Rainbow Trout Fillets Research Articles

Halochromic aerogels with Ca2⁺-induced tailored porosity based on alginate/gellan integrated with Echium amoenum anthocyanins: Characterization and application for freshness monitoring of rainbow trout fillet

This study aimed to fabricate a food freshness halochromic aerogel based on alginate, gellan, and Echium amoenum anthocyanins (EA). The porosity and morphological properties of the aerogels (AG2, AG6, and AG10) were regulated by varying the concentration of CaCl2 (2, 6, 10 %). FE-SEM analysis revealed that increasing the CaCl2 content led to the formation of aerogels with enhanced overall porosity and larger pore sizes. The AG6 aerogel, characterized by a density of 23.44 ± 0.04 mg/cm³, a porosity of 91.66 ± 0.06%, and an average pore size of 306.93 ± 122.89 μm, was identified as the optimal support for the incorporation of the EA pigment. FT-IR analysis verified the formation of hydrogen bonds between the AG6 aerogel and EA molecules. Incorporating anthocyanin increased the crystallinity and thermal stability of the aerogel, as evidenced by XRD and DSC analyses. The AG6EA aerogel displayed a color shift from red to yellow over a pH range of 2–12. The AG6EA aerogel demonstrated high sensitivity to ammonia vapor and proper color stability and reversibility. The AG6EA aerogel color transitioned from purple to blue and then green through rainbow trout storage, correlating with changes in pH, total volatile basic nitrogen (TVB-N), and total viable microbial count (TVC and TPC) of the fish samples. This research extends a new insight to develop cutting-edge, susceptible, and accurate pH indicators capable of quality assessment of protein-based food products.

The active kappa-carrageenan coating and oxygen absorber packaging for the preservation of chilled rainbow trout fillets

The objective of the current research was to evaluate the effects of incorporating kappa-carrageenan (KCA) coating with dill essential oil (DEO), in conjunction with oxygen absorber (OA) packaging, on the quality attributes of rainbow trout fillets throughout a 20-day period of refrigerated storage. The administered treatments included OA, KCA + OA, KCA + DEO, KCA + DEO + OA, and control. Treating the trout fillets with DEO-loaded coating and/or using OA packaging was found to be more effective in restricting the growth of total mesophilic and psychrotrophic bacteria, Enterobacteriaceae, and lactic acid bacteria. The aforementioned treatments were more efficient in slowing down the rate of increase in pH, total volatile nitrogen, conjugated dienes, thiobarbituric acid reactive substances, protein carbonyls, electric conductivity, and organoleptic deterioration in the trout fillets. Notably, the most effective treatment in this context was KCA + DEO + OA. The shelf-life of trout fillets was established through the assessment of multiple parameters. It was determined to be 4 days in both the control and KCA groups, 8 days in the OA and KCA + OA groups, 16 days in the KCA + DEO group, and a minimum of 20 days in the KCA + DEO + OA group. Consequently, our recommendation is to apply an active coating based on KCA, incorporating DEO in conjunction with OA packaging, for the preservation of fish fillets stored in refrigeration.

INCREASING THE SHELF-LIFE TROUT FILLETS BY SODIUM CASEINATE-PERSIAN GUM BIOCOMPOSITE FILM INCORPORATED WITH GINGER EXTRACT

The effects of sodium caseinate (SC)-Persian gum (PG) films enriched with Zingiber officinale extract (ZOE) were investigated on the quality of rainbow trout over a 16 day at 4°C. The trout filets were divided to 4 groups as uncoated, coated with SC-PG, SC-PG-1% ZOE and SC-PG-1.5% ZOE. Sensorial, chemical and microbial characteristics of trout samples were evaluated on 0, 4, 8, 12 and 16 days of storage. GC-MS analysis exhibited that ZOE is rich in phenolic compounds including zingiberene and cis-6-shogaol. Active films embedded with 1.5% of ZOE revealed a remarkable decline in bacterial growth over the storage time. Wrapping with SC-PG-1.5%ZOE composite film tended to delay the elevation of thiobarbituric acid and peroxide value. Samples containing 1.5% ZOE were mostly preferred by sensory panelists. Based on the results of the present study, the edible films were suitable candidates for preserving quality properties and extending the shelf life of rainbow trout fillets.

