In vivo determination of fat content in Atlantic salmon (Salmo salar) with a mobile NMR spectrometer

Abstract

A new method for the rapid measurement of the fat content in live (or slaughtered) Atlantic salmon, based on a mobile low-field NMR analyser, has been developed and tested. The instrument, calibrated against a set of reference samples (fish oil in agarose), was used for non-destructive fat determination of the Norwegian quality cut (NQC) of anaesthetized fish. The total analysis time per fish was about 20 s. The fat content (range 90-182 g kg −1 ) showed significant correlation (r = 0.92) with chemical extraction data obtained after slaughtering the same fish. The spatial distribution of fat in the NQC was obtained and visualized as a 'fat image' using novel software. It was concluded that the mobile NMR spectrometer has potential for implementation in connection with on-line quality control.

Real-time ultrasound (RTU) imaging methods for quality control of meats

“…It is also an important factor in consumer acceptance (Probert and Shannon, 2000;Romvári et al ., 2002;Veliyulin et al ., 2005). Traditionally, carcass composition in fish was determined by comparative slaughtering followed by chemical analysis (Oberle et al ., 1997).…”

“…Other methods such as ultrasound velocity (Suvanich et al ., 1998;Sigfusson et al ., 2000) or near-infrared techniques (Wold and Isaksson, 1997) are based on fillet samples or dead fish. However, fish production is heavily dependent on quick, accurate and, above all, non-invasive methods to predict carcass composition in live fish (Probert and Shannon, 2000;Veliyulin et al ., 2005;Silva et al ., 2010a). Comprehensive studies using image techniques such as CT (Romvári et al ., 2002;Hancz et al ., 2003;Kolstad et al ., 2004), MRI (Collewet et al ., 2001;Veliyulin et al ., 2005) and RTU (Bosworth et al ., 2001;Rodrigues et al ., 2010;Silva et al ., 2010a) have shown that these techniques are able to predict carcass traits in fish.…”

“…However, fish production is heavily dependent on quick, accurate and, above all, non-invasive methods to predict carcass composition in live fish (Probert and Shannon, 2000;Veliyulin et al ., 2005;Silva et al ., 2010a). Comprehensive studies using image techniques such as CT (Romvári et al ., 2002;Hancz et al ., 2003;Kolstad et al ., 2004), MRI (Collewet et al ., 2001;Veliyulin et al ., 2005) and RTU (Bosworth et al ., 2001;Rodrigues et al ., 2010;Silva et al ., 2010a) have shown that these techniques are able to predict carcass traits in fish. From a practical point of view, CT has several characteristics that make it the preferred technique for in vivo evaluation of carcass composition in fish.…”

Portable NMR in food analysis

“…The same unilateral NMR device was tested by Veliyulin et al [43] to set up rapid non-destructive measurement of the fat content in live or slaughtered Atlantic salmon. The total analysis time per fish was about 20 s. The distribution of transverse relaxation times when measured with a conventional benchtop NMR instrument shows three peaks.…”

Rapid determination of the fat content in packaged dairy products by unilateral NMR

“…5 A number of interesting applications have been demonstrated, including determination of fat content in live Atlantic salmon, 6 one-dimensional imaging of heterogeneous rubbers, 7 characterisation of polymer materials, 8 self-diffusion measurements, 9 tendon anisotropy studies 10 and detection of water ingress in model aerospace composites. 11 Unilateral NMR has other advantages over a traditional benchtop time domain NMR.…”