Silver Carp Fillets Research Articles

Quality changes and microbiological spoilage analysis of air-packed and vacuum-packed silver carp (Hypophthalmichthys molitrix ) fillets during chilled storage

The effects of air-packed (AP) and vacuum-packed (VP) on quality and microbial characteristics of silver carp (Hypophthalmichthys molitrix) fillets during chilled storage (4 ± 1 °C) were investigated. The fillets were analyzed for sensory scores, total volatile basic nitrogen (TVB-N), ATP-related compounds (ATP, IMP, HxR, and Hx), K value, and biogenic amines (BAs). The results proved that VP inhibited the increase of microorganisms, TVB-N, Hx, and putrescine in silver carp, and slowed the reduction in sensory score. Therefore, VP can be applied for preservation of the silver carp fillets to improve its quality. For identification, 16S rRNA genes of the isolated pure strains were sequenced and analyzed. On the initial day of storage, Chryseobacterium was the dominant bacterial genus. At the end of shelf life, Pseudomonas was the most common group in AP fillets and Aeromonas followed by Yersinia were found mainly in VP samples. Practical applications Silver carp (Hypophthalmichthys molitrix) are distributed widely in fresh water systems. The world aquaculture production of silver carp was 4,354,638 tons, and it ranked second highest among freshwater fish species in 2015, but they are perishable during storage because of microbial spoilage and biochemical reactions. Vacuum packaging (VP) has proved to be effective for extending the shelf-life of aquatic products by excluding oxygen that prevents the growth of spoilage bacterial. However, little information is available on the microbial succession of VP silver carp. Therefore, this work was to determine the differences of microbiological succession on chilled silver carp fillets under air-packed (AP) and VP conditions using a combination of culture-based and 16S rRNA gene analysis methods. Furthermore, this study will give valuable information about development and spoilage of VP silver carp fillets.

Dynamic rheological, microstructural and physicochemical properties of blend fish protein recovered from kilka (Clupeonella cultriventris) and silver carp (Hypophthalmichthys molitrix) by the pH-shift process or washing-based technology

This study aimed to evaluate how blending pH-shift produced protein isolates from gutted kilka (Clupeonella cultriventris) and silver carp (Hypophthalmichthys molitrix) affected dynamic rheological and chemical properties of the proteins as well as microstructural and physico-mechanical properties of produced gels. Studied variables were protein solubilization pH (acid vs. alkaline) and blending step (before or after protein precipitation). Comparisons were made with conventionally washed minces from kilka and silver carp fillets; either alone or after blending. Rheological studies revealed that blending alkali-produced protein isolates before precipitation resulted in rapid increase of G' reflecting the formation of intermolecular protein-protein interactions with higher rate. Furthermore, blending of alkali-produced protein isolates and washed minces, respectively, of kilka and silver carp improved physico-mechanical properties of the resultant gels compared to pure kilka proteins. However, the pH-shift method showed higher efficacy in development of blend surimi at the same blending ratio compared to the conventional washing.

Effect of vacuum packaging on the shelf-life of silver carp (Hypophthalmichthys molitrix) fillets stored at 4 °C

This study was carried out to evaluate the chemical changes, microbial load and sensory attributes of silver carp (Hypophthalmichthys molitrix) fillets when packaged at two vacuum levels (30 and 50 kPa) and stored at 4 °C for 14 days. The fillets packaged at 30 kPa had significantly lower pH values and total volatile basic nitrogen (TVBN) contents than those packaged at 50 kPa and normal atmospheric pressure (control). The increase in viable bacterial population was significantly lower in samples packed at 30 kPa and the control. The results of sensory evaluation and electronic nose (E-nose) analyses showed good agreement with the results obtained from chemical and microbial analyses. Both vacuum levels combined with refrigerated storage resulted in an extension of the shelf-life of fillets; up to 11 days at 30 kPa, 9 days at 50 kPa compared to 6 days in control samples. The headspace vacuum level of 30 kPa combined with storage at 4 °C was found to significantly slow down the undesirable chemical changes, retard the lipid oxidation, improve the sensory attributes and extend the shelf-life of silver carp fillets.

