m. seifzadeh

Collagen has diverse general and biomedical applications and its important role in the future of society have made it a key biopolymer for human health and well-being. Therefore, the present study was conducted with the objectives of extracting collagen from the skin of farmed carp, determining the quality characteristics of collagen, and comparing them. Collagen was extracted from the skin of carp fishes by acidic enzymatic method using 0.5 M acetic acid and pepsin in 48 hours. Collagen treatments (5 treatments) included collagen prepared from the skin of common species, grass carp, bighead, silver, and cow (control). Collagen treatments were not capable of hemolysis and did not show toxic effects on human fibroblast cells. Heavy metals (0.01-0.18 ppm) in collagen extracted from cultured carp species were within the standard range. The color (brightness) of experimental collagen (92.74-93.68) and control (92.38) showed no significant difference (p<0.05). Amino acids cysteine and tryptophan were not observed in collagen. Glycine and hydroxylysine amino acids (352 and 3 residues 1000g-1, respectively) had the highest and lowest amounts in collagen. Amino acids profile and collagen production efficiency (10.51-10.59%) did not show significant differences in carp fish species (p<0.05). Based on the results of the present study, production efficiency, safety and quality characteristics of collagen in cultured carp species did not show any significant difference (p<0.05), and no significant difference was observed between these characteristics and the control (p<0.05). Therefore, the skin of these species can be used to produce collagen and introduce it to the industry as a substitute for mammalian collagen.

The purpose of this study was to evaluate the chemical and microbial spoilage indicators, such as TVN, Peroxide and the total count of mesophilic, Coliforms, Staphylococcus aureus, Escherichia coli and Salmonella bacteria in two types of fish and meat burgers during three months of storage at -18°C.Silver carp and red meat were immediately transferred to the laboratory of National Fish Processing Research Center (UNIDO), in the presence of ice, after purchase. After weighing, the raw paste was prepared along with other additives, according to the general method of burger production ‎from meat. Chemical and biological tests were based on the method recommended by Iranian National Standards Organization.‎ The results showed that with increasing storage time, TVB-N and peroxide were significantly increased in silver carp burgers, in cold storage,. The mean (±SD) of TVB-N of fish burger changed from 12.6±0.14 mg% at the time of production to 14.4±0.14 mg% and the peroxide changed from zero to 1.33±0.14 meq of oxygen at the end of three months of storage. Total count of mesophilic bacteria, coliform and staphylococcus aurous were lower in fish burgers compared to meat burger products, and for both treatments statistically significant difference was observed for the mean total count of mesophilic bacteria in the first month and for coliform, Staphylococcus aurous bacteria in the second month(p<0.05). Salmonella and E.coli were not observed in any of the treatments and at the end of the storage period they were in accordance with the standards recommended by Iranian National Standards Organization. Therefore, it can be concluded that fish burgers have longer cold storage period compared to burgers produced from red meat.

Shrimp is a highly perishable product with limited shelf life due to melanosis and biological composition. Controlling the destructive effects of melanosis is one of the major challenges for the industry. Melanosis in crustaceans is usually controlled by inhibitors such as sodium metabisulfite. However, the use of synthetic inhibitors for melanosis and antioxidants in food processing is usually limited by considerations related to safety and impact on food quality. Thus, over the last decade, the trend towards studies on the use of natural extracts to control shrimp melanosis has increased. Data from some articles published by ScienceDirect, PubMed, Scopus, SpringerLink, and Scopus databases on the occurrence of melanin black pigment in shrimp skin were used. The shrimps were dipped in extracts and stored in ice or refrigerator. In Iran, only the effects of grape seed extract to prevent melanosis have been studied. Some studies have reported higher effects of plant extracts such as Garcinia cowa Roxb, Persicaria Odorata, rosemary, green tea, avocado, Arabic coffee grounds, and chamomile than sodium bisulfite. Some researchers have described the effects of extracts such as olive, rosemary, and thyme along with metabisulfite in preventing melanosis more than metabisulfite alone. Plant extracts were effective in reducing black spots in shrimp for 2-28 days. Studies have shown that plant extracts can act as antioxidants and be an effective natural alternative to inhibit melanosis after shrimp death.

