|PRIETO, NURIA - Lacombe Research Centre
|SWIFT, MARY - Tri-Gen Fish Improvement Ltd
|SUMMERFELT, STEVEN - Freshwater Institute
|JUAREZ, MANUEL - Lacombe Research Centre
|ZIJLSTRA, RUURD - University Of Alberta
|AALHUS, JENNIFER - Lacombe Research Centre
Submitted to: Journal of Food Analytical Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2015
Publication Date: 4/12/2015
Citation: Prieto, N., Swift, M., Summerfelt, S., Juarez, M., Zijlstra, R., Aalhus, J. 2015. A feasibility study on the use of near infrared spectroscopy for the authentication of depurated salmon fillets. Journal of Food Analytical Methods. 8:2660-2664.
Interpretive Summary: Fish cultured in recirculating aquaculture systems (RAS) can bioaccumulate the off-flavor compounds (MIB and geosmin) produced by certain species of bacteria. These common off-flavors are often described as “earthy” or “musty” by the consumer, and if present at high enough concentrations can result in product that is unpalatable and unacceptable for the marketplace. Therefore, it is critical for RAS facilities to have access to reliable measurement techniques for off-flavor compounds in fish and in water. The potential of near infrared spectroscopy (NIRS) to quantify off-flavor concentrations in salmon tissue was tested. NIR spectra correctly classified 100%of non-depurated and depurated salmon fillets, but not necessarily a difference in geosmin or MIB between non-depurated and depurated fillets. Further studies are needed to test NIRS technology, where portable equipment applied directly on the whole salmon through the skin could be used to authenticate salmonwith enhanced quality for marketing purposes.
Technical Abstract: Some species of actinomycetes, fungi, and bluegreen algae produce semivolatile off-flavor compounds responsible for earthy-musty odorants in water from aquaculture facilities and tend to bioaccumulate within fish flesh. Although these off-flavor compounds are harmless to human health, high levels within fish tissue lead to an undesirable taste leading to an unmarketable consumption quality. Preharvest processes such as depuration can be used to eliminate most of these off-flavor compounds and ultimately enhance salmon quality. This study examined the potential of near infrared spectroscopy (NIRS) to discriminate depurated from nondepurated salmon fillets (n=62). Partial least squares discriminant analysis based on NIR spectra correctly classified 100%of non-depurated and depurated salmon fillets. The successful classification was likely a consequence of statistically significant differences in the content of off-flavor compounds between both samples, which could have been detected by NIR spectra. Thus, NIRS is a fast, inexpensive, solvent free, and non-destructive technology that can be used for the authentication of salmon with enhanced quality for marketing purposes.