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Cilok was a traditional food originating from Bandung and comes from the abbreviation of "Aci dicolok". As the name implies, a snack made from tapioca flour mixed with condiment and sometime using meat or fish fillet. It was tasty and chewy. Cilok has quietly different from meatball because meatball using wheat flour. Cilok usually consumed using a sauce made from crushed peanuts, sugars, salt, mixed with chili sauce, tomato sauce, or soy sauce which can be modified as you want. Recently, cilok sales in the city of Surakarta have become increasingly popular. In almost every corner we can find cilok sellers. This study aims to determine the level of microbiological contamination found in cilok and peanut sauce in Surakarta. The research method used was simple random sampling method from 5 districts in Surakarta. The number of contaminants was calculated by the direct plate count method. The tests performed were to determine the total plate count (ALT), total Staphylococci, total Salmonella shigella, and total coliforms of the cilok and also for the sauce. As for the cilok sample, the average log value of ALT was 6.57 - 7.97 log CFU / g, total Staphylococci 4.57 - 4.96 log CFU / g, Salmonella shigella was 0.53 - 1.23 log CFU / g, and total coliforms 1.00 - 2.26 log CFU / g. Peanut sauce sample, the average log value of ALT was 7.40 - 8.18 log CFU / g, total staphylococci 5.84 - 6.68 log CFU / g, total Salmonella shigella was 2.24 - 3.23 log CFU / g, and Escherichia coli 2.35 - 5.79 log CFU / g. From the test results of the peanut sauce and peanut sauce samples, it can be concluded that the peanut sauce and peanut sauce sold in Surakarta are still not suitable for consumption.

This study aimed to increase the antibacterial activity of chitosan-polylactic acid (PLA) composite film by adding nisin and ethylenediaminetetraacetic acid (EDTA). We evaluated the mechanical, physicochemical, and antibacterial properties of various PLA composite films, as well as the enhancement effect of PLA composite films with EDTA + nisin on the preservation of grouper fillets. Films of PLA alone, PLA plus chitosan (C5), PLA plus nisin + EDTA (EN2), and PLA plus chitosan plus nisin + EDTA (C5EN1 and C5EN2) were prepared. The addition of EDTA + nisin to the chitosan-PLA matrix significantly improved the antibacterial activity of the PLA composite film, with C5EN1 and C5EN2 films showing the highest antibacterial activity among the five films. Compared with the fish samples covered by C5, the counts of several microbial categories (i.e., mesophilic bacteria, psychrotrophic bacteria, coliforms, Aeromonas, Pseudomonas, and Vibrio) and total volatile basic nitrogen content in fish were significantly reduced in the samples covered by C5EN1. In addition, the counts of samples covered by C5EN1 or C5 were significantly lower compared to the uncovered and PLA film-covered samples.

MALDI-TOF MS approach for determination of six quinolones residues in fillets of pangasius (Pangasionodon hypophthalmus) was studied, considering that is a very sensitive analytical technique with simple and high-throughput operation, contributing to knowledge regarding application of this technique to the determination of small-molecular-weight organic compound residues in foods. LIFT-MS/MS showed to be a successful approach to identify the presence of all quinolone residues in the fish fillet, at their respective MRL level. This study opens an important field of research for the development of simple and high-throughput bioanalytical screening methods for the determination of veterinary drug residues in foods.

Ready-to-eat (RTE) meat products sandwiches are one of the most popular fast foods on which consumers depend. Unfortunately, it may be exposed to many contamination sources and harbored many food poisoning factors, especially with street vendors emerging in the developing world. Staphylococcus aureus (S. aureus) and its enterotoxins (SEs) are one of the most recorded food intoxication causes which contribute a health hazard risk. Therefore, one-hundred and twenty samples of beef kofta, bovine liver, chicken nuggets, and fish fillet RTE sandwiches (30 of each) were collected randomly from different street vendors and restaurants in Benha city, Qalubiya Governorate, Egypt, for bacteriological and molecular detection of coagulase-positive enterotoxigenic S. aureus contamination. Results revealed that beef kofta sandwich samples recorded the highest incidences and mean counts of S. aureus detection 40% and 12x103 CFUg, respectively; followed by chicken nuggets, fish fillet, and bovine liver sandwich samples; conducting antimicrobial sensitivity on the isolated strains revealed totally resistance to nalidixic acid while mostly sensitive to erythromycin; On the other hand, molecular detection of S. aureus enterotoxin (SE) genes revealed detection of SeA, SeC, and SeD genes carrying strains where SeA was the most frequently detected, mixed strain carrying both SeC and SeD was detected; while failed to detect SeB gene in any of examined isolates. It is obvious that RTE meat product sandwiches may pose a risk to consumer’s health and encourage the authorities to exert more control over street vendors and fast food restaurants.

Fish fillet is heavily influenced by swimming exercise and other factors leading to a great change in fish physiology. During the present study, muscle cellularity, texture and composition, antioxidant activities and flavor characteristics were assessed and compared between non-exercised (N-EXF) and long-term exercised Largemouth bass. Exercised fish (EXF) showed improve in muscle cellularity and texture with high protein, hydroxyproline, collagen and low crude lipid compared to N-EXF. In addition, EXF showed Higher INOS, T-AOC, CAT and lower MDA, indicating high antioxidant activities in EXF compared to N-EXF. Furthermore, EXF showed lower hydrocarbons and alcohols content but higher in carboxylic acid, esters and aromatic compounds content compared N-EXF. EXF also showed lower TMAO, TMA, HX and high IMP content, indicating better freshness. Generally, EXF largemouth bass should be preferred depends on its high nutrition value, better flesh and freshness quality; and pleasant flavor.

The use of biopsy plugs to sample fish muscle tissue for mercury analyses is a viable alternative to lethal sampling; however, the practice has yet to be widely implemented in routine monitoring due to concerns about variability of mercury concentrations in fish muscle tissues. Here we examine distribution of mercury in fillets of four fish species (Walleye, Northern Pike, Smallmouth Bass and Lake Trout), suitability of left/right side of fillet for biopsy sampling, and appropriateness of re-using a biopsy punch. The results showed that average mercury concentrations in left and right fillets of fish are similar. Mercury concentrations in biopsy plug samples, taken from the anterior dorsal area of the fish fillet, were statistically equivalent to the mercury concentrations in homogenized fillets. There was no discernible cross contamination between samples when a biopsy punch was reused after washing in hot soapy water, and as such, biopsy punches can be recycled during sampling to reduce the sampling cost. If a tissue mass collected from a specific site on the fillet is insufficient, then we suggest sampling corresponding locations on the other fillet rather than sampling two adjacent sites on one fillet to obtain more tissue. The results presented here can improve the accuracy of fillet biopsy plug sampling, minimize fish mortality for mercury monitoring, and reduce labor and material costs in monitoring programs.

