• Food Science and Biotechnology
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• v.15 no.2
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• pp.183-188
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• 2006

The tocopherol and tocotrienol contents of 39 vegetable oils, margarines, butters, and peanut butters typically consumed in the Korea diet were determined by direct solvent extraction method followed by normal phase liquid chromatography. All samples were locally obtained in the Cheongju area in 2003 and 2004. The study examined data on 19 vegetable oils, 10 margarines, 6 butters, and 4 peanut butters. ${\gamma}$-Tocopherol (${\gamma}$-T) and ${\alpha}$-tocopherol (${\alpha}$-T) were detectable in all products except butters and were usually present in the vitamin E form in greater quantity than the other isomers. Usually, ${\gamma}$-T content was higher than ${\alpha}$-T content in many samples. Tocotrienols were measurable in some samples but usually at levels less than the corresponding tocopherols. Three analytical method validation parameters, accuracy, precision, and specificity, were calculated to ensure the method's validity and were all confirmed to be reliable and satisfactory.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.468-471
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• 2004

Tocotrienol $(T_3)$ and tocopherol (T) are well-known antioxidant vitamin E isomers that are enriched in rice bran, most of which is removed during polishing process. To verify the polishing-dependent fractional content of tocotrienol and tocopherol, harvested brown rice of 4 cultivars were polished by 4.0, 6.4, 8.0, 9.6, and $12\%$ (w/w) and resultant bran powder and rice were used for $T_3$ and T analysis. Polishing degree affected bran $T_3$ content in that bran polished by $6.4\%$ exhibited highest $T_3$ content compared to other polishing degrees except in cv. Chucheongbyeo which showed similar $T_3$ content from 4.0 to $8.0\%$ polishing. In case of tocopherol, bran polished by $8.0\%$ exhibited highest T content in all tested cultivars. In general, $T_3$ distributed in higher quantity in exterior i.e., in less polished bran, while T showed relatively less decrease with enhanced polishing degree. Consequently, total vitamin E content in bran as calculated by the summation of $T_3$ and T became less dependent on polishing degree in that bran polished between 6.4 to $9.6\%$ exhibited no statistical differences. The rice of cv. Chuchongbyeo, remained after polishing, exhibited similar vitamin E content up to $6.4\%$ polishing, above which significant vit E loss could be observed. These results suggest that polishing less than $6.4\%$ is desirable to minimize the loss of tocotrienols and tocopherols during polishing.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.31-31
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• 2017

Understanding the mechanism(s) to overcome or prevent seed ageing deterioration during storage is of fundamental interest to seed physiologists. Vitamin E (tocols) is known as a key metabolite to efficiently scavenge lipid peroxy radicals which cause membrane breakdown resulting in seed ageing. However, in rice research this hypothesis has been tested for very few lines only without considering intraspecific variation in genomic structure. Here, we present a correlation study between tocols and seed longevity using a diverse rice panel. Seeds of 20 rice accessions held in the International Rice Genebank at the International Rice Research Institute, representing aus, indica, temperate japonica and tropical japonica subpopulations, were used for tocols analysis (quantification of ${\alpha}$-, ${\beta}$-, ${\gamma}$-, ${\delta}$-tocopherol/tocotrienol by ultra performance liquid chromatography) and storage experiments at $45^{\circ}C$ and 10.9% seed moisture content (sample taken for germination testing every 3 days up to 60 days). To examine interactions between DNA sequences and phenotype, the 700k high-density single-nucleotide polymorphism marker data-set was utilized. Both seed longevity (time for viability to fall to 50%; $p_{50}$) and tocols content varied across subpopulations due to heterogeneity in the genetic architecture. Among eight types of tocol homologues, ${\alpha}$-tocopherol and ${\gamma}$-tocotrienol were significantly correlated with $p_{50}$ (negatively and positively, respectively). While temperate japonica varieties were most abundant in ${\alpha}$-tocopherol, indica varieties recorded 1.3 to 1.7-fold higher ${\gamma}$-tocotrienol than those of other subpopulations. It was highlighted that specific ratio of tocol homologues rather than total tocols content plays an important role in the seed longevity mechanism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1064-1070
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• 2005

Tocopherol and tocotrienol contents of commonly consumed foods in Korea were determined by saponification or direct solvent extraction followed by normal phase liquid chromatography. All samples were locally obtained in the year of 2002 and 2003. The study included 13 meats, 15 fishes and shellfishes, 4 seaweeds, 7 mushrooms, 19 milk and milk products, 6 legumes, 12 nuts, 17 processed foods and 17 Korean traditional foods. All of the vitamin E isomers were quantitated and the results were expressed as $\alpha-tocopherol$ equivalent $(\alpha-TE)$. The relatively higher amount of vitamin E was found in beef boiled in soy, dried squid, toasted seaweed, milk powder, soritae, sunflower seeds, ramyon (instant noodle), and kochujang from meats, fishes, seaweeds, milk products, legumes, processed foods, and traditional foods, respectively. This study provided reliable vitamin E data in commonly consumed foods in Korea for the nutritional information and food composition database.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.663-672
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• 2013

