불포화지방산의 대표적인 물질 중 하나인 올레산에 백열등 조사와 리보플라빈에 의해 생성되는 휘발성 물질들을 분리 및 동정하였다. 리보플라빈 첨가 시료에서는 리보플라빈 무첨가 시료 보다 39시간 동안 270%의 휘발성 물질이 더 생성되었으며 수용액형태가 비수용액 시료보다 휘발성 물질이 유의적으로 많이 발생하였다(p<0.05). 2-Heptenal은 리보플라빈 첨가 시료에서만 검출되었으며 heptane, octane, heptanal, octanal, nonanal, 2-nonenal은 리보플라빈 광산화 시료에서 대조구에 비해 39시간 동안 각각 8.71, 5.88, 2.58, 2.16, 2.80, 5.84배 이상 증가하였다. 2-Nonenal과 heptanal과 같이 기존 삼중항산소 산화기작에 의해 설명될 수 없었던 휘발성물질의 생성 기작을 일중항산소에 의한 산화 기작을 통해 제시하였다. 본 연구는 올레산 첨가 식품의 광산화에 의한 휘발성분 profile 규명 자료로 활용될 수 있을 것이다.
Formation mechanisms of light-induced volatile compounds were studied using riboflavin-photosensitized oleic acid model systems. Volatile compounds in model systems with 4000 ppm riboflavin at $35^{circ}C$ under light or in the dark for 39 hr were isolated and identified by a combination of solid phase microextraction (SPME), gas chromatography (GC), and mass spectrometry (MS). Total volatiles in oleic acid with riboflavin under light for 13, 26, and 39 hr increased by 90, 190, and 270%, respectively, compared to those in oleic acid without riboflavin under light. Total volatiles in samples without riboflavin under light or samples with riboflavin in the dark were not significant in tested conditions (p>10.05). Riboflavin did not act as a photosensitizer when it was dispersed in oleic acid. Heptane, octane, heptanal, octanal, nonanal, and 2-nonenal were significantly increased in riboflavin-photosensitized samples compared to those in samples without riboflavin (p<0,05). Light-induced volatile compounds including heptanal and 2-nonenal from oleic acid could be explained using singlet oxygen oxidation, the formation mechanism of which were not understood using triplet oxygen oxidation. These results will help to understand volatile formation in oleic acid containing foods stored under light.
