Abstract: A rapid method based on near infrared (NIR) spectroscopy was developed for the determination of synthetic pigments in fruit-flavored beverage. NIR spectra of sunset yellow, tartrazine, ponceau 4R and amaranth solutions at different concentrations were recorded in the wavenumber range of 1 100–1 650 nm at a 0.2 nm interval, respectively and preprocessed by first derivative and second derivative. The modified partial least square (MPLS) regression models were established after spectral preprocessing by standard normal variate (SNV) + detrending and applied to predict the synthetic pigment contents in beverage. The results showed that the maximum correlation coefficient of prediction (Rp) was 0.991, the minimum standard error of prediction (SEP) was 0.009%, and the maximum standard deviation ratio (SDR) was 3.51. Accordingly, NIR spectroscopy can be used as a simple, rapid, nondestructive and reliable method to determine the contents of synthetic pigments in beverage.

Key words: near infrared spectroscopy, fruit-flavored beverage, synthetic food pigments, determination