Can spectroscopy in combination with chemometrics replace minks in digestibility tests?

One of the most relevant but expensive methods of assessing the quality of fish meal is the physiological digestibility test with minks. The purpose o f this study was to determine whether spectroscopic and chemical analyses e valuated with chemometrics can replace minks in digestibility tests. The sp ectroscopic methods used were the two complementary techniques of fluoresce nce emission and near-infrared reflectance. The investigation included 54 s amples of high-quality fish meal ranging from 89.6 to 93.9 on the mink dige stibility index. The investigation also included determination of seven qua lity parameters in the fish meal to substantiate the spectroscopic models o n the mink digestibility. These quality parameters include the content of p rotein, oil, water, water-soluble protein, ash and the biogenic substance c adaverine as well as the titration value. The study demonstrates that the m ink digestibility could be predicted from combining the two reference quali ty parameters oil and ash with a correlation coefficient of 0.89. The best spectroscopic calibration models on the mink digestibility resulted in a co rrelation coefficient of 0.94 and a prediction error of 0.5 using the near- infrared spectral ensemble and a correlation coefficient of 0.92 and a pred iction error of 0.5 using the fluorescence spectral ensemble. In addition, the seven reference quality parameters could be predicted from the spectros copic ensembles with good precision. (C) 2000 Society of Chemical Industry.