• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.178-184
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• 1971

Samples of refined soybean oil were irradiated with lights from a 20-watt incandescent tungsten lamp, a 20-watt fluorescent daylight type lamp, a 20-watt low-pressure mercury vapor germicidal lamp, and direct sunlight for an experimental period of 147 days. Some samples were stored in a dark room throughout the period as a control. The peroxide values of all samples were measured every week. The induction period of the samples was arbitrarily taken as the time required for the samples to reach a peroxide value of 15. The induction period of the control was estimated at 198 days. Those of the samples irradiated with the incandescent light, the fluorescent light, the ultraviolet light, and the sunlight were estimated at 196, 119, 52 and 6 days, respectively. The sunlight showed by far the strongest prooxidant activity whereas the incandescent light showed the weakest but distinct prooxidant activity. The small temperature differences observed among the various samples throughout the experimental period did not seem to affect the oxidation rates of the irradiated samples in any significant way.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1899-1907
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• 2013

We investigated the effects of unripe black raspberry water extract (UBR-W) and oxidation-LDL treatment on cholesterol levels. Experiments using an established human hepatocellular carcinoma cell line (HepG2) showed a time-dependent increase in expression of LDL receptor after UBR-W treatment. Expression of LDL receptor-related genes, such as SREBP1 and 2, increased upon UBR-W treatment. However, expression of HDL-related genes was unaffected by UBR-W. HMG-CoA reductase activity was reduced by UBR-W treatment, whereas HMG-CoA mRNA expression significantly increased. In addition, the ApoB/ApoA1 mRNA level, which is a predictor of cardiovascular risk, was reduced in a time-dependent manner by UBR-W treatment. Macrophage-like cells (RAW 264.7) showed increased expression of ox-LDL-related genes, such as CD36, scavenger receptor-A, adipophilin, and PPAR-gamma, upon ox-LDL treatment compared to untreated control cells, and quantitative lipid analysis indicated a dramatic increase in lipid accumulation. However, UBR-W treatment significantly reduced expression of ox-LDL-related genes and largely prevented lipid accumulation. The results indicate that UBR-W mediates a cholesterol-lowering effect via inhibition of cholesterol synthesis and induction of LDL uptake through SREBP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.247-254
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• 1989

In deep-fat frying, the fats and oils are used over and over again, and moisture and air are mixed in to the hot oil. Many reports related to these fats and oils have been established that thermal and oxidative decomposition products and polymers formed under the conditions of deep fat frying are harmful to health. This work was carried out with 3 domestic frying oils and 6 used oils commercially, and that there were difficulties in finding a good definition between fresh oil and used oil with adding unheated oil. As starting materials, commercially used soybean oil and rapeseed oil already passed over induction period in the lipids oxidation standard. From the qualitative point of view, they were inferior to domestic frying oils. Free fatty acid and peroxide value of heated oils were increased gradually by the time pass whereas iodine value were decreased. After adding unheated oil to the heated oil, these values were restored to that of initial levels. On the other hand, content of polar components in the heated oil were directly related to the heating time. This result showed that polar compounds may be a clear indicator of used oils. Fatty acid composition in the used oils, unsaturated fatty acids such as linoleic and linolenic acid decreased while saturated fatty acid content increased with heating.

• Journal of Life Science
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• v.25 no.4
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• pp.397-405
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• 2015

S-allylcysteine (SAC) is a water-soluble organosulfur compound abundant in the aged garlic extract and has been drawing attention as a diet-derived alternative agent not only for the effects of anti-oxidation and anti-inflammation but also for the prevention and treatment of various types of cancer. However, there is no report about the anticancer effects of SAC on cervical cancer cells. The aim of this study was to analyze the inhibitory effects of SAC on cell proliferation of cervical cancer cell line, HeLa and to examine its effects on the apoptosis and cell cycle as the cellular mechanisms of anti-proliferation. For this, we examined effects of different concentrations of SAC on cell proliferation according to treatment periods. Treatment with SAC not only induced morphological changes but also resulted in the reduction of cell viability and the inhibition of concentration- and time-dependant cell proliferation of HeLa. Furthermore, SAC also induced fragmentation of DNA in both DNA fragmentation and TUNEL assays, and induced cell cycle arrest at the G₂/M phase in cell cycle analysis. These results suggest that SAC inhibits proliferation of HeLa at least in part through the induction of apoptosis and the cell cycle arrest.

