Natural origins of off-flavours in fish related to feeding habits

2007 ◽  
Vol 55 (5) ◽  
pp. 301-309 ◽  
Author(s):  
Zs.Gy. Papp ◽  
É. Kerepeczki ◽  
F. Pekár ◽  
D. Gál

The objective of our study was to survey the accumulated 2-methylisoborneol (MIB) and geosmin (GSM) in fillets of five important farmed fish species in Hungarian aquaculture in relation to MIB and GSM concentrations in water and sediment in the aquatic systems where they were raised: (the planktivorous silver carp (Hypophthalmichthys molitrix), the herbivorous grass carp (Ctenopharyngodon idella), the bottom-feeding omnivorous common carp (Cyprinus carpio), the omnivorous tilapia (Oreochromis niloticus) and the carnivorous African catfish (Clarias gariepinus)). Water, sediment and fish samples were collected from different experimental aquatic systems which included a combined aquaculture–algae (CAA) system, effluent-fed fishponds, a pond recycling system and a traditional fishpond. MIB and GSM contents were extracted with distillation-headspace solid-phase – microextraction (SPME) and extracts analysed by GC-MS. Results showed that off-flavour contents in fish fillets were related to the feeding habits of the studied fish species. Higher GSM concentrations were found in the fillet of bottom-feeding common carp than in the silver carp or African catfish in all studied aquatic systems. Usually, low GSM concentrations were detected in the water of fishponds but sometimes the levels of this odour compound in carp fillet were well above the limits of human detection. This suggests that the off-flavour tainting of common carp may originate from the sediment or benthic algal/actinomycete sources. Negligible MIB levels were found in all samples in all of the studied aquatic systems.

2003 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
H. Syakuri ◽  
Triyanto Triyanto ◽  
K. H. Nitimulyo

Fish naturally has a non-specific defense against several pathogens. The non-specific defense is anatomical and physiological function that varies according to genetical and environmental factor. The differences of non-specific defense against Aeromonas hydrophila infection were studied in blackfinpacu (Colossoma macropomum), gourami (Osphronemus goramy), common crap (Cyprinus carpio), African catfish (Clarias gariepinus), and red nile tilapia (Orochromis sp.). This study also examined the differences on several parameters of non-specific defense, including differentiation anc number of leucocytes, serum total, titer of antibody, and antibacterial activity of skin mucus.The fishes were intramuscularly infected at the media lethal doses for common carp (7,4 x 108cfu/fish). Pathological changes, survival rate, and mean time to death were observed every day. The observation of non-specific defense parameters were carried out prior and at seven day after infection.The results showed thahblackfinpacu was the most resistant species against A. hydrophila infection. African catfish and red nile tilapia were most resistant than gourami and common carp. The antibody titer and percentage of thrombocytes were the causative factor for the difference of the resistence against A. hydrophila. The five fish species also showed differences on leucocytes number, monocytes and eosinophiles percentage, and serum total, but they did not showed the differences of neutrophile percentage. The skin mucus of all fish species did not exhibited antibacterial activity against A. hydrophila. This study also found increase in antibody titer and leucocytes number after A. hydrophila infection.


2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Furhan T. Mhaisen ◽  
Abdul-Razzak L. Al-Rubaie

Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), and the silver carp (Hypophthalmichthys molitrix) as well as from three freshwater fish species (Carassius auratus,Liza abu, andHeteropneustes fossilis) which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species,L. abu13 species,C. auratusone species, andH. fossilisone species. A host-parasite list for each fish species was also provided.


2019 ◽  
Vol 46 (3) ◽  
pp. 163-184
Author(s):  
B. O. Onunkwor ◽  
T. O. Akinpelu ◽  
O. J. Oladipupo ◽  
R. N. Ugbaja ◽  
O. J. Olaoye ◽  
...  

Most rivers in Nigeria are polluted without conscious efforts to abate ensuant consequences. Thus, Clarias gariepinus, an aquatic commercial food from Ogun River, Nigeria, was studied to investigate the impact of pollution on antioxidants and proximate composition. During the rainy season, 50 C. gariepinus (average weight 426.53 ± 24.40g and length 37.73 ± 0.95cm) were site sampled, 10 from each of Ago-Odo, Ago-Ika, Oke-Sokori, and Quarry along Ogun River course. Ajegunle-Adao cultured pond, served as control. The parameters assayed for included: some heavy metals and physico-chemical properties of sampled water, antioxidants and proximate composition of the fish samples. Physicochemical parameters of river studied showed that temperature of all sites ranged from 26 to 29°C, pH: 6.9 to 7.8, dissolved oxygen: 9.5 to 21.6, biochemical oxygen demand: 3.60 to 14.10, and chemical oxygen demand: 60 to 650. Lead (Pb) concentration ranged from 4.0 to 17.0 μg/L and cadmium (Cd): 0.0 to 6.0 μg/L. Blood Pb, Cd, activities of: superoxide dismutase, catalase, glutathione-S-transferase, plasma xanthine oxidase, and lipid peroxidation level of fish samples from Ago-Ika were most significantly (p < 0.05) high, with significant (p < 0.05) lowest reduced glutathione concentration amongst the samples from polluted sites when compared to control fish. Proximate analysis showed that the fish samples from Ogun River had significantly (p < 0.05) lower protein, fat contents, and higher nitrogen-free extract while Ago-Ika, Oke-Sokori and Quarry sites had significantly (p < 0.05) lower moisture, ash and fibre contents when compared with control. It can be concluded that the impact of pollution induced oxidative stress and significantly diminished the nutritional value of C. gariepinus from Ogun River.


