Quality Of Fish Products Research Articles

Escherichia coli as a sentinel in the assessment of antimicrobial resistance in the tilapia production chain: from production environment to the final product

IntroductionThe intensification of tilapia production has increased animal density in tanks, leading to more frequent exposure to pathogenic agents and compromising the quality of fish products. Antimicrobial resistance is a global concern that affects human treatment, and sentinel microorganisms like Escherichia coli are crucial for monitoring production chains, especially in aquaculture, where research is still limited. The aim of this study was to identify the presence of E. coli and investigate its antimicrobial resistance profiles throughout the entire tilapia production chain.MethodsA total of 240 samples were collected from various points in the production process: carcasses before scaling (Ca), scaling wastewater (Sw), filleting wastewater (Fw), fillet washing wastewater (Tw), fillet handling surfaces (Su), and pre-packaged fillets (Pf). The samples were collected during 10 visits, each corresponding to animals from different farms. E. coli isolates were identified using MacConkey agar and biochemical tests. Phenotypic resistance profiles were determined using nine classes of antimicrobials. Extended- spectrum b-lactamase (ESBL) production was identified with ceftazidime and cefotaxime and confirmed by a double-disc synergy test. Isolates were classified as sensitive or resistant based on the inhibition zone. Multidrug-resistant (MDR) was defined as resistance to at least one agent in three or more antimicrobial categories, while extensively drug-resistant (XDR) was defined as resistance to at least one agent in all but two or fewer categories.ResultsOverall, 50.8% of the samples (122/240) tested positive for E. coli, with 403 isolates identified. Of these, 33% (133/403) were resistant to at least two antimicrobials, and 20% (48/240) of the samples had MDR isolates, with the highest frequency found at the filleting point (Fw), which also had the only XDR profile. Resistance was most commonly observed against amoxicillin (35.73%), tetracycline (30.77%), and ciprofloxacin (26.30%).DiscussionThese findings emphasize the importance of E. coli as an indicator of antimicrobial resistance throughout tilapia processing and highlight the need for good production practices and qualified technical support to mitigate risks to public health, animal health, and the environment.

Effects of varied exercise intensities on growth, muscle quality and volatile compounds in largemouth bass (Micropterus salmoides) cultured in recirculating aquaculture system

To explore the impact of different exercise intensities on the growth, muscle quality, and volatile compounds of largemouth bass, this study involved 270 fish with an initial weight of 96.05 ± 18.87 g. They were divided into three groups: a control group (CG) exposed to a constant current speed of 0.30 cm/s for 24 h/day; an interval exercise group (IE) exercising at a rate of 2 body lengths per second (bl/s) for 8 h/day; and a sustained exercise group (SE) exercising continuously at 2 bl/s for 24 h/day. The experiment was conducted in a recirculating aquaculture system over a period of 90 days. Results revealed that SE exhibited remarkably greater body mass and condition factor (CF), with higher weight gain rate (WGR) and specific growth rate (SGR) compared to IE and CG (P < 0.05). SE exhibits superior growth performance. No significant differences was observed among the three groups in terms of centrifugal loss, drip loss, liquid loss, stored loss, and cooked rate. However, in terms of frozen leakage, the IE was considerably lower than the CG and SE (P < 0.05).In terms of raw meat texture, the hardness, chewiness, and shearing of the SE were notably greater than the CG (P < 0.05), and the SE were superior in hardness compared to the IE (P < 0.05). Regarding cooked meat texture, the SE exhibited significantly superior hardness, chewiness, springiness, and shearing compared to both the CG and IE (P < 0.05). The IE demonstrated higher levels of chewiness, springiness, and shearing compared to the CG (P < 0.05). With respect to nutritional indicators, the crude protein content of both the SE and IE was significantly higher than that of the CG. In terms of volatile substances, the CG had relatively high levels of carboxylic acid compounds and alcohol compounds in this experiment. The ketone compounds in the IE were significantly higher than those in the CG and SE. 2-Methylbutanoic acid methyl ester had the highest content in the SE. The results show that interval swimming exercise training and sustained exercise training can effectively improve the sensory quality of fish muscle, effectively remove the irritating smell in the muscle, and produce aromatic odor. Consequently, exercise training at varying intensities has been demonstrated to significantly enhance the growth and muscle quality of largemouth bass, offering potential strategies for improving fish product quality in the aquaculture industry. This contributes to increased efficiency and sustainability in fish farming practices and provides valuable insights for regulating the nutritional quality of fish muscle in future recirculating aquaculture system models.

