GAS-CHROMATOGRAPHY OLFACTOMETRY OF ORANGE JUICE TO ASSESS THE EFFECTS OF PLASTIC POLYMERS ON AROMA CHARACTER

Changes in orange juice composition in a model system simulating Brik-Pak aseptic packaging composed of two polymers, LDPE and Surlyn, were measured. GC-FID was used to measure the amount of d-limonene in the juice, while gas chromatography-olfactometry (GCO) was used to measure the odor-active volatiles in orange juice. More than 70% of the limonene was absorbed by the polymers in 24 h at 25-degrees-C. However, results from the GCO analysis indicated that limonene had only trace odor activity. Furthermore, the plastic polymers tested did not substantially alter the odor-active components detected in orange juice. GCO was also used to compare the aroma components of pasteurized, mechanically squeezed orange juice (MS), unexposed to plastics, and fresh orange juice hand squeezed (HS) from oranges of the same lot. Although the overall aroma intensity of both juices was the same, large changes in odor activity were observed for several key aroma constituents.