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8409603 
Meetings & Symposia 
Determination of polyphenols in olive oil by means of fluorescence analysis 
Gracia, A; Zude, M; Leã³N, L 
2009 
Potsdam 
5th International Technical Symposium on Food Processing, Monitoring Technology in Bioprocesses and Food Quality Management 
1364-1368 
English 
The fluorescence spectroscopy may provide a powerful tool for analyzing nondestructively native components constituting the quality of olive oil. Polyphenols are natural antioxidants that can be found in the virgin olive oils and essential compounds in the prominent 'Mediterranean diet'. In the present work, a total of 65 samples of olive oils obtained in selections from a breeding program were analyzed by reference methods to obtain data on total polyphenol content. The fluorescence spectroscopy explored the excitation (cex) and emission (cem) characteristics of raw oil and diluted 1/10 in hexane, using a fluorimeter (LS55, Perkin-Elmer, USA) equipped with a xenon flash lamp serving as light source and photomultiplier tube as detector with two grated monochromators for excitation and emission with a resolution of 0.5 nm. Oil spectra were analyzed using different methods of data pre-processing such as multiplicative scatter correction, standard normal variate, and the Savitzky-Golay first derivative algorithm. Calibration models were developed using partial least-squares regression to evaluate the potential of fluorescence spectroscopy in olive oil quality monitoring. Most feasible results were obtained in the calibration on diluted samples with correlation coefficients of r = 0.88 and standard error of cross validation of SECV = 71.48 applying the first derivative of oil fluorescence spectra with ex = 200-500nm and em = 525nm. These results demonstrate the potential of fluorescence spectroscopy for monitoring quality parameters in olive oil, being a rapid technique and saving time and costs, and therefore an useful tool in olive breeding programs where a high number of samples have to be evaluated every year. 
Fluorescence spectroscopy; Nondestructive; Olive (Olea europaea L.); Polyphenols; Quality