Effects of edible film of sodium alginate on quality changes of dressed kilka in frozen storage

The likely effects of sodium alginate edible coating on the quality of dressed kilka fish in the frozen storage was investigated. Sodium alginate edible coating was prepared in four concentrations (0.25, 0.75, 1.25, and 1.75%). Then, dressed kilka fish were coated with sodium alginate for 1h, packed in polyethylene dishes with cellophane blanket and stored at - 18°C. The amount of hem Iron, pH, percent lipid and organoleptic characteristics (odor, color) were assessed within 0, 1, 2, 3 and 4 months (sample size: 125 packs of 250g). Results showed a significant difference between the mean hem iron and percent lipid and increase in sodium alginate concentration (P0.05) with different levels of coating. Organoleptic results showed that the mean color and odor value of the samples were affected significantly by different levels of coating (P<0.05). Use of sodium alginate edible coating to protect hem iron and improve organoleptic properties can increase the quality of kilka in frozen storage up to 4 months

Short communication: Study on bioaccumulation of heavy metals (cadmium, nickel, zinc and lead) in the muscle of wels catfish (Silurus glanis) in the Anzali Wetland

After entering aquatic ecosystems, heavy metals accumulate in the organs and tissues of aquatics including fish and finally enter the food chain. These heavy metals can enter the human body through eating contaminated fish. Absorbance values and accumulation of heavy metals in aquatics especially the fish depend on ecological conditions, physical, chemical and biological factors of water, the element type, and the physiological state of the aquatic (Oryan et al., 2010). Among aquatic ecosystems, wetlands and rivers are considerably important from the point of ecology. Rivers act as carriers of nutrients and non–nutrients and wetlands act as sinks for these substances. Now this effect will be more apparent if the wetland is an intermediary between a river and a static ecosystem. The Anzali Wetland is the type of ecosystem that embraces water from 11 rivers from one side and passes water into the Caspian Sea through a second outlet on the other side. The rivers passing through urban and rural areas and forests carry different types of organic matter, minerals, sediment, and industrial sewage (Taheri, 2013). The Anzali Wetland is one of the valuable wetlands registered in the Ramsar International Convention the contamination of which has become the main challenge for the people and officials during the past two decades (Khosravi, 2011)

Heavy metals (Cd, Ni and Zn) concentrations in the edible muscle tissue of Pike perch (Esox lucius) from Anzali Wetland

Pike (Esox lucius) is a native species in Anzali Wetland and has been considered for its flesh. This study was carried out to compare the rate of accumulation and concentration of heavy metals such as cadmium, nickel and zinc in edible muscle tissue of pike at three stations (west, center and east) of Anzali wetland in 2012.Ten fishes were randomly caught by gillnet from different stations in standard weights. After removal of the tissue samples, for chemical digestion through mixed acid digestion (HNO3 / HClO4) was performed on samples. Heavy metal concentrations were measured using flame atomic absorption spectrophotometer. The average concentration of cadmium in pike in western station was 0.05 and in eastern and central part of wetland was 0.09 (μg/g dry weight), Mean concentrations of nickel metal in west, center and east, were 0.44, 0.37 and 0.22 (μg/g dry weight), Average concentrations of zinc in western, central and eastern part of wetland were 28, 25.55 and 13.55 (μg/g dry weight) respectively. In this study, concentrations of cadmium, nickel and zinc in edible muscle tissue of pike did not show significant differences between stations (P>0.05). The cadmium, nickel and zinc standards in American Food and Drug Administration (FDA), World Health Organization (WHO) were compared. The results showed that toxicity of nickel in samples of central was near but in western part was more than the permissible limit compared with the standard WHO = 0.38, therefore consumption of this fish could be a warning of a threat to the health of these fish in vulnerable groups of society

Protein and lipid changes of FPC produced from Caspian Sea kilkas in VP and MAP during storage at different temperatures

