Sungkyunkwan University · Chemistry
Professor JaeHwan Lee's research lab specializes in lipid oxidation mechanisms, natural antioxidants, and the development of analytical methods to assess oxidative stability in edible oils and plant-based foods. The lab investigates the role of bioactive compounds—such as isoflavones, sesamol, and synthetic antioxidants—under various thermal and photochemical conditions, with a focus on their antioxidant capacity and degradation pathways. Key research directions include the impact of processing conditions (e.g., roasting, heating, light exposure) on volatile profile formation and oxidative stability, as well as the application of advanced analytical techniques like HPLC, GC/MS, electronic noses, and radical scavenging assays. The lab also explores the interplay between oxygen availability, moisture content, and lipid oxidation kinetics in model systems such as lard and oil-in-water emulsions.
Figures are computed from collected data and may differ slightly.
Seventeen Ohio soybeans were screened for isoflavone content and antioxidant activity. Isoflavone content was determined by C(18) reversed phase high-performance liquid chromatography coupled with a photodiode array detector. Antioxidant activities of soybean extracts were measured using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and photochemiluminescence (PCL) methods. The highest and lowest total isoflavone contents were 11.75 and 4.20 micromol/g soy, respectively, while the average w
Headspace volatiles of sesame oil (SO) from sesame seeds roasted at 9 different conditions were analyzed by a combination of solid phase microextraction (SPME)-gas chromatography/mass spectrometry (GC/MS), electronic nose/metal oxide sensors (MOS), and electronic nose/MS. As roasting temperature increased from 213 to 247 °C, total headspace volatiles and pyrazines increased significantly (P < 0.05). Pyrazines were major volatiles in SO and furans, thiazoles, aldehydes, and alcohols were also det
The effects of riboflavin photosensitization on the oxidative stability of oil-in-water (O/W) emulsions were determined using lipid hydroperoxides and headspace volatile analyses. The influences of a metal chelator, sodium azide, and superoxide dismutase (SOD) on oxidation pathways were tested to gain a better understanding of the role of transition metals, singlet oxygen, and superoxide anion, respectively. Emulsions with riboflavin and visible light irradiation had significantly higher lipid h
Abstract Sesamol is a natural antioxidant found in sesame oil from roasted sesame seeds. Activation energy and antioxidant capacity of sesamol were determined and compared with other free radical scavengers (FRSs) including tert ‐butylated‐hydroxyquinone (TBHQ), butylated‐hydroxyanisol (BHA), or α ‐tocopherol in a lard model system treated with different heating temperature. Each FRS was added in lard and heated at 90, 120, 150, and 180°C for 48, 24, 8, or 2 h, respectively and antioxidant capac
Antioxidant effectiveness of free radical scavengers (FRSs) of alpha-tocopherol, sesamol, butylated hydroxytoluene (BHT), and tert-butylhydroquinone (TBHQ) were evaluated in thermally-oxidized lard using methods of 2,2-diphenyl-1-picrylhydrazyl (DPPH), conjugated dienoic acid (CDA), and p-anisidine value (p-AV). Absorbance of DPPH with lard containing 2.5 micromol/g FRSs were low before oxidation while those with control lard was high due to the hydrogen atom donating ability of FRSs. During oxi
Abstract The role of oxygen‐limitation on lipid oxidation and moisture content were tested in corn oil heated to 60, 100, and 140 °C. The degree of oxidation was determined by analyzing headspace oxygen content, conjugated dienoic acids (CDA), and p ‐anisidine value ( p ‐AV). The moisture content in bulk oil was analyzed by the Karl Fischer method. Oxygen‐limited samples heated to 100 and 140 °C had significantly more lipid oxidation than oxygen‐unlimited samples at early timepoints ( p < 0.0
The explosive puffing process may provide characteristic physicochemical properties in red ginseng. The effects of explosive puffing on the changes of volatiles in red ginseng were investigated using headspace-solid phase microextraction (HS-SPME)-gas chromatograph (GC) with a mass selective detector (MS). Formation of porous structures and smaller pieces were clearly observed on the surface of puffed red ginseng by scanning electron microscopy. Total volatiles in puffed red ginseng increased by
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