Sumi Oh

Effects of relative humidity on the antioxidant properties of α-tocopherol in stripped corn oil.

The effects of relative humidity (RH) on the antioxidant properties of α-tocopherol (10, 20, 42, and 84 ppm) were determined in stripped corn oil oxidised at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids (CDAs). Changes in moisture and α-tocopherol content were also monitored. The oxidative stability of stripped corn oil and stability of α-tocopherol differed significantly depending on the RH. As the concentration of α-tocopherol increased from 10 to 84 ppm, oxidative stability decreased significantly irrespective of RH. The remaining α-tocopherol content decreased as RH increased, suggesting an important role for moisture content in the stability of α-tocopherol. Antioxidant properties of α-tocopherol were greatly influenced by both moisture content in oil and α-tocopherol concentration.

Antioxidant properties of ascorbic acid in bulk oils at different relative humidity.

The effects of relative humidity (RH) on the antioxidant properties of ascorbic acid (10, 20, 42, and 84ppm) were investigated in stripped corn oils stored at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids. The oxidative stability of bulk oils without addition of ascorbic acid was significantly different depending on the RH. As the concentration of ascorbic acid increased from 10 to 84ppm, oxidative stability increased significantly irrespective of RH (p<0.05). Generally, oils containing ascorbic acid at low RH had higher oxidative stability after storage at 60°C than those at high RH. The antioxidant properties of ascorbic acid were greatly influenced by both the moisture content in the oil and the ascorbic acid concentration.

Effects of deuterium oxide on formation of volatiles in linoleic acid model systems at different temperatures and oxygen limitation conditions

Effects of 30, 60, and 90°C treatments and oxygen limitation on formation of volatiles were determined for linoleic acid model systems containing deuterium oxide (D2O) and deuterium free water. The presence of D2O accelerated consumption of headspace oxygen, indicating that the rate of lipid oxidation increased in the presence of D2O. The presence of deuterium in headspace volatiles was indirectly determined based on comparison of the amount of the fragmented mass to charge ratio (m/z) (molecular weight, Mw), which was 73.1/72.1 for d1-pentane/pentane and 125.1/124.1 for d1-2,4 octadienal/2,4 octadienal. The ratio of 73.1/72.1 (m/z) for pentane was significantly (p<0.05) higher for samples containing D2O than for samples containing deuterium free water at 30, 60, and 90°C. Other volatiles did not follow the same pattern. 2,4-Octadienal in samples under unlimited oxygen conditions confirmed this trend, indicating that water was incorporated into volatiles during oxidation of linoleic acid under these conditions.

Evaluation of In vitro antioxidant properties of roasted hulled barley (Hordeum vulgare L.)

The antioxidant properties of roasted hulled barley (Hordeum vulgare L.) were tested using in vitro assays, including the total phenolic content (TPC), total flavonoid content (TFC), and DPPH, ABTS, and ferric reducing antioxidant power (FRAP) assays. Hulled barley was roasted at 0, 170, 210, and 250°C for 20 min. The effects of the aqueous heating time at 100°C from 0 to 60 min and the blending ratio of barley and water from 1:2 to 1:5 in aqueous solutions were evaluated. p-Coumaric and ferulic acid contents were analyzed. The highest antioxidant activities were observed in 250°C roasted samples, although the p-coumaric and ferulic acid contents were high at 210°C. The highest antioxidant capacity in aqueous solution was observed at 60 min of extraction and in samples with a 1:2 blending ratio.

Antioxidant Properties of Aqueous Extract of Roasted Hulled Barley in Bulk Oil or Oil‐in‐Water Emulsion Matrix

UNLABELLED Antioxidant properties of the aqueous extracts of hulled barley (Hordeum vulgare L.) that had been roasted at 210 °C for 20 min were determined in bulk oil and oil-in-water (O/W) emulsions. Bulk oils were heated at 60, 100, and 180 °C, and O/W emulsions were oxidized under riboflavin photosensitization. The content of phenolic compounds was analyzed by high-performance liquid chromatography, and in vitro antioxidant assays were also conducted. The major phenolics contained in the aqueous extract of roasted hulled barley (AERB) were p-coumaric, ferulic, protocatechuic, chlorogenic, 4-hydroxybenzoic, and vanillic acids. Depending on the concentration and oxidation temperature, AERB had antioxidant or prooxidant properties in bulk oil. At 60 °C, AERB at a concentration of 0.5% acted as a prooxidant, whereas at 1.0% it acted as an antioxidant. At 100 °C, AERB acted as an antioxidant irrespective of concentration. In 180 °C conditions, 0.5% AERB acted as a prooxidant, whereas other concentrations of AERB acted as antioxidants. In the case of riboflavin photosensitized O/W emulsions, AERB showed antioxidant properties irrespective of concentration. Antioxidant abilities of AERB are affected by the food matrix, including bulk oil and O/W emulsions, and concentrations of AERB, even though diverse phenolic compounds may display high antioxidant properties in in vitro assays. PRACTICAL APPLICATION Roasted barley has been widely used as a tea ingredient in East Asian countries such as Korea, China, and Japan. The highly antioxidative properties of the aqueous extracts of roasted barley have been confirmed in bulk oil and O/W emulsions as well as in vitro assays because of the presence of phenolic compounds. The results of this study can contribute to the development of antioxidant-rich beverages using roasted barley by aiding in the selection of proper food matrix-containing extracts of high phenolic compounds, as well as by expanding consumers’ choices for healthy beverages.