Made available in DSpace on 2019-10-06T16:27:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Protocols that improve growth performance in fish while assuring product quality are important for aquaculture. Fasting followed by refeeding may promote compensatory growth, thus optimizing growth performance. During fasting and refeeding, fast-twitch muscle, which comprises most of fish fillet, undergoes intense plasticity. In this work, we studied the proteome of pacu (Piaractus mesopotamicus)fast-twitch muscle after 30 days of fasting (D30), 30 days of refeeding (D60)and 60 days of refeeding (D90)with two-dimensional electrophoresis, mass spectrometry and bioinformatics. Body mass, growth rate and muscle histology were also assessed. At D30, fish presented muscle catabolism and decreased growth. Proteomic analysis showed that metabolism proteins were the most affected, up and downregulated. Cytoskeleton and amino acid biosynthesis proteins were downregulated, while nuclear and regulatory proteins were upregulated. At D60, fish showed accelerated growth, despite the body mass not completely recovering. Metabolism proteins were still the most affected. Amino acid biosynthesis proteins became upregulated, while cytoskeleton proteins remained downregulated. At D90, the fish presented total compensatory growth. Many metabolic proteins were up or downregulated. Few cytoskeleton proteins remained differentially expressed. Amino acid biosynthesis proteins were mostly upregulated, but less than at D60. Prolonged fasting followed by refeeding also led to the regulation of possible meat quality biomarkers, such as antioxidant enzymes. This fact suggests possible consequences of this protocol on fish meat quality. Our work also enriches our knowledge on proteomic changes during muscle plasticity that occur during fasting and refeeding diet protocols. Department of Morphology Institute of Biosciences of Botucatu São Paulo State University (UNESP) Department of Chemistry and Biochemistry Institute of Biosciences of Botucatu São Paulo State University (UNESP) Department of Biology University of Western São Paulo (UNOESTE) São Paulo Agency for Agribusiness Technology (APTA) Department of Morphology Institute of Biosciences of Botucatu São Paulo State University (UNESP) Department of Chemistry and Biochemistry Institute of Biosciences of Botucatu São Paulo State University (UNESP) CNPq: 116795/2016 FAPESP: 2017/12237-6 CNPq: 302656/2015-4 CNPq: 447233/2014

This study was aimed to evaluate the effects of dietary supplementation of Bacillus cereus as probiotics on growth, fillet quality, serum biochemical parameters and intestinal histology of Pengze crucian carp (Carassius auratus var. Pengze). Fish were fed basic diet (Control group) and three diets such as CD7, CD9 and CD11 supplemented with B. cereus at dose of 10⁷, 10⁹ and 10¹¹ CFU/kg for 70 days. The results showed that supplementation of 10⁹ CFU/kg B. cereus significantly improved the growth performance compared to that in the Control group. The textures of muscle were improved by dietary supplementation of probiotics, and the hardness, gumminess, chewiness and the resilience of fish fillet increased with increasing dose of B. cereus. Total cholesterol including high‐density lipoprotein and low‐density lipoprotein level in serum decreased correspondingly with increasing level of probiotics whereas, acid phosphatase and catalase activities increased in serum. B. cereus supplementation enhanced the immunity and antioxidant capacity via an increase in acid phosphatase, alkaline phosphatase, glutathione peroxidase, reduce glutathione, and catalase, accompanied by a significant reduction in malondialdehyde. Higher intestinal fold height was observed in CD9 group than other groups. The lowest enterocyte height was exhibited in the Control group, HE values increased with increasing dose of probiotics. Moreover, dietary inclusion of B. cereus significantly affected the digestive enzymes activities in terms of higher lipase and trypase activities. In conclusion, dietary supplementation of B. cereus could promote the growth, elevate the immunity and antioxidant status of carp, and importantly improve the texture of fish fillet.

Obesity is associated with changes in amino acid metabolism, and studies show that ingestion of fish proteins influence amino acid composition in plasma and urine, in addition to affecting risk factors for metabolic syndrome. Since the majority of fish proteins consumed by humans are as fish fillet, it is of interest to investigate if cod fillet intake affects amino acid composition and metabolic disorders. We hypothesized that a modified AIN-93G diet containing cod fillet would affect amino acid compositions in plasma and urine in obese rats, and also affect risk factors for metabolic syndrome when compared to rats fed a regular AIN-93G diet with casein as the protein source. Obese Zucker fa/fa rats, a rat model of metabolic syndrome, received diets containing 25% protein from lyophilized baked cod fillet and 75% protein from casein (Baked cod diet), or a Control diet with casein for four weeks. The Baked cod diet affected the amino acid composition in plasma, with e.g., lower glycine, histidine, homoarginine, homocysteine, methionine, proline and tyrosine concentrations, but did not affect amino acid concentrations in urine. The concentrations of markers for kidney and liver dysfunction were lower in the Baked cod group, however blood pressure development, fasting and postprandial glucose, and hepatic triacylglycerol concentrations were similar to the Control group. To conclude, substituting 25% of dietary protein with baked cod fillet affected concentrations of some amino acids in plasma and delayed development of kidney and liver dysfunction, but did not affect blood pressure, glucose concentration or fatty liver. publishedVersion

Recently, dried dressed fish fillets have been reported as a cause of food poisoning. Hence, 364 samples of 58 packages of thes e products were collected from 9 counties; Keelung, Taipei, Hsinchu, Taichung, Tainan, Kaohsiung, Ilan, Taitung and Penghu in 1998 an d their toxicities and labels were investigated. It was found that over 65% of products had no label listing the product name, manufact uring date, manufacturer, or food additives. Based on the detecting limit of 5 mouse units per gram (MU/g), the frequency of toxicity occur rence in the samples collected from Taiwan markets was 1.1%. The highest toxicity was 15 MU/g. The toxin obtained from toxic samples was partially purified by ultrafiltration and Bio-Gel P-2 column chromatography. Results of analyses by thin-layer chromatography, ele ctrophoresis and high performance liquid chromatography showed that the toxin was composed of tetrodotoxin and anhydrotetrodotoxin.

