We use cookies on our website. Some are necessary for the operation of the website. You can also allow cookies for statistical purposes. You can adjust the data protection settings or agree to all cookies directly.
Data Protection Declaration
Imprint
Studies on quality changes during processing and storage of selected products from organic and conventionally produced trout trout as a prerequisite for the development of a practical aid for artisan trout farms
Project
Project code: 2802OE007F
Contract period: 15.11.2004
- 28.02.2007
Budget: 37,933 Euro
Purpose of research: Applied research
The study dealt with the investigation of the rearing conditions incl. comparative feeding experiments and the evaluation of the product quality of portion size trout. Two ecologically certified and three conventional trout farms were examined. The development of different parameters of water chemistry at the in- and outlets of ponds incl. temperature, oxygen, pH, ammonia, nitrite, total and ortho – phosphate as well as COD and particulate matter were measured during the day course. Two ecofeeds were tested in two trials in the laboratory against conventional trout feeds available on the market with regard to growth, feed efficiency and protein utilisation. Both ecofeeds had an unfavourable protein/energy relation yielding in a lower raw fat content. Additionally ammonia excretion patterns of rainbow trout as related to the feeds were investigated. Ecofeeds demonstrated a stronger environmental impact and resulted in a lower growth rate and a worse protein utilisation in comparison to conventional trout feeds.
Investigations on product quality included the determination of biological parameters, microbiological and sensory evaluation of portion size fishes, colour, texture and flavour measurements as well as determination of the chemical composition and the content of contaminants. The overall quality and the microbiological status of trout samples from all farms were excellent. Chemical composition exhibited differences in the fat content of the edible part. All contaminant levels were far below national limits. Differences in quality with respect to ecological or conventional rearing conditions were not found. The study presents the actual situation of the farms investigated but general quality statements can not be derived. (Project code 02OE007/F1)
Section overview
Subjects
- Freshwater fisheries
- Food Processing
Framework programme
Federal Organic Farming Scheme and other forms of sustainable agriculture (BÖLN)
