Tilapia Fillets Research Articles

The efficiency of washout strategy on decreasing the deposit linoleic acid of tilapia fillet and viscera

This study was designed to explore the effectiveness of washout strategy on decreasing the linoleic acid (LA) deposition in a short time frame to improve the tilapia fillet quality. Two diets of different lipid sources, soy oil diet (S) and fish oil diet (F) were formulated and employed to create three different feeding regimes. The three regimes were; feeding on S diet for six weeks (S6), feeding on F diet for six weeks (F6), and feeding on S diet for three weeks followed by F diet for another three weeks (S3F3). Tilapia with average initial weight of 71 g ± 0.25 had been fed twice daily by hand till satiation for six days weekly. After 6 weeks, linoleic acid decreased (11.6% total fatty acid (TFA) in the fillet of tilapia fed on F6 regime compared to fish fed on S6 regime, which had a linoleic acid content of 25.9% TFA. Fish performance and feed utilization did not differ significantly among feeding regimes except for feed intake, which improved significantly for fish fed fish oil continuously (F6). The feeding regimes had no significant effect on the unsaturated fatty acids of fish viscera except for oleic acid. Higher oleic content noticed in the viscera of fish subjected to soybean oil regimes. The results showed the ability to decrease linoleic acid and the possibility to improve the quality of tilapia fillet for human using fish oil for 6 weeks before harvest. Moreover, it could be concluded that viscera from freshwater fish subjected to washout strategy before harvest can be used as a functional ingredient in aquafeed which is a step toward responsible aquaculture and sustainability.

Astaxanthin improves the shelf-life of tilapia fillets stored under refrigeration.

Astaxanthin, classified as a xanthophyll, has antioxidant properties about 500 times greater than α-tocopherols and ten times greater than β-carotenes. Based on the antioxidant activity of this carotenoid, this study aimed to evaluate the shelf-life of tilapia fillets (Oreochromis niloticus) fed with astaxanthin, by determining the microbiological quality (colimetry, counts of mesophilic and psychrotrophic microorganisms), physicochemical analyses (colorimetry, pH, thiobarbituric acid reactive substances (TBARS)) and sensory analysis. Tilapia supplemented with astaxanthin presented a reduction in the counts of microorganisms (mesophiles and psychrotrophics) and lower lipid oxidation index (TBARS), when compared to fillets of control fish. Colorimetric changes of fillet degradation were observed, associated with increased pH during storage, as well as loss of brightness and texture in addition to worsening of appearance and odor. These deteriorating changes were minimized using astaxanthin. Our results demonstrate the beneficial performance of astaxanthin in the shelf-life of tilapia fillets stored under refrigeration. Therefore, dietary supplementation with astaxanthin (100 and 200 mg kg-1 of feed) improves the microbiological and physicochemical quality of tilapia fillets during 50 days of shelf-life. © 2022 Society of Chemical Industry.

Delivering a Nutritionally Enhanced Tilapia Fillet Using a Pre‐Harvest Phase Omega‐3 Thraustochytrids Protist Enriched Diet

AbstractNile tilapia (Oreochromis niloticus) offers an affordable food source to many low‐income consumers. However, farmed tilapia has drawn much criticism over the low omega‐3 (n‐3) and high omega‐6 (n‐6) lipid levels. Subsequently, it has been questioned whether it is truly healthy food. This study fed tilapia with a specialized “finishing” diet with the inclusion of commercial Thraustochytrids protist biomass and oil before the harvestable fish size. The fish are fed with two different dietary regimes over 6 weeks. One is a commercially available tilapia feed used as a reference. The second diet is composed of an exclusive oil source from Thraustochytrids protist (HI‐n3). The results show that HI‐ n3 has significantly increased the fillet n‐3 content by 400% in comparison to commercial diet (COM) after Week 6 of feeding. Specifically, docosahexaenoic acid (DHA, n‐3) content is the attributing fatty acid for the n‐3 increase. This is particularly evident when DHA is expressed as a percentage of total lipid content. The n‐3:n‐6 ratio increased in tilapia fed with the HI‐n3 diet attributed to the DHA accumulation. The investigation shows that it is possible to favorably “lipid tailor” tilapia before harvest.Practical applications: The practical application of this technique is to enrich farmed tilapia with a high dietary omega‐3 (n‐3) Thraustochytrids protist oil source for a short‐term period before harvesting. It is an objective that the fillet product would be more functional in its nutritional content by supplying more than just high‐quality protein for consumers. This would have paramount implications for low‐income consumers, where high n‐3 oil foods are not readily available or affordable (e.g., landlocked nations). Furthermore, tilapia is widely consumed in China and Southeast Asian countries but is also promoted as a high nutritional value food source in the western hemisphere. This investigation advocates the ability to change the image of this fish species by a simple dietary manipulation. In an era of elevated intake of omega 6 (n‐6) fatty acids food sources, n‐3 rich fish is a vital balance to counter this negative trend in human health.