Evaluation of Allium paradoxum (M.B.) G. Don. and Eryngium caucasicum trauve. Extracts on the shelf‐life and quality of silver carp (Hypophthalmichthys molitrix) fillets during refrigerated storage

AbstractThe present study examined the effects of Allium paradoxum (M.B.) G. Don. and Eryngium caucasicum Trauve. extracts on the lipid oxidation and quality deterioration indices, microbiological as well as sensory characteristics in silver carp (Hypophthalmichthys molitrix) fillets during storage at 4 °C ± 1. Treatments applied in the study including the following: control (without plant extracts), 2% and 4% (w/v) plant extracts. The addition of plant extracts significantly delayed oxidative deterioration in silver carp fillets during refrigerated storage as shown by the PV, TBARS, Acid Value and TVB‐N data (P < 0.05). The results also showed that natural compounds from A. paradoxum and E. caucasicum extracts resulted in lower bacterial growth in fish fillets during the refrigerated storage period. Comparing to the control samples, the psychrophilic bacterial counts (PTC) and total viable count (TVC) values for the E. caucasicum (2.0%) and E. caucasicum (4.0%), A. paradoxum (2.0%), A. paradoxum (4.0%) treatments were above the acceptability limit (7 log10 colony‐forming unit/g) at the end of 6, 9, 12, 9 and 15th day of storage, respectively. It was observed that addition of A. paradoxum at 4% to fish fillets increased its shelf‐life while the addition of E. caucasicum at 4.0% made a positive effect on sensory quality. These results suggested that A. paradoxum and E. caucasicum extracts have the potential to be used as natural preservatives for shelf‐life extension of fish products.Practical ApplicationsThe exploration of naturally occurring antimicrobials in food preservation receives increasing attention because of consumer awareness of natural food products. Biopreservatives are useful in extending the foods shelf‐life, reducing or eliminating pathogenic bacteria and increasing the overall quality of food products. In this work, we evaluated the effects of two natural extracts, from Allium paradoxum and Eryngium caucasicum, on the fish product quality, such as rancidity indices, microbiological and sensory qualities during refrigerated storage. To our knowledge, the application of A. paradoxum and E. caucasicum extracts in shelf‐life extension of fish product has not been studied previously. The present study showed that both E. caucasicum, A. paradoxum extracts, regarding to their antioxidant and antibacterial properties, could efficiently retard microbial growth, delay chemical deterioration, maintain or improve sensory attributes and extend the shelf‐life of the silver carp fillets during refrigerated storage.

The impact of stunning methods on stress conditions and quality of silver carp (Hypophthalmichthys molitrix) fillets stored at 4 °C during 72 h postmortem

This study aimed to evaluate different stunning methods [percussion (T1), immersion in ice/water slurry (T2), and gill cut (T3)] on quality and stress conditions of silver carp (Hypophthalmichthys molitrix) fillets stored at 4°C in 72h postmortem. Rigor index (RI%), behavioral analysis, levels of lactic acid and muscle glycogen were measured for stress level evaluation. Meanwhile, sensory assessment, texture properties, cooking loss, adenosine triphosphate (ATP) related compounds, adenosine monophosphate deaminase (ADA) activity, and acid phosphatase (ACP) activity were analyzed. The least stress condition, significantly (P<0.05) higher initial glycogen content was observed in T1. Ice/water stunning reduced the rate of ATP degradation, reflected in the lowest K value during 72h. Aversive behaviors, significantly (P<0.05) higher cooking loss, hypoxanthine riboside (HxR) content, and lower sensory score were observed in T3. The results indicated that gill cut in aquatic processing industry should be avoided for inferior quality and aversive reactions during stunning.

