High hydrostatic pressure processing of pumpkin: Identification and quantification of the volatiles profile

The aim of this study was to evaluate the volatiles profile of a pumpkin puree processed by high hydrostatic pressure (HHP) at various pressure values and holding times, specifically, 400 MPa and 600 MPa for 200 s, 400 s and 600 s. The content of volatiles was evaluated by the method of solid-phase microextraction with gas chromatography-mass spectrometry (SPME GC-MS). A total of 42 volatile compounds were identified. Major compounds were alcohols and aldehydes, while minor compounds were ketones, esters, aromatic compounds and terpenes. Significant changes were found after processing in all chemical groups except for ketones and esters. The effect of the increment of the volume of pressure was higher than the increment of holding time. Most volatile compounds detected have their origin in lipid oxidation reactions, few compounds were formed by carotenoids degradation, while none volatile compound was formed by Maillard reaction. Most compounds isolated in pumpkin puree were formed by lipid oxidation reactions, especially by the activity of oxidative enzymes such as lipoxygenase. The control of the development of these reactions could be essential to preserve the original aroma of this fruit.