摘要

Synchronous front-face fluorescence and visible spectroscopies are utilized for the simple, rapid, and nondestructive quantification of extra virgin olive oil (EVOO) adulteration with corn, soybean, and sunflower oils. For each adulterant, 42 adulterated EVOO samples in the adulterant amount in the range 1.0-50 g/100 g were prepared. The partial-least-squares regression was executed for quantification. Both full (leave-one-out) cross-validation and external validation were performed to evaluate the predictive ability. The plots of observed vs. predicted values exhibit high linearity. The coefficient of determination (R-2) values are larger than 0.99. The root mean square errors of both cross-validation and prediction are no more than 2%. The detection limits for the three seed oils using fluorescence and visible spectroscopies are in the range of 1.5-2.2% and 1.8-2.4%, respectively. The merit of this method is that both the front-face fluorescence and visible spectroscopies are recorded toward neat oils, avoiding any sample pretreatment including dilution.