2020 ◽  
Vol 01 (02) ◽  
pp. 28-35
Author(s):  
W. M. Namaga ◽  
B. Yahaya ◽  
M. A. Salam

Fish is highly nutritious, tasty, and easily digestible. It is much sought after by a broad cross-section of the world’s population, particularly in developing countries as it provides the cheapest protein source. Nigeria is blessed with numerous inland freshwater rivers and lakes scattered all over the country. This freshwater habitat consists of many species of fish that have successfully dominated all niches over time and have for many reasons remained unstudied. The situation concealed a lot of scientific information particularly on food security and safety to the inmates and the country at large. Jega River which transcended many States in the North-Western part of Nigeria to open into the river Niger is one of such rivers largely uncared for, study-wise. African catfish (Clarias gariepinus) and Tilapia (Tilapia zillii) have been wisely selected for the present proximate composition studies. The juveniles of these fishes were purchased from local fishermen in Mariner Waje landing site of the river which flows by Jega town, a local government area in Kebbi State, Nigeria. For the study, the methodology approved by the Association of Official Analytical Chemists (AOAC) was used to determine the proximate composition of the fishes. The highest percentage crude protein content of 49.18 ± 0.30% was observed in juvenile female C. gariepinus; while the lowest protein content of 39.22± 0.50% was observed in juvenile male T. zilli. The highest percentage lipid content of 11.75± 1.50% was observed in juvenile female tilapia; while the lowest percentage lipid content of 6.25± 0.29% was observed in male African catfish. The highest percentage fibre content of 4.00 ± 0.29% was observed in male and female C. gariepinus, while the lowest percentage fibre content of 0.75± 0.29% was observed in male tilapia. There were variations (p< 0.05) when the protein and lipid contents of both the species were compared with each other. There was also a significant difference (p< 0.05) when the carbohydrate contents were compared between the fish species, but there was no significant difference (p > 0.05) when the fibre content was compared within the species. The analyses showed that both the male and female fish species studied had high protein contents.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Hirut Geremew ◽  
Melesse Abdisa ◽  
Goraw Goshu

The aim of the study was to determine the proximate composition of each sex of Oreochromis niloticus, Clarias gariepinus and Labeobarbus intermedius fish species from the southern Gulf of Lake Tana, Ethiopia. The fish samples were collected during the dry season of 2014 from the three fish landing sites, i.e., Bata, Micheal and Giorgis, where local fishermen sell their catches. Species were identified via morphological examination and color. Sexes were identified by observing genital papilla and gonads after dissection. After measuring weight and length of young fish species, fish weighing 201-310 g were selected for the study. A total of 72 fish, eight and four fish per species and sexes were selected, respectively, for each site. The sample size was determined using “resource equation" method. Only edible fillet was labeled and transferred to plastic bags according to species and sex. Then the sample was transported for proximate analysis to Addis Ababa Food Science and Nutrition laboratory using icebox at about 4 °C. Fish sample composites were prepared by taking the fish samples from the three fish landing sites for each sex and species. Samples were thawed at room temperature and oven-dried at 60 °C for 72 h, then ground into a fine powder. Proximate composition was determined following the procedure of Association of Official Analytical Chemists (AOAC). Data analysis was conducted using analysis of variance (ANOVA). Nutrient content significantly varied among fish species; more protein was recorded from O. niloticus and fat from L. intermedius. Also, fat, ash and gross energy content were different between sexes; female fish contained significantly more fat and gross energy than males. In conclusion, consumers are advised to consume these species to obtain required nutrients.


