was a difference of < 1% in the proximate composition of S-FR-TY vs. S-FI-TY, and of S-FR-TY vs. F-FR. The Hunter a value of F-FR-TY was lower compared with that of F-FR cultured in Jecheon (F-FR-JC), but higher than that of F-FR cultured in Pyeongtaek (FFR-PT). However, no difference in the Hunter a value of S-FR-TY compared with any other F-FR was observed. The odor intensity of S-FR-TY was lower compared with that of F-FR, while the taste of S-FR-TY was milder than that of S-FI-TY, but stronger than that of F-FR. Although its total amino acid content was lower, the essential amino acid content of S-FR-TY was higher compared with S-FI-TY; the potassium content of S-FR-TY was also significantly greater. S-FR-TY contained high levels of nutritional and functional components, such as anserine, lysine, threonine, and eicosapentaenoic and docosahexaenoic acid. These results suggest that S-FR-TY could be used as a resource of canned food or fish jerky for children.

In Vivo Molecular Responses of Fast and Slow Muscle Fibers to Lipopolysaccharide in a Teleost Fish, the Rainbow Trout (Oncorhynchus mykiss).

The physiological consequences of the activation of the immune system in skeletal muscle in fish are not completely understood. To study the consequences of the activation of the immune system by bacterial pathogens on skeletal muscle function, we administered lipopolysaccharide (LPS), an active component of Gram-negative bacteria, in rainbow trout and performed transcriptomic and proteomic analyses in skeletal muscle. We examined changes in gene expression in fast and slow skeletal muscle in rainbow trout at 24 and 72 h after LPS treatment (8 mg/kg) by microarray analysis. At the transcriptional level, we observed important changes in metabolic, mitochondrial and structural genes in fast and slow skeletal muscle. In slow skeletal muscle, LPS caused marked changes in the expression of genes related to oxidative phosphorylation, while in fast skeletal muscle LPS administration caused major changes in the expression of genes coding for glycolytic enzymes. We also evaluated the effects of LPS administration on the fast skeletal muscle proteome and identified 14 proteins that were differentially induced in LPS-treated trout, primarily corresponding to glycolytic enzymes. Our results evidence a robust and tissue-specific response of skeletal muscle to an acute inflammatory challenge, affecting energy utilization and possibly growth in rainbow trout.

Analyzing the quantitative risk and hazard of different waterborne arsenic exposures: case study of Haraz River, Iran

In this study, arsenic concentration of Haraz River water at 20 stations and relative risk and hazard levels regarding ingestion and dermal exposure routes are evaluated. Furthermore, the quantitative threat caused by the consumption of Rainbow trout muscle from the area is also analyzed. The concentration of arsenic increases from upstream areas towards the downstream estuarine zone with a substantial rise in the central part. Arsenic-containing drainage discharged from the Central Alborz coal mine, hot spring spas, as well as municipal (Amol city) and agricultural (numerous rice paddies) land uses that become denser towards downstream are considered as major pollution sources. The inhabitants are not exposed to a significant hazard or risk regarding dermal exposure. However, for the oral ingestion exposure route, all 20 samples present hazard quotient values greater than unity and risk values greater than one in ten thousand. The results show that if the river water is used for drinking, a high-risk status would be imposed on consumers. Finally, the concentration of arsenic in muscle tissues of ten Rainbow trout fish samples was found to range from 0.48 to 1.30 μg/kg of dry weight which is below the allowed daily intake. However, if we consider that lots of other constituents in the total daily intake within the study area contain arsenic, estimated values may be interpreted as a trigger for further health threats.

Determination of Salt Diffusion Coefficient in Rainbow Trout (Oncorhynchus mykiss)

ABSTRACTThe diffusion properties of sodium chloride in rainbow trout muscle during dry salting at 10°C were investigated. The average initial dry matter content of the samples increased from 27.80 ± 0.10 to 36.01 ± 0.16%, and the average salt content increased to 17.98 ± 0.38 g NaCl/100 g dry matter at the end of the 10-h dry salting process. The analytical solution of Fick’s second law considering one-dimensional diffusion through an infinite slab was used to calculate effective salt diffusion coefficients (Deff). The Deff values in rainbow trout fillets decreased with increasing salting time and ranged from 6.64 × 10−10 to 16.45 × 10−10 m2/s.

Muscle Coloration of Rainbow Trout with Astaxanthin Sources from Marine Bacteria and Synthetic Astaxanthin

This study was performed to investigate the effects of marine bacteria (Paracoccus sp.) and synthetic astaxanthin (Asx) as Asx sources on coloration (skin and muscle) of rainbow trout (Onchorhynchus mykiss). In the 12-week trial duplicate groups of 30 fish (28.1 ± 0.3g) were fed one of the four experimental diets. Three experimental diets contained 30 mg Asx/kg diet of synthetic Asx, marine bacteria or combined synthetic Asx and marine bacteria. One diet was served as a control diet. The fish fed diet supplemented both marine bacteria and synthetic Asx provided the highest total carotenoids and Asx content in the skin and muscle.