Study of the influence of fish feeding on the example of carp (Cyprinus carpio L.) under conditions of chemical pollution of the aquatic environment

The study of the influence of chemicals in the aquatic environment on the nutrition of fish, which lead to gradual pollution of the aquatic environment and violation of living conditions, and the development of methods for improving the nutritional properties of fish, which is an important branch of science that combines fish biology, in-depth study of nutrition and rational management, has been established fish resources and environmental sustainability. In recent years, a significant amount of research has been conducted aimed at understanding the relationships between fish nutrition, their development and the quality of fish products, the influence of chemicals on these processes in today's conditions using the example of carp (Cyprinus carpio L.). Analyzing the data, it was found that the quality of fish nutrition depends on the quality and composition of water, which affects the growth, development and health of fish. Considering the requirements of nutrients such as proteins, fats, vitamins and minerals, good nutrition can improve the quality of fish production. Special attention is paid to the role of proteins in the metabolism of fish using the example of cyprinus carp (Cyprinus carpio L.), growth and development, as well as adaptation to the interesting study of the composition of tissue proteins of carp during cadmium and lead intoxication. This year's carp (Cyprinus carpio L.), which is a widespread object of pond culture in Ukraine, was used for the experiment. A detailed analysis indicates that taking into account the effect of toxic substances on fish nutrition is necessary to ensure their health and optimal fish production. The development of new feeding strategies and the use of special additives is becoming a key aspect not only for improving the quality of products, but also for ensuring compliance with safety standards and environmental sustainability in the field of aquaculture and fisheries. Such research identifies new ways to create sustainable and healthy fish populations, contributing to the coordinated development of the agro-industrial sector and the preservation of aquatic ecosystems.

Framework for fish freshness detection and rotten fish removal in Bangladesh using mask R–CNN method with robotic arm and fisheye analysis

Fish-exporting countries must meet international standards and customer expectations to avoid trade disruption and economic repercussions. Ensuring the quality of fish products is therefore not just a matter of reputation but also of economic stability. Bangladesh, a major fish exporter, maintaining the quality of exported fish products is crucial. A single faulty product can have serious consequences, potentially causing harm. For this reason, we develop a deep learning-based approach capable of detecting and dividing rotten fish. We have used the Mask R–CNN method for our model. A device captures images of fish eyes and sends them to a computer system. The condition of a fish, whether fresh or rotten, can be determined by its eyes. A collection of 5000 image datasets is developed in this research work. The input images start matching the dataset through the Mask R–CNN and give us the result. Based on the result, if the fish is found fresh, it will proceed through the conveyor system; however, if it is identified as rotten, a robotic arm will separate it. To test its efficiency and reliability, we have tested it with 5000 images. And the test satisfied us with the results of 96.5% accuracy. With the assistance of our model, fish-exporting nations can efficiently distinguish between fresh and rotten fish, enhancing their ability to export more significant quantities of high-quality fish.