Azolla is certainly a valuable laboratory plant that will thrive with very little care. The use of Azolla may be an important factor in the world's future food needs. Azolla is unique because it is one of the fastest growing plants on the planet – yet it does not need any soil to grow. Azolla is a small floating fern and is the only known pteridophyte that lives in symbiosis with a diazotrophic cyanobacterium. Azolla spp. are heterosporous free-floating freshwater ferns that live symbiotically with Anabaena Azollae, a nitrogen-fixing blue-green algae. There are six species of Azolla in the world. Azolla is a genus of aquatic ferns in the family Salviniaceae. The genus Azolla belongs to the single genus family Azollaceae. Azolla filiculoides is a species of Azolla. Azolla filiculoides is under the sub-genus Euazolla. It is native to warm temperate and tropical regions as well as most of the old world including Asia, Australia and Anzali wetland. This plant is dark green to reddish and float on the water surface, either individually or in mats, which can reach a thickness of up to 20 cm. When A. filiculoides plants are exposed to strong sunlight they obtain a red color. The same occurs in winter time. In shade they always remain green. A. filiculoides settles in ponds, ditches, water reservoirs, wetlands, channels and slow flowing rivers. A. filiculoides is very rich in protein, fat, ash and carotenoids. The chemical composition of Azolla species varies with ecotypes and with the ecological conditions and the phase of growth. The dry matter percentage of different Azolla species varies widely. Lysine and methionine contents in this species are moderate. But, essential amino acids in this species are poor. Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms. Carotenoids are considered key molecules for life. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. Carotenoids as natural pigments, are used by the industry as pharmaceuticals, nutraceuticals, and animal feed additives, as well as colorants in cosmetics and special foods. Carotenoids have been studied for their ability to prevent chronic disease due to the free radical theory of aging in chronic disease etiology. The effect of carotenoids on biotechnology and the food industry is significantly attributed. Finally, carotenoids as fortified substances in foods and special aspects about carotenoids as health promoters are well presented along with a glance of carotenoids economics. β-carotene is one of the carotenoids. β-carotene is the main source of pro-vitamin A and is widely used as a food colorant. The majority of the β-carotene commercialized in the world is obtained by chemical synthesis from β-ionone. Therefore, research for the production of natural colors for use in food industry has particular importance.

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 winter 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, calorimetry 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, calorimetry, 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 food hygiene, it is recommended that natural β-carotene extracted from Azolla filiculoides be substituted for synthetic β-carotene in the food industry.

Rainbow trout fillet is susceptible to microbial and oxidative spoilage. Therefore, it is essential to use preservatives to extend its shelf life. Date extract has significant antibacterial and antioxidant properties. This research was conducted to study the effect of aqueous date extracts on chemical, microbial and sensory properties of farmed rainbow trout during refrigeration. Total phenolic and flavonoid content were determined through Folin-Ciocalteu and colorimetric method. The first step of study was performed for determination the antimicrobial activity of date extracts against the inherent flora of fish fillet, lactic acid bacteria, Pseudomonas and Enterobacteriaceae by disc diffusion method. In parallel with antimicrobial tests, sensory evaluation was also performed for choosing the best concentration of extracts in order to applying on fish fillets. In the second step of study, fish fillet samples were immersed in date extracts (3% w/v for 5 minute), packaged in zip–bags and stored at 4 oC over a period of 17 days. The extract-free fillet was used as control. The samples were analyzed for microbiological (mesophilic, lactic acid bacteria, Pseudomonas and Enterobacteriaceae counts) and chemical (PV, TBARS and TVB-N) parameters. The 5-point hedonic method was carried out for sensory evaluation by 30 trained panelists. Analyses were conducted at 2 h after preparation and 1, 3, 5, 7, 9, 11, 13, 15 and 17 days of storage.  Phenolic and flavonoids contents showed no significant differences between date extracts (p>0.05). Total bacterial counts, Enterobacteriaceae, Pseudomonas, TBARS, PV and TVB-N showed no significant difference in test samples (p>0.05). These parameters were within an acceptable range up to 15 days for test samples while the control samples had a shelf life of 5 days. Samples preserved by Piaroum extract had the longest shelf life while samples preserved by the combination of extracts had the shortest. According to the results, the Piaroum, Zahedi, Mozafati date extracts and their combination could be used as natural preservatives for trout fillet shelf-life extension.

Beta-carotene was prepared from Azolla by Lejeune et al. (2000). Beta carotene production from Azolla filiculoides in the Anzali wetland has not been investigated in Iran so far. The present project was aimed at determining the content, quality, and purity of β-carotene extracted from Azolla filiculoides in the Anzali Wetland, and comparing it with synthetic β-carotene. One treatment had β-carotene derived from Azolla filiculoides in the Anzali Wetland through the organic solutions method in the Autumn of 2014. The treatments were kept at 5 °C for one year. Synthetic β-carotene was used as the control. The quality of the treatments was assessed by the measurement of the content and quality of β-carotene, colorimetry using the Hunter-LAB method, determination of the purity and vitamin A employing 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, colorimetric, vitamin compounds, dwell time, and solubility in the experimental β-carotene, compared with those in the control, revealed 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). According to the achieved results from chemical tests and the shelf life of the test samples, the natural β-carotene had a desirable chemical quality during the storage period at 5 °C for one year. Since there was a 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 as the natural β-carotene derived from Azolla filiculoides takes precedence over the synthetic one in terms of the food hygiene, it is recommended that natural β-carotene extracted from Azolla filiculoides be substituted for synthetic β-carotene in the food industry.