Nile tilapia production in polyculture with freshwater shrimp using an aquaponic system and biofloc technology

This study aimed to evaluate the performance of Nile tilapia, freshwater shrimp, lettuce, and watercress in an aquaponic system used in conjunction with biofloc technology. Experimental units consisted of an aquaponic module comprising two containers, one to accommodate vegetables (500 L media-filled bed with gravel) and the other to stock fish and shrimps (1000 L rearing tank). The experiment was carried out in a randomized complete block design with two treatments [an aquaponic system with clear water (ASCW) and an aquaponic system with biofloc technology (ASBFT)] and two blocks (periods). Each treatment had three replicates within each block, totaling six experimental units per block. The final weights of Nile tilapia (ASCW = 546.0 g; ASBFT: 565.0 g), freshwater shrimp (ASCW = 18.82 g; ASBFT: 18.44 g), and vegetable biomass (ASCW: 1.10 kg/m2 of lettuce and 1.57 kg/m2 of watercress; ASBFT: 0.94 kg/m2 of lettuce and 1.98 kg/m2 of watercress) did not differ significantly between the two treatments. Similarly, there were no significant differences between treatments with respect to other zootechnical performance variables of the evaluated organisms. There was, however, a greater (P < 0.05) accumulation of fat in the fillets of Nile tilapia reared in the ASBFT system (0.97%) than in those of fish reared in the ASCW system (0.76%), as well as a lower oscillation of nitrite levels. Therefore, the use of biofloc technology in conjunction with aquaponics facilitated the maintenance of zootechnical performance and contributed to an increase in the fat content of Nile tilapia fillets and better control of nitrite production.

The effect and mechanism of four drying methods on the quality of tilapia fillet products

AbstractTilapia (Oreochromis niloticus) holds a major position in the fishery market worldwide. This study aimed to investigate the effect of four drying methods, namely vacuum freeze (VFD), vacuum microwave (VMD), hot air (HAD) and microwave (MD), on texture, amino acids, microstructure, lipid oxidation and protein degradation of tilapia fillets. The results showed that vacuum combined with refrigeration (VFD) or VMD had better color, chromatic aberration, shrinkage ratio and microstructure. The total essential amino acid content (31.16%), α‐helical (28.06%) structure and protein denaturation temperature of nonthermal VFD were higher than the VMD, HAD and MD methods. In thermal drying processing, VMD had some advantages in protein stability, microstructure, lipid oxidation and flavor compared with HAD and MD products. Therefore, a combined drying method was discovered to have prospects for use in tilapia processing. VFD was considered the appropriate nonthermal drying method of fillets with high product quality and protein stability. Meanwhile, considering the advantages of its efficiency, quality and energy consumption, the VMD had the best potential of the four methods employed to dry tilapia fillets.

Fish breaded made with tilapia fillet and inclusion of minced fish derived from salmon processing: nutritional, technological, and sensory properties

The fish processing processes generate a large volume of residues, so, an alternative for the use is the production of minced fish (MF). Thus, this study aimed to develop breaded with different concentrations of MF of salmon and tilapia fillet, and to analyze the chemical, physical and microbiological characteristics, as well as to determine the acceptability and purchase intention of the formulations. In technological and nutritional terms, the use of salmon MF in the production of breaded products did not detract from the quality of the final product, indicating a viable alternative for the use of salmon waste.

