Proton transfer reaction mass spectrometry: A new technique to assess post harvest quality of strawberries

It has recently been shown that Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) can detect a wide range of volatile organic compounds (VOCs) with a very limited fragmentation, if any, at a very high sensitivity (5 ppt have been reported) without any need of pre-treatment or pre-concentration. These characteristics make PTR-MS a powerful method for monitoring in real time traces of VOCs (response time ranging from some seconds to few minutes). It is therefore complementary to other, well established, analytical tools such as those based on gas chromatography. This technique has been successfully applied in various fields ranging from medical applications to the physics of atmosphere and food research and technology. We used PTR-MS to monitor the post harvest evolution of VOCs emitted by intact berries of Elsanta from the harvest to the senescence. Moreover the analysis of two different cultural techniques shows different intensities both in the aromatic compounds and in the products of catabolic processes. Results demonstrate that this method provides a new way to investigate on fruit physiological processes and their consequences in post harvest quality and storage ability.