Using HS-SPME to determine the effects of reducing insoluble solids on aromatic composition of orange juice

This present study compares the qualitative and quantitative characteristics of the volatile compounds found in the headspace of freshly extracted orange juices, with insoluble solids content of 3% or less and 10 to 15%. The analysis of volatile components was carried out using a solid-phase micro-extraction device with two different types of coating fibres, polydimethylsiloxane and polyacrylate. Results showed that reductions of the insoluble solids correspond to reductions in the headspace quantities of many of the volatile components. Aldehydes, terpenic hydrocarbons and alcohols exhibited reductions in headspace concentration, while most of the esters and ketones did not. For aldehydes, this reduction was more obvious when polyacrylate was used as the coating. Polydimethylsiloxane coating proved to be better for detecting changes in the headspace concentrations of terpenic hydrocarbons and alcohols. Similar results were obtained using simultaneous steam distillation extraction. (C) 2001 Academic Press.