Study of measuring Tilapia (Oreochromis niloticus) freshness using quality index method (QIM)

Fish freshness by using QIM and according to scoring to all of parts variable (positive and negative) was by sensory method and finally become the parameters of quantitative and qualitative with statistical analysis is based, tables used in volatility score of 0 to 23, with a score of 0 to 3 respectively, for their excellent quality, 3 to 7good, from 7 to 10 and from 10 to above average evaluation is unacceptable. In this study to measure the freshness of fish species Nile Tilapia (Oreochromis niloticus), black and red in 4 treatments, whole fish and empty stomach is considered and the objective of this study was to calculate the survival rate of fish in ice cover practically immediately after harvest to measure qualitative factors (sensory evaluation, chemical and microbiological).For this study 50 pieces of red and 50 pieces black Tilapia after weighed, washed and then selection 25 pieces for each treatment in unlit, ratio of 3 to 1 (ice - fish) was covered .The mean (± SD) change in temperature the fish flesh during study were between 0.2 ±0.07 a to 0.3 ±0.1a degrees Celsius, that need to raise the quality temperature is maintained at 0 degrees Celsius in unlit center. Fish covered with ice keep at ambient temperature, and after measuring the change free nitrogen, pH and microbial tests, the results showed maximum shelf life of whole fish in ice cover 9 and for empty stomach fish was7 days .And also statistical analysis (Duncan test) of data between treatments (Whole and empty fish covered in ice ) was significant (P<0.05)

A survey on lethal concentration of Cu and Pb in Caspian Sea Kutum (Rutilus frisii kutum)

The Guilan province in the north of Iran has witnessed a rapid industrial development in recent years causing pollution of water resources in rivers, wetlands and the Caspian Sea coastal areas. We studied the acute toxicity of Copper and Lead in kutum fingerlings through acute toxicity and M.A.C value determination in summer and autumn 2006. A total of 21 aquariums with a capacity of 30 liters each stocked with 10 fingerlings were used in our experiments with the two metals. Six aquaria and six concentrations of Cu and Pb composed the 18 treatments while 3 other aquaria were used as control. For each treatment, three replications were conducted. The relevant physical and chemical parameters of water during the experiments were measured including pH which was in the range 7-7.5, DH=200-250mg/l (CaCO _3), DO= 80% and temperature which was recorded as 24 plus or minus 1°C. Fish investigations were conducted in 24 hour intervals. The results indicated that the lethal concentration (LC sub(50)96h) for Copper and Lead are 1.92mg/l and 252.12mg/l respectively and M.A.C. value for Copper and Lead are 0.192mg/l and 25.212mg/l respectively in the Caspian Sea kutum. Hence, we conclude that Copper is more toxic than Lead for the fish

Cold pasteurization of rainbow trout fillet (Oncorhynchus mykiss) with gamma rays and shelf life assessment at refrigerated condition

