Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/26/2004
Publication Date: 4/30/2005
Citation: Jordan, M.J., Goodner, K.L., Castillo, M., Laecnina, J. 2005. Comparison of two hs-spme fibers for the detection of volatile chemical concentration changes due to industrial processing. Journal of the Science of Food and Agriculture. 85:1065-1071.
Interpretive Summary: Two sampling techniques were used to isolate and quantitate orange juice flavor compounds during differing processing stages. The two techniques were largely consistent and there were few concentration determinations that were statistically different. The processing steps had different effects. The deaeration of the juice significantly affected the flavor compounds, while pasteurization had little influence. In general, it seemed that one technique (solid phase microextraction with polyacrylate coating) was slightly better in that the results were more precise.
Technical Abstract: Solid phase microextraction (SPME) with two polymeric coatings, polydimethyl siloxane and polyacrylate (PDMS and PA), was used to isolate and quantitate orange juice volatile compounds from the headspace of fresh orange juice after the finishing, deaeration, and pasteurization processes. The results from the two fibers were largely consistent. Statistically significant changes in concentration were detected for medium volatility alcohols, hexanal, and seven terpenes as measured by SPME-PDMS due to the deaeration process. However, when using the PA coated fiber more statistically significant changes in concentration were detected for aldehydes and esters. Alcohols and terpenes presented similar results using both polymeric coatings. The pasteurization 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 aromatic fraction during industrial processing.