An active protein‐based film was developed by incorporating cinnamon essential oil (CEO) into whey protein concentrate (WPC) at a level of 0.8 and 1.5% v/v. The effects of CEO on microstructure, physical, mechanical and antimicrobial properties of the films were evaluated. Adding CEO to the WPC matrix decreased the water vapor permeability of the films and water solubility by 38.03 and 29.4%, respectively. The films containing CEO also displayed lower affinity to water; the contact angle increased up to 89.61% in 1.5% CEO concentration. Films containing CEO showed notable antibacterial activity against both gram‐positive and gram‐negative strains, and exhibited good inhibitory effect on the studied fungi. However, CEO containing films showed a heterogeneous cracked structure which decreased their tensile strength. This combination of the results confirmed good potential to the film for application in food packaging. Practical Application As a result of the increased concerns about environmental problems caused by synthetic packaging material, the food industry has paid growing attention to biopolymer and edible films during the last two decades. They can control the transfer of moisture, gases, lipids and flavor components in the packaging environment. In addition, these films can function as carriers of many ingredients, such as antimicrobial and antioxidant agents. The present study prepares some information about production of an active protein‐based film containing CEO. The film is environmental friendly and its antimicrobial and antioxidant properties make it useful for application in food preservation and packaging industry.

This study was undertaken to evaluate the role of polychaete Nereis diversicolor in bioremediation of waste water and its growth performance and fatty acid composition in an integrated culture system with great sturgeon, Huso huso. Three treatments consisting of N. diversicolor fed with H. huso waste (FNW), N. diversicolor fed with fish feed waste (NW), and fish waste without the worm (FW) were considered at water temperature of 23°C for 8 weeks. The obtained results demonstrated that N. diversicolor in the flow‐through system could grow via feeding with the fish waste water. The pure production and survival rate of harvested Nereis in NW treatment were significantly higher than those of FNW treatment (p < .05). However, no significant difference was observed in specific growth rate and weight gain between these two treatments (p > .05). The highest removal efficiency of waste water including total nitrogen (56%), total phosphorus (53%), NO2‐N (91%), NH3‐N (35%), PO4‐P (47%), BOD5 (60%) were seen in FNW treatment. Also, the highest additional efficiency of NO3‐N occurred in FW (37%) treatment. Certain fatty acids specifically 20:5 ω3 (eicosapentaenoic acid [EPA]) and 22:6 ω6 (docosahexaenoic acid [DHA]) were also abundant in Nereis, and analysis revealed some differences due to the diet. These results demonstrated that the promotion of growth by cultured Nereis can enhance the decomposition rate of organic matter in enriched sediment and minimize negative effects in fish farms. These results also suggest that the use of N. diversicolor is an excellent potential candidate for an integrated aquaculture and nutrient recycling including the removal of organic wastes.

The objective of this study was to assess the effects of rearing density on the growth and fatty acid profile of Nereis diversicolor and on its capability to bioremediate wastewater in an integrated culture system with rainbow trout (Oncorhynchus mykiss). To this end, a batch of juvenile N. diversicolor (0.03 ± 0.01 mg) was assigned into four different densities (T 1 = 250, T 2 = 500, T 3 = 1,000, T 4 = 2,000, besides T 0 = with no worm) in three replicates. The worm groups were fed with solid waste that was supplied from tanks containing rainbow trout (107.17 ± 13.5 g;1.39 ± 0.18 kg/m 3 ). During the experiment (60 days), the water temperature was 17.71 ± 0.6°C. The results revealed that SR%, SGR% and WG% of N. diversicolor in T 1 were significantly higher than those of T 2 , T 3 and T 4 . Both FER rate and biomass gain in T 4 were significantly higher than those in the other groups. The highest removal rate of NO 2 -N (73.72%), NH 3 -N (65.70%), PO 4 -P (59.32%), BOD 5 (69.60%) and TSS (82.33%) were observed in T 4 . The major fatty acids presents were palmitic acid, oleic acid, linoleic acid, stearic acid and alpha-linolenic acid in all worm-treated groups, with no difference observed in the concentration of these fatty acids among them. Taken together, these findings suggest that organic wastes from rainbow trout farms could be recycled to achieve a sustainable aquaculture goal, and demonstrate that a high percentage of fatty acids in fish feed is not absorbed by rainbow trout but is done by N. diversicolor. K E Y W O R D Sbioremediation, fatty acid profile, integrated aquaculture, Nereis diversicolor, Oncorhynchus mykiss

This study evaluated the effect of whey protein concentrate (WPC) coating incorporated with 1.5% cinnamon essential oil (CEO) on the quality of beluga sturgeon (Huso huso) fillet during refrigerated storage (4 ± 1C). Microbial, chemical, and sensorial properties of the fillets were measured for 20 days. Whey protein edible coating containing 1.5% CEO could extend preserving ability of beluga sturgeon by about 8 days by retarding lipid oxidation and microbial deterioration as reflected by Peroxide Value, Thiobarbituric acid and total viable count. Samples coated with WPC containing CEO also had the lowest pH and Total Volatile Basic Nitrogen. Moreover, the coating did not negatively affect sensory attributes of the fillets. Practical Applications Extensive research has shown the potential application of natural antimicrobial agents in food preservation. But the efficiency of these materials is limited due to intense odor and aroma changes as well as organoleptic problems. One strategy to decrease their bad effects would be incorporating these compounds with edible coatings. In addition, the incorporation of essential oil (EO) with edible coatings provides additional antioxidant and antimicrobial properties in them which can extend shelf life of food. The present study reveals some information about application of an active protein based film containing cinnamon essential oil on shelf life of refrigerated Bluga sturegeon.

Replacement of olive pomace (OP) with wheat flour in diet was studied in diet of yearling Siberian sturgeon (Acipenser baerii). Fish (165 ± 6.8 g) were randomly allocated to 15 fibreglass tanks (15 fish/tank, in triplicate). Fish were assigned to one of five dietary treatments at 19.1 ± 1.5°C for 8 weeks: control diet (crude protein and crude lipid at 514.6 and 188 g/kg, respectively) and four experimental diets with 20, 50, 75 and 100 g/kg OP to replace wheat flour in the experimental diets. No significant difference was observed in the final weight, feed conversion ratio, specific growth rate, hepatosomatic index, viscera‐somatic index and survival rate among the treatments (p > 0.05). No change was seen in digestibility of protein and lipid in diets containing 20 g/kg and 50 g/kg OP compared to control group, while these values decreased with increasing in OP above 50 g/kg. Digestibility of dry matter and gross energy among the treatments demonstrated no significant difference (p > 0.05). Polyunsaturated fatty acids, especially C22:6n3 (DHA), in the muscle of the fish fed 75 g/kg and 100 g/kg OP in diets were significantly higher than control group (p < 0.05). These data show that OP could be recommended as a substitute for wheat flour in diet of S. sturgeon but its utilization for other species warranted future works.

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