• Journal of Life Science
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• v.26 no.7
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• pp.758-763
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• 2016

Fatty acid transporters are key mediators of skeletal muscle lipid metabolism. Several protein groups have been implicated in cellular long-chain fatty acid uptake or oxidation, including fatty acid transporter proteins (FATPs), the plasma membrane fatty acid-binding protein (FABPpm), and the fatty acid translocase (FAT/CD36). FAT/CD36 is highly expressed in skeletal muscle and known to be regulated by various factors such as exercise and hormones. Insulin-like growth factor-I (IGF-I) is a well-known regulator of skeletal muscle cells. However, it has not been studied whether there is any interaction between IGF-I and FAT/CD36 in skeletal muscle cells. In this study, the effects of IGF-I treatment on FAT/CD36 induction were examined. Differentiated C2C12 cells were treated with 20 ng/ml of IGF-I at different time points. Treatment of C2C12 cells with IGF-I resulted in increased FAT/CD36 mRNA and protein expression. After 24 and 48 hr of IGF-I treatment, FAT/CD36 mRNA increased 89% and 24% respectively. The increase of both proteins returned to the control level after 72 hr of IGF-I treatment, suggesting that the FAT/CD36 gene is regulated pretranslationally by IGF-I in skeletal muscle cells. These results suggest that IGF-I can regulate the expression of FAT/CD36 in skeletal muscle cells. In conclusion, IGF-I induces a rapid transcriptional modification of the FAT/CD36 gene in C2C12 skeletal muscle cells and has modulating effects on fatty acid uptake proteins as well as oxidative proteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1314-1319
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• 2005

The purpose of this study was to investigate the antioxidative effects of Lycii fructus powder (LFP) solvent extracts and Maejakgwa made with LFP. The solvent extracts of LFP were added to soybean oil in the quantity of $0.05\%$. The solvents used were methanol, ethanol, ethyl acetate and petroleum ether. Soybean oil without the addition of LFP was used as a negative control. Soybean oil with $0.02\%$ butylated hydroxytolune (BHT) and $\alpha$-tocopherol were used as positive controls. Each sample was stored at $50^{\circ}C$ for 30 days. The oxidation level of these samples was determined by measuring the acid value, peroxide value and thiobarbituric acid (TBA) value. The oxidation level of solvent extracts of $0.05\%$ LFP was lower than both the negative control and $\alpha$-tocopherol. Especially, methanol extract of $0.05\%$ LFP was the lowest. The methanol extract (320 min) and ethanol extract (316 min) demonstrated longer induction periods, compared to the control (253 min), $\alpha$- tocopherol (255 min) and BHT (309 min) by Rancimat method. Acid value of Maejakgwa was increased during the storage time, but it was lower in Maejakgwa made with LFP than in the control group. Peroxide value was increased rapidly for 30 days and then decreased. TBA value was lower in Maejakgwa made with 3, 6, $9\%$ LFP than in those made with $15\%$ LFP and the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1409-1416
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• 2007

Seven selected commercial pure or refined olive oils were obtained from the market, and their physicochemical properties and volatile characterizations were investigated. Fatty acid profiles of the analyzed olive oils showed oleic $(61.2{\sim}74.7mole%)$, palmitic $(10.2{\sim}16.8mole%)$, linoleic $(9.4{\sim}18.0mole%)$, stearic $(1.9{\sim}3.0mole%)$, palmitoleic $(0.7{\sim}2.4mole%)$ and linolenic acid $(0.5{\sim}0.9mole%)$. According to Hunter#s color measurement, pure or refined olive oils showed $L^*$ value of $92.2{\sim}99.0$, $a^*$ value of $-22.2{\sim}-3.2$, and $b^*$ value of $18.5{\sim}55.0$. Their total phenol contents ranged from 1.9 to $13.3mg/100g$ while ${\alpha}-tocopherol$ content showed $7.91{\sim}13.88mg/100g$. Oxidation stability of the pure or refined olive oils were observed by Rancimat. The induction period ranged from 17.37 to 34.72 hr while their POV were $6.83{\sim}20.31meq/kg$ oil. Electronic nose and gas chromatograph-mass spectrometry with head-space solid phase microextraction were applied to identify and discriminate the volatile compounds and flavors in pure or refined olive oils, respectively.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.99-110
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• 2018

In this study, oil of Platycodon grandiflorum seeds was prepared using supercritical carbon dioxide extraction (SCE) and its physicochemical indices as a new edible oil were investigated. Compared to Soxhlet solvent extraction, SCE under the condition of 6,000 psi at $40^{\circ}C$ produced more oil, especially from the roasted seeds to 32.7%. TLC analysis showed triacylglycerols accounted for most of the oil obtained from roasted Platycodon grandiflorum seeds by SCE similarly to commercial soybean oil or perilla seeds oil. The oil had highly unsaturated lipid with considerable amount of linoleic acid(73.27%) much more than two commercial oils followed by oleic acid(13.16%). Physicochemical properties of the oil were as follows; specific gravity, 0.92; dynamic viscosity, 45.37 cP; refractive index, 1.48; color, L=47.30, a=-3.69, b=25.72; iodine value, 141.57 g $I_2/100g$ oil; saponification value, 191.21 mg of KOH/g of oil; acid value, 2.60 mg of KOH/g of oil. Among those, refractive index, viscosity and iodine value, which were related to unsaturation degree of lipid, were ranged between those of two commercial oils. The oxidation stability of oil(2.03 hr) was also ranged between less stable perilla seeds oil(1.79 hr) and more stable soybean oil(2.94 hr) based on the induction time measured by Rancimat assay. In addition to extraction yield increase, seeds roasting provided further benefits such as reductions of cholesterol ester content and acid value without change in fatty acid composition. In conclusion, oil was extracted from the roasted Platycodon grandiflorum seeds at high yield by supercritical carbon dioxide and it seemed to have proper characteristics as a edible oil.