Laser Analysis of Strawberries

Phenolic compounds in fruits and vegetables enhance their nutritional value, so it is useful to identify and quantify the various native compounds. Scientists from Leibniz Institute for Agricultural En- gineering Potsdam-Bornim and from Technical University Munich, both in Germany, have tried laser-induced fluorescence spectroscopy to perform such measurements in strawberries.

Researchers used laser-induced fluorescence spectroscopy to identify and quantify phenolic compounds in strawberries.

They identified 18 phenolic compounds using a high-performance liquid chromatography (HPLC) analyser from Gilson-Abimed Systems and a PerkinElmer mass spectrometer. A laser fluoroscope with a pulsed nitrogen laser and fibre optic probe excited and measured the fluorescence at the fruit surface. A Zeiss NIR-enhanced spectrophotometer measured the reflectance from 300 to 1100 nm.

The researchers experimented with various preprocessing and statistical analysis approaches to overcome reabsorption and masking effects and achieved the best correlation using direct orthogonal signal correction.

(Journal of Agricultural and Food Chemistry, 14 May 2008, pp. 2875-2882)