• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.690-695
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• 1994

The perilla seed and the germinated perilla seed $(25{\sim}28^{\circ}C$, $2{\sim}3\;days)$ were extracted by n-hexane, and from the extracted oil the antioxidative components were separated, and then the effect of the change in the contents of antioxidative components by germination on the oxidative stability of the perilla oil was studied. The perilla oils were solved acetone and methanol, and kept at $-60^{\circ}C$ overnight and separated into the frozen oil fraction and unfrozen solvent soluble fraction. By comparing the antioxidative stability of the frozen oil fraction the antioxidative components in the perilla oil were found to be methanol soluble. The methanol soluble fraction of perilla oil was applied to silica gel column chromatography and the separated fractions were compared in terms of antioxidative activity. The fraction of n-hexane : ethyl acetate (7 : 3, v/v) showing the highest antioxidative activity was further separated by TLC. The components included in the band $(R_f\;0.71)$ showing the highest antioxidative activity was separated by HPLC. Four peaks were observed on the HPLC chromatogram and the peak areas were changed by germination (perilla seed : peak 1; 46.5%, peak 2; 25.6%, peak 3; 22.6%, germinated perilla seed : peak 1; 43.8%, peak 2; 20.6%, peak 3; 29.8%). The comparative change in the contents of these components was considered to be one factor affecting the antioxidative stability of perilla oil by germination.

• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.451-458
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• 2005

For the storaging and frying stability in soybean oil, the kind of treating antioxidants were mixed tocopherol and phosphatidyl choline(PC), phosphatidyl ethanolamine(PE), phosphatidyl inpsitol(PI), phosphatidyl serine(PS), phosphatidic acid(PA), phosphatidyl glycerol(PG), treating amounts were 0.03%, 0.05%(w/w), respectively. Acid value(AV), peroxide value(POV) and oxidative stability index(OSI) were determined during storage period at $50^{\circ}C$ in soybean oil. Antioxidation effect at frying condition was determined through changes of smoke point. The antioxidation effect according to AV change was $PA>PC>PI{\geq}PG>PS{\geq}PE$, preventing effect about POV change was PA>PG>PC>PS>PE>PI and preventing effect about OSI decreasing was PI>PC>PA>PG>PS>PE. At the result, antioxidation effect of individual phospholipid components in soybean oil was appeared different result according to determination code. Determination result of preventing effect of SP decreasing according to frying at $180^{\circ}C$ during 20 hours was PA>PC>PG>PE>PI>PS. But treating effect of mixed tocopherol in preventing effect about AV, POV was not. In the case of storage at $50^{\circ}C$ in soybean oil, mixed tocopherol was affected as a kind of pro-oxidant. In OSI had some antioxidation effect, preventing effect of SP decreasing had not. Treatment of mixed tocopherol in soybean oil was undesirable as frying oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.933-940
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• 2013

In this study, methyl esters with different saturated fatty acids (SFA) were prepared by urea fractionation to make an oil-in-water emulsion. Emulsion characteristics (emulsion stability and oxidative stability) of the methyl ester emulsion were then studied at different percentages of methyl ester saturation (5, 28, 39, 50, and 72%, termed ${\Sigma}$SFA5, ${\Sigma}$SFA28, ${\Sigma}$SFA39, ${\Sigma}$SFA50, and ${\Sigma}$SFA72, respectively). The stability of emulsions (ES) with different SFA content was 46.0 (${\Sigma}$SFA5), 39.5 (${\Sigma}$SFA28), 32.7 (${\Sigma}$SFA39), 32.6 (${\Sigma}$SFA50), and 27.3 (${\Sigma}$SFA72). Results from Turbiscan showed that creaming or clarification, based on the backscattering intensity, was more pronounced with increases in the saturation degree of the emulsion. These results implied that the emulsions with lower saturation were more stable. During 30 days of storage, the lipid peroxide value increased for all emulsions, with the increase less pronounced with the increasing saturation of the emulsion; 1.880 (${\Sigma}$ SFA5), 1.267 (${\Sigma}$SFA28), 1.062 (${\Sigma}$SFA39), 0.342 (${\Sigma}$SFA50) and 0.153 (${\Sigma}$SFA72) mg $H_2O_2/mL$ emulsion. In addition, thiobarbituric acid reactive substances (TBARS) values were significantly lower in emulsions with high saturation (4.419 mg for ${\Sigma}$SFA50 and 4.226 mg for ${\Sigma}$SFA72) than emulsions with low saturation (6.229 mg for ${\Sigma}$SFA5, 6.801 mg for ${\Sigma}$SFA28 and 6.246 mg for ${\Sigma}$SFA39). In conclusion, the emulsions with a higher saturation degree of methyl esters showed lower emulsion stability but better oxidation stability.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5145-5151
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• 2013

