نشریه علوم و فنون شیلات
سال نهم شماره 3 (پیاپی 31، تابستان 1399)

Brown algae are a valuable source of natural antioxidant compounds, especially Phlorotannins. In this study, the effect of solvent concentration (water / ethanol) on the the amount of Phlorotannin compounds and antioxidant properties of extracts from brown alga Sargassum angustifolium were investigated. The extraction was performed by solvent method at room temperature (28-26 °C) with ethanol/ water solvent with three ratios (30:70), (50:50) and (70:30). The amount of Phlorotannin, total phenolic content, ferric reducing antioxidant power, DPPH radical scavenging activity and total antioxidant capacity of different extracts were evaluated. The results showed that the yield of Phlorotannin extraction was dependent on the solvent concentration and with increasing polarity of the solvent, its amount increased, So its amount in ethanol/ water treatment (30:70) is significantly more than the other two treatments (P<0.05). Also, the highest amount of DPPH radical scavenging activity was obtained in ethanol/ water treatments 50:50 and 70:30 which contained less Phlorotannin. Finally, it was found that the ethanol/ water treatment 30:70 of the brown alga Sargassum angustifolium was a good choice for extracting Phlorotannin compounds as a natural bioactive compound for food and medicine purposes.

The effect of different levels of fucoidan on fatty acid profile and growth of rainbow trout were investigated. 150 fish (average weight 18.84 ± 70.7) were distributed in 15 fiberglass tanks (100 liters) and fed for 8 weeks at different levels (0 (control), 0.1%, 0.5%, 1% and 2% fucoidan). The results showed that the treatment with the highest amount of fucoidan had the highest final weight, specific growth rate and body weight gain, and there was a significant difference between treatments (p <0.05). There was no significant difference between feed conversion ratio and different treatments (p> 0.05). The difference between EPA, DHA, SFA, MUFA, n-3, HUFA and ratio of n-3 to n-6 was not significant (p >0.05), while PUFA and Arachidonic acid significantly different between treatments (p <0.05) and the highest value was observed in in treatment 2 and 1% respectively. Based on the results of this study, it can be concluded that this type of Polysaccharide at high doses (1 and 2% of fucoidan) can improve the growth performance and maintain the quality of muscle fatty acids.

The aim of this study was to produce protein isolates from rainbow trout (Oncorhynchus mykiss) and to investigate its nutritional, structural, functional and sensory properties. Fish protein isolates were produced by pH change method using alkaline and acidic pHs (2.5, 3.5, 11 and 11.5). The extracted proteins were evaluated for nutritional value, and functional properties, sensory properties, color, and structural changes of proteins. The extracted proteins showed relatively high nutritional value in the amount of essential amino acids. The solubility, gelling and foaming capacity of the proteins depended significantly on its extraction pH. So that the percentage of solubility and foaming capacity of proteins extracted under alkaline conditions showed a higher rate than acidic conditions while the least gelation concentration was related to pH 11.5. Examination and comparison of color (L, a, b and whiteness) and sensory properties of isolated proteins showed that proteins at acidic pH had a brighter and whiter color and better sensory properties than those from alkaline pH. The change in pH caused extensive protein degradation as shown by FTIR and SEM. The above results showed that the protein isolated from rainbow trout waste has good functional and nutritional properties in alkaline conditions, while the sensory properties and color of acidic conditions showed better results

The aim of the present study was to estimate growth and mortality parameters and length-weight relationship of Barilius mesopotamicus populations in difrent Iran basins. For this purpose, 460 fish specimens from Diala, Jarrahi, Karun, Karkheh and Bushehr basins and subbasins, including Zardmashin, Aalaa, Jarrahi, Dez, Shur, Meymeh, Changooleh, Kangir, Doyrej, Ahram, Zohreh, Kheirabad, Karzin, Shahpur and Darolmizan rivers, were sampled. Total length, fork length and standard length were measured by a digital caliper (cm) and total weight by a digital scale (g). Also, some scales were prepared and studied for age determination. The length-weight relationships showed that population from Bushehr, Jarahi, Karun and Dila, had negative allomeric growth pattern while Karkheh population had an isometric growth pattern. The highest estimated total length and weight was 9.2 cm and 5.4 g. Age of the fish was between 0+ and 2+. The highest asumptetic total length was observed in Diala basin with Bertallanfy equation of Lt= 9.22[1-e-1.3(t+0.07)]. The condition factor was about 0.5. Considering body indices, Bushehr, Jarahi, Karun and Diala had a better condition, and Karkheh population had a lower index, probably indicating a poorer condition in this river.

