Claire Corlett

Fish Food, Fish Tanks, and More
How should farmed fish taste? – the Aquafresh project with results

How should farmed fish taste? – the Aquafresh project with results

The Swedish University of Agricultural Sciences and Örebro University have conducted a groundbreaking research project into cultivated fish using their specialities in environmentally friendly animal production and gastronomy Spearheading the project is Professor Anders Kiessling, a leading figure in the field of aquaculture. Cultivated gives us options to produce a completely new product line adding to the wild line. Aquaculture offers the possibility to relieve the pressure of over fishing in the wild and to tailor a product to the palate of a chef. In order to do so we need to produce a fish that is both environmentally friendly and be of the highest quality. Fish is something that we really like to work with especially in the nordic regions where we have great fish with the cold climates and the cold waters, of course we wanted to use fish that’s sustainable. The uniqueness of this project is the combination of the latest analytic technology and sensory evaluation. This will help us understand what factors during production affects the gastronomic appreciation of the product as food. i.e. the terroir of the fish, or as we now say menoar. In this initial project the researchers want to create a basic knowledge of how storage time and rigor affect the sensory qualities, and if taste difference can be measured by the changes in the metabolites within the flesh. Today we are in Stockholm in Sweden and Ulriksdals Värdshus. So we are doing our sensory testing for the fish here today. You need the trained panels for the assessments and we always use the students. So today we are testing char. We both cook them in a water bath as well as serve them raw. And when we cook a product that hasn’t gone through rigor it will behave in one way, when we taste it raw it will be a very different thing. Today we have Sebastian Gibrand, and of course we have other chefs working for this restaurant taking part in this sensory testing as well. It was super interesting to see how the fish really behaved after a few hours, and it was a big difference. The fish has been stored for 72 hours, 24 hours and 5 hours on ice before we took out the samples. The fish was first of all filleted by the chefs they took out the fillets from one side for evaluation of the taste, and the other side of the fish was cut in smaller pieces and given to us so we could freeze them down in liquid nitrogen. Cut it in small pieces, made an extraction with chloroform and methanol. To destroy the cells we also treated with ultrasound, centrifugation to separate the water phases and the chloroform. We need to cut off the proteins so we can run the N.M.R. (Nuclear magnetic resonance). We extract the the compounds that are existing in the fish muscles and then we measure them using different analytical methods and then we try and see if there is correlation between the size of these signals coming from different metabolites and the sensory quality judged by a chef. We can see totally different metabolites are dominating in both cooked and raw. Scientists are now looking into which groups of substances those are representing. We can see in this graph a distinct difference between storage times sweeter taste dominate the start of the process and with storage develops more free amino acids, bitter flavours and umami, with the taste fading out over time. We are still in the initial stages of this work but it will open up a whole new world. The results from the chefs is in line with the results from the trained panel. They didn’t like the the 5 hour stored on ice fish either. Both the chefs and the panel agreed that the fish stored 72 hours on ice had developed a deeper taste of umami, sharing a similar reaction on taste as when meat is stored. Basically what our results are indicating here in this project is saying that the fish are actually benefiting on being stored on ice for hours or even days in order to extract the unique flavour, to create the perfect meal. Maybe it’s not just the freshest that’s the best, in certain products or certain dishes super fresh is the perfect, with other dishes you may want to wait some time. It’s super important to make science of what we are feeling when we are eating. This kind of a link is important because big companies, chefs and everyone who is working with these kinds of products and working with the end consumers and the guests they need to understand the science part behind that. So you think Sweden has a potential of aquaculture farming? Sweden is very well placed to actually get circular production of food through aquaculture This kind of interaction between the farmer and the good chef is happening now because aquaculture has opened that possibility

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