Comparison of two headspace solid phase microextraction fibres for the detection of volatile chemical concentration changes due to industrial processing of orange juice

Solid phase microextraction (SPME) with two polymeric coatings, polydimethylsiloxane (PDMS) and polyacrylate (PA), was used to isolate and quantitate orange juice volatile compounds from the headspace of fresh orange juice after the finishing, deaeration and pasteurisation processes. The results from the two fibres were largely consistent. Statistically significant changes in concentration due to the deaeration process were detected for medium-volatility alcohols, hexanal and seven terpenes as measured by SPME-PDMS. However, when using the PA-coated fibre, more statistically significant changes in concentration were detected for aldehydes and esters. Alcohols and terpenes presented similar results using both polymeric coatings. The pasteurisation process did not modify the aromatic profile of the deaerated orange juice, except for methyl butyrate. These results indicate that the PA coating seemed to be more suitable for the analysis of the evolution of the orange juice aromatic fraction during industrial processing. (c) 2005 Society of Chemical Industry.