Controlled delivery technology of protein/peptide drugs from biodegradable particles has emerged as one of the eminent areas to overcome problems related to macromolecules formulation. The goal of the present study was to develop protein-loaded micro-particles using biodegradable polymer, polycaprolactone (PCL) and hydrogel from beluga cartilage. Bovine serum albumin (BSA) was used as a model for protein/ peptide molecules such as GnRH. The double emulsion (W/O/W) technique was selected as one of the most appropriate methods for preparing a drug delivery system for soluble proteins in water. The first emulsion was prepared using ultrasonic and the mechanical agitator was used for achieving the second emulsion. The hydrogel prepared by enzymatic digestion was used in the first aquatic solution. At the present investigation, three groups were considered as the drug delivery system: G1; (PCL/hydrogel/BSA), G2; (PCL/BSA) and G3; (PCL/Alginate/BSA). Findings showed that the morphology of particles was spherical and non-conglomerated in all groups. The comparison of average particle size among groups was also indicated that the particles.

In the present study, the effect of different levels of magnetized water on the biochemical parameters of rainbow trout was investigated. 120 rainbow trout with mean weight (150±7 gr) were introduced to 12 tanks (500 L). Magnetizers in different intensities including 1500, 2500 and 3500 Gauss (3 replicates per treatment) were installed at the entry of every tank. Experimental period was eight weeks. The blood sampling was done at the beginning and end of the study to evaluate the biochemical blood parameters like Glucose, Lysozyme, total protein, Cortisol, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). The results showed that the magnetized water had a significant effect on the biochemical parameters of the rainbow trout blood (P˂0.05). Totally, the liver enzymes (ALT, AST and ALP) decreased significantly (P˂0.05) with increasing of the magnetic intensity compared to the control treatment and in the case of lysozyme and total protein significantly increased (P˂0.05). The effect of magnetized water on stress-related parameters did not follow a specific pattern, however, the amount of glucose and cortisol in 2500- gauss treatment was 55.50±0.86 mg/dl and 11.65±0.08 ng/ml, respectively in which was decreased significantly (P˂0.05). In conclusion, some blood parameters of rainbow trout improved using different intensities of the magnetized water up to 2500 gauss.

The aim of this study was to measure the level of Arsenic, Cadmium, Nickel and Mercury in gill, muscle and hepatopancrease tissue of Aras dam Astacus leptoductylus and compare of them concentration in different body tissues. For this purpose, 271 samples of Astacus leptoductylus were randomly collected in Aras dam from December 1 to December 31, 2017 and transferred to the laboratory. After that tissue samples processed for injection in atomic absorption for apparatus for measuring the level of Arsenic, Cadmium, Nickel and Mercury. For measuring the protein, ash and moisture content of the samples AOAC method was conducted. The results showed that Arsenic, Cadmium, Nickel and Mercury were present in the Astacus leptoductylus samples and the highest level of these metals was in the muscle and the lowest in the gills. The highest level of metals existing in Astacus leptoductylus muscle was related to Cadmium (0.338± 79 0.79 ppb), and also Nickel (0.285±0.066 ppb) was in the second rank. The level of Arsenic and Mercury in muscle were ranked third and fourth. However, it was found that the total moisture content of the gills was higher than muscle and hepatopancrease tissue. On the other hand, the results of correlation between metals of different tissues of Astacus leptoductylus showed that the correlation between Cadmium and Nickel was higher than Arsenic and Nickel. The level of total protein and ash in Astacus leptoductylus muscles was higher than other tissues. The present study showed that analyzed Arsenic, Cadmium, Nickel and Mercury level were in the muscle, gill, and hepatopancrease tissue samples of the Aras dam A. leptoductylus in detectable concentrations, and Nickel and Mercury in the samples were lower than the WHO standard. As a result, the levels of metals in the Astacus leptoductylus samples collected from Aras dam were safe and reliable and therefore there is no problem.