Dietary astaxanthin alleviates negative changes of flesh quality, long chain unsaturated fatty acids content and muscle growth on rainbow trout (Oncorhynchus mykiss) induced by black soldier fly oil via mammalian target of rapamycin and AMP-activated protein kinase α pathway: Evidence of transcripts and proteomics

This study evaluated the effect of black soldier fly (Hermetia illucens) larvae oil (BO) produced by a novel technique, subcritical butane extraction, on the muscle growth, flesh quality and lipid nutrients of rainbow trout (Oncorhynchus mykiss), and investigated the alleviating mechanisms of dietary astaxanthin supplementation. Two hundred and forty fish (215.16 ± 2.30 g) were distributed to three groups with four replicates. Fish were fed three experimental diets for 8 weeks: the control diet (CD diet), total fish oil of the CD diet was replaced with BO to formulate the BO100 diet, and then 1 g/kg astaxanthin was supplemented with the BO100 diet to formulate the AST diet. Results showed that the final body weight and the sarcomere length of fillet were significantly increased and the protein phosphorylation levels of mammalian target of rapamycin (mTOR) and p70 S6 kinase were enhanced in the BO100 group compared to the CD group (P < 0.05). However, there was a reduction in the hardness, springiness and chewiness of fillets, with a decrease in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels in the fish of the BO100 group (P < 0.05). Supplementation of astaxanthin in the BO100 diet mitigated the impairment of springiness and chewiness and further promoted the sarcomere length of fillet (P < 0.05). Furthermore, dietary astaxanthin partially restored the EPA and DHA content of fillet by increasing the phosphorylation levels of serine/threonine kinase (AKT) and AMP-activated protein kinase α (AMPKα) (P < 0.05) and activating the gene expression of unsaturated fatty acid synthesis. To conclude, BO produced by subcritical butane extraction can be a readily available oil source for rainbow trout feed that can be used to promote muscle growth in rainbow trout. Further dietary astaxanthin supplementation can alleviate BO-induced lipid accumulation, restore DHA levels and improve the flesh quality of rainbow trout fillet.

Effect of low-dose irradiation on lipid quality and fatty acid composition in vacuum-packed hot smoked trout (Oncorhynchus mykiss) fillets during cold storage

The effects of gamma irradiation at different doses (0, 3 and 5 kGy) on lipid quality and fatty acid composition in vacuum-packed hot smoked rainbow trout (Oncorhynchus mykiss) fillets during cold storage (2 °C) were investigated. The major fatty acids were identified as palmitic, oleic, linoleic and docosahexaenoic acids (DHA). The fatty acid compositions were not affected by the irradiation process initially. However, the increase on the total saturated fatty acids (SFA) of irradiated fillets was higher than the control group at the end of the storage. While a significant decrease was observed in the control group of total polyunsaturated fatty acids (PUFA), no change was observed in the groups irradiated with 3 and 5 kGy doses at the end of the storage. The TBA values of 0, 3 and 5 kGy irradiated groups were 1.27, 1.46 and 1.58 mg MA / kg, respectively, the PV values were 6.12, 9.18 and 9.97 meq / kg and the FFA values were 5.36%, 5.67% and 6.10%, respectively, at the end of the storage. Using a combination of techniques to various processed or fresh seafood products will likely play a significant role in enhancing the manufacture of safe meals with extended shelf lives.

