Trout Fillets Research Articles

Effect of Chitosan Coating Impregnated with Thymoquinone and Eugenol on the Quality Parameters of Rainbow Trout (Onchoryncus mykiss) during Cold Storage (4ºC)

ABSTRACT This study aimed to evaluate the effect of chitosan coating impregnated with Thymoquinone (TQ) and Eugenol (EUG) on the quality of rainbow trout fillets during cold storage (4ºC). In-vitro and In-vivo techniques were used to evaluate biopreservative effects of chitosan coating containing TQ, EUG and their combination. In-vitro evaluation of chitosan (2%) solution containing TQ, EUG demonstrated antibacterial and antioxidant effects. In-vivo assays on coated rainbow trout fillet as a food model demonstrated that the growth of spoilage bacteria, lipid oxidation and formation of volatile nitrogen bases reduced significantly in treated samples during 12 days cold storage in comparison with control samples and the treated samples were consumable until the 12th day without adverse sensory changes (P <0.05). Chitosan coating containing TQ and EUG can be used as a high quality packaging material to increase the shelf life of various foods, including fish, seafood, meat and meat products.

Protein complex nanoparticles reinforced with industrial hemp essential oil: Characterization and application for shelf-life extension of Rainbow trout fillets

Essential oil of industrial hemp (Cannabis sativa L.) (IHEO) was reinforced in complexation of whey protein nanofibrils and mung bean protein nanoparticles (WPNF-MBP NPs) as a novel nano-carrier. A desirable retention rate range of 50.9–90.4% was confirmed for IHEO reinforced in WPNF-MBP NPs. Fourier transform infrared (FTIR) spectroscopy revealed that IHEO was successfully loaded within WPNF-MBP NPs without specific chemical interaction with the carrier matrix. The results indicated that incorporation of IHEO-reinforced WPNF-MBP NPs into active material coatings having acceptable inhibition activity against total viable and psychrotrophic bacteria. The coated fishes also retarded the increase of PV (peroxide value), TBA (thiobarbituric acid) and TVB-N (total volatile basic nitrogen) values during storage. The IHEO-reinforced WPNF-MBP NPs coating led to an extension in the shelf life of Rainbow trout fillets within 8–14 days of storage. Accordingly, IHEO-reinforced WPNF-MBP NPs can be suggested as a natural preservative for coating fishes.

Gamma-irradiated rosemary (Rosmarinus officinalis) dips treatment effect on quality of rainbow trout (Oncorhynchus mykiss) fillets during refrigerated storage

The effect of the gamma-irradiated extract of rosemary and butylated hydroxyanisole (BHA) antioxidant on sensory, chemical and microbiological changes of rainbow trout fillets stored at 4 ± 1°C was investigated for 16 days. The fillets were divided into: control (C), 750 and 1500 rosemary extract (RE) (immersed in 750 and 1500 ppm rosemary extract); 250 and 500 gamma-irradiated rosemary (GIR), (immersed in 250 and 500 ppm gamma-irradiated rosemary) and 250 and 500 BHA (immersed in 250 and 500 ppm BHA). The shelf life of fillets was reported to be 8 days for C, and 12 days for 500 GIR group according sensory, microbiological and chemical parameters. The pH, peroxide value (PV), total volatile basic nitrogen (TVB-N), free fatty acid (FFA), thiobarbituric acid (TBA), psychrotrophic counts (PTC), and total viable aerobic bacterial counts (TVC) values were 7.62 ± 0.21, 17.17 ± 1.6, 51.07 ± 1.1, 6.05 ± 0.13, 3.42 ± 0.18, 12.03 ± 0.19, and 13.16 ± 0.16 respectively for C group and also, 7.42 ± 0.16, 15.2 ± 1.7, 42.5 ± 1.5, 4.48 ± 0.39, 2.59 ± 0.15, 9.98 ± 0.15, and 10.5 ± 0.15 respectively for 500 GIR group. Finally, the following trend in effectiveness was reported: gamma-irradiated rosemary PBS extract &gt; BHA &gt; rosemary PBS extract.