Analysis of muscle fibre input dynamics using a myog:GFP transgenic trout model.

The dramatic increase in myotomal muscle mass in teleosts appears to be related to their sustained ability to produce new fibres in the growing myotomal muscle. To describe muscle fibre input dynamics in trout (Oncorhynchus mykiss), we generated a stable transgenic line carrying green fluorescent protein (GFP) cDNA driven by the myogenin promoter. In this myog:GFP transgenic line, muscle cell recruitment is revealed by the appearance of fluorescent, small, nascent muscle fibres. The myog:GFP transgenic line displayed fibre formation patterns in the developing trout and showed that the production of new fluorescent myofibres (muscle hyperplasia) is prevalent in the juvenile stage but progressively decreases to eventually cease at approximately 18 months post-fertilisation. However, fluorescent, nascent myofibres were formed de novo in injured muscle of aged trout, indicating that the inhibition of myofibre formation associated with trout ageing cannot be attributed to the lack of recruitable myogenic cells but rather to changes in the myogenic cell microenvironment. Additionally, the myog:GFP transgenic line demonstrated that myofibre production persists during starvation.

Dietary fatty acid composition and the homeostatic regulation of mitochondrial phospholipid classes in red muscle of rainbow trout (Oncorhynchus mykiss).

Although dietary lipid quality markedly affects fatty acid (FA) composition of mitochondrial membranes from rainbow trout red muscle (Oncorhynchus mykiss), mitochondrial processes are relatively unchanged. As certain classes of phospholipids interact more intimately with membrane proteins than others, we examined whether specific phospholipid classes from these muscle mitochondria were more affected by dietary FA composition than others. To test this hypothesis, we fed trout with two diets differing only in their FA composition: Diet 1 had higher levels of 18:1n-9 and 18:2n-6 than Diet 2, while 22:6n-3 and 22:5n-6 were virtually absent from Diet 1 and high in Diet 2. After 5 months, trout fed Diet 2 had higher proportions of phosphatidylcholine (PC) and less phosphatidylethanolamine (PE) in mitochondrial membranes than those fed Diet 1. The FA composition of PC, PE and cardiolipin (CL) showed clear evidence of regulated incorporation of dietary FA. For trout fed Diet 2, 22:6n-3 was the most abundant FA in PC, PE and CL. The n-6 FA were consistently higher in all phospholipid classes of trout fed Diet 1, with shorter n-6 FA being favoured in CL than in PC and PE. Despite these marked changes in individual FA levels with diet, general characteristics such as total polyunsaturated FA, total monounsaturated FA and total saturated FA were conserved in PE and CL, confirming differential regulation of the FA composition of PC, PE and CL. The regulated changes of phospholipid classes presumably maintain critical membrane characteristics despite varying nutritional quality. We postulate that these changes aim to protect mitochondrial function.

The Anticancer Effects of Hexane Extract of Rainbow Trout (Oncorhynchus mykiss) Muscle Enriched with Vegetable Oil Brasica sp.

Background: As Canola oil (Brasica sp.) has beneficial compositions of essential fatty acids like saturated fatty acids, mono unsaturated fatty acids (MUFA) and poly unsaturated fatty acids (PUFA), practically it use in many experimental purposes. There are considerable amounts of oleic acid which is mono unsaturated fatty acids in canola oil that caused a good resistance to thermal processes such as deep frying. Rainbow trout is the main fish species farmed in about 85% of the total rate allocated to producing aquaculture fish in Iran. Rainbow trout has found in food baskets of many people due to its high nutritional value. Methods: in this study the hexane extracts of fish muscle isolated with purity of 250, 50, 10, 5 and 0.5 μg/ml at regular intervals of 24, 48 and 72 hours to determine the effects of hexane extracts on parameters which are associated with the survival of skin cancer cells A431 by MTT method in vitro comparison. Results: The effect of various concentrations of hexane extracts from fish muscle showed that the extracts of muscle at varying time intervals in hexane extracts administration had different effects on mortality of A431 cancer cells. Increasing of hexane extracts had significantly decreased the carcinogenic cells. The concentrations of hexane extract in 250 μg/ml at 24 hours were killed 50 percent of skin cancer A431cell lines. The addition of Brasica sp. vegetable oil as a dietary supplement is required to fish diet rations. Conclusion: In the present study the hexane extract inhibit the growth of cancer cells where the extract can be used as an anticancer agent for the operation of this lineage.

