방사선 조사에 의한 Allium속 식물의 휘발성 유기성분 변화 연구

Abstract

I. Analysis of volatile organic components in Allium spices • The volatile organic components in Allium spices, such as dried garlic, onion, Welsh onion and leek were extracted by simultaneous distillation and extraction (SDE) method and identified by GC and GC/MS analysis. • Components of 48 were identified in dried garlic, including 28 S-containing comopunds (94.25%), 7 aldehydes (0.46%), 3 alcohols (1.14%), 2 ketones (0.05%), 2 esters (1.94%), 2 N-containing compounds (1.46%) and 5 miscell- aneous (0.7%). Major compounds were diallyl disulfide, diallyl trisulfide, 2-butyltetrahydrothiophene, allyl methyl disulfide, 2-allylthiopropionic acid, 3-vinyl-1,2-4H-dithiin and methyl propyl trisulfide. Diallyl disulfide and diallyl trisulfide were abundant in dried garlic and peak area% of these compounds were 36.61 and 33.73%, respectively. • Compounds of 32 were identified in dried onion and the major components were dipropyl trisulfide (21.66%), methyl propyl trisulfide (15.61%) and 1- propanethiol (13.10%). (E)-Propenyl propyl trisulfide, 2-methyl-2-pentenal, dimethyl trisulfide and (Z)-propenyl propyl trisulfide were identified, and trisulfides contributed on characteristic flavor of dried onion. • Compounds of 35 were identified and 18 S-containing compounds (83.43%) were detected as a major constituents of volatile compounds of dried Welsh onion. The major components were dipropyl trisulfide and 1-propanethiol, the amount of these components were 91.80 and 63.06 mg/kg, respectively. (E)-propenyl propyl disulfide, 3,5-diethyl-1,2,4-trithiolane, (Z)-propenyl propyl disulfide, propylene sulfide and methly propyl trisulfide were also identified. • Compunds of 43 were identified in dried leeks, including 19 S-compounds (96.65%), 9 alcohols (0.83%), 9 aldehydes (1.57%), 2 esters (0.39%), 2 N- compounds (0.41%) and 2 miscellaneous (0.15%). Dimethyl trisulfide (314.88 mg/kg) and (Z)-propenyl methyl trisulfide (155.15 mg/kg) were the major compounds with dimethyl disulfide, (E)-propenyl methyl disulfide and methyl allyl disulfide were detected in large amounts. II. Analysis of change of volatile organic components in Allium spices by γ- irradiation • The volatile organic compounds from dried and irradiated dried Allium spices with doses of 1, 3, 5, 10 and 20 kGy using 60Co were extracted by simultaneous steam distillation and extraction (SDE) method and identified with GC/MS analysis. • In dried garlic, the total contents of the characteristic volatile sulfur containing compounds like diallyl disulfide and diallyl trisulfide formed when the cellular tissue was disrupted, and 3-vinyl-4H-1,2-dithiin and 2-vinyl- 4H-1,3-dithiin formed from allicin was not changed significantly with irradiation, but were found the ratio of diallyl disulfide to dially trisulfide and 3-vinyl-4H-1,2-dithiin to 2-vinyl-4H-1,3-dithiin decreased with increasing the radiation doses. • In dried onion, major compounds of S-containing compounds such as 1-pro- panethiol, methyl propyl trisulfide, propenyl propyl disulfide and dipropyl trisulfide in the control sample were clearly increased in 10 kGy irradiated samples but those compounds were decreased in 20 kGy irradiated samples. 2-Methyl-2-pentenal and hexanal were also changed by γ-irradiation in the similar pattern with major S-containing compounds. Exceptionally, dimethyl disulfide and dimethyl trisulfide showed different trend with major S-containing compounds. In dried onion, γ-irradiation seemed to be high enough to change the levels and proportions of flavor components. • In dried Welsh onion, the several S-containing compounds (methyl propyl disulfide, (Z)-propenyl methyl disulfide, (E)-propenyl methyl disulfide, dimethyl trisulfide, methyl propyl trisulfide, 2,4-dimethyl thiophene) were highly induced at 20 kGy of irradiation. Our result suggests that application of γ-irradiation at 20 kGy did not bring any significant lose in total content of volatile flavor compounds of dried welsh onion. • In dried leeks, dimethyl trisulfide and dimethyl disulfide were dramatically decreased at 1 and 10 kGy, but not changed at 5 kGy compared with unirradiated leeks. Moreover, content of other functional groups are not apparent different before and after irradiation while contents of esters increased by irradiation. • In this study, effects of γ-irradiation on the volatile organic components in Allium spices were determined by analyzing changes of volatile composition. The composition of volatile components were little changed but, few specific compounds induced by γ-irradiation were identified. The total amount of volatile organic components in Allium spices were decreased after irradiation at high dose (up to 10 kGy), even though there was no correlation between irradiation dose and volatile concentrations.