Recently, hyperspectral-imaging (HSI), as a rapid and non-destructive technique, has generated much interest due to its unique potential to monitor food quality and safety. The specific aim of the study is to investigate the potential of the HSI (430–1010 nm) coupled with Linear Deep Neural Network (LDNN) to predict the TVB-N content of rainbow trout fillet during 12 days storage at 4 ± 2 °C. After the acquisition of hyperspectral images, the TVB-N content of fish fillets was obtained by a conventional method (micro-Kjeldahl distillation). To simplify the calibration models, nine optimal wavelengths were selected by the successive projections algorithm. A seven layers LDNN was designed to estimate the TVB-N content of samples. The LDNN model showed acceptable performance for prediction of TVB-N content of fish fillet (R2p = 0.853; RSMEP = 3.159 and RDP = 3.001). The performance of LDNN model was comparable with the results of previous works. Although, the results of the meta-analysis did not show any significant difference between various chemometric models. However, the least-squares support vector machine algorithm showed better prediction results as compared to the other models (RMSEP: 2.63 and R2p = 0.897). Further studies are required to improve the prediction power of the deep learning model for prediction of rainbow-trout fish quality.

The quality and sensory acceptability of fish fillet (Oreochromis niloticus) with alginate-based coating containing ginger and oregano essential oils (EO) were evaluated. The antioxidant activity of essential oil, coating, and fish were also investigated. In relation to lipid oxidation, a decrease was observed in fish with the edible coatings compared to the control being the coating with oregano EO the most effective and also with the highest antioxidant activity. Loss in color and weight were significantly lower with coating. Fish with coating maintained firmness whereas fish without coating became softer. Fish with edible coating and oregano essential oils showed higher sensory acceptability regarding to odor evaluated by consumers. Thus, edible coatings with essential oils as natural antioxidant improved the product quality and sensory acceptability.

This study evaluated the effect of feed supplementation with chia and canola oils as a substitute for soybean oil on the composition of Nile tilapia muscle tissue using chemometrics. Diets were sup...

Background/Aims: Fish is a protein-rich food and is increasingly favored by consumers. It has been well recognized that the flesh composition of fish is closely related to its maturation and growth stage, but few studies have explored these differences. Additionally, hormone residues in fish after artificial induction of reproduction also attract consumer concern. In this study, we attempt to address these concerns by using a combination of transcriptomics and metabolomics analyses to identify key regulated pathways, genes, and metabolites that may affect the flesh nutrition of one typical aquaculture species in China, blunt snout bream (Megalobrama amblycephala). Methods: The four groups of fish were used for transcriptomics and metabolomics analyses, including one-year-old immature (group I), two-year-old immature (group II), two-year-old mature (group III) and successfully spawned (group IV) female M. amblycephala after artificial induction of reproduction. Results: We identified a total of 1460 differential compounds and 1107 differentially expressed unigenes in muscle among the different groups. Differential metabolites related to fish age (group II vs group I, group III vs group I) were largely enriched in “Glycerophospholipid metabolism”, “Linoleic acid metabolism”, “α-Linolenic acid metabolism”, and “Biosynthesis of unsaturated fatty acids”. Between these two pairwise comparisons, metabolites that are beneficial to human health, such as docosapentaenoic acid, α-Linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were found to be significantly decreased in two-year-old (group II, group III) compared with one-year-old (group I) M. amblycephala. Only one differential metabolite related to fish maturation, a triglyceride, was detected between groups III and II. Transcriptomics data showed that differently expressed genes (between group III vs group II, group III vs group I) related to maturation were highly enriched in “Cell adhesion molecules (CAMs)”, “Sphingolipid metabolism” and “Phagosome”. DEGs (between group II vs group I, group III vs group I) relating to fish age were enriched in the “cGMP-PKG signaling pathway”, “FoxO signaling pathway”, and “AMPK signaling pathway”. The gene-metabolite interaction network showed pivotal genes, including fumarate hydratase and GNPAT, which played a major role in the regulation of glycerphospholipid metabolism. The nutritional components were also measured, which verified the metabolomics results. Moreover, the metabolomics results showed that after 24 hours of artificial hormone injection, the drug was completely metabolized. Conclusion: Integrated analysis demonstrated that the nutrition value of fish fillet was much more related to fish age compared with maturation status in M. amblycephala females.

Made available in DSpace on 2020-12-12T01:56:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-02 Due to the lack of drugs regulated for aquaculture, we have evaluated the use of albendazole (ABZ)–a potential drug to be regulated for fish–under food safety perspectives assessing the depletion profile of ABZ and its main metabolites (albendazole sulphoxide–ABZSO, albendazole sulphone–ABZSO2 and albendazole amino sulphone–ABZ-2-NH2SO2) in fish fillets (muscle and skin) after single dose oral administration of 10 mg ABZ kg-1 body weight. For the drug administration, a suitable procedure for ABZ incorporation into fish feed was employed, obtaining good homogeneity of ABZ concentration among feed pellets (CV

The aim of this study was to evaluate the effect of active coatings prepared from the chitosan on the quality parameters of fish fillets. Antimicrobial and antioxidant properties were improved by addition of tea and cinnamon extracts. Different quality parameters including free fatty acids (FFA), thiobarbituric acid value (TBA), trimethylamine (TMA), total volatile basic nitrogen (TVBN), whiteness, and pH of coated and noncoated samples were evaluated during storage for 20 d at 5 ± 1°C. Moreover, FTIR characterization (i.e., wavenumber and absorbance values) was used to investigate the oxidative stability. Extracts addition to chitosan coating had noticeable influence on reducing FFA and TBA. Moreover, modified chitosan coating decreased TVBN and TMA significantly. Based on FTIR finding, control sample showed the highest oxidation value, while the treated samples with chitosan\incorporated with tea and cinnamon extracts (CTCECS) had the lowest oxidation. The results showed that FTIR technique could be successfully applied to monitor the lipid oxidation of fish fillet. Therefore, FTIR provides a fast approach to study the compositional changes of food products rather than conventional chemical analysis. The findings of our research showed that chitosan coating modified with tea and cinnamon extracts could be used as a novel active packaging to prolong the shelf life quality of fish fillet.

The aim of the present survey was to investigate the effectiveness of different chitosans (oligosaccharide and acid soluble) and cooking methods (deep‐fat frying and barbecuing) on the formation of four potentially carcinogenic heterocyclic amines (PhIP, IQ, MeIQ, and MeIQx) in fish fillet of huso (Huso huso). The results demonstrated that chitosans imparted significantly (p ≤ .05) favorable characteristics on texture profile, cooking traits, and proximate composition in the fillet. Concerning heterocyclic aromatic amines (HAAs) compositions, PhIP (Non‐detected [Nd]—2.51 ng/g), IQ (Nd—0.62 ng/g), MeIQ (0.41–0.92 ng/g), and MeIQx (Nd—1.20 ng/g) were evaluated. The total HAA amounts in the barbecued samples were higher than the deep‐fat frying samples. The fried samples treated with 1% acid soluble chitosan had the highest inhibitory effect (68.09%) against HAA formation. Based on the results, chitosan could reduce the formation of HAAs in huso fillet in the deep‐fat frying fillet. PRACTICAL APPLICATIONS: Chitosan can be utilized in fish processing company to reduce HAA contents in them. In addition, chitosan can reinforce antioxidant and antimicrobial properties in them.