Evaluation of the freshness of rainbow trout (Oncorhynchus mykiss) fillets by the NIR, E-nose and SPME-GC-MS.

A comparison study on the freshness of rainbow trout (Oncorhynchus mykiss) fillets in the course of their sale was performed using near-infrared spectroscopy (NIRS), solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS), and the electronic nose (E-nose) technique. Quantitative analysis of the volatile salt nitrogen (TVB-N) of rainbow trout fillets with different freshness using NIR combined with the partial least squares (PLS) method revealed that the predicted values of TVB-N of the samples were significantly correlated with the true values (P < 0.01). SPME-GC-MS combined with E-nose analysis demonstrated that there were significant differences in the volatile flavor components of rainbow trout fillets at different freshness, and E-nose combined with principal component analysis (PCA) and linear discriminant analysis (LDA) could achieve rapid and non-destructive freshness ranking of rainbow trout fillets based on volatile flavor characteristics. Consequently, the NIRS and E-nose non-destructive testing techniques are capable of acting as rapid screening tools for detecting the freshness of rainbow trout fillets during their sale.

Marination Increased Tyramine Levels in Rainbow Trout Fillet Strips Packaged Under Modified Atmosphere

Marination Increased Tyramine Levels in Rainbow Trout Fillet Strips Packaged Under Modified Atmosphere

Developing and Improving the Production Technology of Canned Cold Smoked Rainbow Trout Fillet

Fish and fish products are foods of high nutritional value. The current research aimed at improving the technology of manufacturing canned products from cold-smoked rainbow trout fillets has a certain scientific-practical significance. Physicochemical indicators of the mentioned product were studied in the experimental and control samples. It has been revealed that energy value of the product is higher in the experimental sample than in control one, due to the content of proteins and fats. HACCP system research has indicated that safety and biological indicators of the finished product meet the accepted standards. Therefore, the product is safe and can be offered to consumers.

Preservation effect of Lippia citriodora and Laurus nobilis nanoemulsions incorporated with polylactic acid composite film for rainbow trout fillet packaging

The present study was conducted to characterize poly (lactic acid) ‐Lippia citriodora and Laurus nobilis essential oils (EOs) and Nanoemulsion-based films. Following Gas chromatography–mass spectrometry and in vitro antimicrobial activity test, 12% of Nanoemulsions of both herbs were selected for further evaluations. Accordingly, Atomic Force Microscopy and Dynamic light scattering analysis showed that the scale sizes of Nanoemulsions of L. citriodora and L. nobilis were 24-60 and 15-28 nm, respectively with no significant changes in their PDI up to 90 d. The inhibition zone of both herbs against E. coli and Staphylococcus aureus alongside MIC and MBC tests showed higher efficiency in their nanoemulsions. In conclusion, two types of incorporated PLA/L. citriodora films could effectively extend the shelf life of rainbow trout fillet at refrigerated temperatures.

Acute heat stress during transportation deteriorated the qualities of rainbow trout (Oncorhynchus mykiss) fillets during chilling storage and its relief attempt by ascorbic acid

The work was to investigate the impacts of acute heat stress during transportation on the tissue structure, physicochemical and microbial qualities of rainbow trout (Oncorhynchus mykiss) fillets during chilling storage and its relief attempt by ascorbic acid. Different transportation groups were performed: transported samples under controlled temperature, T1; transported samples without temperature control, T2; and transported samples with the addition of 30 mg L-1 ascorbic acid, T3. Rainbow trout without transportation were set as the control. In comparison with non-heat stress treatment (control and T1 group), the acute heat stress (T2 and T3 group) significantly increased the relaxation time of free water (T22), total volatile basic nitrogen (TVB-N) and malondialdehyde (MDA) content, total viable count (TVC) and K value of fillets during chilling storage. T3 group had tissue with relative integrity cell shapes and lower expressible moisture (0–3 d), TVB-N and MDA content and TVC (0–7 d) compared with acute heat stress group (T2 group). Therefore, acute heat stress during transportation accelerated the quality deterioration of fillets during the storage, and treatment of control water temperature or the addition of ascorbic acid partially relieved the damage caused by acute heat stress.