Effect of Chitosan Edible Coating Enriched with Eucalyptus Essential Oil and α‐Tocopherol on Silver Carp Fillets Quality During Refrigerated Storage

AbstractThe effects of chitosan coating incorporated with eucalyptus essential oil and α‐tocopherol on the quality of silver carp fillet during chilled storage (4 + 1°C) were examined over a period of 16 days. The control samples (without any coating), chitosan coating (CH), chitosan coating incorporated with eucalyptus essential oil (CH+EEO) and chitosan coating incorporated with eucalyptus essential oil and α‐tocopherol (CH+EEO+α) were analyzed by chemical, microbiological and sensory characteristics. Results showed that, total viable counts, total psychrotrophic counts and total volatile basic nitrogen of CH+EEO and CH+EEO+α were significantly lower than control and CH (P ≤ 0.05). Addition of α‐tocopherol to EEO retarded lipid oxidation. According to the sensory analysis results, CH+EEO+α was acceptable even at the end of the 16‐day storage. The results indicated that chitosan coating was improved extending of meat shelf life. Using eucalyptus essential oil and α‐tocopherol increased its efficiency significantly.Practical ApllicationsFresh fish are usually more perishable than most other muscle foods. Many attempts have been made to prevent the spoilage of fresh fish. To avoid the use of synthetic food additives, numerous studies are currently focused on using natural products to improve the quality of sea food products. The results of the present study report the efficacy of chitosan edible coating enriched with eucalyptus essential oil and α‐tocopherol as a new natural preservative for developing the shelf life of silver carp fillets.

The effects of washing with Tamarind (Tamarindus indica L.) water solution on shelf life of silver carp (Hypophthalmichthys molitrix) fillet during refrigerator storage

This study evaluated the antibacterial and antioxidant effects of tamarind water solution on shelf life of silver carp ( Hypophthalmicthys molitrix ) fillet during refrigerator storage. Treatments of this study were unwashed samples (control), and samples washed with 1% and 2% tamarind water solution. Microbial, physicochemical and sensory analysis including total viable count (TVC), peroxide value (PV), thiobarbituric acid (TBA), total volatile base (TVB-N) and pH were measured during 15 day storage at refrigerator (with 3 days intervals). Proximate analysis of samples also measured at day 0. TVC content was 0.93, 0.50 and 0.10 log CFU/g for control and treatments 1% and 2%, respectively and reached to 6.24, 5.82 and 5.21 log CFU/g at the end of storage period. At the end of storage period, the PV, TBA and TVB-N content were 8.4, 4.3, and 3.0 meq O 2 /Kg for control, 2.75, 1.35, and 0.50 mg/100g for 1% treatment, and 33.17, 23.90, and 22.10 mg N/100g for 2% treatment, respectively. This results showed the positive effect of tamarind to inhibit and delay fish fillet spoilage. According to sensory evaluation, the density of 1% tamarind was selected as the best density.

Effect of Edible Coating Containing Pomegranate Peel Extract on Quality and Shelf Life of Silver Carp (Hypophthalmichthys molitrix) Fillet during Refrigerated Storage

Effects of edible coating containing pomegranate peel extract (PPE) on the quality and shelf life of silver carp fillet during refrigerated storage were investigated. Freshly fish fillet were assigned to three treatments: control (fillet treated with edible coating and no antioxidants); fillet treated with edible coating and 5% PPE (T1) and fillet treated with edible coating and 10% PPE (T2). Chemical (pH, peroxide value and thiobarbituric acid) and microbiological (total viable count and psychrotrophic count) analysis were used to evaluated the effect of this treatments during refrigerated storage. The results show that addition of PPE considerably delayed lipid oxidation in silver carp fish fillet in T1 and T2 compared control samples. According to microbiological assay, T1 and T2 samples at days 12 reached to maximum acceptability limit while it was happened in day 9 for control samples. There were significant differences (P<0.05) between treated and control samples at all the days during the refrigerated storage.

Combined Effects of Coating and Zataria multiflora Boiss Essential Oil on the Shelf Extension of Silver Carp Fillet Stored at 4°C

Combined Effects of Coating and Zataria multiflora Boiss Essential Oil on the Shelf Extension of Silver Carp Fillet Stored at 4°C

The effect of encapsulated fennel extracts on the quality of silver carp fillets during refrigerated storage.