Shelf life (onset of sensory spoilage) and the potential for toxin production by Clostridium botulinum type E in retail-type packages of fresh aquacultured salmon fillets packaged in high-barrier film bags under selected atmospheres (100% air, a modified atmosphere containing 75% CO2:25% N2, and vacuum) and stored under refrigeration (4°C) and temperature-abuse conditions (8 and 16°C) were investigated. Chemical spoilage indicators (trimethylamine and surface pH) and microbial populations were compared with sensory spoilage characteristics. Storage temperature influenced the time to onset of both sensory spoilage and toxin development in salmon fillets packaged in all atmospheres. The shelf life of fillets packaged in all atmospheres decreased with increase of storage temperature from 4 to 16°C. Trimethylamine content associated with the onset of spoilage for 100% air-packaged fillets increased as storage temperature increased. However, for modified-atmosphere-packaged fillets, the trimethylamine content associated with the onset of spoilage increased as storage temperature decreased from 8 to 4°C. Surface pH was not a good spoilage indicator for modified-atmosphere-packaged fillets. Toxin development preceded sensory spoilage at 16°C storage for fillets packaged in modified atmospheres. Toxin development coincided with sensory spoilage or was slightly delayed for the fillets packaged in all the atmospheres at 8°C storage. At 4°C none of the fillets packaged in either of the atmospheres developed toxin, even 20 days after spoilage as determined by sensory characteristics.

The growth of Clostridium perfringens inoculated in fish fillets of jack mackerel subsequently packaged under a controlled carbon dioxide gas atmosphere (40% CO2, 60% N2) was investigated at marginal growth (15°C) and stimulative ambient (30°C) handling temperatures. The fish fillets were inoculated with C. perfringens , packaged either with air or the modified controlled carbon dioxide atmosphere and stored at 15°C and 30°C. No increase in the C. perfringens population in the fish was noted regardless of the type of packaging at 15°C in 3 days storage time, when all samples were spoiled. C. perfringens rapidly increased in the abuse temperature (30°C) after a 2- to 4-h lag phase regardless of the package type, but growth was significantly more stimulated under the controlled carbon dioxide gas atmosphere within 6 h of storage time. When fish fillets inoculated with C. perfringens were stored at 5°C for 24 h before being held at 30°C for 6 h, C. perfringens did not grow during the abuse-temperature storage. This suggests a reduction of a health hazard risk by the organism when the distribution temperature of the fish fillets is strictly controlled below 5°C. However, the combination of two temperature-abuse events during distribution and consumer handling may lead to a higher food-poisoning risk by the organism in controlled CO2 modified atmosphere-packaged fish compared to air-packaged fish. Product control of the initial contamination of organisms at low levels during raw fish processing will prevent food poisoning.

The measurement of Clostridium botulinum type E toxin in fish was accomplished using an amplified immunoassay (enzyme-linked immunosorbent assay-enzyme-linked coagulation assay [ELISA-ELCA]) based on the coagulation cascade. Fresh catfish fillets inoculated with a mixture of spores from five strains of C. botulinum type E were packaged in high barrier film with air, vacuum and modified atmosphere and stored at 4, 8 or 16°C for up to 75 days. Toxin production was monitored during storage by both mouse bioassay (trypsin and non-trypsin treated) and ELISA-ELCA on the non-trypsinized samples. All 26 inoculated products that were positive by the mouse bioassay were also positive by ELISA-ELCA. Of 35 uninoculated samples which were not toxic in mouse bioassay, none were positive by ELISA-ELCA; of 73 inoculated samples which were not toxic by mouse bioassay, 14 had toxin measurable by the ELISA-ELCA. The position of these immunoassay-positives in the sampling sequence indicated that the toxin was identified by the immunoassay before it was found in the mouse bioassay. These results suggest that the ELISA-ELCA technique is a usable alternative to the mouse bioassay for monitoring C. botulinum type E toxin production in fish challenge studies.

Our goal is to analyze spectral imaging data using multiple optical imaging instruments available in USDA-ARS and SafetySpect laboratories to provide analysis along three axes of classification of fish fillets: 1. farm-raised vs. wild-caught species; 2. fresh vs. frozen fillets; 3. Species A vs. Species B targeting most mislabeled fish types in the US market. We are collecting spectral signatures using four imaging systems: (1) Reflectance spectral imaging in the visible and NIR (400-1000 nm), (2) Reflectance spectral imaging in the short wave infra-red (SWIR) (1000-2500 nm), (3) Fluorescence spectral imaging with UVA and violet illumination, (4) Raman imaging with a 785 nm laser excitation. The fish fillet samples were purchased from online vendors. We image with each of the modalities and then freeze, thaw and reimage each fillet (2 cycles of freeze/thaw) to demonstrate effect of freeze/thaw process in the multimode spectral signatures. All fish fillet samples are DNA tested to ensure the species marketed are not mislabeled. We use feature extraction/selection strategy for different modes of measurements based on the measurement physics and biological/chemical characteristics. We analyze different combinations of feature extraction and selection techniques and operate an exhaustive search, optimization, and fusion to find out the most important features using different imaging modes. This process helps identify which imaging mode (or combination) will have the highest impact and yield 95%+ classification accuracy. This optimization procedure will be based on cost function (sensitivity, specificity, area under the curve) from receiver operating characteristics (ROC) curve.

