Abstract:

Synchronous fluorescence scanning was conducted on freshly prepared orange juice and commercial orange
juice to obtain the three-dimensional fluorescence spectra. Three groups of characteristic peaks were obtained and based on
their fluorescence characteristics, these peaks were identified as VB2, VB6 and flavonoids, respectively. At the same time,
the synchronous fluorescence spectral data of all the orange juice samples obtained by scanning at excitation wavelengths
of 240–640 nm with a wavelength difference of 30 nm compared to the emission wavelength were analyzed using principal
component analysis (PCA). Quite good results were obtained showing that the combination of fluorescence spectroscopy and
spectral pattern recognition method can provide the powerful technical support for the identification of orange juice quality.

Key words:  orange juice, synchronous fluorescence spectrometry, principal component analysis (PCA)