감마선 조사가 5가지 지방원료의 산패, 후각강도, 지방산 이성체와 휘발성 물질의 조성에 미치는 영향

Abstract

This study was conducted to investgate the effect of gamma irradiation on the lipid oxidation, olfactory properties, fatty acid isomer and volatile compound profiles of five different oil sources. Three plant oils, canola oil, corn oil and soy oil, and two animal fat, tallow and fish oil, were irradiated with 0, 5, 10, and 20 kGy level of dose by Co-60 as a radiation source. Lipid oxidation parameters, FFA, POV and TBARS, were determined according to the AACC and AOCS method. Olfactory property of irradiated oil sources was analyzed using electronic nose (FOX3000, AlphaMOS Co., France) with 12 metal oxide sensors and the result was interpreted using principle component analysis program. Fatty acid isomer profiles and volatile compound profiles of irradiated oils were also measured by GC and GC-MS, respectively. Although the free fatty acid level of oil were the highest by high dose level (20 kGy) of irradiation, changes of both TBARS and POV values by gamma irradiation were varied between oil sources and irradiation level of dose. Electronic nose analysis showed a distinct difference among dose levels of irradiation. Although there was no new volatile compound produced by gamma irradiation, amounts of each volatile compounds were increased by irradiation. Only cis isomer, 9c12c15c of linolenic acid was dose-dependently decreased as irradiation level increased but there was no difference among other isomer profiles of linoleic acid and linolenic acid by gamma irradiation. This study showed that changes in physico-chemical properties of both plant and animal oil were remarkable by gamma irradiation. Therefore, a further study should be needed to scrutinize the interaction among lipid oxidation, production of volatile compounds and off-flavor, and isomerization of fatty acid by gamma-irradiation