نشریه علوم و فنون شیلات
سال دهم شماره 1 (پیاپی 33، زمستان 1399)

There is a rising concern about the potential risks of nanomaterials to human health, the environment, and aquatic ecosystems. The chemical composition and small size of the nanomaterials are the most important factors in the toxicity of these materials. Histological study of gill and investigation of hematological parameters are important for monitoring the health condition in aquatic animals. Therefore, the effects of subacute concentrations of copper oxide nanoparticles were examined on some hematological parameters of Caspian Roach (Rutilus rutilus) in this study. The experiment was performed at 15 liters aquariums in three experimental groups including 10, 40, 80 ppm copper oxide nanoparticles and the control group for 42 days. Each treatment included three replicates consisting of seven juvenile carp with an approximate weight of 42± 2 gr. The results of this experiment showed that copper oxide nanoparticles caused hyperplasia, lamellar fusion, epithelial hypertrophy, lamellar aneurism, and reduce secondary lamellae length. Besides, red blood cells (RBC) was significantly decreased with the increase in the concentration of copper oxide nanoparticle (P<0.05). RBC had a significant reduction from 2.11±0.004 to 1.98±0.005 at the end of treatment. Hematocrit and hemoglobin reduced from 1.37±0.011 to 1.34±0.001 and 7.8±0.01 to 6.9±1.32, respectively (P<0.05). A significant reduction was recorded in hematocrit among the control groups and other treatments (P<0.05). it can be concluded that the sub-acute particles may cause damage to the surface of tissues, especially gill tissue, and changes in the level of blood factors in fish, which can be due to the destructive effects of nanoparticle type on hematopoietic organs such as the liver and kidney. Therefore, a definite conclusion requires more and more extensive research on the same species and other species.

This study was designed and performed to evaluate the effect of using the active edible coating of sodium alginate containing different levels of rosemary extract on physicochemical and microbial properties of silver carp-chicken fillet mixed burger during storage. 5 treatments including uncoated burgers (control) with sodium alginate coating enriched with levels of 0, 0.5, 1 and 1.5% of rosemary extract were considered. Burgers were stored at -18 ° C for 3 months. Results showed that the use of sodium alginate coating significantly decreased the percentage of burger cooking drop. Enrichment of sodium alginate coating with different levels of rosemary extract improved its performance (P<0.05). The lowest total microbial count, psychrophilic bacteria count, TVN, PV and TBA were observed in coated burgers containing 1.5% of rosemary extract (P<0.05). There was no statistically significant difference in the performance of coatings containing levels of 1 and 1.5% of rosemary extract in decreasing TBA. Thus it is possible to use the active edible coating of sodium alginate containing 1.5% of rosemary extract to delay bacterial and oxidative spoilage of silver carp-chicken fillet burgers during a 3-month storage period at -18 ° C used.

The purpose of this study is to evaluate the purchase amount of shrimp in the market and the relationship between consumption amount and some of demographic characteristics. The statistical population of this study is the whole country that 10 cities including Mashhad, Tehran, Tabriz, Birjand, Kermanshah, Gorgan, Yazd, Bandar Abbas, Ilam and Shiraz were randomly selected and a total 1000 questionnaires were completed by citizens proportionate to the household population of the studied cities. In order to evaluate the number of shrimp purchases per year as well as the amount of each purchase, from the output of SPSS software and to investigate the existence of a significant relationship between consumption amount and demographic characteristics, correlation tests were used. According to the results the number of times shrimp were bought by the household varied from one to twelve times a year (average 1.71±1.11). 44.2% of households of the consumption society bought shrimp once a year and 28.6% of them bought shrimp twice a year. It was further found that the amount of shrimp purchased by household varies from 0.5 to 2 kg per purchase (average 0.92±0.26 kg). while 76.3% of households of the consumption society purchase one kilogram of shrimp in per purchase. According to the findings, consumption amount had no significant relationship with the age, job and field of study variables (p>0.05). But the relationship between this index with the education level and number of household members variables was significant (p<0.05).