Влияние заменителей рыбьего жира в кормах сиговых рыб (Coregonidae) на рост, физиологические показатели и жирнокислотный состав липидов

The results of a study on the replacement of fish oil in the feed for two-year-old whitefish with other sources of lipids have been carried out. When replacing a fifth of the fish oil (4 out of 20%) with flaxseed oil, there was no significant difference in growth, fish survival, physiological parameters, and fatty acid composition of lipids. In the following experiments, fish oil was changed to linseed, soybean, rapeseed and camelina oils. When replacing 5, 7, 10 and 15 of 20% of fish oil with flaxseed oil, the content of omega-3 acids in fish muscles increased from 9 to 27%, including the sum of long-chain acids – docosahexaenoic (DHA) and eicosapentaenoic (EPA) – from 2.4 to 23.5%, which demonstrates the ability of whitefish to transform maternal alpha-linolenic acid, which is rich in linseed oil, into long-chain polyunsaturated acids. At the same time, the amount of monounsaturated oleic acid decreased from 41.4 to 21.7%. An improvement in the fatty acid composition of feed when vegetable oils were introduced instead of fish oil indicates its low quality, as indicated by high mortality, a decrease in vitamin C, and a deterioration in the fatty acid composition of lipids in fish that received food with the highest amount of fish oil. Based on the consideration of all indicators, the best results were obtained when replacing half of the fish oil with linseed oil (10% out of 20%). At the same time, the quality of fish products was preserved. The amount of DHA and EPA in 100 g of farmed fish muscle was 0.89 g, which satisfies the daily human need for these important omega-3 acids for health. When replacing fish oil with camelina, soybean and rapeseed oils, the results were slightly worse.

Fish Freshness Detection Through Artificial Intelligence Approaches: A Comprehensive Study

Fish is regarded as an important protein source in human nutrition due to its high concentration of omega-3 fatty acids In traditional global cuisine, fish holds a prominent position, with seafood restaurants, fish markets, and eateries serving as popular venues for fish consumption. However, it is imperative to preserve fish freshness as improper storage can lead to rapid spoilage, posing risks of potential foodborne illnesses. To address this concern, artificial intelligence techniques have been utilized to evaluate fish freshness, introducing a deep learning and machine learning approach. Leveraging a dataset of 4476 fish images, this study conducted feature extraction using three transfer learning models (MobileNetV2, Xception, VGG16) and applied four machine learning algorithms (SVM, LR, ANN, RF) for classification. The synergy of Xception and MobileNetV2 with SVM and LR algorithms achieved a 100% success rate, highlighting the effectiveness of machine learning in preventing foodborne illness and preserving the taste and quality of fish products, especially in mass production facilities.

Production of Smart Packaging Chitosan Films Utilizing Malva sylvestris Mucilage and Rubia tinctorum Extract for Enhancing Fish Freshness and Prolonging Shelf Life

In the dynamic landscape of food technology, where ensuring freshness and extending shelf life are paramount concerns, active packaging stands at the forefront of innovation. This study explores the utilization of natural resources in the development of smart packaging solutions aimed at enhancing the freshness of perishable foods. Specifically, chitosan films incorporating Malva sylvestris mucilage and Rubia tinctorum extract are investigated for their efficacy in preserving the quality of fish products. Through a series of experiments and analyses, this research elucidates the potential of these bio‐based materials to revolutionize packaging practices, offering a sustainable and effective means of prolonging the shelf life of perishable goods while maintaining their quality and safety. Assessment of the antimicrobial properties of Rubia tinctorum hydroethanolic extract revealed that Staphylococcus aureus displayed higher susceptibility to this extract with the lowest MIC value (2.60 ± 0.09 mg/ml) and MBC value (5.20 ± 0.09 mg/ml) as well as the highest inhibition zone (16.33 ± 0.50 mm). For the composites with different concentrations of hydroethanolic Rubia tinctorum extracts, the lightness value significantly (p &lt; 0.05) increased at neutral pH. After days of storage, the pH in the fish sample surpassed the threshold (7), leading to a corresponding change in the indicator film’s color. Also, samples coated with higher levels of Rubia tinctorum extract in active/smart chitosan films with Malva sylvestris mucilage had lower pH, thiobarbituric acid, total volatile nitrogen, and microbial population (mesophile, psychrophile, and Enterobacteriaceae). The highest appearance score, surface glaze score, and overall odor acceptance in samples 4 (fish coated with active/smart chitosan with Malva sylvestris containing 0.6% Rubia tinctorum extract) and 5 (fish coated with active/smart chitosan with Malva sylvestris contained 1.2% Rubia tinctorum extract) (p ≤ 0.05) suggest that this application may contribute to the observed perceptual qualities. This novel indicator film has the potential to function as intelligent packaging for monitoring fish freshness. Additional research can delve into the precise mechanisms driving these effects and fine‐tune the formulation for particular applications.

