The introduction of NIR analysis will result in more consistent and higher quality shrimp feed as analyses can be completed in a few minutes rather than the hours required for conventional wet chemical methods. NIR is used to check incoming raw materials for quality and safety. The quality results are used to make precise calculations for feed formulation. NIR analysis is used again to confirm that the finished feed matches the required specifications and to generate data for documentation.
Uniquely long record
NIR stands for near infrared spectroscopy. In essence, the sample is illuminated with near infrared light and the spectrum of light reflected by the sample is recorded. That spectrum is automatically compared with standard spectra held in a central database and the results are delivered almost instantly. Skretting has a uniquely long record of using NIR for raw material and feed analysis.
We began using NIR almost 20 years ago, reports rjan Breivik, the research scientist at Skretting Aquaculture Research Centre (ARC) with global responsibility for NIR.
New generation of NIR instruments
One of the special features of NIR is that the more you use it, the more data you gather and the more accurate your analyses become. With close to 40 instruments in our feed plants and at the ARC we have an unmatched set of data. Recently we raised the level of accuracy further with a new generation of NIR instruments.
We use NIR to check raw materials for undesirable substances and to assess their quality. Nutritional data, for example on protein, fat and moisture content, is used to calculate exact proportions of raw materials to match the nutritional specification for the feed. When checking the composition of the finished product, the minimal sample preparation required and quick response time mean it is fast enough to provide results before the feed goes for delivery.
Shrimp feeds
Breivik and his team check and calibrate all new instruments and provide the training required to operate them. Together with the ARC laboratory they prepare the basic set of standard calibration spectra required for comparative purposes, a task they completed for shrimp feed during recent months.
While we could use some information from our existing fish feed database, several different raw materials occur in shrimp feeds. Also shrimp feed is different in composition from fish feed, so we prepared a new set of calibrations to permit the checking of final products. In addition to raising quality and consistency standards at the Skretting companies producing shrimp feed today, this data means we can quickly bring further acquired shrimp feed producers up to Skretting standards.
In Norway, Chile, Australia and Canada, Skretting also offers an NIR service to customers, providing analyses of pigment content, fats and fatty acids in samples of salmon and trout.