The effect of fennel extract on the quality of silver carp (Hypophthalmicthys molitrix) fillets, and the possible efficacy of liposomal encapsulation in the improvement of its antimicrobial and antioxidant activity during chilled storage (4+1°C) of the fillets were examined over a period of 15days. Silver carp fillets were treated with pure fennel extract (0.3% and 0.5% w/v) and liposomal encapsulated fennel extract (0.3% and 0.5% w/v), and their quality changes in terms of total volatile basic nitrogen (TVB-N), peroxide value (PV), thiobarbituric acid (TBA), microbial counts, and sensory properties were investigated. Fennel extract could retard the deterioration of silver carp fillets, as reflected in lower TVB-N, PV and TBA value. Moreover, the efficacy of fennel extract was improved when it was encapsulated into liposome. Silver carp fillets treated with the encapsulated fennel extract showed the lowest amount of lipid oxidation and microbial deterioration during the storage period compared with the control and pure extract treatments. Sensory evaluation revealed that shelf life of silver carp fillet was longest for samples treated with encapsulated fennel extract at 0.5% (15days), as compared to the control (6days) (P<0.05).

Effect of alginate/carboxyl methyl cellulose composite coating incorporated with clove essential oil on the quality of silver carp fillet and Escherichia coli O157:H7 inhibition during refrigerated storage.

The effects of alginate/carboxyl methylcellulose composite coating incorporated with clove essential oil on quality of silver carp fillet chilled storage (4+1°C) were examined over a period of 16days. The control samples (c), alginate/carboxyl methylcellulose coating (C-A), alginate/carboxyl methylcellulose composite coating incorporated with clove essential oil (with different concentration 1 and 1.5%) (C-A+CEO1% and C-A+CEO 15% respectively) were analyzed by bacteriological (total viable counts (TVC) and total psychrotrophic counts (TPC)), biochemical (Peroxide value (PV), free fatty acid (FFA), total volatile base nitrogen (TVB-N), and pH) and sensory characteristics. Also, the efficacy of these treatments was investigated in control of the population of Eschershia coli O157:H7 inoculated in silver carp fillet. According to the obtained results, C-A+CEO 1.5% showed lowest (p<0.05) and acceptable biochemical, bacteriological and sensory characteristics attributes up to 16days storage at 4°C compared to the others. Also, this treated sample was acceptable even at the end of the 16-day storage and it could reduce the population of E. coli O157:H7 below the acceptable level (<2) from day 4 until the end of the storage period. The results indicate Alginate/carboxyl methylcellulose composite coating with clove essential oil might be recommended as a preservative in the meat products.

Effects of grape pomace extract on the quality and shelf life of silver carp (Hypophthalmicthys molitrix) fillets during chill storage

The effects of grape pomace extract (0, 2 and 4%) on quality and shelf life of silver carp ( Hypophthalmicthys molitrix ) fillets during chill storage (4°C) were investigated. The control and the treated fillets were analyzed periodically for microbiological (TVC and PTC), chemical (TVB-N), and sensory characteristics. The results showed that grape pomace-treated samples have lower TVB-N (24.2 and 21.2 mg N/100 g, respectively), TVC (7.33 and 7.09 log cfu/g, respectively) and PTC (7.26 and 7.03 log cfu/g, respectively) at the end of the storage period. The results revealed that the addition of grape pomace extract has a positive effect on the sensory quality of silver carp fillets by retaining proper quality characteristics for a longer time and extends their shelf life during chill storage.

Development of hyperspectral imaging coupled with chemometric analysis to monitor K value for evaluation of chemical spoilage in fish fillets

K value is an important freshness index widely used for indication of nucleotide degradation and assessment of chemical spoilage. The feasibility of hyperspectral imaging (400–1000nm) for determination of K value in grass carp and silver carp fillets was investigated. Partial least square (PLS) regression and least square support vector machines (LS-SVM) models established using full wavelengths showed excellent performances and the PLS model was better with higher determination coefficients of prediction (R2P=0.936) and lower root mean square errors of prediction (RMSEP=5.21%). The simplified PLS and LS-SVM models using the seven optimal wavelengths selected by successive projections algorithm (SPA) also presented good performances. The spatial distribution map of K value was generated by transferring the SPA-PLS model to each pixel of the images. The current study showed the suitability of using hyperspectral imaging to determine K value for evaluation of chemical spoilage and freshness of fish fillets.