Effect of active composite coating based on nanochitosan-whey protein isolate on the microbial safety of chilled rainbow trout fillets packed with oxygen absorber

This study aimed to assess the effect of coating based on nanochitosan-whey protein isolate (NCH-WPI) containing summer savory essential oil (SEO) combined with oxygen absorber (OA) packaging on Pseudomonas aeruginosa, Listeria monocytogenes, and Escherichia coli O157H7, inoculated to rainbow trout fillets stored under refrigeration. Except control and OA groups, L. monocytogenes decreased (0.49–1.82 log CFU/g) in all treatment groups until the eighth day, and then increased (0.39–0.68 log CFU/g). This indicates that the treatments were ineffective to inhibit the proliferation of this bacterium. Considering the forced aerobic nature of inoculated P. aeruginosa, the counts of these bacteria become undetectable in groups packed with OA after the fourth day of storage, while the other groups showed an increase (0.99–2.23 log CFU/g) in this bacteria population during entire storage period. This growth rate was slower in the NCH-WPI + 1%SEO and NCH-WPI + 2%SEO groups. Regarding the inoculated E. coli, its count was decreased (1.48–2.41 log CFU/g) during storage, and this reduction (2.24–2.41 log CFU/g) was the highest in NCH-WPI + 1%SEO + OA and NCH-WPI + 2%SEO + OA groups. In conclusion, NCH-WPI treatments delayed the growth of all pathogenic bacteria, but the ternary treatment (NCH-WPI + SEO + OA) was the most effective treatment in this regard.

Effect of Replacing Fishmeal with Algal Meal on Growth Parameters and Meat Composition in Rainbow Trout (Oncorhynchus mykiss W.)

Aquafarms should reduce the use of fishmeal and fish oil in nutritional feed. One such accessible and relatively inexpensive food component that could successfully meet the challenge posed by aquaculture is algae. The objective of the present study was to evaluate the algae meal inclusion of Chlorella and Spirulina sp. in a diet for rainbow trout, evaluating its effects on fish growth, histological parameters and fillet quality. Experiments were carried out to replace 50% and 100% of fishmeal with Spirulina sp. and Chlorella vulgaris in feed for rainbow trout (Oncorhynchus mykiss W.) cultured in a recirculation system. At the end of the experimental period, the highest mean live weight was measured in rainbow trout fed a feed containing 50% algal meal in the feed. The absorptive vacuolization of cells was increased the most and lamina propria was average thickened when fed 50% algae diets. Fat droplets in the hepatocytes were larger in the 50% algae meal fed group, and their nuclei were replaced in the peripheral zone of the cells. Substitution of fishmeal with 50% algal meal in fish feed resulted in a 36.44% reduction in the lipid content of rainbow trout fillets compared to control fish.

Characterization and performance evaluation of colorimetric pH-sensitive indicator based on Ҡ-carrageenan/quince seed mucilage hydrogel as freshness/spoilage monitoring of rainbow trout fillet

The aim of research was to fabricate a novel indicator by using κ-carrageenan and quince seed mucilage (QSM) hydrogels and red cabbage anthocyanin. The porosity of the hydrogel was controlled using different ratios of κ-carrageenan(C):QSM(Q) (C90:Q10, C70:Q30, and C50:Q50). The hardness of hydrogels decreased from 28.6 ± 0.3 N for C90Q10 to 11.0 ± 1.0 N for C50Q50 sample. However, according to field emission scanning electron microscopy (FE-SEM) analysis, the C50R50 sample had the best morphology with smooth surface and uniform interconnected porous network. Hydrogen bonding interactions among anthocyanins, QSM, and κ-carrageenan were confirmed by Fourier transforms infrared (FT-IR) spectroscopy. The indicator showed a color variation from red to yellow over the pH range of 2–12. Also, the indicator exhibited high sensitivity to ammonia vapors (SRGB = 115%) and good color stability. The C50QRA indicator was used for monitoring rainbow trout fillet spoilage and revealed a visually-detectable color change from red to green upon detecting total volatile basic nitrogen (TVB-N) content produced throughout storage at 4 °C. Generally, the halochromic hydrogel developed in this research can be suggested as a more sensitive and accurate freshness indicator than conventional indicator solid supports.

Optimizing shelf life and quality of rainbow trout fillet using slurry ice containing sodium dodecyl sulfate and citric acid

Optimizing shelf life and quality of rainbow trout fillet using slurry ice containing sodium dodecyl sulfate and citric acid

Ultrasound-Assisted Nanoemulsion Loaded with Optimized Antibacterial Essential Oil Blend: A New Approach against Escherichia coli, Staphylococcus aureus, and Salmonella Enteritidis in Trout (Oncorhynchus mykiss) Fillets.