P08.01: A predictive model of large-for-gestational-age infant and internal validation among Korean women with gestational diabetes mellitus: a Korean multicentre study: Poster discussion hub abstracts

had a longer induction-to-delivery duration in comparison with those with non-OP position. Conclusions: Fetal occiput and spine positions are dynamic in a considerable proportion of women undergoing induction of labor. Furthermore, both assessments do not seem to correlate with the mode of delivery. Occiput and spine position assessment prior to induction of labor are unlikely to be clinically useful in women undergoing IOL.

OC10.08: *The risk of preterm birth in vanishing twin: a multicentre prospective cohort study

S. Jisu1, S. Lee1, Y. Han2, M. Kim2, J. Shim3, M. Lee3, S. Oh4, J. Lee5, S. Kim6, D. Cha6, G. Cho7, H. Kwon8, B. Kim9, M. Park10, H. Cho11, H. Ko12, C. Park1, J. Park1, J. Jun1, H. Ryu2, S. Lee1 1Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Republic of Korea; 2Obstetrics and Gynecology, Cheil General Hospital and Women’s Healthcare Centre, Dankook University College of Medicine, Seoul, Republic of Korea; 3Obstetrics and Gynecology, University of Ulsan College of Medicine, Asan Medical Centre, Seoul, Republic of Korea; 4Obstetrics and Gynecology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; 5Obstetrics and Gynecology, Institute of Women’s Life Medical Science, Yonsei University College of Medicine, Yonsei University Health System, Seoul, Republic of Korea; 6Obstetrics and Gynecology, CHA Gangnam Medical Centre, CHA University, Seoul, Republic of Korea; 7Obstetrics and Gynecology, Korea University College of Medicine, Seoul, Republic of Korea; 8Obstetrics and Gynecology, Konkuk University School of Medicine, Seoul, Republic of Korea; 9Obstetrics and Gynecology, Seoul Metropolitan Government Seoul National University Boramae Medical Centre, Seoul, Republic of Korea; 10Obstetrics and Gynecology, Ewha Woman’s University, Seoul, Republic of Korea; 11Obstetrics and Gynecology, CHA Bundang Medical Centre, CHA University, Sung Nam, Republic of Korea; 12Obstetrics and Gynecology, Catholic University of Korea College of Medicine, Seoul, Republic of Korea

High-intensity focused ultrasound treatment for skin: ex vivo evaluation.

High‐intensity focused ultrasound (HIFU) has been used for skin tightening. However, there is a rising concern of irreversible adverse effects. Our aim was to evaluate the depth of thermal injury zone after HIFU energy passes through different condition.

Oxidative stability of extracts from red ginseng and puffed red ginseng in bulk oil or oil-in-water emulsion matrix

Background Explosive puffing can induce changes in the chemical, nutritional, and sensory quality of red ginseng. The antioxidant properties of ethanolic extracts of red ginseng and puffed red ginseng were determined in bulk oil and oil-in-water (O/W) emulsions. Methods Bulk oils were heated at 60°C and 100°C and O/W emulsions were treated under riboflavin photosensitization. In vitro antioxidant assays, including 2,2-diphenyl-1-picrylhudrazyl, 2,2′-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid, ferric reducing antioxidant power, total phenolic content, and total flavonoid content, were also performed. Results The total ginsenoside contents of ethanolic extract from red ginseng and puffed red ginseng were 42.33 mg/g and 49.22 mg/g, respectively. All results from above in vitro antioxidant assays revealed that extracts of puffed red ginseng had significantly higher antioxidant capacities than those of red ginseng (p < 0.05). Generally, extracts of puffed red and red ginseng had high antioxidant properties in riboflavin photosensitized O/W emulsions. However, in bulk oil systems, extracts of puffed red and red ginseng inhibited or accelerated rates of lipid oxidation, depending on treatment temperature and the type of assay used. Conclusion Although ethanolic extracts of puffed red ginseng showed stronger antioxidant capacities than those of red ginseng when in vitro assays were used, more pro-oxidant properties were observed in bulk oils and O/W emulsions.

Effects of α-tocopherol on the oxidative stability and incorporation of deuterium in volatiles from a linoleic acid-deuterium model system

The effects of α-tocopherol on the oxidative stability and incorporation of deuterium in volatiles were evaluated in linoleic acid-water model systems treated at 60°C by analyzing headspace oxygen depletion, formation of lipid hydroperoxides, and profiles of headspace volatiles. Deuterium oxide accelerated the rates of linoleic acid oxidation compared to samples in deuterium-free water. As the concentration of α-tocopherol increased from 0 to 1500 ppm, the consumption of headspace oxygen and the formation of volatiles decreased, whereas the contents of lipid hydroperoxides did not decrease in the linoleic acid-water system. The mass to charge ratios (m/z) of volatiles in linoleic aciddeuterium oxide were significantly higher than those with deuterium oxide-free water. Generally, the presence of α-tocopherol decreased the mass to charge ratios (m/z) of volatiles including pentanal, hexanal, t-2-heptenal, and 2-octenal, implying that α-tocopherol may be involved in the aldehyde formation from lipid oxidation.