Measurement of fat content of cultured Pacific bluefin tuna Thunnus orientalis by near-infrared spectroscopy

Abstract

 Near-infrared spectroscopy (NIR) was used to measure the fat content of cultured Pacific bluefin tuna Thunnus orientalis. The back abdomen part of 32 tuna was individually scanned by a portable near-infrared spectrophotometer (NIRGUN), and the fat content of the flesh meat at the same part was chemically analyzed to derive the calibration equation. From 2008 to 2015, the fat content of more than 3000 fish was measured by NIRGUN. The data showed that the fat content of cultured tuna was not affected by fish age from three to six years old, but was strongly affected by water temperature.