This study aimed to obtain and characterize an oil-in-water nanoemulsion (NE) loaded with an in vitro optimized bactericidal essential oil blend of 50% oregano, 40% thyme, and 10% lemongrass and to evaluate its potential at three different concentrations (0.5%, 1%, and 2%) in the inactivation of Escherichia coli, Staphylococcus aureus, and Salmonella enterica serotype Enteritidis inoculated in rainbow trout fillets stored at 4 °C for 9 days. Regarding the NE, the nanometric size (<100 nm) with low polydispersion (0.17 ± 0.02) was successfully obtained through ultrasound at 2.09 W/cm2. Considering the three concentrations used, S. Enteritidis was the most susceptible. On the other hand, comparing the concentrations used, the NE at 2% showed better activity, reducing S. Enteritidis, E. coli, and S. aureus by 0.33, 0.20, and 0.73 log CFU/g, respectively, in the trout fillets. Thus, this data indicates that this is a promising eco-friendly alternative to produce safe fish for consumption and reduce public health risks.

The effects of Juniperi fructus essential oil and vacuum packing on the shelf life of rainbow trout fillets during storage at 2±1°C.

We hypothesized that the combined effect of vacuum packaging and Juniperi fructus essential oil addition would increase shelf life. Six different treatments were tested. The effects of the different concentrations of J. fructus essential oil (0%, 0.3% and 0.6%) and packing method (non-vacuum and vacuum) on the fish (Oncorhynchus mykiss) fillets of stored 4±1 °C were investigated in terms of its microbiological (mesophilic aerobic bacteria and yeast-mold), chemical (pH, total volatile alkaline nitrogen (TVB-N), thiobarbituric acid (TBA value)) and sensory quality. The results showed that J. fructus essential oil had a positive significant effect on quality parameters (p<0.05). In conclusion, based primarily on sensory, TVB-N and mesophilic bacteria data the shelf-life of fresh rainbow trout was 4 days (non-vacuum packaged), 13 days (vacuum packaged), 19 and 28 days treated with J. fructus oil (0.3 and 0.6%, v/w) under vacuum packaged, respectively. J. fructus essential oil application and vacuum packaging; extended the shelf life of fish fillets by an average of 15 days. The combined use of J. fructus essential oil and packaging techniques could form the basis for new studies.

BIOLOGICAL AGENTS AS AN ALTERNATIVE TO CHEMICAL PRESERVATIVES IN THE SEAFOOD PROCESSING INDUSTRY, A REVIEW

The present research investigated the possibility of replacing probiotic bacteria instead of chemical preservatives in the seafood processing industry. The data were used from articles published in the databases including Science Direct, Pub Med, Scopus Springer Link, and Scopus. The search was carried out using the keywords fish fillet, beneficial non-dairy foods, increasing shelf life, biological protection, probiotic food, microbial treatment, and Lactobacillus bacteria. A biological preservation technique was used to maintain the quality of hake, spanish mackerel, mackerel, sea bass, tilapia, swordfish, rainbow trout, and ribbon fillets. Swordfish coated with L. paracasei IMPC 2.1 was acceptable for 3 months. Followed by spanish mackerel and rainbow trout fillets coated with L. casei and L. plantarum subsp. plantarum ranked second and third for 30 and 21 days, respectively. The minimum shelf life of fillets was 48 hours (Tilapia coated with L. plantarum 1.19). In freezing, L. brevis could maintain the quality of rainbow trout fillet for 6 months. The present study suggests Lactobacillus strains, especially L. paracasei IMPC 2.1, as a preservative to preserve the quality of fish fillets. However, the use of this species in the seafood processing industry requires wider research to investigate its effect on other aquatic species.