Fish Protein Concentrate (FPC) is a healthy, sustainable and high nutritive product that produced from fish and protein and other nutrients are more concentrated than in the fresh fish. The aim of this research is to study the sustainability of FPC produced from Kilka (combination of three Caspian Sea Kilka species, Clupeonella engrauliformis, C. grimmi and C. cultriventris which were not identified and processed separately) in VP (Vacuum Packaging) and MAP (Modified Atmosphere Packaging) at different temperatures during six months of storage. According to result of chemical analysis performed, protein content was evaluated 91.2%, lipid 0.5%, ash 3.6%, moisture 2.3%, TVN 10 mg/100g and peroxide 5 meq/kg in the produced FPC before packing. Amino acids and fatty acids were also determined. Lipid amount in FPC after 6 months at 35°C in VP changed from 0.50 to 0.45 and in MAP (combined of 60% CO2, 30% N2 and 10% O2), decreased from 0.50 to 0.36. It was also detected that increase in temperature leads to more decrease in lipid content but it was not significant (P>0.05). Protein content of FPC has changed from 91.2% to 73.6% during six months at 35°C in VP and 69.4% in MAP. But at 5°C, protein contents were changed from 91.2% to 88.4% and 81.2% in VP and MAP, respectively; these changes were significant (P<0.05) but the decrease in MAP was again more than VP

Impacts of whey protein edible coating on chemical and microbial factors of gutted kilka during frozen storage

The aim of the present study was to investigate the impact of whey protein coating on quality and shelf life of Kilka fish. Whey protein edible coating was prepared in three different concentrations, including 3, 7, 10 and 13%. Then gutted Kilkas were coated for 1h, packed in polyethylene dishes with cellophane blanket and stored at -18 °C. Total microbial count, total volatile nitrogen (TVN) and moisture evaluation were carried out within 0, 1, 2, 3 and 4 months (sample size: 75 packages, weighted 250 grams each). Results showed that there was no significant difference between total microbial count and total volatile nitrogen among samples (p>0.05). Moisture of coated samples with 13% concentration of whey protein had significant difference with other treatments (p<0.05) suggesting that whey protein edible coating with 13% concentrations can enhance quality and increase shelf life of Kilka fish in storage of freezing up to 4 months

The evaluation of the quality of beta-carotene derived from Azolla filiculoides in the Anzali Wetland using the alkaline hydrolysis method in summer

The present project was aimed at determining the content, quality, and purity of β-carotene extracted from Azolla filiculoides in the Anzali Wetland, comparing it with synthetic β- carotene, and measuring its economic value. One treatment had β-carotene derived from Azolla filiculoides in the Anzali Wetland through the alkaline hydrolysis method in the summer of 2014. Treatments were kept at 4 °C for one year. Synthetic β-carotene was used as the control. The quality of the treatments was assessed by applying some chemical tests, including the measurement of the content and quality of β-carotene, colorimetry using the Hunter-LAB method, determination of the purity and vitamin A employing high-performance liquid chromatography (HPLC), estimation of the dwell-time duration at 5 °C, and measurement of the solubility of β-carotene in water. The results of the tests regarding the purity, concentration, colorimetry, vitamin compounds, dwell time, and solubility in the experimental β-carotene, compared with those in the control, revealed no significant difference (p>0.05). Moreover, the factors showed no significant difference between the control and experimental treatments during the dwell time (p>0.05). The natural β-carotene had a good quality during the storage period at 5 °C for one year. Since there was no significant difference between the β-carotene derived from Azolla filiculoides and the synthetic one in terms of the chemical tests, purity, and dwell time, and since the natural β- carotene derived from Azolla filiculoides takes precedence over the synthetic one in terms of the economic value, it is recommended that natural β-carotene extracted from Azolla filiculoides be substituted for synthetic β-carotene in the food industry

Mesh size improvement of beach seine in the Iranian coastal waters of the Caspian Sea and its effects on the target fish catch

We measured biometrical properties of kutum (Rutilus frisii kutum) and mullet (Mugil cephalus) in Iranian coastal waters of the Caspian Sea along caught with a new Beach Seine mesh size and the results were compared with that of common Beach Seine (control). The results indicated that newly designed Beach seine, catches less nonftbstandard fish than the control. The proportion of non-standard kutum and mullet in the new Beach Seine was 7.7 and 1.1 percent respectively; these results in control were 67.1 and 29.98 percent. The average length and weight of kutum and mullets, caught by newly designed Beach Seine was higher than the control. The Catch per Unit Effort (CPUE) in the two types of Beach Seines was approximately the same. The results showed, by promoting this newly Beach Seine, we can largely prevent fishing of non-standard bony fish (immature) in the Caspian Sea coastal waters