Background: Numerous carcinogens and reactive oxygen species (ROS) may cause DNA damage including oxidative base lesions that lead to risk of nasopharyngeal carcinoma. Genetic susceptibility has been reported to play a key role in the development of this disease. The base excision repair (BER) pathway can effectively remove oxidative lesions, maintaining genomic stability and normal expression, with X-ray repair crosscomplementing1 (XRCC1), 8-oxoguanine glycosylase-1 (OGG1) and apurinic/apyimidinic endonuclease 1 (APE1) playing important roles. Aims: To analyze polymorphisms of DNA BER genes (OOG1, XRCC1 and APE1) and explore their associations, and the combined effects of these variants, with risk of nasopharyngeal carcinoma. Materials and Methods: We detected SNPs of XRCC1 (Arg399Gln), OGG1 (Ser326Cys), APE1 (Asp148Glu and -141T/G) using the polymerase chain reaction (PCR) with peripheral blood samples from 231 patients with NPC and 300 healthy people, furtherly analyzing their relations with the risk of NPC in multivariate logistic regression models. Results: After adjustment for sex and age, individuals with the XRCC1 399Gln/Gln (OR=1.96; 95%CI:1.02-3.78; p=0.04) and Arg/Gln (OR=1.87; 95%CI:1.29-2.71; p=0.001) genotype variants demonstrated a significantly increased risk of nasopharyngeal carcinoma compared with those having the wild-type Arg/Arg genotype. APE1-141G/G was associated with a significantly reduced risk of NPC (OR=0.40;95%CI:0.18-0.89) in the smoking group. The OR calculated for the combination of XRCC1 399Gln and APE1 148Gln, two homozygous variants, was significantly additive for all cases (OR=2.09; 95% CI: 1.27-3.47; p=0.004). Conclusion: This is the first study to focus on the association between DNA base-excision repair genes (XRCC1, OGG1 and APE1) polymorphism and NPC risk. The XRCC1 Arg399Gln variant genotype is associated with an increased risk of NPC. APE1-141G/G may decrease risk of NPC in current smokers. The combined effects of polymorphisms within BER genes of XRCC1 399Gln and APE1 148Gln may contribute to a high risk of nasopharyngeal carcinoma.

• Journal of Nutrition and Health
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• v.12 no.1
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• pp.51-58
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• 1979

It is a general trend everywhere that the uses of vegetable oils are increasing due to the fact that they are effective in curing and preventing symptoms of high blood pressure and various heart failure conditions. At the same time the concept that oxidative rancidity is caused by the oxidation of unsaturated fatty acid moieties whose subsequent decomposition gives rise to various undesirable, sometimes toxic compounds is now well accepted. Linolenic acid (C, 18:3) is one of highly unsaturated and readily oxidizable fatty acid. The content of this essential polyunsaturated fatty acid in perilla seed oil (PSO) was found to be as high as 48% while only 1.5% in sesame seed oil (SSO). In this experiment the oxidative stability of PSO was compared with that of SSO. The experimental test group were as follows: A) Stored at different temperatures, namely $4^{\circ}C,\;30^{\circ}C,$ and $60^{\circ}C,$ B) Stored at room temperature $(20{\pm}5^{\circ}C)$ ; a. protected from sunlight and air, b. exposed to air without sunlight c. exposed to sunlight but protected front air, d. completely exposed to both air and sunlight. The following results were obtained; 1) It was found to be most stable against oxidation to store both PSO and SSO under the low temperature $(4^{\circ}C)$ condition. According to P.V. measurements it was found to be safe to keep both oils up to $30^{\circ}C$ for at least 8 weeks. When exposed to air, sunlight and high temperature $(60^{\circ}C)$, P.V. of PSO reached there peak values, which were much higher than those of SSO. This explains much of its instability as compared to SSO against oxidation. 2) The effect of high temperature $(60^{\circ}C)$ on A.V. was found to be more striking than those of all the other storage conditions. The condition of refrigeration was most effective in keeping A.V. low for both oils as was the case in P.V. 3) For both oils, I.V. decreased throughout the experimental period (8 weeks). The range of decrement was larger for PSO than SSO. 4) There was no significant change in the compositions of fatty acids of SSO caused by various experimental storage conditions. But for PSO the compositions of stearic, oleic and linoleic acid were decreased, whereas linolenic acid was increased proportionally.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.347-352
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• 2003

In order to compare quality characteristics and oxidative stabilities of rice germs prepared under different roasting conditions, sensory evaluation, color value, tocols (tocopherol+tocotrienol) contents, and peroxide value were investigated. Optimum roasting temperatures for the best acceptability were 20, 10, and 6 min at 170, 180 and 190, respectively. Hunter color a values of rice germ increased as roasting temperature and time increased, whereas L value decreased. Peroxide values of unroasted, and roasted rice germs at $170^{\circ}C$ for 20 min, $180^{\circ}C$ for 10 min, and $190^{\circ}C$ for 6 min were 2.0, and 145.6, 169.5, and 182.9 meq/kg, respectively, after 9 days storage at $60^{\circ}C$. Four tocopherol and three tocotrienol isomers were identified, whereas no ${\beta}$-tocotrienol was detected. The major tocopherol and tocotrienol isomers in rice germ were ${\alpha}$-tocopherol and ${\alpha}$-tocotrienol, respectively. ${\alpha}$-Tocopherol content in roasted rice germ decreased significantly during storage, whereas those of ${\beta}$- and ${\gamma}$-tocopherols slowly decreased. ${\delta}$-Tocopherol had the highest stability among tocopherol isomers in roasted rice germ. Similar trends were observed in tocotrienol isomers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.37-43
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• 1973

