Springer Science and Business Media LLC

Health concerns related to sodium intake have instigated work towards using salt replacers in salted foods such as smoked salmon. However, innovations in food may influence sensory perception and consumer acceptance for a product. This study investigates salt replacement and brine injection salting in smoked salmon from descriptive and hedonic sensory perspectives. Smoked salmon samples were produced by combining traditional or novel salting techniques (dry salting or brine injection) with traditional or novel salt types (NaCl or NaCl + KCl in a 2:1 ratio). The samples were evaluated with regard to their appearance, odour, taste, flavour and texture by a trained panel in a quantitative descriptive analysis. They were also evaluated by 102 Norwegian consumers in blind (taste only), expectations (product information only) and full information (taste and information combined) conditions. In addition to hedonic liking, the participants evaluated their willingness to pay for the products in a non-hypothetical, incentive-compatible procedure. Descriptive results show that brine injection samples differed in appearance, taste and texture from dry-salting samples, while NaCl + KCl samples obtained the same sensory profile as NaCl samples. Consumers prefer dry-salting samples, but do not discriminate between salt types, neither in liking nor in willingness to pay. Consumers most attracted by the fully traditional treatment are characterised by a frequent consumption of smoked salmon and a focus on nutrition and healthiness in food. Consumers most attracted by the fully innovative treatment tend to be convenience oriented and price conscious. The results indicate a market potential for partially salt-replaced smoked salmon.

The original version of this article unfortunately contained an error where the figure caption for Figures 3 and 4 was mixed.

A 10-week feeding experiment was conducted to evaluate the nutritional value of menhaden oil (MO), soybean oil (SO) and soybean lecithin oil (SL) at different ratios (MO/SO/SL) in practical diets for juvenile Litopenaeus vannamei by determining their effects on survival, growth, blood chemistry and fatty acid composition of hepatopancreas and muscle tissue. Eight isonitrogenous and isolipidic diets were formulated using 3% MO(3/0/0), 3% SO(0/3/0), 3% SL(0/0/3), 1% MO + 1% SO + 1% SL (1/1/1), 1% SO + 2% SL (0/1/2), 1% MO + 2% SL (1/0/2), 2% SO + 1% SL (0/2/1) and 2% MO +1% SL (2/0/1), respectively. There were no significant differences in body weight gain among all treatments. However, shrimp fed diets with SL supplementation showed significantly (P < 0.05) higher survival than those fed diets without SL supplementation (3% MO and 3% SO diets). The fatty acid (FA) composition of hepatopancreas and muscle tissue reflected, to a certain extent, FA composition of the test diets. Shrimp fed the 3% SL diets showed significantly (P < 0.05) higher triglyceride (TG) concentration in serum than those fed the other experimental diets. Shrimp fed diets containing SL have relatively higher total cholesterol (TC) and phospholipid (PL) concentration in serum than those fed the diets without SL (3% MO and 3% SO). The results of the present investigation are encouraging and confirmed soybean lecithin supplement in shrimp practical diets, when sufficiently high levels of phospholipid are present, survival is enhanced.

Eastern oyster, Crassostrea virginica is a keystone species in many estuarine bays. They clean the water by filtering out suspended particulates from the water column, while their reefs serve as valuable habitat for many ecologically and economically important macrofaunal species. However, with the ever-increasing development along our coastlines, the oyster population throughout the Mid-Atlantic region has plummeted as a result of overharvesting, extreme eutrophication, and disease. In response to this detrimental decline, many conservation organizations in the area have developed community-involvement programs commonly referred to as ‘oyster gardening’ to help restore the oyster population, while instilling within the community a strong sense of stewardship for their bays. Although the oyster gardening program in Delaware is relatively new, its popularity has grown tremendously. It is the hope of many Delaware residents that the reintegration of oysters into the Inland Bays will help to return their bays to the state of health in which they once were. Despite the expansion, further development of designated reef area is necessary to ensure the successful proliferation of C. virginica in Delaware’s Inland Bays.