The aim of the present study was to evaluate the effects of chitosan-gelatin film incorporated with grape seed extract (GSE) (1 and 2%) and Ziziphora clinopodioides essential oil (ZEO) (1 and 2%), separately and in combination, on survival of Listeria monocytogenes and shelf life extension of minced trout fillet during refrigerated storage (4 ± 1 °C) over a period of 11 days. The control and wrapped fillet samples were analyzed for chemical (PV and TVB-N), microbial (Total mesophilic and psychrotrophic bacteria, Pseudomonas spp., P. fluorescens, Shewanella putrefaciens, lactic acid bacteria and Enterobacteriaceae family) and sensory properties (odor, color and acceptability). The GC-MS analysis of the essential oil components revealed that carvacrol (65.22%) and thymol (19.51%) were the most representative components of the essential oil. In comparison with control group, fish spoilage was significantly delayed in samples wrapped in chitosan-gelatin film containing different concentrations of GSE and/or ZEO (P

Australian underutilised fish species may serve as a potential source of valuable proteins and potent bioactive peptides. This novel research is the first to investigate the effects of storage-processing conditions and an in-vitro simulated gastrointestinal digestion (pepsin–pancreatin) on bioactive peptides’ release during storage of fish fillet, derived from Australian silver warehou (Seriolella punctata). In-vitro bioactivities including angiotensin-converting enzyme and trypsin inhibitory and antioxidant activities were analysed. The antioxidant power was evaluated by DPPH free radical scavenging activity, Cu2+ chelating and Fe3+ reducing abilities. Fillets were stored at chilled (4 and 6 °C) and freezing (−18 °C) temperatures for 7 and 28 days, respectively. Results indicated that during postmortem storage, endogenous enzymes released from fillets an array of polypeptides during storage. The demonstrated physiological activities were further increased during simulated digestion. Bioactivities were greater at 4 °C, increasing over 7 days as compared to at 6 and −18 °C. An increase by 2 °C for chilled temperature was enough to cause significant changes in activities. The crude extracts obtained by pancreatin treatment demonstrated the highest metal chelating activities at 4 °C (86.3 ± 0.1 % on day 7). Physiological potency, especially metal chelating activity, of fillets obtained from silver warehou may be manipulated by storage conditions that would consequently be further enhanced during simulated digestion.

The objective of this study was to evaluate the use of soybean oil (SO) and two microalgal meals derived from Schizochytrium limacinum (SL1 and SL2) to replace fish oil (FO) in diets for Totoaba macdonaldi juveniles. Nine isoproteic (54% crude protein, CP) and isolipidic (14% crude fat, CF) diets were formulated based on a 3 × 3 factorial design, using the three lipid sources and three replacement levels, 33%, 66% and 100%. A control diet containing FO as the main lipid source served as a reference. Diets were fed for 6 weeks and were randomly assigned to six replicate tanks of a recirculating aquaculture system, with 25 fish stocked per tank. Initial mean fish weight was 8.08 g; at the end of the trial, statistical differences for growth responses such as weight gain (WG; P = 0.0069) and thermal growth coefficient (TGC; P = 0.0027) were detected. WG (SL1 = 50.75 g, SL2 = 51.43 g) and TGC (0.148) of fish fed the S. limacinum meals were significantly higher than in those fed SO (WG = 41.13 g; TGC = 0.129). Conversely, the hepatosomatic index (HSI; P = 0.0009) of fish fed SO was significantly higher (1.38%) compared to those fed the microalgae meals (SL1 = 1.13%, SL2 = 1.22%). Also, proximate composition of liver was significantly influenced by the lipid source and CF was significantly higher (P = 0.0067) in fish fed SO (47.68%) than in fish fed SL1 (37.44%) or SL2 (39.86%). The fatty acid (FA) profile of muscle and liver reflected the dietary FA composition; SO prompted increased concentrations of 18:2n-6 and total n-6 FA in fish fillet; whereas, the S. limacinum meals increased 22:6n-3, total n-3 FA and the n-3/n-6 ratios, which is highly desirable in food destined for human consumption. In addition, the concentration of pancreatic lipase 1 (70.2 kDa) in anterior intestine and pyloric caeca of fish significantly decreased (P = 0.0019) from 2.93 to 1.85 mg g−1 as the level of FO replaced increased. These findings indicate that up to 100% of FO can be replaced by S. limacinum meals improving the growth of T. macdonaldi and preserving the nutritional value and the health benefits of the fillet for human consumption; whereas, SO decreased growth and the concentration of 22:6n-3, 20:5n-3, total n-3, and n-3/n-6 ratios, while increasing the HSI and the risk of hepatic dysfunction and steatosis.

Large quantities of protein-rich cod residuals, which are currently discarded, could be utilized for human consumption. Although fish fillet intake is related to beneficial health effects, little is known about the potential health effects of consuming cod residual protein powder. Fifty lean adults were randomized to consume capsules with 8.1 g/day of cod residual protein (Cod-RP) or placebo capsules (Control group) for eight weeks, in this randomized, double-blind study. The intervention was completed by 40 participants. Fasting glucose and insulin concentrations were unaffected by Cod-RP supplementation, whereas plasma concentrations of &alpha, hydroxybutyrate, &beta, hydroxybutyrate and acetoacetate all were decreased compared with the Control group. Trimethylamine N-oxide concentration in plasma and urine were increased in the Cod-RP group compared with the Control group. To conclude, the reduction in these potential early markers of impaired glucose metabolism following Cod-RP supplementation may indicate beneficial glucoregulatory effects of cod residual proteins. Trimethylamine N-oxide appears to be an appropriate biomarker of cod residual protein intake in lean adults.

Background: Fish fillet consumption is associated with beneficial health effects; however, little is known about whether consuming other parts of the fish such as head, backbone, skin, cut-offs, and entrails (collectively known as residuals) will provide comparable effects. Objective: The aim of the study was to investigate if daily supplementation with cod residual protein powder would impact lipid metabolism in healthy adults. Methods: Forty healthy, lean, physically active participants (18 women, 22 men) with normal body mass index consumed 8.1 g of proteins daily from cod residual protein powder (Cod-RP) or placebo (control) for 8 weeks. Results: Cod residual protein powder supplementation lowered fasting serum nonesterified fatty acids and increased serum total bile acid concentrations significantly when compared with control supplementation. Fasting serum low-density lipoprotein cholesterol and apolipoprotein (Apo) B concentrations, as well as the total cholesterol:high-density lipoprotein (HDL) cholesterol and ApoB:ApoA1 ratios, were significantly decreased within the Cod-RP group, but these changes were not different from the control group. Fasting serum concentrations of triacylglycerol, total cholesterol, HDL cholesterol, and ApoA1 were not changed within or between groups. Conclusion: Eight weeks of daily supplementation with 8.1 g Cod-RP seems to be sufficient to affect lipid metabolism in healthy, lean, physically active adults. publishedVersion

The effects of high pressure (HP:600 MPa, 5 min, 25 °C) on European sea bass fillets were investigated using microbiological, physicochemical and sensory indices, and “omics” technologies. HPP led to more than a 5 log(cfu/g) reduction in initial bacterial total viable counts and altered the bacterial microbiome, reducing the proportion of food spoilage genera. Lightness and hardness of the fish flesh significantly increased after HPP and were associated with modified muscle tissue histology, with fibers appearing fused and more compact in comparison to the unprocessed control. Sensory evaluation (based on a lower limit of 5 for overall acceptability scoring) indicated a shelf life of 11 days for untreated control samples and 2 months for the HP-treated fillets. Quantitative SWATH proteomics revealed 281 proteins that had modified levels between control and HP-processed fish flesh. The metagenomics and proteomics provided detailed insight into how the change in HP-processed sea bass fillets is linked to the modifications in the microbiome and proteome. info:eu-repo/semantics/publishedVersion