Author(s):  
J. D. Dabak ◽  
L. J. Dabal ◽  
A. G. Jakwa ◽  
E. A. Ajiji

Aim: This study was designed to assess the levels of chromium (Cr), manganese (Mn), cobalt (Co) and nickel (Ni) in water and fish to monitor the toxicity risk of consuming these fish. Place and Duration of Studies: The water and fish samples were obtained from Farin gada river, Liberty Dam, Dahwol-Tohort and Diye-Tohort mining ponds, all within Jos Metropolis, Plateau State, Nigeria, between March and April, 2018. Methodology: Water and six fish species samples were collected from four different locations, digested and analysed using Buck Scientific Atomic Absorption Spectrophotometer, model 210VGP. Results: Farin gada river had all the four metals studied in varying concentrations in the following order Mn>Ni>Co>Cr with Mn having the highest mean concentration of 0.4133±0.0100 mg/L. The concentrations of the metals in the other three sources were in the order of Ni>Co>Cr with Mn not detected. Cr also was not detected in Lamingo Dam. The concentrations of Mn and Ni in all the water sources were higher than the World Health Organisation (WHO) maximum permissible limits of 0.05 mg/L and 0.06 mg/L respectively. Petrocephalus bovei recorded the highest mean concentrations of Mn and Ni, while Co was highest in Clarias gariepinus species. The concentrations of these metals in the head, body and gills of the fish species showed that the head of Petrocephalus bovei species had the highest concentrations of all the metals except chromium. Fish species from other water sources exhibited the same general pattern of Head˃gill˃body except Co which was found to accumulate more in the body than in other parts of the fish. Conclusion: The results showed that there was biomagnification of these metals from water to the fish as the concentration of the metals in the fish far exceeded those of the water sources from which they were obtained and Petrocephalus bovei species has the highest potential to biomagnified all the metals.


2021 ◽  
Vol 910 (1) ◽  
pp. 012105
Author(s):  
Khadeeja Sadiq ◽  
Jaffer Al-Hussainy ◽  
Hala Yhya Essa Al-Robeay

Abstract The current study dealt with the use of methods of preserving (freezing and salting with drying), cooking methods (grilling and cooking in broth and frying) and studying their effect on functional characteristics (solubility, amount of water and oil absorbed, viscosity, emulsification, foaming, gel formation) of myofibrillars and sarcoplasmic proteins separated from carp meat, common and silver carp diagnosed with electrophoresis technique, the study was conducted during the period (10/2018-1/2020). The results were as follows: 1. Dried fibrous proteins and dried sarcoplasm proteins separated from fish meat have given a good functional properties compared to commercial cow's albumin. 2. It was found that the percentage of solubility and gelatinization of commercial cow's albumin protein was higher than in the myofibrillars and sarcoplasmic proteins separated from the two types of fish, whereas the amount of water absorbed by the commercial cow's albumin protein was less than of myofibrillars and sarcoplasmic proteins, while the amount of absorbed oil, viscosity, and emulsion composition. The commercial cow's albumin was comparable to the myofibrillars and sarcoplasmic proteins, and when comparing the foam properties of the myofibrillars and sarcoplasmic proteins of common carp and silver carp with the commercial cow's albumin at a concentration of 1% and at the normal pH=7, it was found that the foam size and persistence of sarcooplasmic proteins were close to the size and persistence of the foam for the commercial protein at the normal pH, while the volume and stability of the foam for myofibrillars proteins were slightly lower than in cow's albumin. 3. It was observed that the solubility values in the myofibrillars proteins and the sarcoplasmic proteins of the samples were close to each other when using preservation methods while the solubility of the myofibrillars proteins was lower than the solubility of the sarcoplasm proteins of the cooked samples. It was found that the amount of oil absorbed by the myofibrillars proteins was higher than the sarcoplasmic proteins, but that its viscosity and its ability to bind water and its ability to form gel were lower than it, and the capacity of emulsifiers of protein myofibrillars and their stability was higher than the capacity and the stability of emulsions of sarcoplasm proteins, as for the type of fish and the type of protein stability of emulsions, it was noted that there was a slight difference in the capacity of emulsions and the stability of emulsions for myofibrillars proteins as well as for sarcoplasm proteins. The emulsification values did not seem different between the two types of fish. 4. It was found that freezing contributed to reducing solubility and the amount of water absorbed while it had a role in increasing the amount of oil absorbed to fish proteins more than salting and drying. The freezing, as well as salting and drying were reduced the viscosity of proteins a little bit, also freezing reduced stability of emulsionsfor two type of fish proteins,but salting and drying was rised it, and the degree of influence of the measured foam property in myofibrillars and sarcoplasmic proteins of the fish species by means of preservation and cooking different methods was very small because the values were closely related, and we did not find a specific pattern that we could apply in terms of challenging degree of difference, freezing and salting with drying, grilling and frying and cooking in the broth sometimes susceptibility raises values formation of foam and other reduce it. 5. The solubility of proteins that measured on fish which cooked in broth was more than the solubility of grilled and fried samples. It was observed that the solubility values in myofibrillars proteins and sarcoplasm proteins for the cooked samples were close to each other, and the amount of water and absorbed oil, foam properties and viscosity of the measured proteins in cooked fish were not affected by the cooked methods whose used because the closely related of values. 6. Generally the results showed that the solubility and viscosity values in the samples of common carp were lower than in the silver carp which preserved and cooked by different ways, but the ability of common carp to bind the oil was higher than that of silver carp when using conservation methods while the values were close at the use of cooking methods, and we noted that there were no noticeable differences between myofibrillars proteins and sarcoplasmic proteins for the two fish species in their ability to bind water and their ability to form gel. It was also noted that there was a slight difference in the capacity of emulsions and their stability to myofibrillars proteins as well as to proteins sarcoplasm between the two types of fish. 7. The fish type, preservation methods, cooking methods, and di-interference had a significant effect at the probability level (P ≤ 0.05) on the percentage of solubility and the amount of water and oil absorbed by the myofibrillars and sarcoplasmic proteins separated from the meat of these fish, but did not significantly impact the viscosity of the protein.