Spatio-Seasonal Habitat Suitability Model of Anisakis spp. in Chub Mackerel (Scomber Japonicus) as a Scientific-Based Approach to Provide Safety Assessment Policy of Fisheries Product in Indonesia

The infestation of Anisakis spp. in Chub mackerel (Scomber japonicus) may have significant health and socioeconomic implications. Understanding the spatio-seasonal occurrence of Anisakis spp. in its host, S. japonicus, is crucial ecologically and for effective management. This research aimed to develop a predictive map (spatial-seasonal patterns) for Anisakis’s infestation in S. japonicus using the maximum entropy (MaxEnt) algorithm. Anisakis spp. and S. japonicus occurrences were obtained through a comprehensive Bibliographic analysis of the Scopus database (2017-2022) and the Ocean Biodiversity Information System (OBIS) database to collect the necessary data. Environmental predictors were sourced from the Global Marine Environment Data. The resulting model demonstrated a reliable performance, as indicated by an Area Under Curve (AUC) value on the Receiver Operating Characteristic (ROC) chart exceeding 0.8. The findings of this study revealed that the infestation of Anisakis spp. in S. japonicus is projected to be more prevalent during the fourth quarter of each year. Furthermore, the environmental factors influencing the infestation were identified as diffuse attenuation, water depth, and distance from the coast. These research outcomes can be a foundational reference for developing an effective control system for inspecting fresh or frozen fish within the quarantine department. By utilizing the spatial-seasonal patterns and environmental predictors identified in this study, authorities can implement targeted measures to prevent and mitigate the infestation of Anisakis spp. in S. japonicus, safeguarding public health and maintaining the quality of fish products.

Hygienic assessment of water quality and safety according to national requirements

There are only 15 % of water reservoirs in Ukraine that can be used as sources of water supply, taking into account water treatment facilities. 55 % of polluted objects and 30 % very dirty, water from these sources cannot be used even after cleaning. With the help of sanitary-hygienic, ecological and water management assessment, they ensure the quality of water in the impact on the environment and the quality of fish products. The main documents that determine the quality, properties and chemical composition of drinking water are DSTU 7525:2014 and DSTU 27384:2005, they specify the main toxicological and organoleptic concentrations of chemicals that must be contained in water. The standard “Sources of centralized economic drinking water supply, hygienic and ecological requirements for water quality and selection rules” makes it possible to develop a complex of interrelated standards and norms, including the use, protection and restoration of water resources, objective assessment of the ecological state and quality of surface and underground waters and their compliance with the requirements of EU standards. Water treatment equipment and technologies used nowadays for wastewater treatment do not provide a sufficient degree of purification and disinfection. Surface water reservoirs, along with impurities of natural origin, contain chemical pollution – heavy metals, pesticides, insecticides, oil products, phenols. The methods of wastewater disinfection are divided into chemical, physical, physico-chemical and in the conditions of artificial and natural biocenoses.