Analysis of the Degree of Quality of Fish Fillet in Refrigeration

Fish is a highly nutritious food widely consumed around the world. The production of fish for human consumption is from capture fishing and aquaculture activities. Tilapia is considered one of the fish with the highest production worldwide, being a source of quality protein at an affordable price. On the other hand, and in addition to its nutritional properties, fish is highly susceptible to deterioration and contamination, mainly due to its intrinsic properties, making it able to consume it for short periods of time, so to extend its availability, it is subjected to common conservation processes like refrigeration. Therefore, the present study is focused on the analysis of the degree of freshness and quality of tilapia fillet through sensory evaluation during refrigerated storage for 12 days. The results indicated that the tilapia fillet during storage had a grade of first quality from day 0 to 4th of storage recommended for consumption, second quality on the 6th day and out of quality from the 8th of storage, the latter being not recommended for human consumption.

Mercado de filés de tilápia na cidade de São José do Rio Preto, estado de São Paulo.

The objective was present the potential of selling tilapia fillets in hypermarkets, supermarkets, restaurants and food trucks, identifying the number of establishments that sell and buy this product, as well as prince of products, year 2019. A field research was carried out in three regions of the city. The values of the three species of fish competing in the filet market, tilapia had the highest value with R$ 35.94, followed by pangasius with R$ 26.95, hake in third with R$ 25.97 and finally mapará with R$24.77. Food trucks purchase a large amount of steaks per month, showing that this segment heats up the regional economy.

Microbiological Analysis of Tilapia Fillet Stored Under Refrigerated Conditions

Fish is a food susceptible to deterioration and contamination by microorganisms through the food chain, affecting its quality and safety. Fish is subjected to various processing and preservation methods in order to maintain availability, quality and safety for a longer time. The objective of the study was the microbiological analysis of tilapia fillets in refrigeration for 12 days. The tilapia processing was carried out to obtain fillets. The fillets were packed in polyethylene bags and later in an isothermal polystyrene container and kept in refrigeration for 12 days and the microbiological analysis was carried out through quality and safety indicators. The results of the microbiological analysis indicated a regular growth dynamic during storage, reaching maximums for Aerobic Mesophylls (AM) and Aerobic Psychrophiles (AP) of 12.5 and 8.6 Log CFU/g respectively, Fungi and Yeast (FY) 9 Log CFU/g, Lactic Acid Bacteria (LAB) 9 Log CFU/g, Total Coliforms (TC) 8.3 Log CFU/g and Pseudomonas (P) 7 Log CFU/g. According to different microbiological criterion related to deterioration and acceptability in food, the counts obtained in fillet reached maximum values on day 4 of storage for AM, day 6 for AP, day 8 for P, day 2 for TC and after day 2 for LAB. The analysis of microbial growth in fillet under refrigeration through quality and safety indicators, allow estimating conditions and periods of availability of healthy and nutritious food.

Influence of saline environment and depuration time on quality and proximate composition of Nile tilapia fillet (Oreochromis niloticus)

This study investigated the depuration time of tilapia in saline and freshwater environments and its influence on animal performance and meat quality. Depuration until the seventh day resulted in significant reductions in average weight, condition factor, viscerosomatic index, hepatosomatic index and fillet yield in both environments. Regarding proximate composition, the saline environment promoted the maintenance of crude protein, moisture and ash percentages. Depuration in the freshwater environment resulted in reduced percentages of crude protein, ash and energy and increased humidity. Total lipids were reduced in both environments, but with a significantly lower in saline. Maximum rigor index occurred in up to three and nine hours for fish depurated in freshwater and saline environments, respectively. During the post-rigor period, the rigor index experienced a sharp drop in the freshwater environment, while in the saline environment it remained similar to that of the pre-depuration group. Depuration in a saline environment for up to seven days was efficient at maintaining of proximate composition and rigor mortis, however, depuration until the fifth day is indicated to maintain performance indices.

