Valencia Late orange juice preserved by pulp reduction and high pressure homogenization: Sensory quality and gas chromatography-mass spectrometry analysis of volatiles

Low pulp Valencia Late orange juice was obtained by high-pressure homogenization (HPH) at 150 MPa as an alternative to thermal pasteurization processes. Colour and cloudiness were improved through a soft pre-homogenization at 20 MPa applied before centrifugation. Initially and until 0.5 months of refrigerated storage, it was not distinguishable from the fresh juice and was more acceptable than its counterpart pasteurized at 85 degrees C for 15 s. At 1.5 months onwards of storage (till 3.5 months), acceptability, colour and transmittance of both juices became similar. Moreover, the effects of processing and storage on the aroma profile of juices were evaluated by Gas Chromatography coupled to Mass Spectrometry (GC-MS) analysis with an automated data processing performed by the Automated Mass Spectral Deconvolution and Identification System (AMDIS). There were determined a total of 88 volatiles, following the evolution of 32 aroma descriptors. Compared with the pasteurized sample, the aroma profile of the double homogenized juice was initially closer to fresh juice and presented lower concentrations in off flavour compounds during storage. (C) 2012 Elsevier Ltd. All rights reserved.