Infection of bream with Ligula plerocercoids (Ligula intestinalis) of the Chernovsky reservoir of the Orenburg region

In recent years, much attention has been paid in the Orenburg region to the issues of increasing fish stocks in natural and artificial reservoirs. Annually, the Ural River, reservoirs of the region are stocked with carp, sturgeon species of fish, as well as land reclamation activities. One of the reasons that worsen the quality of fish products from the reservoirs of the region is helminthiases. They reduce fatness and fat content, spoil the marketable appearance of caught fish, thereby causing significant economic damage [1]. Ligullosis is a common helminthic disease of many species of freshwater fish, especially often recorded in cyprinids. The disease in fish is caused by plerocercoids of Ligulidae from the genus Ligula (family Ligulidae). Parasitizing in the abdominal cavity, the helminth compresses the internal organs, disrupts their functions, which can lead to atrophy and infertility [2]. The natural causes of the spread of ligulosis include fish-eating birds - the final hosts of the Ligula. In the intestines of birds, helminths become sexually mature and live only a few days, standing out with litter and not causing much harm. It is quite difficult and not always possible to control the number of fish-eating birds in water bodies [3]. The aim of our research was to study the degree of infestation of bream with plerocercoids of the genus Ligula in the Chernovsky reservoir of the Orenburg region.

Quality Assurance for Frozen Fish (Decapterus sp) Utilizing Fault Tree Analysis at PT XYZ (Fish Freezing Company)

Fish product quality is crucial, and any flaws in frozen fish, such as unpleasant odor, breakage, dents, tears, or texture damage, can negatively impact its overall quality. These defects can lead to reduced customer satisfaction and adversely affect the company's brand reputation. To enhance product quality, the company must establish an efficient quality assurance system and closely monitor the handling of raw materials. The main objective of this practical work is to identify potential risks of damage and develop strategies to prevent such incidents from occurring. The Fault Tree Analysis method is utilized to systematically identify and analyze the root causes of existing errors and find appropriate solutions to address the problem. The FTA results reveal 18 basic event factors that can cause damage to fish, including worker negligence during raw goods placement, inadequate use of plastic protection, lack of rubber carpets in baskets, failure to adjust freezing temperature properly, insufficient inspections, non-compliance with Standard Operating Procedures, improper fish arrangement, excessively hard freezing temperature, employee laziness and carelessness, absence of basket mats, prolonged freezing step, unset temperature checks, mishandling of raw goods due to a rush to finish quickly, and irregular temperature checking schedules. The study aims to understand the step-by-step process of handling flying catfish, identify the factors contributing to fish damage, and analyze the potential damage scenarios.

Postharvest Fish Processing in the Southwest Region of Cameroon and the Effect of Smoke-Drying on Quality

Fish processing in Cameroon is mostly carried out by untrained individuals using different methods which often produce fish products of poor quality. This study was aimed at identifying the main fish processing technologies used in 5 fishing communities in Limbe Subdivision in the Southwest Region of Cameroon. A total of 120 questionnaires were administered in the study area to identify the most popular unit operation in fish processing and to evaluate its effect under controlled conditions on the quality of fish products. It was found that the main fish technology employed was smoke-drying and that most of the processors dried the Ilisha africana species. Smoke-drying of Ilisha africana was carried out under controlled conditions of temperature and time, and smoked fish samples of different colours ranging from pale brown to dark brown were obtained. Laboratory analysis of the fish samples revealed that the moisture content and microbial content of the fish decreased significantly ( p &lt; 0.05 ), while protein content increased significantly ( p &lt; 0.05 ) with an increase in smoking time and temperature. The optimum moisture content was achieved at temperature ranges of 61-70°C for 18 h (12.3%), 71-80°C for 12 h (10.7%), and 18 h (7.3%). The pH and microbial content of all the samples were within the recommended levels for consumption and safe storage. It was concluded that the best temperature ranges and times for smoke-drying Ilisha africana were 61-70°C for 18 h and 71-80°C for 12 h.

Fish Freshness Indicator for Sensing Fish Quality during Storage.