In this paper, non-enzymatic browning reactions as a factor of self stability of boiled and dried anchovy were studied to discuss the effect of water activity to the discoloring reaction and the preservative moisture content. The development of rancidity of the fish meat was also mentioned since the fish is fatty and the lipid oxidation is a functional deteriorative reaction. Fresh anchovies were boiled in $10\%$ salt solution immediately after the catch, sun dried, and stored at room temperature ($20^{\circ}C$) for two months in humidistat chambers maintaining different levels of water activity as described in Table 1. The pigments formed by non-enzymatic browning reations were extracted in two fractions, those were chloroform-methanol soluble and water dialyzed fraction, and analyzed spectrophotometrically at the wavelength of 460 nm. These two fractions were considered, respectively to be the brown pigments formed by lipid oxidation reactions for the formler and for the latter, to be the pigments developed by sugar-amino or Maillard reaction. The oxidation of lipid in anchovy meat during the storage was measured as the changes in Peroxide value and the color development of thiobarbituric acid reaction. It is summarized from the results that the rate of both reactions, lipid oxidation and browning, was affected by water activity levels. In regard to the changes in peroxide and TBA value during the storage, the propagation of lipid oxidation was obviously accelerated at lower humidities whereas the development of browning progressed at the higher. These two reactions occurring simultaneously and contrary in activity resulted in that the rate of deterioration occurring oxidatively or by browning, was the minimum at the water activity of 0.32-0.45 which were $7-9\%$ as moisture content and slightly higher value than that of monolayer (Aw=0.21, $5.11\%$ as moisture content). It is also noted that the lipid oxidative browning was presumed to dominate sugar-amino reactions so that the rate of browning of the meat was ultimately depended on the development of rancidity although sugar-amino reactions initiated earlier than the other at the first ten days of storage, particulary at higher humidity. At the lower humidity sugar-amino reactions were occurred gradually but lower levels in color development in contrast to the consistent increase in lipid oxidative browning.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.404-410
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• 2009

We investigated the physicochemical stabilities and biological activities of ethanol- extracted pigment from marine bacteria Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14. The bacterial pigment of strain Ju11-1 was very stable at pH 5.0 below $25^{\circ}C$. The stability of the pigment showed higher stability in the presence of metal ions such as $Cu^{2+}$ and $Mg^{2+}$. The pigment has activity of free-radical scavenging ($IC_{50}$ $95.2{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $82.3{\mu}g$/ml) against DNA damage in human lymphocytes. The bacterial pigment of strain Ju14 was very stable at pH range between 4.0 and 8.0 below $40^{\circ}C$. In the presence of light, the pigment was also very stable, showing more than 90 percent of remaining absorbance during 14 days at $25^{\circ}C$. The stability of the pigment, when metal ions were present, showed higher stability in all examined metal ions except for $Fe^{2+}$, $Al^{3+}$, and $Cu^{2+}$, especially in the presence of $Na^+$. The pigment has activity of freeradical scavenging ($IC_{50}$ $208.6{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $ 96.4{\mu}g$/m) against DNA damage in human lymphocytes. The result indicates that the bacterial pigments from marine bacteria, Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14 showed higher physicochemical stability and significant effects for reduction in oxidative DNA damage. Therefore, the results suggest that these bacterial pigments could be used as a natural colorant having the advantages of antioxidant.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.128-131
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• 2005

Sesame seed is known as a good nutritional source containing high oil (51%) and protein (20%). Sesame oil contains a very high oxidative stability compared to other vegetable oils. To obtain basic information for quality evaluation, imported and domestic sesame seeds were investigated to measure general components (ash, protein, moisture and oil), fatty acid composition and lignan content. Although the protein contents were the highest in domestic sesame seeds, yet the lipid contents were the highest in imported sesame seeds. Unsaturated fatty acids such as oleic acid and linoleic acids were the highest in the domestic sesame seeds. Lignan contents, the most important component known as antioxidant, were significantly higher in domestic sesame seeds than other imported sesame seeds. These results suggest that domestic sesame seed may have the best quality in terms of the functional components.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.1-5
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• 1988

Changes in the quality characteristics of three sizes of boiled-dried anchovies packaged in kraft paper laminated with 0.03 mm PE film during storage for six months at $5^{\circ}C$ were studied. In case of Dae-myul (78-80mm), the reaction of thiobarbituric acid, browning rate of lipid oxidation and Hunter-Scale color values. L, a, and b, were higher than those in Joong-myul (45-49 mm) or So-myul (30-34 mm). Organoleptic evaluation suggests that boiled-dried anchovy be good in sequence as So-myul, Joong-myul and Dae-myul. Shelf life of Dae-myul was half times lower than that of Joong-myul or So-myul. Regression equation for the sensory score prediction with lipid oxidative browning was determined.