By Rodrigo Arévalo
Director Derwent Trading
Converting inedible biomass into fish feed.
Examples of new generation food sources are microalgae, yeast and bacterial biomass. These single-celled organisms are proliferating much faster than any other biomass on the planet, with an excellent amino acid profile in their protein and a high digestibility rate in research model animals. The production of this protein does not compete with any other established food protein source. The growth of the single-celled organisms and therefore their protein is much faster than any other protein source.
Microalgae are well known as an immune booster and unlimited source of protein. The space required for microalgae growth is negligible. In general, microalgae do not require any arable land, or a fresh water supply.
In addition to protein, microalgae contain valuable polyunsaturated fatty acids, which are a more sustainable source of these valuable nutrients for aquatic organisms than fish oil. Microalgae are rich sources of pigments, chlorophylls and carotenoids. The inclusion of microalgae in the diets of various fish resulted in a positive growth effect and increased gut functionality. Due to their chemical composition, they are a promising alternative to increase the nutritional value of conventional aquafeeds and as a partial substitute for fishmeal in intensive aquaculture.
The insect meal revolution.
Insects offer enormous market potential. Insect meal has a similar protein content to fishmeal. In addition, insect meal can contain high-grade fatty acids. About 40% of fishmeal can be successfully replaced by insect meal for small fish diets. In Norway researchers managed to replace up to 100% of fish protein in salmon diets without adverse effects on fish growth or later on the peculiar taste of fish fillets.
Advances in fermentation technologies.
Several scientific investigations concluded that yeast represent sustainable ingredients in aquafeeds due to their ability to convert low-value biomass into high-value food ingredients with almost no dependence on agricultural land, water or climate change. Depending on the species and strain, yeast can be produced from fermentation of food waste or residues from the agricultural or forestry industry. Advances in fermentation technology have led to more efficient and cheaper yeast production, making yeast more economically viable as a source of nutrients for aquafeeds.
A study conducted at the Swedish University of Agricultural Sciences in Uppsala showed that the level of yeast species in diets had no effect on gut microbiota. The yeast species found in the feed diets were not found in the gut of the fish, demonstrating the complete digestibility of the yeast materials. A study at the Norwegian University of Life Sciences showed that Candida utilis and Kluyveromyces marxianus were good sources of protein in Atlantic salmon diets. These single-celled organisms were shown to replace up to 35% of high-quality fishmeal, without any detrimental effect on fish growth performance, digestibility or nutrient retention.
From Derwent Trading, as strategic partners in the supply of high value raw materials to the Dibaq Group, we are immersed, aware and at the forefront of everything that generates added value to the entire aquaculture chain and all this, seen from a sustainable, reliable and supply assurance point of view.