Effect of tomato seed mucilage coating enriched with shallot essential oil on frozen rainbow trout (Oncorhynchus mykiss) fillet quality

The present study aimed to investigate the interaction effects of tomato seed mucilage (TSM) coating and shallot essential oil (SEO) (0%, 1%, and 2%) on the physicochemical, and microbial properties of Rainbow Trout (Oncorhynchus mykiss) during frozen storage (0, 1, 2, 3, and 4 months). The results indicated that the TSM coating treatments, especially, with the increase in SEO concentration effectively reduced the total viable count (TVC) and psychrotrophic bacteria count (PTC). Moreover, it decreasing the rate of changes in thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), and peroxide value (PV). The TVB-N levels were within acceptable limits, except for the Ctrl treatment in the fourth month, where the TVB-N in fish fillet was exceeded 25 mg/100g. The incorporation of SEO to the TSM coating led to a decrease in pH variations, protein solubility, and moisture content of the Rainbow Trout fillets during frozen storage. At the end of the storage period, Hardness in the Ctrl treatment at the end of storage period were respectively 14.95%, 21.91%, and 24.52% lower than those in the TSM-0% SEO, TSM-1% SEO, and TSM-2% SEO treatments. Furthermore, at the end of the frozen storage period, the color changes in all treated fillets were significantly lower compared to the Ctrl treatment (p < 0.05). Overall, utilizing a 2% SEO-containing TSM treatment demonstrated the best performance in delaying undesirable qualitative changes. Hence, there is promising potential in using TSM as agricultural waste in combination with active compounds like SEO to produce an active coating. These coatings, according to their characteristics, can serve as a cost-effective, efficient, and safe option for preserving perishable marine products.

Oil-in-water emulsion loaded with optimized antioxidant blend improved the shelf-life of trout (Oncorhynchus mykiss) fillets: a study with simplex-centroid design.

This study aimed to obtain optimized mixture with three essential oils (EOs) for maximum antioxidant activity through the augmented simplex-centroid mixture design and evaluate the effect of this optimized blend on total aerobic psychrotrophic count (TAPC), lipid and protein oxidation, instrumental color parameters and texture profile in rainbow trout fillets at refrigerated storage for nine days. Considering the DPPH and FRAP assays, the ideal EO blend was 66% lemongrass and 34% oregano. During refrigerated storage, this blend at 2000ppm was equally effective as BHT (100ppm) (p > 0.05), mitigating the discoloration (a* and b*), lipid, and protein oxidation in 38.83%, 12.95%, 76.13%, and 35.13%, respectively, besides shows greater effectiveness for preserving texture changes (p < 0.05) and extending the shelf life in 13h. The lemongrass + oregano EO blend reveals a promising natural alternative to enhance the quality of rainbow trout fillets under refrigerated storage. Furthermore, the multiresponse optimization showed to be a strong ally in enabling the use of these EOs by food industries.

Development of halochromic electrospun labels for non-invasive shelf life assessment of rainbow trout (Oncorhynchus mykiss): Incorporation of barberry anthocyanin extract in protein-based smart packaging.

Using barberry (Berberis vulgaris L.) as a natural dye in combination with electrospinning technology represents a promising approach for the development of intelligent packaging systems. In this study, the influence of different concentrations of zein (16, 18, and 20%) and barberry anthocyanin-rich powder (BARP) (16, 18, and 20%) on the surface tension and rheological properties of the solution were evaluated. The most favorable nanofibers (NFs) were obtained from a solution containing 18% (w/w) zein under constant voltage. The surface morphology, size, and color-changing properties of electrospun NFs derived from zein polymers containing different concentrations of BARP (16, 18, and 20%) under various electrical fields (20, 22, and 24 kV) were evaluated. The Fourier-transform infrared spectroscopy analysis confirmed the interaction of BARP within the zein-based NFs. The results indicated that the concentration of BARP had a noticeable impact on the physicochemical properties of the NFs. Furthermore, efficacy of the appropriately fabricated halochromic label was evaluated for monitoring the packed rainbow trout fillet during refrigerated storage. On the 10th day, a noticeable visual color turned from pink to pale yellow was observed in response to pH variations. Additionally, the TVN value confirmed the effectiveness of halochromic electrospun labels for non-invasive assessment of fish fillet quality.