The present study was conducted to evaluate the effect of different doses of gamma rays on shelf life and fatty acids composition of Rainbow trout fillet (Oncorhynchus mykiss) during refrigerating condition. Quality and shelf life of non-irradiated and irradiated (0, 0.75, 1.5, 2.25, 3, 3.75 and 4.5 kGy) Rainbow trout stored at +4 C was investigated by measurement of microbiological, chemical and sensory analysis .Irradiation of fillets was performed by gamma rays from a Co60 source. Microbial counts for non-irradiated trout fillet samples were higher than respective irradiated fish. Total volatile base nitrogen (TVB-N) values was increased from 7 mg/100 g for non-irradiated to 52.7 mg/100 g after 15 days storage at refrigerator, whereas for irradiated fish lower values of 39.4, 37.6, 28.7, 25.6, 24.8 and 23.2 mg/100 g were recorded at 0.75, 1.5, 2.25, 3, 3.75 and 4.5 kGy, respectively (day 15).initial amount of peroxide value in non irradiated sampleswas 0.8 meq/kg and was increased to 7 meq/kg (7 day).Highest amount of peroxide after irradiation process was belonged to samples irradiated by 4.5 kGy (1.5 meq/kg). Also, total viable count of irradiated samples were decreased significantly (p<0.05). On nutritional aspect, results showed that total saturated fatty acid concentrations increased significantly (p<0.001) with increasing irradiation dose , so that the control sample and fish muscles that irradiated with 4.5 kGy had the lowest and highest amounts of total saturated fatty acids (20.454 ± 0.011% and 19.228 ± 0.040% , respectively). The amount of total polyunsaturated fatty acids (PUFAs) in irradiated samples were significantly lower than control sample (p<0.001) and amounts of total monounsaturated (MUFAs) were significantly higher than control samples (p<0.001). The results were indicated that the highest content of MUFAs and PUFAs were in samples irradiated with 3.75kGy (37.783± 0.092 %) and control samples (37.677± 0.104 %), respectively .The lowest level of MUFAs and PUFAs were in control samples (36.596 ± 0.024%) and 4.5 kGy (36.459 ± 0.047%), respectively. Altogether, results of this study were determined that irradiation treatment changes significantly the fatty acid composition especially polyunsaturated fatty acids in rainbow trout muscle (P<0.001). Overall, irradiation of fillet by 3.75 kGy had best results on increasing shelf life of fillet at refrigerator (between 11-15 days) and had no advers effect on fatty acid composition of Rainbo trout fillet

Investigation on the effects of different batters on quality of breaded kilka

The aim of this study was investigated to produce of new product using by Caspian Sea Anchovy (Kilka) with different sensory and textural properties .To achievement this purpose, breaded kilka was coated ( row and fried) using with common and Tempora batter. For determination of quality assessment and shelf life, samples were stored at freezer (-18°C). Results showed that frying of Breaded kilka affect total fat content and moisture, so that significant reduction in moisture value and increase in fat content of fried kilka was found in compared with raw breaded kilka (p<0.05). Protein content of both treatments in compared with fresh fish meat was significantly different. Comparison of four treatments showed that a significant increase in the amount of peroxide, thiobarbituric acid and free fatty acids in fried kilka samples which indicates high fat oxidation during the frying process. Also total count of microrganisms and Coliforms was reduced after frying process. According to ICMSE Standard, all of samples had a high quality at processing time. According to the results, using of Tempora batter improved sensory properties of breaded kilka. Difference of taste, tenderness and adhesiveness of two types of batter in products was significant (p< 0.05) as the sensory properties of breaded kilka with Tempora batter in compared with common batter were high in different phase of storage. with due attention to progressing of oxidative deterioration in breaded kilka at forth months after production and decreased of sensory properties, we found that the shelf life of row , fried breaded kilka was 3 month at frozen condition (-18°C)

Production of the burger combination kilka-silver carp and evaluation the nutritional value and shelf life it during cold storage period

Kilka fish burger and silver fish is product of minced fish meat kilka and silver carp are mado of flavors , fillings, vejetables and spices.this fusion can be made on a toasted (fried or raw) and be marketed. The project was to replace the effects of different amounts of kilka fish instead of meat silver carp burger in preparing the consolidated on acceptance and qualitative changes in the past 5 months were examined and selected the best treatment for the industrial manufacturing industry in presented .Therefore , the four treatments with a variety of burger meat mixed with kilka and silver carp have been defined and the sensory evaluation were prepared . Based on statistical tests , selected treatment 3 (kilka hundred percent) in terms of flavor and color is in the highest rating. Also, the control treatment in term of taste, odor and color is in second priority. It is noteworthy that treatments 1 and 2, in the next priority is accepted. Goals of this plan is consolidation of kilka and silver carp in preparation of consolidated burger in order to financial purpose in final product. Chemical, microbiological, sensory evaluation and free fatty acie of the product during the 5 months storage at -18°C is illustrated that, the product is maintained its quality during the entire sensory and chemical paraments