Coating Effects of Orange and Pomegranate Peel Extracts Combined with Chitosan Nanoparticles on the Quality of Refrigerated Silver Carp Fillets

The coating effects of orange and pomegranate peel extract combined with chitosan nanoparticles on the quality of silver carp (Hypophthalmicthys molitrix) fillets during refrigerated storage at 4C were evaluated. Solutions of orange and pomegranate peel extracts (1%, w/v) was used for dip pretreatment, and nanochitosan solution (2%, w/v) was used for the coating. The control and the coated fish samples were analyzed periodically for microbiologic (total mesophilic and psychrotrophic count), physicochemical (pH, total volatile basic nitrogen, thiobarbituric acid reactive substances) and sensory attributes. The results indicated that nanochitosan coating was effective for the preservation of silver carp fillets during refrigerated storage. However, a dip pretreatment in orange or pomegranate peel extract combined with nanochitosan coating were significantly inhibited the development of lipid oxidation in fish samples. In this context, pomegranate peel extract was significantly stronger than orange peel extract. Practical Applications The combination of orange or pomegranate peel extract and chitosan nanoparticles can be utilized as a safe preservative for fish under refrigerated storage.

Comparing the effectiveness of chitosan and nanochitosan coatings on the quality of refrigerated silver carp fillets

The coating effects of chitosan and chitosan nanoparticles on the quality of silver carp (Hypophthalmicthys molitrix) fillets during refrigerated storage at 4 °C were compared. Solutions of Chitosan (2%, w/v) and nanochitosan (2%, w/v) were used for the coating. The control and the coated fish samples were analyzed periodically for microbiological (total mesophilic and psychrotrophic count), physicochemical (pH, TVB-N, TBARS), and sensory attributes. The results indicated that both chitosan and nanochitosan coating were effective for the preservation of silver carp fillets during refrigerated storage. However, nanochitosan exhibited higher antimicrobial activity than chitosan during the storage period. Furthermore, nanochitosan showed a stronger ability to inhibit the TVB-N content than chitosan. Therefore, to extend the shelf life and delay the deterioration of fresh silver carp fillets during refrigerated storage, nanochitosan coating is more effective.

Effect of Methylcellulose Coating Enriched with Pimpinella affinis Oil on the Quality of Silver Carp Fillet during Refrigerator Storage Condition

The effects of methylcellulose (MC) coating enriched with Pimpinella affinis essential oil (PAO) on quality and shelf life of fresh silver carp fillets during refrigerated storage (4 ± 1C) were examined over a period of 16 days. MC solution (3%) and MC enriched with PAO (1.5% v/v concentration) were prepared for coating of the fish samples. The control and the treated fish samples were analyzed periodically for microbiological (total viable count), chemical (pH, thiobarbituric acid [TBA], total volatile basic nitrogen [TVB-N], free fatty acid [FFA] and pv) and sensory characteristics. According to results (pv, FFA, TBA, TVB-N, pH), color and odor on MC contain 1.5% PAO and have less change in comparison to other treatments (P < 0.05), and it could inhibit a total bacteria growth and psychrophilic counts of fillet. The results indicated that MC contains 1.5% PAO, a good antioxidant activity, so it can be used for fish preservation without any undesirable changes in antimicrobial and sensorial attributes. Practical Applications The main practical application behind the development of chitosan coating is used to preserve fish quality with the fact that these polysaccharides represent a renewable source of natural biodegradable polymers and meet with the emergence of more and more food safety problems. The results of this study are a useful tool for the development of new environment-friendly and healthier commercial applications in the food processing industry because of its antimicrobial and antioxidative characteristics.

Antioxidant Effects of Grape Pomace on the Quality of Silver Carp (Hypophthalmichthys molitrix) Fillets During Refrigerated Storage

This study aimed to determine the phenolic content and antioxidant effect of grape pomace extract on silver carp fillets during refrigerated storage. Total phenolic content of grape pomace extract was quantified by colorimetric methods. Silver carp samples were treated with 0, 2, and 4% of grape pomace extract (g extract/100 g flesh) and stored 15 days in a refrigerator (4°C). Changes in pH, peroxide value, thiobarbituric acid, and heme iron at 0, 3, 6, 9, 12, and 15 days of storage were investigated. Results showed that the values of pH, peroxide value, and thiobarbituric acid increased and iron levels decreased in all treatments during storage (p < 0.05). The phenolic contents were generally much more influenced by the quality parameters treated compared to the control. The addition of grape pomace extract delayed lipid oxidation in silver carp fillet considerably during refrigerated storage. These results suggested that grape pomace extract has the potential to be used as a natural antioxidant.