The effect of basil seed gum coating containing black cumin seed essential oil (Bunium persicum) on the quality and shelf life of rainbow trout fillet during refrigerated storage (4 ±1 оC)

The effect of basil seed gum coating containing black cumin seed essential oil (Bunium persicum) on the quality and shelf life of rainbow trout fillet during refrigerated storage (4 ±1 оC)

Preservation status and microbial communities of vacuum-packed hot smoked rainbow trout fillets

Vacuum-packed hot smoked rainbow trout fillets from two different smokehouses of Greece were stored at 2 and 7.9 °C. Microbiological, sensory, and physicochemical changes were monitored. Microbial communities grown on MRS of three different pHs (5.4, 6.4 and 7.4) were also classified and identified using Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Shelf-life was found to differ between products from the two smokehouses (A: 104 and 45 days, B: 100 and 45 days, at 2 and 7.9 °C, respectively). At the time point that sensory rejection was recorded, counts on MRS were found at higher population levels than the other microorganisms tested, almost in all cases. Out of the 567 colonies isolated from MRS of three different pHs, 71 classified as Enterococcus spp., 383 as Candida spp. and 113 as Lactobacillus spp.. Candida zeylanoides dominated exclusively in fillets from the smokehouse A during storage at 2 °C, while Lactobacillus sakei dominated clearly against C. zeylanoides at 7.9 °C, in all pH values. For the smokehouse B, C. zeylanoides or Enterococcus faecalis found to dominate initially in MRS of three pHs, C. zeylanoides, and/or Candida famata in the middle and/or the time point that sensory rejection was recorded at 2 °C, while Lactobacillus curvatus or E. faecalis at 7.9 °C. This study reveals the predominant cultivable spoilage microbiota of vacuum-packed hot smoked rainbow trout, and provides valuable information to the researcher and producers towards the production of more stable products with improved shelf-life.

Preparation of three-layer flaxseed gum/chitosan/flaxseed gum composite coatings with sustained-release properties and their excellent protective effect on myofibril protein of rainbow trout

Plant essential oils lose their activity due to unstable chemical properties and volatility, and the coating can improve their stability by encapsulating. The three-layer coatings were prepared by tape casting method with flaxseed gum (FG) and chitosan (CS) as film-forming materials, eugenol (EG) and laurel essential oil (LEO) as preservatives. The composite coatings were characterized, and their physicochemical properties, release properties, antibacterial and antioxidant properties were determined. Meanwhile, the protective effect of the composite coatings on rainbow trout fillets myofibril protein was studied. The mechanical properties of the FG/CS/FG coatings are better than FG coating. The release of EG and LEO from the coatings are followed simple diffusion mechanism. After added essential oils, the antibacterial and antioxidant properties of the composite coatings are significantly enhanced. In the preservation process of the rainbow trout fillets, the composite coatings can reduce the carbonyl content, increase the sulfhydryl content and Ca2+-ATPase activity. The β-sheet content is 6.09%–15.63% higher than that of control, indicating the coatings are helpful to maintain the order of myofibril protein. The composite coatings slowed down the decrease of antioxidant enzyme activity, thus delay the protein oxidation. Because of long-term antibacterial and antioxidant properties, the composite coatings have potential value in food preservation or food packaging materials.

Effect of Nanocomposite Clay/low-density Polyethylene Film on the Quality of Rainbow Trout (Oncorhynchus mykiss) Fillets Stored with Four Different Packaging Conditions

ABSTRACT To improve the quality and increase the shelf life of rainbow trout fillets, nanocomposite clay/low-density polyethylene films were used during 25 days of refrigerated storage (4 °C). Low-density polyethylene (LDPE) films with 5 wt% clay nanoparticles (sodium montmorillonite, MMT) were used for packaging of rainbow trout fillets using 4 different packaging conditions (modified atmosphere packaging (MAP): 60 N2, 35 CO2, and 5% O2; vacuum packaging (VP); air packaging (AP); and control). Fish samples were analyzed on the first day and every 5 days to determine the extent of microbial deterioration, chemical changes, and sensory properties. Based on obtained results, the shelf life of rainbow trout fillets was determined as ~10 days for the control group, and 15, 20, and 25 days for the AP, VP, and MAP packages, respectively.