This review article stresses the effective role of dietary fish fillet docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on overweight as a risk factor of cardiovascular disease (CVD) via platelet phospholipid modification. Several reports have demonstrated that saturated fat in overweight evokes systemic inflammation and more importantly predisposes it to cardiovascular disorder. Prospective studies have shown that saturated fat is directly proportional to the level of arachidonic acids (AA), precursor of thromboxane in the platelet phospholipid membrane as omega-6 fatty acid in overweight and obese people. Some literature has demonstrated that omega-3 fatty acid from fish fillet ameliorates inflammation, reduces proinflammatory cytokine, inhibits signaling pathway, and regulates the physical composition of inflammatory leukocytes and free radicals (ROS). Yellow stripe scad (YSS) is a local Malaysian fish that has been shown to contain a comparable level of EPA/DHA content as observed in salmon. This review article will focus on the dietary role of fish fillet that will balance the omega-6 fatty acid/omega-3 fatty acid ratio in platelet phospholipid from YSS to manage and prevent healthy overweight/obesity-related risk factor of CVD and to avoid the risk orthodox drug treatment.

Increasing evidence indicates that lean fish consumption may benefit cardiovascular health. High cholesterol and low n-3 PUFA concentrations in serum are associated with an increased risk of coronary heart disease, therefore, it is of interest to investigate effects of cod intake on cholesterol and n-3 PUFAs in serum and tissues. Hypercholesterolemic obese Zucker fa/fa rats were fed diets containing 25% protein from baked cod fillet and 75% protein from casein (Baked Cod Diet), or casein as the sole protein source (Control Diet) for four weeks. Consuming Baked Cod Diet resulted in lower serum cholesterol and lower hepatic mRNA concentrations of HMG-CoA reductase and sterol O-acyltransferase-2 without affecting serum bile acid concentration, faecal excretion of cholesterol and bile acid, and hepatic concentrations of bile acids, cholesterol and cholesterol 7 alpha-hydroxylase mRNA when compared to Control Diet. Rats fed Baked Cod Diet had higher concentrations of n-3 PUFAs in serum, liver, skeletal muscle and adipose tissue. To conclude, baked cod fillet intake resulted in lower serum cholesterol, which was probably caused by lower endogenous cholesterol synthesis, and higher n-3 PUFA in serum and tissues in obese Zucker fa/fa rats. These findings support the evidence that lean fish consumption might benefit cardiovascular health.

Consumption of frozen fish and fish products has increased worldwide. Levels of Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium and Listeria monocytogenes in frozen fish products marketed in Cairo and Sharkia Governorates, Egypt, were investigated. A total of 150 samples including peeled shrimp, surimi, fish fillet, oyster and lobster tail (30, each) were examined. The overall contamination rate of frozen fish products was 6%. E. coli , L. monocytogenes and S. Typhimurium were identified in 2.7%, 2% and 1.3% of the examined samples, respectively. Health and food safety organizations should follow up fish products in all markets and apply the laws that prevent selling any fish products of unknown sources. Moreover, to ensure safety of fishery products, improvement of hygienic processing and handling from fish farming to markets is recommended.

Essential oils of clove, coriander, caraway, marjoram, cinnamon, and cumin were tested for their antilisterial activity by application of agar diffusion assay (experiment 1). Marjoram essential oil (MEO) showed the highest inhibitory effect, followed by clove and cinnamon. Subsequently, these essential oils were incorporated to alginate/clay nanocomposite films and antilisterial effectiveness of the films was studied in a model solid food system during 12 days at 10 °C (experiment 2). The results revealed that the films with MEO were more effective against Listeria monocytogenes in the model step. Finally, alginate-clay film incorporating 1 % MEO was applied to inoculated trout slices during refrigerated storage (4 °C) for 15 days (experiment 3). The control and the wrapped fish samples were analyzed periodically for microbiological (L. monocytogenes, total viable count, psychrotrophic count) and chemical (TVB-N) properties. The results demonstrated that alginate-clay films enriched with 1 % MEO significantly delayed the growth of L. monocytogenes during the 15-day storage with final counts reaching 6.23 log CFU/g while the counts in control samples were significantly higher reaching 7.38 log CFU/g (p

High Intensity Focused Ultrasound (HIFU) can be used for the localized heating of biological tissue through the conversion of sound waves into heat. Although originally developed for human medicine, HIFU may also be used to weaken the attachment of pin bones in fish fillets to enable easier removal of such bones. This was shown in the present study, where a series of experiments were performed on HIFU phantoms and fillets of cod and salmon. In thin objects such as fish fillets, the heat is mainly dissipated at the surfaces. However, bones inside the fillet absorb ultrasound energy more efficiently than the surrounding tissue, resulting in a “self-focusing” heating of the bones. Salmon skin was found to effectively block the ultrasound, resulting in a significantly lower heating effect in fillets with skin. Cod skin partly blocked the ultrasound, but only to a small degree, enabling HIFU treatment through the skin. The treatment of fillets to reduce the pin bone attachment yielded an average reduction in the required pulling force by 50% in cod fillets with skin, with little muscle denaturation, and 72% in skinned fillets, with significant muscle denaturation. Salmon fillets were treated from the muscle side of the fillet to circumvent the need for penetration through skin. The treatment resulted in a 30% reduction in the peak pulling force and 10% reduction in the total pulling work, with a slight denaturation of the fillet surface.

