Determination of alpha beta-unsaturated aldehydes formed from deteriorated deep fried oils and food in large scale cooking.

Research Project

Project/Area Number	06680059
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	家政学
Research Institution	Shizuoka University
Principal Investigator	FUKUDA Yasuko Shizuoka University, Education, Professor, 教育学部, 教授 (40141444)
Co-Investigator(Kenkyū-buntansha)	NAGASHIMA Mayumi Ichimura Gakuen College, Nutrition, Assistant Professor, 生活文化学科, 助教授 (80261105)
Project Period (FY)	1994 – 1995
Project Status	Completed (Fiscal Year 1995)
Budget Amount *help	¥2,100,000 (Direct Cost: ¥2,100,000) Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	determination / 4-hydroxynonenal / alpha beta-unsaturated aldehydes / thermal oxidation / edible oil / linear gradient HPLC / 短鎖α,β-不飽和アルデヒド / HNE / ELISA / フライ油の劣化 / フライ油の酸化的劣化 / フライ食品の劣化 / ヒドロキシノネナ-ル / 生体毒性 / 油による胸やけ / フライ食品の劣化の評価
Research Abstract	To determine the amount of reactive low molecular alpha beta-unsaturated aldehydes, which were secondary formed from peroxides in autoxidation or thermal oxidation of oils and fats, a new method was investigated. As these unsaturated aldehydes were unstable, they were stabilized with carbonyl reagent, 2,4-DNPH.With the hydrazone of 4-hydroxy-2-trans-nonenal (HNE), which was the most unstable aldehyde, extracting solvent and some reactive conditions with 2,4-DNPH were examined. The extremely high recovery of hydrazone of HNE during the processes was obtained as 99.38% in preliminary HPLC examination (ODScolumn, acetonitrile/H_2O/ THF 70 : 29 : 1, detect : uv 350nm). The nine hydrazones of these alpha beta-unsaturated aldehydes were able to separate by linear gradient HPLC (ODS column, acetonitrile : H_2O : THF from 60 : 39 : lto 90 : 9 : 1 by 30min, detect : uv 350nm) and to calculate the amount of each aldehyde by heptenal, as an internal standard. The eight vegetable oils, which were purchased in some local markets, were heated in hot block bath at 200ﾟC,for 5 hours and dtermined these aldehydes by this new method. The total amout of these unsaturated aldehydes was 1200mug/ml oil in corn and safflower oils, on the other hand, 600 mug/mloil in perilla and roasted sesame oils. These results were shown that the reactive and toxic in vivo aldehydes produced from deteriorated edible oils were separated and determined with high sensitiveness by linear gradient HPLC.