2020 ◽  
Vol 10 (26) ◽  
pp. 200608 ◽  
Author(s):  
Khin Myint Mar

Background. Pollution of the aquatic ecosystem by heavy metals is increasing due to anthropogenic activities. Cadmium (Cd) can accumulate in soil, be taken up by plants, and passed on in the food chain to animals and humans. Objectives. The present study was conducted to analyze the uptake of Cd in muscles of sampled fish with different feeding habits and to compare levels of Cd in fish from the Ayeyarwady River, Myanmar with international standards. Methods. The acid digestion procedure was used for sample preparation. Cadmium concentrations in fish samples were determined by flame atomic absorption spectrophotometry (Perkin Elmer AAanalyst 800 and Winlab-32 software). Results. In herbivorous fish species, Cd content ranged from 0.07 ( Catla catla ) to 0.086 mg/kg ( Osteobrama belangeri ). In carnivorous fish species, Cd ranged from 0.060 ( Mystus leucophasis ) to 0.083 mg/kg ( Wallago attu ). In omnivorous fish species, Cd ranged from 0.07 ( Botia histrionica ) to 0.084 mg/kg ( Gudusia variegata ). Cadmium content did not differ significantly across the three types of feeding habits (p>0.05). Discussion. The accumulation of Cd in the muscle of studied fish was lower than the permissible limit set down by the European Union in 2001 (0.1 ppm), but above the limits set down by the Food and Agriculture Organization/World Health Organization, European Commission (0.05 ppm) and within the limit of United States Food and Drug Administration (0.01–0.21 ppm). The data obtained in the present study indicate that levels of Cd were not significantly different across fish species with different feeding habits. Conclusions. The examined fish samples were not fully safe for human consumption due to high levels of Cd. Competing Interests. The authors declare no competing financial interests.


2020 ◽  
Vol 41 (2) ◽  
Author(s):  
P.P Ayawei ◽  
H.O Imafidor ◽  
G.D.B Awi-Waadu ◽  
A Abah

This study aimed at investigating the sex and age-related parasitic burden of Clarias gariepinus cultured in earthen ponds. Eighty–five (85) fish samples were selected randomly for analyses from three earthen ponds. Sexing was done by the observation of the urinogenital papillae. For parasitological analysis, skin and gill scrapes were taken for external parasites while the stomach and intestines were slit open, rinsed and observed for helminthic worms. Parasites identified included; Chilodonella sp. (0.3%), Ichthyophthirius sp. (41.1%), Trichodina sp. (55%), Icthyobodo sp., (1.0%) and Gyrodactylus sp. (2.4%). From the study 31 out of 56 males and 20 out of 27 females were infected with parasites. Prevalence of infection in males and females were 55.36% and 74.07% respectively. Mean intensity of parasites was also higher for females (150.75) than for males (62.68) Chi square analysis however, revealed no significant effect (p<0.05) of parasitism on gender. It was further observed that juvenile males and early adult females respectively, had more parasites with 55.3 and 92.4 parasite mean intensities. Among age groups, the mid juveniles (25-99g) (19%), late juveniles (100-299g) (65%) and early adults (300-500g) (14%) were most infected, although there was no significant effect (p<0.05). Sex-related prevalence could be based on hormonal changes and reproduction in females, and competitive search for mates by males. Age-related infection was predicated upon active feeding habits reported among fish of these ages It is therefore recommended that routine health checks be carried out for pond cultured fish. Furthermore, that older fish be sorted and kept together, as they would have stronger immunity than younger fish. Keywords; Zoonoses, fish infection, late juveniles, earthen pond, Clarias gariepinus, sex, age


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