Six types of Chinese tea were incorporated into diets at four different levels (0, 1, 2 and 4 %) in order to determine their effects on the growth performance, fatty acid composition of muscle lipids and resistance to Aeromonas hydrophila infection of Ictalurus punctatus (channel catfish) fingerlings. Each diet was fed to catfish in triplicate tanks for 8 weeks. Results show that a 1 % Dragon Well tea (DWT) and Maofeng tea were significantly better than other diets (including the control) in improving weight gain (WG) and feed conversion rate (FCR) of fish; while the 4 % DWT increased FCR (P

Objective: To determine the ability of propolis preservative cachama fillets during refrigerated storage. Materials and method. Ethanol extracts of propolis (EEP) were used in cachama fillets. The treatments included: i) 96% ethanol alcohol as the control; ii) 0.8% EEP; iii) 1.2% EEP; and iv) liquid smoke. A in vitro analysis was used to determine the inhibitory effect of propolis on Staphylococcus aureus, Escherichia coli, Salmonella sp. and Clostridium sp. and on the fish matrix to determine the mesophiles, psychrotrophiles, total coliforms, fecal coliforms, sulphite reducing spores and the presence of Salmonella. Results. The results of the in vitro analysis demonstrated the control that the EEP had over the evaluated microorganisms without presenting significant differences between the different concentrations (p>0.05). The analyses of the fish fillet matrix presented acceptable contents for the evaluated microorganisms in the treatments with EEP. A different situation was seen in the treatment with liquid smoke and the control, which had samples that where rejected after 20 days of storage. The sensory analysis showed acceptance for the samples with EEP until the end of the storage period but low marks for the treatment with liquid smoke and the control. Conclusions. The EEP used in this study could be effective for the control of Gram positive bacteria and some Gram negative bacteria that are present in cachama fillets; and could be an alternative to the use of chemical preservatives.

This study shows the effects of dietary activated charcoal (AC) on health status, intestinal morphology and fillet geosmin content of Nile tilapia prior to harvesting (2 and 4 weeks). Four dietary treatments (each diet in six replicates) were formulated to incorporate AC at levels of 0, 10, 20 and 30 g kg−1 of the dry diet. Fish were reared in hapas, which were located in earthen ponds. There were not significant differences in growth performances among experimental treatments. The moisture and protein content in the fillet decreased and increased, respectively, as the incorporation level of AC increased. The hematological indices and several immune parameters did not differ significantly among treatment groups. Among the fifteen blood chemicals parameters examined, the significant reductions in protein and cholesterol and the changes in blood minerals were observed in fish fed dietary AC ≥20 g kg−1. Dietary AC tended to increase the height of intestinal villi and goblet cell number. Dietary AC also influenced the reduction in geosmin in the fish fillet. Taken together, these findings indicate that AC (at 10 g kg−1 diet) could be used as feed supplement for Nile tilapia prior harvesting to reduce geosmin without negative effects.

Fish viscera have been documented to be an important source for obtaining enzymes that can be used for several industrial applications. In this study, trypsin was purified from the pancreas of Scyliorhinus canicula by ammonium sulfate precipitation and soybean trypsin inhibitor (SBTI) sepharose 4B affinity chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the isolated trypsin showed a single band with a molecular weight of approximately 28 kDa and an approximate isoelectric point value of 5.5. The optimum pH and temperature for activity were 8.0 and 55C, respectively. SBTI and phenylmethylsulfonyl fluoride were inhibitors of the isolated fraction, supporting its serine proteinase nature. Stability results with detergents and surfactants suggest that this enzyme can be incorporated as an ingredient in detergent formulations. Practical Applications Characterization of a protease from low-value viscera and discarded fish species, and utilization of the enzyme may add value to this discarded species. Furthermore, the thermolability of the purified trypsin makes it potentially useful in food processing operations because it can be readily inactivated by mild heat treatment. The stability at acidic pH may also find use in operations where low pH is required, such as in the production of fish silage, or in the fish fillet industry. Finally, the stability of the enzyme in commercial detergents suggests that it can be used as an additive in laundry detergents.

In this study, the influence of different treatments was evaluated: nonwashing, washing in chlorinated water and washing/soaking in chlorinated water and sodium chloride on the quality of Nile tilapia (Oreochromis niloticus) fillets during storage at 1.0 ± 0.5°C through daily analysis of pH, moisture, and lipids content. Microbiological analysis and growth modeling for mesophilic and psychrotrophic bacteria and Staphylococcus sp. were also carried out. Finally, we confirmed the microbiological safety through sensory analyses. The main results suggest that fillets washed or soaked in chlorinated water and sodium chloride present clear and narrower blood line coloration; that is, they are less oxidized than those that received other treatments and are microbiologically safe for use within 12 days of storage. It was concluded that the treatments in chlorinated and salinized water favored the quality maintenance of fillets.

This paper describes the method development for sulfadimethoxine (SDM) and ormetoprim (OMP) quantitation in fish feed and fish fillet employing LC-MS/MS. In order to assess the reliability of the analytical method, valuation was undertaken as recommended by guidelines proposed by the Brazilian Ministry of Agriculture. The calibration curve for the quantification of both drugs in feed showed adequate linearity (r > 0.99), precision (CV 0.99), precision (CV < 16%) and trueness around 100%, with CCα < 100.2 ng g–1 and CCβ < 100.4 ng g–1. With a goal of avoiding the risk of drug leaching from feed into the aquatic environment during fish medication via the oral route, different procedures for drug incorporation into feed were evaluated. Coating feed pellets with ethyl cellulose polymer containing the drug s...

This paper describes the development of analytical methods for the quantification of albendazole (ABZ) in fish feed and ABZ and its main known metabolites (albendazole sulfoxide, albendazole sulfone and albendazole aminosulfone) in fish fillet employing LC-MS/MS. In order to assess the reliability of the analytical methods, evaluation was undertaken as recommended by related guides proposed by the Brazilian Ministry of Agriculture for analytical method validation. The calibration curve for ABZ quantification in feed showed adequate linearity (r > 0.99), precision (CV 0.99) for all analytes, precision (CV

Effect of jujube gum (JG; 4, 8 and 12% wt)-based nanoemulsions (NEs) containing nettle essential oil (NEO; 2, 3.5 and 5% wt) as new edible coatings was investigated to preserve Beluga sturgeon fillets (BSFs) during 15 day-refrigerated storage at 4°C. Physical (weight loss, cooking loss, color and texture), chemical (pH, FFA, PV, TBARS and TVB-N), microbiological (total and psychrotrophic bacterial counts), and sensorial characteristics of BSFs were kinetically analyzed. Preliminary studies showed that the NEs formulated with NEO lower than 5% at all JG concentrations were able to form stable coating solutions owing to the highest short-term stability (>90%) and entrapment efficiency (94.4-98.3%). Edible NE coating formulated with 12% JG and 3.5% NEO as a novel antimicrobial and antioxidant biomaterial exhibited the lowest weight and cooking losses, pH changes, textural and color deterioration, lipid oxidation and microbial growth in BSFs refrigerated over a period of 15days (P

Opisthorchis felineus (family Opisthorchiidae) is a parasitic flatworm representing a serious threat to humans in some countries. Opisthorchiasis occurs after consumption of raw or undercooked cyprinid fish infected by the metacercarial stage of the parasite. Due to its small size, detection of the parasite in fish fillet is time-consuming and difficult. Furthermore, isolated metacercariae can be identified to genus but not to species level using morphological features and molecular techniques are necessary. In this work, we describe the development of primers for a diagnostic PCR amplification of a 254-bp fragment of the cytochrome c oxidase I in the mitochondrion of Opisthorchis felineus metacercariae isolated from fish fillet, together with a validation protocol for this method.

