IntroductionSustainable growth of the salmon aquaculture industry is highly dependent on the availability of new feed resources as well as improved management and utilization of waste streams from production. Polychaetes are capable of recapturing and recycling valuable biomolecules contained in aquaculture sludge and at the same time constitute a possible resource for aquafeeds.Material and methodsIn this study, the potential of Hediste diversicolor (OF Müller, 1776) to recover nutrients and energy contained aquaculture sludge was evaluated. Hereby, the effect of two different diets, smolt and post-smolt sludge, and different feed levels on polychaete growth, and biochemical and elemental composition was assessed.Results and discussionSurvival ranged from 80-90%, independent of treatment. Specific growth rates at the highest feed levels were significantly higher than at the lowest feed levels and growth was not affected by the type of diet. Similarly, total lipid and total fatty acid content of polychaetes were positively correlated with feed level while the type of diet had a limited effect. Fatty acid composition of polychaetes reflected feed levels: in both diet groups, polychaetes at lower feed levels showed a higher percentage of saturated fatty acids; monounsaturated fatty acids increased with increased feed supply for smolt sludge-fed group and polychaetes fed post-smolt sludge showed increased polyunsaturated fatty acid content with increasing feed levels. Neither diet nor feed levels affected protein content and amino acid composition of polychaetes. In conclusion, H. diversicolor could be successfully cultivated on both smolt and post-smolt sludge and was rich in proteins and lipids as well as essential amino and fatty acids. The species can be considered a promising candidate for recycling valuable nutrients from different types of side streams salmon aquaculture.

Common beans (Phaseolus vulgaris) have been part of the human diet for millennia and traditionally have been consumed whole or as mashed bean paste. This legume is an important source of nutrients and growing evidence suggests it can be considered a functional food, but today it's consumption is declining. Alternative bean products may be needed to increase bean utilization, however few exist on the market. The objective of this study was to develop a baked bean and rice chip with good nutritional properties. Initially the concept of bean and rice chips was analyzed. Twenty-seven potential consumers (13 men and 24 women between 16 and 40 years-old) were interviewed about their perceptions and opinions concerning bean products in an exploratory study. Afterwards, ten different formulations were evaluated for consumer acceptance, the variables tested were different concentrations of condiments and additives used to obtain a crisp product. Formulations were presented in a random and balanced way to a 100 persons group who evaluated products for acceptability with a 15 cm hedonic scale. Data were analyzed by ANOVA and LSD tests. The most accepted formulation was analyzed for fat, fiber, protein and folic acid content. The exploratory study with potential consumers indicated several aspects such as flavoring, appearance, crispness, shape, fat content, shelf life, and price should be considered in the chip product development. This study also indicated the main negative aspect was the bean and rice chip being an unknown product. However, the group visualized it as being very innovative, highly nutritious and with good marketing potential. Results from acceptability tests showed two main clusters of people with different preferences. The first cluster (46 persons) gave higher acceptance scores to the products than the second cluster (54 persons). Overall, one product received high acceptance scores from both clusters. Chemical analysis of the most accepted formulation showed the developed bean and rice snack can be considered a low fat and high fiber product, since a 30 g portion contains 1,7 g fat and 5,6 g dietary fiber. Protein content per portion is 4,2 g, and it also supplies 10% of daily recommended folic acid intake. Baked bean and rice chips have good marketing potential as a nutritious, low fat and high fiber snack.