Fluorescence Spectroscopic Analysis For The Detection Of Several Kinds Of Fruit Juice Beverages

Fruit juice beverages are one class of popular liquid foods. At present, fruit juiceadulteration and food additive problems occur sometimes for the related detection methodslag behind, which bring potential threats to the benefits and health of the customers. Thecommercial fruit juice beverages available in the market vary considerably in quality, while itis difficult for the customers to recognize by simple sensory judgment. Besides, thecommonly adopted methods are not capable of dynamic monitoring for the fruit juiceproducts. It is necessary to find out one rapid and reliable way to achieve the adulterationrecognition, and hence to monitor and regulate the market order of fruit juice products.Fluorescence spectroscopic analysis is a simple and efficient way to make the qualitativeand quantitative analysis for the target materials. Herein the fluorescence spectroscopy wasapplied to detect the fruit juice products, including orange, apple and grape juices. Theresearch focused on the rapid fruit juice adulteration recognition and food additives detectionby fluorescence spectroscopy. It involves spectral characteristics analysis of three kinds offruit juice samples，the study on the multi-component spectral resolution, fruit juiceadulteration and food additives detection of fruit juice beverages with fluorescencespectroscopy. Firstly, orange, apple and grape juice samples were selected, the fluorescencespectra were measured and analyzed. Meanwhile, inner filter effect in the ultra-violetexcitation region was observed when the concentration and optical length were altered. Inaddition, parallel factor decomposition and two dimensional correlational fluorescence spectrawere both used to resolve the overlapped spectra. The results indicate that the systems cannotmeet the trilinear condition for the influence of inner filter effect, and hence the resolutionwas affected evidently by inner filter effect. It means the trilinear validation must beperformed before the construction of parallel factor decomposition model. The finalresolution shows that the non-enzyme browning reactant and polyphenols compound mainlycontribute to the total spectra of apple juice.In order to achieve the rapid classification of100%fruit juice and fruit juice drinks,fluorescence spectroscopy coupled with pattern recognition was applied. The spectral gravityof three dimensional spectra was extracted and discriminated with robust MahalanobisDistance, the cutoff value C=22，0.9752.7162. Meanwhile, the partial least squareregression and parallel factor analysis model were constructed to estimate the fruit juicecontent in fruit juice beverages, and hence the fruit juice adulteration was detectedFinally, the study on the synthetic food pigment determination in carbonated drinks withfluorescence spectroscopy was also performed. The absorption and three dimensionalfluorescence spectra were both recorded, and combine with second order calibration modelPARAFAC. Simultaneous determination of pigments in drinks was carried out without anyseparation. The result indicate that fluorescence spectra method can rapidly andnon-invasively determine the pigments, which provides reference for the food additives likesynthetic pigments. Fluorescence spectroscopy is one of the ideal non-invasive technologies, which has goodpotential application prospect. The research can prompt to expand the practical scope offluorescence spectroscopy technology in the on-line and real-time analysis.