Rapid non‐destructive determination of fat content in frozen skipjack using a portable near infrared spectrophotometer

:  Non-destructive determinations of the fat content in frozen skipjack by the portable and desktop near infrared (NIR) spectrophotometers were performed. In both spectrophotometers, the RPD value, which is an index of the accuracy, was higher at the abdominal part than at the central part of the body. The RPD value obtained by the portable instrument was higher than that of the desktop instrument when measured at the abdominal part. The rapid determination of the fat content in frozen skipjack was possible by determining the NIR spectra at the abdominal part of the fish body using the portable spectrophotometer.