The objective of this study was to characterize the key aroma-active compounds isolated from omija fruits using gas chromatography-mass spectrometry (GC-MS), orthonasal threshold testing, and descriptive sensory analysis techniques. Omija fruits were prepared using four different methods: raw, pureed, freeze-dried, and hot-air dried. The aromatic compounds were extracted with ethanol. Flavor compounds were further isolated using distillation under reduced pressure, followed by liquid-liquid extraction, and were then identified using GC-MS. A total of 40 volatile compounds were identified in omija fruits; nine were further identified as key aroma-active compounds found in omija fruits. The odor-active values for key flavor compounds were calculated, and aroma descriptions perceived by humans were determined using a highly trained panel. This study found that compounds high in omija fruit extracts were not necessarily the odor active compounds and 4-terpineol (1.84) and α-terpineol (2.58) were high odor-active compounds in omija fruits. Samples with high levels of the two compounds (hot air- and freeze-dried omija fruit) had high intensities of "spicy" and "wet-wood" aromatics.
Keywords: GC-MS; descriptive analysis; flavor analysis; odor activity value; omija; sensory threshold.