Profiling of phenolic and other polar compounds in zucchini (Cucurbita pepo L.) by reverse-phase high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Polyphenolic compounds are widely distributed in vegetables. Zucchini (Cucurbita pepo L.) has a high nutritional value and a low amount of calories. Nevertheless, few studies in the literature focus on the separation and identification of phenolic and other polar compounds in whole zucchini fruit. Therefore, the present study characterizes phenolic and other polar compounds in three kinds of zucchini (Verde, Redondo, and organic Verde) bought in Almeria (Spain). For this purpose, an extraction method using methanol:water (80:20 w/w) has been applied in order to extract the polar fraction from the samples studied. Afterwards, the extracts were injected into the RP-HPLC system and separated by a C-18 column. Q-TOF-MS detection was conducted using a micrOTOF-Q equipped with an electrospray ionization (ESI) interface. The combined use of RP-HPLC coupled to DAD and Q-TOF-MS has proved useful for characterizing numerous phenolic and other polar compounds in zucchini. A total of 57 compounds were identified with the present methodology. In fact, to the best of our knowledge, 41 out of 57 identified compounds are being reported here for the first time in whole zucchini fruit. (c) 2012 Elsevier Ltd. All rights reserved.