To investigate behavior of osmotic dehydration and mass transfer of tilapia fillet in sucrose solution, the changes of moisture content (MC), solid gain (SG) were quantitatively determined during osmotic treatments of fresh tilapia fillets with the sucrose solution concentration (20-40%), temperature (20-30°C), fillet thickness (1-5mm) and osmotic time (1-8h) as the independent treatment factors. Results were as follows: First, MC of fish fillet decreased, and SG of fish fillet increased with increasing of the concentration of sucrose solution. Second, the osmotic dehydration of fish fillet was fast during the first hour and slowed during the 2nd or 4th hour. Third, the dehydration and SG of fish fillet increased with increasing of treatment temperature, but influence of temperature on osmotic dehydration and SG was decreasing with increasing of the concentration of sucrose solution. Finally, a thinner fillet was found to own higher of dehydration and SG than a thicker one.

The manipulation and control of fish health and production by natural substances has been identified as an important area for future developments in aquaculture. A study was conducted to investigate the effect of two phytogenic feed additives, one rich in carvacrol (CARV containing 12 g/kg carvacrol) and the other rich in thymol (THYM containing 6 g/kg thymol) on growth performance, gut microbiota and antioxidant status of rainbow trout (Oncorhynchus mykiss) under commercial farming conditions. Groups of 30 sub-adult trout (113.0 g ± 10.4) were randomly allocated into 3 different treatments with three replicates each. The control group was fed a basal diet, while the other two groups were fed diets supplemented with the two phytogenic diets at the level of 1 g/kg. The fish were fed to apparent satiation for a period of 8 weeks. Body weight, body length and feed intake were recorded weekly. The intestinal bacteria populations (total aerobes, total anaerobes, Lactobacilli spp., Enterobacter spp., coliforms, E. coli and Aeromonas spp.) were enumerated by conventional microbiological techniques using selective agar media. Antioxidant status of fish was assayed for levels of glutathione reductase, glutathione-S-transferase and malondialdehyde levels in fish fillet at day 0 and 5 after slaughter. Lysozyme, nitric oxide (NO), total complement concentrations and catalase activity were also evaluated in fish blood serum. Results showed that dietary phytogenic supplementation with both products improved (P

A 9-week feeding trial was conducted to investigate the impact of dietary lipid sources on the lipid mechanisms of large yellow croaker by feeding three isonitrogenous and isoenergetic diets containing fish oil (FO), soybean oil (SO) and beef tallow (BT) respectively. The effects of the diets on the growth performance, somatic indices, tissue fatty acid composition, histological changes and peroxisome proliferator-activated receptor (PPAR)γ expression were evaluated. Experimental diets were all well accepted by fish and no significant (P>0.05) differences were found in the weight gain, growth rate and feed conversion rate. The fatty acid profile of the fish fillet and liver reflected the fatty acid composition of the diets. Specific-fatty acids were selectively retained, however, in the flesh of the fish; in particular, docosahexaenoic acid and arachidonic acid concentrations were higher than the dietary concentrations. When FO was replaced by SO or BT diets, the reduction in eicosapontaenoic acid in fish tissue was more pronounced, suggesting a preferred utilization of this fatty acid. The consumption of SO displayed intense lipid accumulation in the liver of the fish. The expression of PPARγ increased significantly in the SO group compared with the FO and BT groups (P

This study was designed to evaluate the effect of sodium lactate, citric acid and vinegar on Staphylococcus aureus (S. aureus) in fish fillet. Thirty five fish fillet samples were divided into seven group including the control and inoculated with 1ml containing 105 cfu S. aureus culture, then subjected to six treatments: sodium lactate 2 &3%, citric acid 1 &2% and vinegar 3 &5% , all samples and control were stored at 4oC and followed up at 0, 24 and 48hr. for counting S. aureus. Statistical analysis of the result revealed that, the count of S. aureus was decreased in all treated samples. The highest reduction percentage of S. aureus count was in samples treated with vinegar 5% after 48hr. (97.63%) followed by citric acid (95.21%) then, sodium lactate (82.79%). Therefore vinegar can be used to improve the biological quality of fish fillet during short storage at refrigerator temperature specially for reducing initial S. aureus contamination.

The distribution of trace metals in a ling (Genypterus blacodes) fish fillet was determined from ICP-MS measurements of digests prepared using nitric acid and hydrogen peroxide, followed by microwave digestion. Most trace elements were inhomogeneously distributed in the muscle tissue of the ling with a non-linear increase in concentration towards the tail end of the fillet. This distribution pattern may be connected to the size variation of the individual muscle cells or the change in the ratio of connective tissue to muscle tissue, suggesting that the observed inhomogeneity of muscle elemental distribution may be inherent to all fish species. The concentration of an element in a sample of fish muscle tissue thus depends on the physical location within the fish from which the sample was dissected. Significant differences in trace element concentrations were also detected between the red and white muscle fibres of ling, as well as between the belly flap and the rest of the musculature.

Aims: To characterize freshwater Bdellovibrio-and-like organisms (BALO) isolated in China and examine their potential in controlling growth of Salmonella enterica ssp. enterica serovar Typhimurium on tilapia fillets. Methods and Results: Four BALO isolates were recovered from a pond in Yanzhou of Shandong province, China, with Salm. Typhimurium as prey using double-layer agar method. Partial 16S rDNA sequencing analysis identified BD2GL, BD5GL and BDXGL as Bdellovibrio bacteriovorus and BD2GS as a Peredibacter sp. Lysis experiments on 32 potentially pathogenic strains revealed that BALO lysis rates are in the range of 56·3–65·6%. On the five Salmonella strains tested, only BD2GS achieved 100% lysis rate. When applied on tilapia fillets against Salm. Typhimurium, BD2GS showed its growth control potential. Cell increments of Salm. Typhimurium were significantly lower (P

Performance comparison tests were carried out on Staphylococcus aureus selective media recommended by food safety agencies or approved by international standardization bodies. The performance of mannitol salt agar (MSA), Baird parker agar, Vogel johnson agar, RAPID’ Staph, and CHROMagar staph aureus are compared. Four out of the 5 media showed 100% sensitivity, with MSA showing 96.5%. MSA also showed only 66.6% specificity, while 4 out of 5 media showed 100% specificity. In recovery tests S. aureus was more easily recovered from instant cooked rice than fish fillet. The tested media did not have a significant difference on recovery activity.