Changes of electrophoretic protein profiles of smoked and marinated rainbow trout (Oncorhynchus mykiss) during refrigerated storage

In this study, we aimed to determine the changes of electrophoretic protein profiles of smoked and marinated rainbow trout (Oncorhynchus mykiss) during refrigerated storage. Changes in muscle proteins during 9 weeks refrigerated storage of raw, smoked and marinated trout samples have been examined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE and densitometric analysis revealed that intensity and the number of some protein bands were reduced while the bands of actin didn’t change significantly during marination and smoking of rainbow trout muscle. Myosin heavy chain (MHC) band with molecular weight of 205 kDa disappeared in the 9th week of smoking and marinating process. Subsequently, there were significant weekly changes in the protein percentages of samples caused by smoking and marinating processes (P<0.01). Protein percentages of the raw, smoked and marinated samples were determined as 18.34-18.82%, 23.83-24.70% and 16.29-17.76%, respectively

Feeding increasing levels of corn gluten meal induces suboptimal muscle pigmentation of rainbow trout (Oncorhynchus mykiss)

A 24-week growth trial was conducted to evaluate the effects of feeding levels of corn gluten meal (CGM) on growth performance and pigment deposition in the muscle of rainbow trout (Oncorhynchus mykiss). Three isonitrogenous and isoenergetic (digestible energy basis) experimental diets were formulated to contain increasing levels of CGM (0%, 9% and 18%) and 50 mg kg � 1 of astaxanthin. Each diet was fed in triplicate to groups of 75 fish (initial average body weight = 549 g fish � 1 ) reared at 8.5°C. The inclusion of CGM did not significantly (P > 0.05) affect final body weight, thermal growth efficiency (TGC) or feed efficiency. Carotenoid concentration determined by liquid chromatography showed a significant (P < 0.05) linear reduction in the concentration of one astaxanthin isomer, all-trans astaxanthin and all-trans lutein in the muscle of fish in response to increasing levels of CGM. Tristimulus colour analysis of the muscle showed a significant (P < 0.05) linear reduction in a* (redness) and C*ab (chroma). Salmofan TM score showed a significant (P < 0.05) linear and quadratic reduction in response to increasing levels of CGM. In conclusion, the inclusion of CGM up to 18% does not significantly impact growth performance of rainbow trout. However, the concentration of all-trans astaxanthin as well as the expression of important colour attributes of the muscle can be negatively affected at levels exceeding 9% of CGM in the diet. More research on this topic is needed to discern the mechanism(s) behind the negative effects of dietary CGM and/or its intrinsic yellow pigments on muscle pigmentation of rainbow trout.

Fatty‐acid profiles of white muscle and liver in stream‐maturing steelhead trout Oncorhynchus mykiss from early migration to kelt emigration

The profiles of specific fatty acids (FA) in white muscle and liver of fasting steelhead trout Oncorhynchus mykiss were evaluated at three periods during their prespawning migration and at kelt emigration in the Snake-Columbia River of Washington, Oregon and Idaho, to improve the understanding of energy change. Twenty-seven FAs were identified; depletion of 10 of these was positively correlated in liver and white muscle of prespawning O. mykiss. To observe relative changes in FA content more accurately over sampling intervals, the lipid fraction of tissues was used to normalize the quantity of individual FA to an equivalent tissue wet mass. Saturated and monounsaturated FAs were depleted between upstream migration in September and kelt emigration in June, whereas polyunsaturated FAs were more conserved. Liver was depleted of FAs more rapidly than muscle. Three FAs were detected across all sampling intervals: 16:0, 18:1 and 22:6n3, which are probably structurally important to membranes. When structurally important FAs of O. mykiss are depleted to provide energy, physiological performance and survival may be affected.

Research Regarding Mineral Content 0f Rainbow Trout Meat Differentially Feed

Abstract. Rainbow trout is one of the most spread non-native breeds at world level, being originally both from Asia and also from North America. Growing rhythm of these breed is net superior to other trout breeds from Romania, reaching at the age of four years a weight of 400-500 g. In growing and development of fishes, environmental conditions plays a very important role, because in aquatic environment could be founded different substances necessary for a normal growing and development of organisms. Trout meat contains important quantities of minerals, which are essential for human health, those ones being influenced by a series of factors such as: breed, season, age and nutrition. From this point of view the current paper aimed to highlight the way in which quality of administered feed influence the content of trout muscles in minerals. Biological material was represented by a number of 30 rainbow trout individuals of three different ages. Quantitative determinations for calcium, zinc, sodium and magnesium were realised using an atomic absorption spectrophotometer and determination of phosphorous from trout meat was realised using a spectrophotometer. At the end of research from those five analyzed minerals, the greatest values were founded in case of phosphorous (P) which were between 110.46 and 225.40 mg/kg -1 , on the last rank being placed zinc (Zn) with mean values which varied from 0.74 to 0.99 mg/kg -1 .