Polysaccharides possess diverse biological properties due to complexity of chemical structure and heterogeneity of molecular weight which could be improved through engineering approaches and chemical modifications. The objective of the present study was to determine the antioxidant and anti-diabetic effects of marine and land originated polysaccharides and explore the correlation between molecular weight and biological activities. Hence, four polysaccharides with varying size distribution and average molecular weight including fucoidan and alginate from brown seaweed Padina pavonica and polysaccharides from Flixweed (Descurainia sophia) and Fennel (Foeniculum vulgare) were subjected to hydrolysis in three levels using 0.05N hydrochloric acid at 100 C for 5, 10 and 20 minutes.  The average molecular weight ranged between 2059.5-3781.8 in fucoidan, 1774.4-2324.9 in alginate, 720.4-1373.8 in Flixweed and 5752.6-14077.5 × 103 g/mol in Fennel. The relation between molecular weight reduction and α-amylase activity inhibition was decreasing in fucoidan (52.1-32.8%) and alginate (67.6-32.2%) and increasing in Fennel (61.2-45.0%). Reduction of molecular weight enhanced the DPPH radical scavenging and ferric reducing power of fucoidan (47.9-27.8%; 0.47-0.37 Abs) and Fennel (39.0-12.7%; 0.34-0.16 Abs). The effect of molecular weight reduction was limited on antioxidant activities of alginate and Flixweed. Overall, the findings of the current study revealed that molecular weight is a determinant factor affecting bioactivities of the tested polysaccharides and thus their applications as ingredients having anti-diabetic and antioxidant functions could be possible in their native and/or hydrolyzed forms.

To Aims salt reduction and investigation, the effect of sodium chloride (NaCl) replacement by potassium chloride (KCl) on the nutrition quality and sensory assessment of fish sauce from Common Kilka (Clupeonella cultriventris) with substituting NaCl by KCl at 0%, 25%, and 50% concentration was produced during 45 days of fermentation at 37±2 Co. The proximate composition, free amino acid profile, profile, groups, and rate of the total amino acid (TAA), indices including acid amine score, chemical score, essential amino acid (EAA) index, biological value (BV) and protein efficiency rate (PER) as well as sensory assessment, was investigated. The increase of KCl concentration led to a decrease in the sum of essential free amino acids. The most abundant amino acid in the level of 100% NaCl and 25% KCl was glutamic acid as well in the level of 50% KCl was Lysine. The highest sum of EAA and rate of EAA to TAA respectively in the level of 25 and 50% KCl recorded. Phenylalanine, Methionine, and Threonine were identified as limiting amino acids in produced fish sauces. Fish sauce with 25% KCl concentration contained a higher amount of EAA index, BV, and PER than other samples. According to sensory assessment, levels of 100% NaCl and 24% KCl were accepted by the panelists. In Conclusion, due to partly improvement in nutrition quality as well as acceptable sensory, would suggest that NaCl replaces by KCl in 25% concentration in the production of common Kilka fish sauce.

Citrus peel is a natural source of antioxidants and the use of its natural extracts to improve the quality of fish is increasing. The effect of orange peel extract on the chemical and sensory properties of Huso huso fillet when refrigerated (4±1 °C) was investigated. In this study, fish fillets with aqueous solutions of ethanolic extract of orange peel (w / w 5%) or (5 ml of extract in 100 ml of solvent), orange peel extract (w / w 6%) and orange peel extract (w / w 7%) were tested as natural preservatives for 30 minutes. Control samples were immersed in distilled water for 30 minutes. Control and treated samples were packed with ethanolic extract of orange peel and stored for 15 days. Samples are then taken at regular intervals for chemical properties of pH, free fatty acid (FFA), peroxide (PV), thiobarbituric acid (TBA), total volatile nitrogen bases (TVB-N) and sensory evaluation (texture, color, odor and acceptance) were studied. Analysis of the results of chemical tests and sensory evaluation showed that orange peel extract maintains good quality characteristics and increases the shelf life of fish samples during storage at refrigerator temperature. 7% orange peel extract and then 6% and 5% orange peel extract significantly (P <0.01) delayed the oxidation and hydrolysis of fat in the samples that treated with the Orange peel extract.

Supplying fresh fish and sea products is accompanied with the problem of their rapid spoilage and short shelf life. Therefore, solutions which help increase this shelf life have always been valued. Accordingly, the aim of this study was to evaluate the effect of whey protein coatings containing four different concentrations (100,200,400 and 800 IU/gr) of nisin in perch fillet for storage in refrigerator temperature. Humidity tests, Peroxide Value, Thiobarbituric acid Index, microbial load, water activity and pH were performed over coated and uncoated samples. The results indicated that increasing the shelf life in all treatments led to an increase in peroxide value, Thiobarbituric acid Index, the load of bacteria, pH and water activity, this increase was less in coated samples than the uncoated ones. On the other hand, the findings showed that whey protein and nisin coating with the of concentration 400 IU/gr of perch fillet can add 16 days to increase the shelf life in refrigerator temperature in comparison with the uncoated samples. Based on our findings, it can be concluded that using whey protein coating containing nisin with the concentration of 400 IU/gr of perch fillet as edible coating  can increase the shelf life in the refrigerator temperature.