Tailoring physico-mechanical and antimicrobial/antioxidant properties of biopolymeric films by cinnamaldehyde-loaded chitosan nanoparticles and their application in packaging of fresh rainbow trout fillets

In this study, cinnamaldehyde (CIN)-loaded chitosan nanoparticles (CCNPs) were fabricated and embedded into chitosan/poly(vinyl alcohol)/fish gelatin (CPF) ternary matrices to improve the physico-mechanical and biofunctional performances of the films. The particle size and ζ-potential values of the CCNPs were 370.3 nm and +32.2 mV, respectively. SEM images revealed that the CCNPs were homogeneously dispersed in the CPF ternary film matrices, thereby filling void spaces in the composite matrix, and significantly improving the bionanocomposite films tensile properties (from 28.33 ± 2.17 MPa to 33.0 ± 1.28 MPa) (p < 0.05). However, the water barrier properties and water contact angle of the CPF films were not significantly influenced by the nanofiller embedding. Although the incorporation of the NPs decreased the light transmittance of the films, it provided the CPF-CCNPs nanocomposite films with excellent UV-barrier properties. ATR/FT-IR spectroscopy and X-ray diffraction analysis demonstrated the formation of hydrogen bonds between the NPs and polymer molecules. TGA and DSC studies revealed that CPF-CCNPs nanocomposite films presented better thermal stability than the neat CPF film. AFM imaging also indicated a re-organization of the surface of the nanocomposite films due to the incorporation of the NPs. Release studies suggested that the CPF-CCNPs bionanocomposite film exhibited sustained release behavior of CIN. Likewise, the bioactive nanocomposites displayed antibacterial activity against food-borne pathogens such as Gram-positive (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Salmonella enteritidis). The bionanocomposite films exhibited in vitro DPPH radical scavenging activity (∼16.4%) and ferric reducing power at the maximum CIN loading concentration. Additionally, analysis of storage quality indices (pH, TBARS values, color, and microbiological analyses) revealed the shelf-life of rainbow trout fillets wrapped in CPF-CCNPs0.25 was extended to 12 days.

Fish products developed from ground rainbow trout and tilapia fillet mixtures: Physico-chemical, microbiological and toxicological analyses

ABSTRACT Constant fishing industry innovations in response to consumer demands for novel, balanced healthy products exhibiting high nutritional value, as well as easy to prepare and ready to consume, have led to the emergence of new technologies. Among them, the development of products based on ground beef and fish mixtures are noteworthy. In this context, the purpose of this study was to develop products from different ground rainbow trout and tilapia fillet ratios, in the form of meatballs and nuggets, determining their proximate composition and physico-chemical, microbiological and toxicological characteristics. The average dry matter percentage of the developed products was 29.20±2.30%, while mineral content was 1.45±0.55%, lipid pulp content, 3.70±0.30% and crude pulp protein, 16.60±2.04%. Total psychotropic counts remained below 102 CFU/g, for standard counting on aerobic microorganism plates. Histamine and sulfur-based compounds were not detected in any of the prepared samples. The purpose of the work proposal was to develop foods and technologies that can serve as standards, allowing for simple handling products that apply ground meat mixtures from different fish species to maintain adequate nutritional indices after processing.

Effect of Zataria multiflora Boiss irradiated with moderate dose of gamma rays on the shelf life of rainbow trout fillet (Oncorhynchus mykiss) containing active coating based on sodium caseinate

Effect of Zataria multiflora Boiss irradiated with moderate dose of gamma rays on the shelf life of rainbow trout fillet (Oncorhynchus mykiss) containing active coating based on sodium caseinate

Efecto de la inclusión de carne cruda en un paté cocido de carne mecánicamente recuperada de trucha arcoíris

