SafeFish - Implications of green fish feed for consumer safety - carry-over of plant peptides, natural toxins and bioactive compounds
The continued growth of Norwegian aquaculture depends on the utilisation of new, sustainable protein resources for fish feed since marine reserves are limited. The last decade has seen a tremendous transition from marine to agricultural feed materials, which currently make up to 70 % of the aquafeeds used in Norwegian salmon farming. Commonly used are protein preparations derived from wheat and legume plants, mostly soy and pea.
This complete change in the diet of fish has led to new challenges regarding fish health and welfare, and product quality. Many initial problems have been solved by extensive research on feed processing methodologies and feed compositions. The Norwegian Scientific Committee for Food Safety (VKM) has, however, recently pointed out in an updated benefit-risk assessment of fish and fish products that plant ingredients may introduce new contaminants into feed, which could be transferred into the eatable portion of fish and might be a risk for consumer safety.
The SafeFish project attempts to fill this data gap by determining the carry-over potential of three typical constituents of plants: plant peptides (stable fragments of plant proteins), mycotoxins (products of fungi infections), and hormone-like compounds (phytoestrogens). Custom-made feedingstuffs containing different amounts of typical plant protein preparations will be used in studies in a zebrafish model and in on-growing salmon. Fish muscle and organs will be analysed with a multitude of analytical methods (proteomics, chemical analysis, fish nutrigenomics, fish transcriptomics, immunochemical assays including test with food allergic patients) to study effects on fish physiology and substance carry-over, and finally to access consumer health risk.
This multi-disciplinary project is a collaboration of the Norwegian Veterinary Institute, Nofima, the University of Oslo, the Nord University in Bodø, Haukeland University Hospital in Bergen and the Mass Spectrometry Center of the University of Colorado in Denver, USA. The SafeFish project includes the training of one PhD student. Additionally, a PostDoc project (EpiGreen) and a visiting PhD student from China are associated with the project.
Funding: NFR Havbruk2 2016-2020
The Project is in its second year: Chemical and proteomic analyses have been developed for, respectively, mycotoxins, pseuo-hormones from soy, and peptides from wheat gluten and soy. Custom-made fish feed has been prepared and the feeding studies in zebrafish and salmon are completed. We were successful in developping an in vitro assay for the biotransformation of contaminants in fish using a preparation from salmon liver (first reported functional assay). The method is used to study, a.o., the metabolism of mycotoxins and phytoestrogens. Tissues and organs from zebrafish and salmon fed with the different diets are currently analysed for epigenetical changes indicating differences between the groups. First results have been presented at international conferences.
Fæste CK, Johny A, Ivanova L. In vitro metabolism of enniatin B1 and deoxynivalenol by salmon liver microsomes. 1st MYCOKEY International Conference, 11.-14.9.2017, Ghent, Belgium.
Dhanasiri AKS, Johny A, Fæste CK, Bogevik AS, Fernandes JMO. Nutrigenomic effects of plant protein-based aquafeeds on fish. Aquaculture Europe, 16.-20.10.2017, Dubrovnik, Croatia.
Dhanasiri AKS, Johny A, Fæste CK, Bogevik AS, Zhang Q, Fernandes JMO. Nutrigenomic effects of plant protein-based aquafeeds on fish muscle and spleen. GIA2018 5th International Symposium on genomics in aquaculture. 21.-23.3.2018, Albufeira, Portugal.
Dhanasiri AKS, Johny A, Fæste CK, Bogevik AS, Fernandes JMO. Nutrigenomic effects of plant-based aquafeeds on fish muscle and spleen. Havbruk 2018, 18.-20.4.2018, Oslo, Norway
Johny A, Ivanova L, Fæste CK. In vitro metabolism and phase II biotransformation of isoflavones diadzein, genistein and glycitein in salmon liver microsomes. International Conference on Aquaculture, 4.-6.6.2018, Copenhagen, Denmark.