Trout (Oncorhynchus mykiss) is one of the most popular fish in the world. It is considered to as a best fish, and its pollution is important in terms of health and food hygiene. Trout is of the cold water fish and is in the subgroup of free fish. Animal protein, especially fish, has an important role in tissue retention, health and human happiness, and in general, the growth of the body due to the necessary amino acids and growth promoters, and the deficiency of this protein causes an imbalance in the nervous system, mental retardation, neuroticism, physical weakness in humans. and reduces the resistance of the body to infectious diseases. But, despite having a nutritional value and the body's need for aquatic animals, if the accumulation of heavy metals exceeds the limit, it can be a cause of disease and problem for humans, and therefore research in health matters is of particular importance. The presence of these compounds is harmful to human health and is not permitted. Heavy metals are environmental pollutants. The contamination of fish to heavy metals can lead to the accumulation of these elements in the body of consumers and the appearance of some diseases. Non-degradable pollutants such as heavy metal salts accumulate in the environment. The accumulation of toxic substances in the food chain may increase their concentration in animals at higher levels in the food chain. The accumulation and biological role of heavy metals in marine organisms can lead to the risk of human health from these metals. Exposure of fish to contaminants and its transmission to humans, can cause several diseases. The present research was aimed at determining concentrations of Lead and Cadmium, in muscles of farmed rainbow trout (Oncorhynchus mykiss) in Guilan’s Talesh, Iran, comparing levels of the metals in the flesh of both female and male rainbow trout, and comparing them with standards of Food and Agriculture Organization, Food and Drug Administration and Iran Veterinary Organization. Material and This research had 6 groups, consisting of trout which were 700-900 g and <300 g in weight. They were obtained in December, 2014. The homogenized flesh (15 numbers) was examined using an atomic absorption spectrometer. Trout fish was biometric. The trout were 478.56 g in weight and 318.93 cm in length. Despite pH and temperature, water hardness of studied pools showed significant differences (P<0.05). PH of water ponds was neutral. The water temperature was 15-16 ºC. The water temperature of the pool was not proper for heavy metals absorption to fish. Lead and Cadmium varied between 0.01> and 0.03. In this study, the amount of lead compared to Cadmium was not showed significant reduction(P<0.05). Hardness were 85.50 mg/l in A and B pols and 153.90 mg/l in pole C. Was not observed significant differences in water hardness factor between pools A and B compared with C pool. Water pools A and B were medium hardness and C pool was hard. Water of pools A and C were medium hardness, but water pool B was hard. Water hardness on cadmium in comparison to Lead had more effect. Correlation Lead and cadmium with age, length and weight in some of the pools were positive and in the others were negative. Between age groups similar were not observed significant differences in studied pools of Talesh (P>0.05). No significant differences in per farmed ponds between lead and cadmium concentrations in the age groups below 300 g 700 -900g(P>0.05). Except of the age group 300g< of pond A from Talesh, the other ponds in the age groups including of 300g< and 700 -900g was showed significant differences compared with FDA, FAO, WHO and Iran Veterinary organization in Lead and cadmium concentrations(P<0.05). There was no correlation between the accumulation of cadmium and lead compared with sex. According to achieved results and decreasing accumulation of heavy metals in farmed Trout Talesh compared with international standards, in terms of cadmium and lead contamination and food sanitary, farmed Trout of these regions are no side effects for human consumption in the autumn. According to the achieved results on farmed rainbow trout 700-900 g and <300 g in Talesh in fall, it must be declared that they cause no adverse effects and are fit for human consumption in terms of food hygiene and concentrations of lead and cadmium in them.

This study intends to evaluate the accumulation of heavy metals such as lead and cadmium in the edible tissue of whitefish in Anzali Lagoon and comparewith international standards of FDA and FAO. Whitefish were caught from the west, central and east regions of Anzali Lagoon. Sampling was conducted in the fall season. Levels of heavy metals were measured using flame atomic absorption spectrometry. The average concentration of cadmium in whitefish from center of wetlands was 0.05 μg/g, in western and eastern parts of wetland was 0.03 μg/g dry weight, respectively. There was no significant difference (P> 0.05) in the levels of cadmium in different parts of the lagoon. The average concentration of lead in whitefish in the western parts of wetlands was 0.33 μg/g, in central and eastern parts 0.53 and 0.41 μg/g dry weight, respectively. No significant difference (P> 0.05) was noticed in the lead levels in different parts of the lagoon. Pb in central region of wetland showed no significant increase compared with international standards. Cd concentration in all parts of the lagoon was within the range of international standards

This project was carried out with the aim of increasing shelf life of Kilka Fish and prevent color change during cold storage. Three replicates were used for each method. Whey protein with 3 and 9 % concentrations were used for fish packaging at time 0. Cleaned Kilka fish were packaged in disposable dishes and covered by cellophane were used to control the samples. The samples were kept at -18 oC. Examinations were carried out for a period of six months. Total bacterial count and Staphylococcus bacteria count were lower in the samples covered with 9% concentration compared with the other samples. The Coliform, Escherichia coli and Pseudomonasbacteria contamination were negative until the end of storage period in the covered and control samples. Moisture, protein, fat and ash  were higher in the  samples covered with 9% concentration  compared with the other samples. Peroxide value, TVN and pH were lower in the  samples covered with 9% concentration compared with other samples. Statistically significant differences were observed in their bacterial counts, chemical factors and total acceptance index (p< 0.05). Sensory analysis carried out to the ranking method. Samples covered with 9% concentration compared with the samples covered with 3% concentration had a better quality. The covered samples had a favorable quality until the end of storage period. But control samples lost their quality after three months.