Gelation Characteristics of Surimi Gel from Silver Carp (Hypophthalmichthys molitrix) by Application of Acid-Alkali Processes

Textural characteristics of silver carp surimi gel prepared from acid- and alkali-produced protein isolates were investigated and compared to the surimi gels derived by conventional methods. The acid-aided method showed the most efficiency to recover proteins (86.2%) in comparison to the alkaline-aided (79.8%) and conventional (76.7%) methods. In the washing of fish mince, every step resulted in reduction of sarcoplasmic protein, and consequently the myofibrillar fraction became more concentrated, as shown by the protein patterns in wash water. Some myofibrillar proteins (mainly actin and myosin) were removed along with sarcoplasmic proteins during washing, reducing yield efficiency during the conventional method of making surimi. During the pH shifting process, myosin heavy chain (MHC) was degraded during low (2.5) pH solubilization, whereas there was only a minimal loss of MHC by either hydrolysis or proteolysis during alkaline solubilization. The breaking force and breaking distance of surimi gel prepared in the pH-shifting processes were significantly (p < 0.05) greater than those of surimi gel made by conventional methods, as were expressible moisture, cohesiveness, and springiness. In conclusion, the pH-shifting technique can be considered as an efficient alternative process in recovery of greater quantities of functional protein from silver carp fillet.

Grape seed and clove bud extracts as natural antioxidants in silver carp (Hypophthalmichthys molitrix) fillets during chilled storage: Effect on lipid and protein oxidation

The aim of this study was to investigate the utilization of clove bud extract (CBE) and grape seed extract (GSE) as natural antioxidants for retarding lipid and protein oxidation in silver carp fillets stored at 4±1°C. The results indicate that CBE exhibited higher total phenolic content, DPPH and Fe2+-chelating activity than GSE. GSE and a 20-times dilution of CBE were found to be effective in retarding lipid and protein oxidation; both treatments resulted in low levels of PV and TBA, and protected against the decrease of L∗, a∗, salt-soluble protein content and total sulfhydryl group. CBE20 more efficiently inhibited lipid oxidation than did GSE. The antioxidant effect of the two extracts on protein oxidation was less pronounced than the effect on lipid oxidation. CBE20 and GSE could be used as natural antioxidants to minimize lipid and protein oxidation and to extend shelf life of fillets.

Elements of concern in fillets of bighead and silver carp from the Illinois River, Illinois

Efforts to control invasive bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix) may include harvest for human consumption. We measured concentrations of arsenic (As), mercury (Hg), and selenium (Se) in fillets from silver and bighead carp collected from the lower Illinois River, Illinois, USA, to determine whether concentrations were of health concern and differed by species, size, and location. Concentrations of total As were below detection limits in most bighead (92%) and silver (77%) carp fillets, whereas inorganic As was below detection limits in all samples. Mean Hg concentrations were greater in bighead (0.068mgkg−1) than in silver carp (0.035mgkg−1), and were smallest in carp from the confluence of the Illinois and Mississippi rivers. Mercury concentrations in fillets were positively correlated with body mass in both species. Concentrations of Hg were below the US Food and Drug Administration’s (USFDA) action level (1ppm as methyl-Hg); however, concentrations in some bighead (70%) and silver (12%) carp fell within the range that would invoke a recommendation to limit meals in sensitive cohorts. Mean Se concentrations were greater in silver (0.332mgkg−1) than in bighead (0.281mgkg−1) carp fillets, and were below the 1.5mgkg−1 limit for an unrestricted number of meals/month. The mean molar ratio of Se:Hg in fillets was lower in bighead (14.0) than in silver (29.1) carp and was negatively correlated with mass in both species Concentrations of Hg in bighead and silver carp fillets should be considered when assessing the risks associated with the use of these species as a protein source.