This study aims to develop a freshness indicator for fish products that changes color to indicate ammonia among volatile base compounds (TVB-N) generated during storage. Through an optimization experiment, we observed the indicator's color change relative to the ammonia concentration standard, finally selecting cresol red and bromocresol purple for the indicator mixture. In addition, eco-DEHCH and Breathron film were applied to the freshness indicator, considering environmental and economic values. For the storage experiment, Chub mackerel (Scomber japonicus), Spanish mackerel (Scomberomorus niphonius), and Largehead hairtail (Trichiurus lepturus) samples were stored at three different temperatures (4, 10, and 20 °C) for seven days, and we measured pH, TVB-N, total bacterial count, and ammonia content every 24 h. The pH-sensitive sensors' color changes monitor amine release, especially ammonia, from decomposing fish. The chromatic parameter ∆E value increased significantly with fish product storage periods. We confirmed that when the freshness limit and bacterial spoilage level were reached, the color of the indicator changed from yellow to black and sequentially changed to purple as the storage period increased. Therefore, a developed freshness indicator can be used for determining the quality of fish products quickly and non-destructively by reflecting the freshness and spoilage degree of fish products during storage.

Mechanism of freshness-lock during the quality determination period of farmed turbot Scophthalmus maximus revealed by foodomics

A series of biochemical changes occur in the muscles of postmortem fish, resulting in an extremely easy decline in freshness. The early stage of postharvest can be regarded as the quality determination period (QDP) oficeice seafood. The QDP handlings influence the final quality of fish product. Bleeding at ice seawater was conducted to lock the freshness of farmed turbot. The pH, ATP-related compounds and K values were measured. A non-target metabolomics technique was used to elucidate the mechanism of freshness-lock. The results showed that the levels of pH and ATP-related compounds were decreased slowly in the fish of freshness-lock, while K values were lower than those in no freshness-lock fish during cold storage. The metabolomics analysis revealed that 25 metabolites were significantly changed in the muscles of turbot after 2 d of cold storage. After freshness-lock treatment, 6 metabolites reversed in the muscles of turbot, with the rises in glycerol 3-phosphate, dihydroxyacetone phosphate, and decanoyl-l-carnitine and the drops in pyruvaldehyde, D-lyxose, and d-ribose. This study indicates that locking freshness during QDP of fish has a delayed effect on the quality deterioration and can prolonging the shelf-life of fresh product.

Half-dried fish with improved properties

The research of gelling ability of different grades of food gelatin has been conducted, analytical researches have been carried out to establish the possibility of using a mass and inexpensive object of fishing - pollack for food purposes; the technological scheme of making a new structured fish product has been developed and experiments on its making have been carried out. There has been developed a scale of organoleptic evaluation of structured fish product quality, including significance coefficients, the highest of which are typical sensory indices: appearance, taste, consistency, flavour and also point scale of chewing degree of the molded product. As a result of organoleptic evaluation of structured fish products we have determined close to optimal correlation between fish and structurer of salt-dried finely-milled meat from the total mass of the system. The created product with the indicated ratio of fish and gelatin has got the highest score according to organoleptic evaluation, which testifies to its excellent quality characteristics. The results of investigations show the technological perspectivity of the developed new molded product of salted and dried pollock using as a structure-forming agent the water solution of gelatin of 220 bloom grade in concentration of 10 % at a ratio of fish and gelatinous components 3:7.

Synergy of Nisin Z and Sodium Chloride in the Inhibition of Food-Borne Pathogens and Quality Control of Aquatic Foods

ABSTRACT This study was conducted to investigate the combination of nisin Z and NaCl as a natural food preservative to improve the quality of fish products under refrigerated temperatures. Treatments against Listeria monocytogenes and Staphylococcus aureus included 1000 IU nisin Z (NZ) in 3% (NZ3), 5% (NZ5), or 7% NaCl solution (NZ7). Both NZ5 and NZ7 showed significantly higher antimicrobial activities, and minced Nile tilapia (Oreochromisniloticus) inoculated with L. monocytogenes or S. aureus showed a reduced microbial load compared to the positive control groups. Therefore, the combination of nisin Z and NaCl exhibited potent antibacterial activities, highlighting its usability as a natural alternative to synthetic preservatives.

