Stability of Polyunsaturated Fatty Acids in Storage of Sardine Oil Extracted with BHA added Solvent

BHA 첨가추출 정어리유 저장중의 고도불포화지방산의 안정성

The storage stability of sardine oil and the effect of BHA on the oxidation of fatty acids especially, highly unsatureted fatty acids like EPA and DHA were investigated. The sardine oil was extracted from round sardine, with chloroform-methanol(2:1 v/v) solvent with/without addition of BHA, and then stored at $30^{\circ}C$. The deterioration of oil was examined periodically by measuring acid value(AV), peroxide value(POV), carbonyl value(COV), and oxygen absorption. The changes in fatty acid composition during the storage was determined by GLC analysis to elucidate the oxidative stability of individual fatty acid. Formation of free fatty acid increased rapidly according to the storage time elapsed in the BHA free oil while it was obviously inhibited in the BHA added oil. Peroxides and carbonyl compounds were formed very rapidly at the beginning of storage of BHA free oil. But in the oil extracted with BHA, formation of peroxides was somewhat inhibited and formation of carbonyl compounds was very strongly inhibited. Principal fatty acids of sardine oil were $C_{16:0},\;C_{16:1},\;C_{18:1},\;C_{20:5}\;and\;C_{22:6}$ acids, and $\omega_33$ polyunsaturated fatty acid $(\omega_3\;PUFA)$ content was very high as much as $23\%$ of the total fatty acid content. The oxidative degradation of fatty acids was enhanced at PUFA especially $C_{20:5}$ ana $C_{22:6}$ acid in BHA free oil. However, the oxidation was fairly retarded in the oil extracted with BHA and the both $C_{20:5}$ and $C_{22:6}$ acids remained at the end of a month storage.

정어리유의 산화 안정성과 지질추출시에 첨가한 BHA에 의한 저장중의 산화방지효과를 정토하고 산화로 인한 지방산 조성의 면화를 조사한 결과를 요약하면 다음과 같다. 1. BHA는 유리 지방산의 생성을 현저히 억제하는 효과가 있었다. 2. BHA는 과산화물 생성을 억제하였으며 특히 카르보닐 화합들의 생성을 아주 강하게 억제하였다. 즉 BHA는 과산화을 분해를 억제하는 작용이 있었다. 3. 정어리유는$C_{20:5}$와 $C_{22:6}$의 함량이 $23\%$ 이상으로서 매우 높았다. 4. 산화에 의한 지방산의 감소는 polyene 산에서 급격하였으며 특히 $C_{20:5}$와 $C_{22:6}$산이 급격히 감소하였다. BHA 첨가는 $C_{22:5}$와 $C_{22:6}$산의 산화를 크게 억제 할수 있었다.