Effect of frozen storage on the chemical and sensory properties of red tilapia (Oreochromis niloticus)

Tilapia is one of the fastest growing aquaculture productions in the world and understanding of its storage to ensure the quality of the fish before the product reaches consumer is important. Freezing changes a food physical state by changing water into ice when energy is removed in the form of cooling below freezing temperature and its effect on the quality of fish is widely studied. This present study evaluated the effect of frozen storage of tilapia fillet at -18°C over 120 days. The study revealed that all the chemical quality indices studied like pH (6.60±0.02 to 6.98±0.05), TVB-N (11.81±0.03 N/100g to 22.98±0.18 N/100g), TBA (0.03±0.02 mg malondialdehyde/Kg to 0.18±0.06 mg malondialdehyde/Kg) and PV (0.02±0.00 mEq/kg to 0.80±0.07 mEq/kg) increased in value over the 120 days of storage period. Meanwhile the sensory attribute of the fillet decreased for all parameters evaluated, but were still considered acceptable at the end of the storage period.

Effects of different phosphorus-free water-retaining agents on the quality of frozen tilapia fillets.

Tilapia is an economically important fish worldwide, but its quality is affected by storage practices. To improve the quality of tilapia fillets during frozen storage, we examined the effect of pretreatment with various combinations of different concentrations of trehalose, potassium bicarbonate, and chitosan. Following pretreatment, we analyzed the tilapia fillets using quality indicators, including soaking weight gain, coating weight gain, water‐holding capacity, thawing loss, pH, Ca2+‐ATPase activity, and texture characteristics. Water distribution was analyzed using low‐field nuclear magnetic resonance and the optimal combination of water‐retaining agents was obtained using an L8(27) orthogonal experiment. The results showed that trehalose, potassium bicarbonate, and chitosan improved fillet quality at pretreatment concentrations of 5%–8%, 1.0%, and 0.5%, respectively. The optimal combination was 4% trehalose plus 1.2% potassium bicarbonate plus 0.2% chitosan. The Ca2+‐ATPase activity and mastication property of the frozen fillets that were pretreated with the optimized formulation were 1.39 μmol Pi/mg protein·h and 8.55 mJ, respectively, which were 43.3% and 80.0% greater, respectively, than that of the control group. Using a suitable concentration and combination of water‐retaining agents cannot only lock‐in the internal water content of frozen tilapia fillets but also improve their quality during frozen storage. These results can inform practical storage practices of similar aquatic products.

EGCG-gelatin biofilm improved the protein degradation, flavor and micromolecule metabolites of tilapia fillets during chilled storage

The protein degradation, flavor and micromolecule metabolites changes of (−)-epigallocatechin gallate (EGCG)-gelatin biofilm treatment (EGT) on chilled tilapia fillets in 21 days were investigated. Morphology observations revealed EGT protected good connective myofibrillar protein. It maintained protein secondary structure by significantly increasing the proportion of α-helix (15.20%) and decreasing the ratio of random coils (22.02%) in the EGT group compared to the control (CON) group (P < 0.05). Metabolomics with UHPLC-Q-TOF/MS analysis indicated a distinct separation between the CON and treatment groups at the end of storage. Small peptides analysis demonstrated that the EGT group increased the level of sweet peptides. Additionally, the EGT group significantly reduced the formation of amino acid derivatives and esters and off-flavor development. Overall, EGT effectively improved flavor, inhibited fish protein oxidation/degradation, and verified metabolomics results. This study unveiled the potential of metabolomics to analyze metabolites determined by tilapia and monitor the changes during storage.

