Near-infrared hyper-spectral image analysis of astaxanthin concentration in fish feed coating

The aim of this study was to investigate the possibility of predicting concentration levels of synthetic astaxanthin coating of aquaculture feed pellets by hyper-spectral image analysis in the near infra-red (NIR) range and optical filter design. The imaging devices used were a VideometerLab with 20 wavelengths in the range of 385-1050 nm, and a Specim camera with 256 wavelengths in the range of 970-2500 nm. Linear discriminant analysis (LDA), partial least squares regression (PLSR), and a modified stepwise random selection with ordinary least squares (OLS) for filter selection was used for prediction of the concentration level. The results show that it is possible to predict the level of synthetic astaxanthin coating using either hyper-spectral imaging or three bandpass filters (BPF).