Comparative Evaluation of Wild and Farmed Rainbow Trout Fish Based on Representative Chemosensory and Microbial Indicators of Their Habitats.

Wild and farmed rainbow trout were compared with chemical profiling, chemosensory properties, carbon concentration and isotope analyses, 1- and 2-GC/O-MS, GC-FID, and aroma profile analyses. Results were linked with the prokaryotic and eukaryotic microbiological profile of the fish sources using multivariate statistical analysis. Fish from natural environments proved to have better sensory properties in terms of fruity, sweet, and citrusy attributes, compared to farmed fish. However, the farmed fish were found to have higher nutritional value based on their lipid contents. These differences might relate to the introduction of feed extrudates, which could influence the overall quality of fish products. Thereby, malodor episodes linked to musty/earthy off-odor notes related to odorants including geosmin, β-caryophyllene, (E,Z)-2,4-nonadienal, and (E,E)-2,4-nonadienal. These compounds, in turn, correlated with Asticcacaulis benevestitus, Curvibacter sp., Albidiferax sp., Aquabacterium commune, and Aquabacterium citratiphilum abundance and were further affected by oxygen levels in the water column.

Assessing the fish and fish product quality and the consumer preferences of Ukrainians at the Odesa fish and fish product market

Assessing the fish and fish product quality and the consumer preferences of Ukrainians at the Odesa fish and fish product market

Advances in the Formation and Control Methods of Undesirable Flavors in Fish.

Undesirable flavor formation in fish is a dynamic biological process, decreasing the overall flavor quality of fish products and impeding the sale of fresh fish. This review extensively summarizes chemical compounds contributing to undesirable flavors and their sources or formation. Specifically, hexanal, heptanal, nonanal, 1−octen−3−ol, 1−penten−3−ol, (E,E)−2,4−heptadienal, (E,E)−2,4−decadienal, trimethylamine, dimethyl sulfide, 2−methyl−butanol, etc., are characteristic compounds causing off−odors. These volatile compounds are mainly generated via enzymatic reactions, lipid autoxidation, environmentally derived reactions, and microbial actions. A brief description of progress in existing deodorization methods for controlling undesirable flavors in fish, e.g., proper fermenting, defatting, appropriate use of food additives, and packaging, is also presented. Lastly, we propose a developmental method regarding the multifunctional natural active substances made available during fish processing or packaging, which hold great potential in controlling undesirable flavors in fish due to their safety and efficiency in deodorization.

Effect of Post Slaughter Time Interval (PSI) on the Quality of Heteroclarias

ABSTRACT Post-slaughter time interval (PSI) plays an important role in the resultant quality of fish product. However, there is little information on the effect of PSI on heteroclarias, which is the most cultured fish in the study area. Forty-two samples of heteroclarias (average weight 500 ± 10.0 g) were collected, euthanized using salt, and stored at ambient temperature (27 ± 3°C); samples were collected at 0, 4, 8, 12, 16, 20, and 24 hours for sensory, histological, proximate, biochemical, and microbial assessments using standard procedures. Data obtained were analyzed using SPSS 16.0 version. Most sensory attributes were retained for 12 hours PSI; however, crude protein, minerals, and pH were reduced significantly (p < .05) with increased PSI, and the total volatile base nitrogen, peroxide value, and free fatty acid increased significantly (p < .05) with increased PSI. The total viable count, total fungal count, total coliform count, fecal coliform count, and Escherichia coli also increased significantly (p < .05) with increased PSI but were within acceptable limits for good-quality fish. Heteroclarias should not be delayed beyond 12-hour PSI before preserving or processing in order to get best-quality raw material (fish) for consumers.