Motile Aeromonas Septicemia (MAS) is a serious problem for fish farming industry. Attention has been focused on detecting novel products of plant origin for MAS prevention. Among these plants is Moringa oleifera that has a wide range of medicinal uses. The current study was carried out to evaluate the efficacy of dietary Moringa oleifera leaves (MOLs) and their aqueous extract in prevention of MAS in Cyprinus carpio fingerlings. Median lethal dose (LD50) of Aeromonas hydrophila was determined. Minimum inhibitory concentration, minimum bactericidal concentration, and agar well diffusion methods were used to determine antimicrobial activity of MOLs aqueous extract against Aeromonas hydrophila. Three different fish diets were prepared including diet1 with no additives (control), diet2 containing 1 g of MOLs/kg feed, and the third diet containing 10 ml of 10% MOLs aqueous extract/kg feed. Fish were fed with its specific diet at 5% of body weight for 30 days. At the end of the dietary experimental period, mortality and relative percent survival (RPS) were calculated. Organs were collected for histopathology. The LD50 was 1.5 × 105 CFU/ml. The aqueous extract exhibited excellent antimicrobial activity. No mortalities and 100% RPS were observed in all groups except 10% mortalities and 86 RPS of group fed MOLs then injected with Aeromonas hydrophila and 70% mortalities in control positive group. Severe histopathological alternations were observed in control positive group while that fed MOLs aqueous extract then injected with Aeromonas hydrophila showed normal histological structure of all examined organs. The group fed MOLs then injected with Aeromonas hydrophila showed mild histopathological changes in liver and kidney. Therefore, aqueous extract succeeded in prevention of MAS with no mortalities and no histological alterations. Further studies are needed for comparing between the traditional form of MOLs and their aqueous extract and their nanoparticle form in prevention of MAS disease in fish. Also, further studies are needed to explain the superior effect of MOLs aqueous extract in MAS prevention.

The differences in the ridge structure of the mandibles of different size Astacus leptodactylus (32–80 mm carapace length, CL) were investigated. The results showed that a modification occurs with an increase in size in the incisor ridge of mandibles in A. leptodactylus. The results also showed that A. leptodactylus possesses four different types of ridge structure in the mandibles. These are: (1) Incisor ridge with big teeth (dentate crenate), (2) Blade-like incisor ridge with numerous small teeth, (3) Blade-like ridge (toothless), (4) Blunt ridge. In conclusion, it is thought that the incisor ridge modification of the mandibles may cause the difference in the food choice of different size A. leptodactylus, because, crayfish possessing different ridge structures of the mandible may probably feed on different type of food.

The present study was conducted to evaluate the bioflocculant chitosan and its nano-conjugated form in biofloc production and to evaluate the growth performance of genetically improved farmed tilapia (GIFT) in an insitu biofloc system. A completely randomised design (CRD) was used to evaluate the growth performance of GIFT in insitu biofloc over a 75-day period. The trial was conducted with biofloc control (T1), 30 ppm chitosan (T2) and 30 ppm nano-chitosan (T3) in triplicate. The water quality parameters were maintained in the optimum range for biofloc production. The highest value for flocculation activity, total suspended solids, total dissolved solids and total solids other than floc volume was observed in T3 followed by T2 and T1. The result of this study showed that there was a significant difference (p < 0.05) between treatments in terms of specific growth rate (SGR), weight gain (%WG), feed conversion ratio (FCR), feed efficiency ratio (FER) and daily increment (DI). Good growth performance of fish was observed in biofloc produced with nano-chitosan in terms of average body weight (g) (24.74 ± 2.58), SGR (%/day) (3.56 ± 0.094), PWG (%) (1546.27 ± 143.42), lowest FCR (1.421 ± 0.029), FER (0.62 ± 0.011), PER (1.68 ± 0.03) and DI (g day−1) (0.21 ± 0.014). The highest levels of amylase, lipase and protease activity and increased activity of antioxidant enzymes (SOD and CAT) were found in the T3 treatment compared to T2 and T1 treatments. This study demonstrated that biofloc developed with 30 ppm nano-chitosan could shorten the production time of biofloc, maintain the water quality of the biofloc system and improve the growth of GIFT tilapia reared in an insitu biofloc system with inland saline groundwater.