Comparison of effect of Zataria multiflora and Rosemarinus officinalis extracts on quality of minced frozen silver carp

The aim of the this study was to have a comparison between Zataria multiflora and Rosemarinus officinalis extracts on quality of minced frozen silver carp preserved in cold storage temperature -18°C for six months. In this research, one control and three treatments of minced silver carp were prepared as Tr1 (+ Zataria), Tr2 (+Rosemary) and Tr3 (mixed with Rosemary and Zataria) all in normal packaging. After quick freezing of samples in the spiral freezer they were preserved in cold storage temperature -18°C for six months. In this period, the changes of Peroxide Value, Total Volatile Nitrogen, Tio Barbituric Acid and Free Fatty Acids in all treatments were measured based on a predetermined schedule. The results of this investigation showed a significant effect of anti-oxidant in all treatments (p<.05) and it was concluded that Rosemary containing anti-oxidants maintains the best quality after six months of cold storage and corruption indices are not exceeded. Analysis of Peroxide Value, Total Volatile Nitrogen, Tio Barbituric Acid and Free Fatty Acids in different treatments during six months of reservation in freezing under the temperature of -18°C showed that the obtained results to the end of the reservation period for all treatments has increased and treatment containing Rosemary, with Peroxide Value 6.83±0.35meq.1000g^-1, Tio Barbituric Acid 2.1±0.1mgMAL.kg^-1 and Total Volatile Nitrogen with 19.16±0.28mg.100g ^-1 had the best quality of preservation compared with other treatments during the preservation period. Therefore, based on these results and statistical analyses, the effect of anti-oxidant and time in all treatments is significant (p<.05) and the treatments containing Rosemary had the best quality preservation status in -18°C and did not surpass perishing criteria during this period

The influence of sodium chloride replacement with potassium chloride on quality changes of hot smoked kilka (Clupeonella cultriventris caspia) during storage at ± 4°C

The aim of this work was to study the effect of sodium chloride replacement with potassium chloride on quality changes of hot smoked Kilka during storage at ± 4°C. To achieve this, after initial preparation, samples were exposed to brining process in two salts. This study was designed in two stages: in the first stage, different levels of salt replacement were used to select the best smoked treatment based on sensory test. In this stage, treatments were as: control (100% of NaCl), treatment 1 (75%NaCl/25%KCl), treatment 2 (50% NaCl/50%KCl), treatment 3 (25%NaCl/75%KCl), treatment 4 (100% of KCl). Samples were processed at slow and fast speed smoking for about 4 h, cooled and then tested by test panel. In the second stage, biochemical changes of selected treatment (treatment 1) were compared with control samples during storage at ± 4°C for 15 days. There were no differences (p>0.05) in content of fat, moisture, ash and TBA indices between control and treatment 1. Protein levels and salt intake were significantly (p<0.05) increased while the TVB-N and PV indices decreased in treatment 1. The results indicated that 25% sodium replacement with potassium is desirable for this product

Fatty acid composition of fresh and smoked Black and Caspian Sea sprat, Clupeonella cultriventris (Nordmann, 1840) treated with different salt composition

The effect of salting by different salt composition on fatty acid profile studied in hot smoked Black and Caspian Sea sprat, Clupeonella cultriventris. After initial prepare activities, samples were exposed to brining process within two salt concentrations including of 100 % NaCl (treatment 1 or T1) and 75 % NaCl- 25 % KCl (treatment 2 or T2) under 15% brine solution for 3 hrs. The smoking process included turning the samples into drying and hot smokes by slow and high rates of smoking machine (Atmoos) set and packaged. Fatty acid profiles of treated samples were compared with fresh fish samples (control). Smoking process decreased the content of SFA and contemporary increased the content of PUFA in comparison to control samples. These changes were slightly higher in T2. N-3/n-6 ratio of control samples (7.30) was increased in T1 samples (7.71) and decreased in T2 samples (6.86) after smoking process. Atherogenic index (AI) value was decreased after smoking process in both treatments with higher decrement for T2. Thrombogenic index (TI) value was also decreased after smoking process in both treatments. Partial sodium replacement did not affect fatty acid composition, PUFAs content, AI and TI values