Optimized UVC-LED condition to improve the shelf life of vacuum-packed refrigerated stored rainbow trout (Oncorhynchus mykiss) fillets

Optimized UVC-LED condition to improve the shelf life of vacuum-packed refrigerated stored rainbow trout (Oncorhynchus mykiss) fillets

Studying the impact of phycoerythrin on antioxidant and antimicrobial activity of the fresh rainbow trout fillets

Marine cyanobacteria present a significant potential source of new bioactive compounds with vast structural diversity and relevant antimicrobial and antioxidant activities. Phycobiliproteins (PBPs) like phycocyanin (PC), phycoerythrin (PE), and water-soluble cyanobacterial photosynthetic pigments, have exhibited strong pharmacological activities and been used as natural food additives. In this study, phycoerythrin (PE) isolated from a marine strain of cyanobacterium Nostoc sp. Ft salt, was applied for the first time as a natural antimicrobial as well as an antioxidant to increase the shelf life of fresh rainbow trout i.e., (Oncorhynchus mykiss) fillets. Fresh trout fillets were marinated in analytical grade PE (3.9 μg/mL) prepared in citric acid (4 mg/mL), and stored at 4 °C and 8 °C for 21 days. Microbiological analysis, antioxidant activity and organoleptic evaluation of both control and treated fish fillets were then statistically compared. The results demonstrated noticeable (P < 0.05) differences in the microbial counts, antioxidant activity, and organoleptic characteristic values between PE-treated and non-treated groups. In addition, we observed that treating fresh fish fillets with a PE solution leads to a significant increase in shelf life by at least 14 days. Consequently, PE could be an alternative to synthetic chemical additives since it does not contain the potentially dangerous residues of the synthetic chemical additives and is thus healthier to the consumers.

Bilayer coatings for extension of the shelf life of fish fillets: Incorporating seaweed sulfated polysaccharides in chitosan-alginate LbL structures.

The aim of this study was to develop a new active coating of layer-by-layer (LbL) structure composed of alginate (as polyanions) and chitosan (as a polycation) containing sulfated polysaccharide (fucoidan) from Sargassum angustifolium, to protect rainbow trout fillets during refrigerated storage. Chitosan and alginate do not combine with each other as a homogeneous solution, so they are suitable for multilayer coatings. The results demonstrated that coating samples with chitosan and fucoidan significantly improved the quality of fish fillets and extended their shelf life from 6 to 16 days. The chemical values (TBARS and TVB-N) and bacterial growth (total viable count (TVC), total psychrophilic count (PTC), and lactic acid bacteria (LAB)) indicated lower levels in the LbL coating samples containing fucoidan compared to the alginate and control samples. Among the different coating samples, the LbL coating with fucoidan (AChF1) exhibited lower weight loss, improved chromaticity (L*, a*, and b*), and minimal changes in mechanical and sensory evaluations. Based on the findings, AChF1 was the most effective treatment for increasing the shelf life of rainbow trout fillets during refrigerated storage. Therefore, it has potential applications in the food packaging industry.

Application of electrospun zein/polyvinyl alcohol nanofibers incorporating thymoquinone and electrosprayed resveratrol nanoparticles on the shelf life of fresh rainbow trout fillet and inoculated Escherichia coli O157:H7

Application of electrospun zein/polyvinyl alcohol nanofibers incorporating thymoquinone and electrosprayed resveratrol nanoparticles on the shelf life of fresh rainbow trout fillet and inoculated Escherichia coli O157:H7

Consumer Expectation and Perception of Farmed Rainbow Trout (Oncorhynchus mykiss) Fed with Insect Meal (Tenebrio molitor).

In recent years, insect meal has attracted increasing interest as an innovative protein source to replace fish meal in feed formulations due to its valuable nutritional profile. This research aimed to compare the effects of different levels of dietary inclusion of the yellow mealworm beetle (T. molitor) larvae meal on the sensory quality of rainbow trout (Oncorhynchus mykiss) fillets and retrospectively on the acceptability of this protein source to consumers. The results showed that the inclusion of T. molitor larvae meal did not induce sensory changes in the trout fillets, while regarding consumer acceptability and willingness to buy and pay, it was shown that a certain level of rejection towards this alternative protein still exists. The work described in this scientific manuscript adds more knowledge on the study of consumer acceptability of this protein source.