The fishing industry generates large quantities of by-products, most of which are not used and are therefore discarded. The objective of the present research was the elaboration of a pâté-type sausage from mechanically recovered meat of rainbow trout (Oncorhynchus mykiss). The meat was obtained from trout skelons, which were passed through a grinder and sprayed with a mixture of α-tocopherol (0.02%) and ascorbic acid (0.05%). The formulation of the pate was as follows: mechanically recovered trout meat (74.4%), salt (1.3%), sodium tripolyphosphate (0.8%), starch (2%), soy protein isolate (2.4%), margarine (16.7%), soy lecithin (1.9%), onion powder (0.2%), garlic powder (0.2%) and pepper powder (0.1%). Three formulations were prepared: PCR1 (80% cooked meat and 20% raw meat), PCR2 (90% cooked meat and 10% raw meat) and PCR3 (100% cooked meat). For each formulation, the following were evaluated: texture profile, color and sensory evaluation, the latter with the participation of 30 untrained panelists using a 9-point hedonic scale, in which each formulation obtained an average of 6 ("I like it moderately"). The best formulation was PCR3, whose proximate composition was determined: 64% moisture, 16% fat, 12.5% protein, and 3.5% ash. The pâté of mechanically recovered trout meat proved to have a high nutritional value and a good level of sensory acceptance, demonstrating that it is a good alternative for the use of trout fillet by-products.

The effects of essential oils on inactivation of Listeria monocytogenes in rainbow trout cooked with sous‐vide

This study investigated the combined effect of four different natural antimicrobial essential oil (Rosemary, Coriander, Basil and Laurel) and two different cooking temperatures (50℃ and 55℃) on inactivating of Listeria monocytogenes in rainbow trout. The products prepared with this technology were stored at +4℃ for 36 days and the number of L. monocytogenes was determined. As a result of this study, laurel essential oil was found to be effective on L. monocytogenes invitro whereas coriander essential oil was found to be effective on L. monocytogenes in sous-vide applied trout. In addition, coriander essential oil addition (2 times more than the minimum inhibition concentration value) and 7 min sous-vide application in 55℃ was effective for the inhibition of L. monocytogenes in sous-vide applied trouts. Consequently, the findings indicated that the use of coriander essential oil in sous-vide trout fillets was effective to ensure of L. monocytogenes control. Practical applications Sous-vide technology is a long-term cooking method in vacuum-packed food at low temperatures. Thanks to this application, since the products are cooked in vacuum packaging, the unique aroma and nutritional components of the foods are not lost. This technology offers products with high nutritional value, quality, and high shelf life. Although it is more advantageous than traditional cooking methods, if the applied temperature is low and the time is insufficient, pathogenic microorganisms develop and pose a threat to health. For this reason, the temperature-time parameters and the use of antimicrobials used in cooking are of great importance. In this research, it was determined that the development of Listeria monocytogenes in seafood was prevented by using essential oils with sous-vide technology.

Active packaging based on sodium caseinate-gelatin nanofiber mats encapsulated with Mentha spicata L. essential oil and MgO nanoparticles: Preparation, properties, and food application

The aims of the current study were to encapsulate Mentha spicata L. essential oil (MEO; 0, 0.5, and 1%) and MgO (0 and 0.1 %) into sodium caseinate-gelatin (SC-GE) nanofiber mats via electrospinning and evaluate the effects of designated nanofibers on extending the shelf-life of fresh trout fillets during cold storage. The prepared nanofibers possessed force, tensile strength, elongation at break, water vapor permeability, and swelling index of 10.79–21.35 N, 2.43–4.40 MPa, 107.13–149.62 %, 6.55–15.42 × 10‾4 g mm/m² h Pa, and 12.38–38.22 %, respectively. The addition of MEO and MgO nanoparticles had significant effects on the color property of designated nanofibers (P < 0.05). Our findings indicated that trout samples packaged in SC-GE + MgO 0.1 % + MEO 0.5 % and SC-GE + MgO 0.1 % + MEO 1% had 2.88–4.28 and 2.98–4.80 log CFU/g microbial population lower than the control group at the end of the study (day 13), respectively. The total volatile base nitrogen, peroxide value, and thiobarbituric acid reactive substances of all treatments slowly increased during storage compared to the control (P < 0.05). According to the sensory scores of panelists, SC-GE + MgO 0.1 % + MEO 1% had the best sensory attributes compared to the other groups.