Effect of different thermal processing methods on water-soluble taste substances of tilapia fillets

The composition of free amino acids (FAAs) and nucleotides has an important effect on fish taste. In this study, the content of FAAs and nucleotides in raw, steamed, boiled and air-fried tilapia fillets were quantitatively analyzed. Thermal processing significantly influenced the composition of FAAs and nucleotides in tilapia. Moreover, there were substantial differences in the nutritional composition of tilapia processed by steaming, boiling and air frying. Compared with raw fillets, the total FAA (TFAA) increased after steaming, boiling, and air frying. The main umami and sweet amino acids in tilapia fillets were aspartic acid and glycine. The total nucleotide content of fresh tilapia was 299 mg/100 g, which increased to 305 and 366 mg/100 g after steaming and air frying, respectively, and decreased to 273 mg/100 g after boiling. The main taste nucleotide inosine monophosphate (IMP) with a taste activity value greater than 1, contributed greatly to the taste of tilapia. Equivalent umami concentration was used for taste evaluation: air frying > steaming > boiling. Therefore, our findings establish that the water-soluble taste substances of tilapia fillets, and the mutual regulatory effects of different compounds varied with different thermal processing methods. Hence, tilapia can be thermally processed according to different taste requirements.

Fabrication of sea urchin-like Au@SiO2 nanoparticles SERS substrate for the determination of malachite green in tilapia

The quantitative determination of malachite green (MG) is of great importance in aquatic product safety. Although it has been testifying that sea urchin-like gold nanoparticles (SGNPs) have good enhancement effect, the practical application remains challenging for surface-enhanced Raman spectroscopy (SERS) due to poor stability. Here, sea urchin-like Au@SiO2 nanoparticles (SG@SiO2 NPs) is designed and synthesized through a controllable and surfactant-free hydrothermal method to improve its stability. The morphology of SG@SiO2 NPs and the SiO2 shell thickness were adjusted to obtain good SERS performance. The SERS signal intensity was linear for MG, crystal violet (CV) and methylene blue (MB) at 1619 cm−1, 1623 cm−1 and 1627 cm−1 over the concentration range of 10−5-10−9 M, 10−5-10−9 M and 10−5-10−8 M, respectively. The substrate was easily used for MG detection with limit of detection (LOD) as low as 1.5 × 10−9 M. The recovery of MG added to several tilapia fillets samples at different concentrations ranged from 90 % to 110 %. Results indicated that SERS substrate can be used for the determination of trace amounts of MG in tilapia and demonstrated the potential of SG@SiO2 NPs SERS substrate in food analysis fields.

Use of betel leaf (Piper betle L.) ethanolic extract in combination with modified atmospheric packaging and nonthermal plasma for shelf-life extension of Nile tilapia (Oreochromis niloticus) fillets.

Fish is perishable and has the short shelf-life. To maintain its quality, it is necessary to implement the appropriate technology, particularly nonthermal processing along with safe additive, especially from plant origin under the concept of "hurdle technology". The use of potential vesicle including liposome for loading the plant extract could be a means to enhance the stability and activities of the extract. The current study aimed to evaluate the effect of liposomes loaded with betel leaf ethanolic extract (L/BLEEs) or unencapsulated BLEE (U/BLEE) in conjunction with modified atmospheric packaging (MAP) and nonthermal plasma (NTP) on the quality changes and shelf-life of Nile tilapia fillets (TFs) stored under refrigerated condition (4°C). TFs treated with L/BLEE or U/BLEE at 400ppm, packed under modified atmosphere (CO2 :Ar:O2 =60:30:10) and subjected to NTP for 300 s (L/BLEE-400/MAP-NTP and U/BLEE-400/MAP-NTP, respectively) had the lowest microbial and chemical changes during storage, while the control showed the highest changes (p<0.05). Lipid oxidation was lower in these samples, ascertained by more retained polyunsaturated fatty acids and lower lipid oxidation based on Fourier transform infrared (FT-IR) spectra. Overall likeness scores were similar (p>0.05) between all the samples at day 0 of storage. Only L/BLEE-400/MAP-NTP and U/BLEE-400/MAP-NTP were still sensorially acceptable after 12 days at 4°C. Therefore, L/BLEE or U/BLEE combined with MAP/NTP treatment could be adopted as a potent hurdle for shelf-life extension of TFs. PRACTICAL APPLICATION: Natural additives and nonthermal processing technologies have gained increasing interest for preservation of fish. Liposomes loaded with betel leaf ethanolic extract (L/BLEE) rich in polyphenolics could be used together with modified atmospheric packaging (MAP) and nonthermal plasma (NTP) to retard bacterial growth and chemical deterioration in Nile tilapia fillets. These hurdles were proven to be able to maintain the qualities of tilapia fillets stored at 4°C up to 12 days, especially when L/BLEE was used at 400ppm. Therefore, shelf-life extension of Nile tilapia fillets or other fish can be achieved by using the natural additive and nonthermal processing technologies.