Effect of feeding with insect meal diet on the fatty acid compositions of sea bream (Sparus aurata), tench (Tinca tinca) and rainbow trout (Oncorhynchus mykiss) fillets

Currently, insects are considered a new source of food that could be an alternative to fishmeal (FM) in aquaculture. However, more studies are needed to assess the effects of the inclusion of insects in fish diets on both fish productivity and fish quality. To this end, three trials were conducted to evaluate as feed ingredients the meals of two insects, black soldier fly (Hermetia illucens, HI) and mealworm (Tenebrio molitor, TM), on the fatty acid (FA) profiles of fillets of three fish species: sea bream (Sparus aurata), tench (Tinca tinca) and rainbow trout (Oncorhynchus mykiss). In each trial, the animals were randomly divided into five experimental groups (3 tanks/treatment). The fish were fed until triple their initial weight with isoprotein and isolipid diets at different levels of FM replacement using insect meal: 0% insect meal or control diet (C), 15% inclusion of HI meal (H15), 30% inclusion of HI meal (H30), 15% inclusion of TM meal (T15), and 30% inclusion of TM meal (T30).Overall, the use of insect meal induced a decrease in valuable long chain polyunsaturated fatty acids (LCPUFAs) in fish fillets, and the higher the insect inclusion (H30 and T30 diets), the higher the decreases in EPA and DHA contents. Moreover, insect-containing diets worsened the lipid health indices (n-3/n-6 ratio, atherogenicity AI, and thrombogenicity TI indices) of fillets. However, differences between the three fish species were observed: tench was the more resilient species to insect inclusion, while in rainbow trout, there were very marked decreases in LCPUFA content, especially in DHA, and in the n-3/n-6 ratio. Nevertheless, insect-fed fish could be considered “healthy” based on the n-3 LCPUFA content. Furthermore, several strategies could be implemented to avoid the decline of n-3 LCPUFAs in fish, such as using partially defatted insect meal or the use of insects previously fed n-3 PUFA-rich by-products.

Depletion of oxytetracycline plus epi-oxytetracycline residues in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) under field conditions in Chile

The objective of this research study was to estimate the withdrawal time (WT) for oxytetracycline (OTC), administered intraperitoneally to two species of salmonids, rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). This was done in salmonid farms during the fattening phase in seawater, under field conditions. Seven cages from different marine farms were included, each as an experimental unit, treated with an intraperitoneal dose of OTC (in a range from 20 to 35 mg kg−1). From each sea cage, 10 fishes were randomly selected for laboratory analysis at each sampling point after treatment, which were variable according to the harvest of each cage. All selected fish were treated with a single dose of two different commercial OTC formulations; Formulation A (OTC 30%) and Formulation B (OTC 20%), both extra label. Study was performed according to VICH GL 57 guideline. Samples were kept cold until laboratory analysis. Homogenized samples were analyzed using a mass triple quadrupole spectrometer (Waters®, Xevo TQ-S micro). The analytical method was optimized for use in the laboratory and an internal validation procedure was performed following European Commission Decision 2002/657/EC for linearity, recovery and precision. The detection range, including the limit of detection (LOD) and limit of quantification (LOQ), were calculated according to VICH GL49 guidance.According to the degree days obtained from the residue depletion study and those observed in the last sampling, most of the sampled cages had concentrations that allow the veterinary drug to be suitable for a market with a maximum residue limit (MRL) value of 200 μg kg−1, but not for a market with an MRL of 10 μg kg−1, as might be expected, regardless of the dose and commercial veterinary drug used. Depending on the considered MRL, withdrawal times ranged from 5390 to 1676- and 4061–1641-degree days, for rainbow trout and Atlantic salmon, respectively. These estimates, obtained from field samples, can provide references regarding the WTs that must be considered in order to avoid the presence of OTC + 4-epi-OTC residues in Atlantic salmon and rainbow trout fillets, and thus protect the consumer health. Further studies are needed to assess the impact of other factors on WT under field conditions in different salmonid species.