Differences in physicochemical quality, texture, and fractal dimensions of tilapia fillets in different specifications and partitions

This study investigated the differences in physicochemical quality, texture, and fractal dimensions of tilapia fillets in different specifications and partitions. Clear white texture, bright color, good completeness, and luster were used as the criteria for selecting fresh tilapia fillets. The pH value, color parameters, electrical conductivity (EC), total volatile basic-nitrogen (TVB-N) value, and texture parameters of tilapia fillets in different specifications and partitions were analyzed. Finally, the profile fractal dimension of the tilapia fillets was measured. The results showed that tilapia fillets could be divided into three partitions: back, abdomen, and tail, and fresh tilapia fillets with different specifications and partitions had more differences in color and EC, but there are slight differences in pH, TVB-N, and texture. The fractal dimension values of the fillet tissue in the transverse and longitudinal sections were also determined. Practical applications Tilapia fillets for export lack deep processing and are gradually at a disadvantage in the face of increasingly fierce market competition. This work divided the tilapia fillets according to the quality differences on the surface of the fillets, and then determined the quality differences of the fillets in different parts. At the same time, the fractal dimension was also introduced to evaluate the quality of fillets. The quality differences of different partitions and the determination of the profile fractal dimension provided the possibility for the deep processing of export tilapia fillets and quality monitoring.

Effects of Radio Frequency Tempering on the Texture of Frozen Tilapia Fillets.

Radio frequency (RF) tempering has been proposed as a new alternative method for tempering frozen products because of its advantages of rapid and volumetric heating. In this study, the texture of RF-tempered frozen tilapia fillets was determined under different RF conditions, the effects of related factors on the texture were analyzed, and the mechanisms by which RF tempering affected the texture of the tempered fillets were evaluated. The results show that the springiness (from 0.84 mm to 0.79 mm), cohesiveness (from 0.64 mm to 0.57 mm), and resilience (from 0.33 mm to 0.25 mm) decreased as the electrode gap was increased and the power remained at 600 W, while the shear force increased as the power was increased for the 12 cm electrode gap (from 15.18 N to 16.98 N), and the myofibril fragmentation index (MFI) values were markedly higher at 600 W than at 300 W or 900 W (p < 0.05). In addition, the tempering uniformity had a positive effect on hardness and chewiness. The statistical analysis showed that the texture after RF tempering under different RF conditions correlated relatively strongly with the free water content, cooking loss, and migration of bound water to immobilized water. The decrease in free water and bound water migration to immobilized water resulted in a significant increase in cohesiveness and resilience.

Effects of different thawing methods on microstructure and the biochemical properties of tilapia (Oreochromis niloticus) fillets during frozen storage

AbstractThis study investigated the effects of different thawing methods (water immersion thawing [WIT, 25 °C], air thawing [AT, 25 °C] and refrigerator thawing [RT, 25 °C]) on the biochemical properties and microstructure of tilapia (Oreochromis niloticus) fillets during storage at −18 °C for 6 months. The results indicated that the thawing time for WIT, AT and RT were approximately 7, 83 and 616 min, respectively. Thawing and cooking losses in the RT samples were significantly lower than those in WIT and AT samples (P &lt; 0.05). The microstructural integrity of RT samples was less compromised than that of WIT and AT treated samples. Ca2+‐ATPase activity and SH content decreased with increasing storage time and the frozen storage time. Compared with the other two thawing groups during frozen storage, RT had the highest fluorescence, which was significant for the quality of tilapia fillets. However, no significant difference (P &lt; 0.05) was observed in protein secondary structure changes, especially β‐sheets and β‐turns. Therefore, RT is suggested to be an effective thawing method to minimise quality change during frozen storage and the frozen storage time has a greater impact on its quality. These results demonstrate the interaction between frozen storage and thawing processes on selected quality parameters.

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.