To characterize the nutraceutical property of Italian millet (Setaria italica) and sorghum (Sorghum bicolor), ten Korean landraces of each crop were collected and their vitamin E (tocopherols and tocotrienols), squalene and phytosterols (campesterol, stigmasterol and ${\beta}$-sitosterol) contents as well as fatty acid composition in seeds were evaluated. Italian millet seeds exhibited 5 forms of vitamin E isomers: three (${\alpha}$-, ${\gamma}$- and ${\delta}$-) tocopherols and two (${\alpha}$- and ${\gamma}$-) tocotrienols, while sorghum seeds showed only three forms of vitamin E isomers: ${\alpha}$- and ${\gamma}$-tocopherol and ${\alpha}$-tocotrienol. In both crops, ${\gamma}$-tocopherol was the major constituent of vitamin E in terms of highest quantity. Total vitamin E content in Italian millet and sorghum landraces were 88.3 mg/kg and 44.3 mg/kg, respectively. Among three phytosterols (campesterol, stigmasterol and ${\beta}$-sitosterol) analyzed, ${\beta}$-sitosterol was the major form comprising about 85% and 65% in Italian millet and sorghum landraces, respectively. Total phytosterols content ranged from 443.0 to 568.5 mg/kg and 442.3 to 719.2 mg/kg in Italian millet and sorghum, respectively. Squalene, a precursor of phytosterols biosynthesis, ranged from 6.8 to 10.2 mg/kg in Italian millet and from 62.2 to 115.2 mg/kg in sorghum. Linoleic, oleic and palmitic acids were the major fatty acids in both of the crops and about 80% of the total fatty acids were unsaturated fatty acids. Among the tested landraces, M09 and S10 showed relatively higher proportion of phytonutrients, suggesting their potential as a gene source for further breeding program.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.37-43
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• 2008

Recent consumption of germinated brown rice is increasing due to its health-beneficial effects. To clarify germination-dependent changes in functional compound contents, 5 different types of (ordinary, glutinous, green-kerneled, red-colored and black-colored) rices were selected and their pre- and post-germination content changes in vitamin E (${\alpha}-$, ${\beta}-$, ${\gamma}-tocopherols$ and ${\alpha}-$, ${\gamma}-$, ${\delta}-tocotrienols$), squalene, and phytosterols (campesterol, stigmasterol, sitosterol) were evaluated. In the case of vitamin E isomer contents, germination generally resulted in decreasing tendency around 10% in most isomers as well as in total tocopherol and tocotrienol contents in all types of rices. In the case of squalene, significant increase could be observed in glutinous rice (by 31%), while other types of rices exhibited no changes or slight reduction by germination. Regarding stigmasterol contents, all tested types of germinated brown rice exhibited significant increment by 19 to 27% compared to nongerminated cases, except for green colored-rice which showed statistically not significant 5% increment. No changes or slight reductions, however, could be observed in campesterol and sitosterol, as well as in total phytosterol contents. As a conclusion, most of tested pharmaceutical compounds exhibited statistically not significant changes except for stigmasterol which were increased by the germination process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48
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• pp.1-12
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• 2003

Vitamin E is a fat-soluble vitamin that exists in eight different forms, which are $\alpha$, $\beta$, $\gamma$, and $\delta$ tocopherol, and $\alpha$, $\beta$, $\gamma$, and $\delta$ tocotrienol. Tocopherols and tocotrienols are important antioxidant in foods, feeds and their raw materials, where they scavenge lipid radicals. Each form has its own biological activity, the measure of potency or functional use in the body. Antioxidants such as vitamin E act to protect cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism. Free radicals can cause cell dam-age that may contribute to the development of cardiovascular disease and cancer, The content of tocopherols and tocotrienols vary depending on the environmental condition such as growing regions, temperature, crops and varieties. This report deals with chemical and physical properties and extends to their nutritional and health effect on the tocopherols and tocotrienols in cereal grains.

• Korean Journal of Plant Resources
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• v.21 no.6
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• pp.435-439
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• 2008

Due to the fact that tocopherols and tocotrienols have antioxidant and anticancer properties, the commercial utilization of unsaponifiable fractions in rice bran is increasing. These nutraceutical compounds, however, are fairly unstable and readily break down when exposed to oxygen or lighting conditions. To compare the relative sensitivity of vit E isomers to heat and oxygen, concentrated unsaponifiable fractions extracted from crude rice bran oil were exposed to various temperature, oxygen (nitrogen-balanced), and bathing solvent conditions and resultant concentration changes in ${\alpha}$- and ${\gamma}$-tocopherols (T) and tocotrienols (T3) were evaluated. Each isomer exhibited different heat stability. Among them, ${\alpha}$-T3 degraded more rapidly compared to other vit E isomers while ${\alpha}$-T was the most stable isomer. Oxygen level also showed significant impact on each isomer's stability where severe reductions of ${\gamma}$-T (by 20%) and ${\gamma}$-T3 (by 29%) were observed under 2% oxygen conditions, while under 0% oxygen conditions no degradation could be observed even after exposure to $95^{\circ}C$ for 4 hours. When various blending solvents were mixed with concentrated unsaponifiable fractions, organic solvents such as isooctane and hexane were more effective in maintaining the stability of ${\gamma}$- T3 compared to edible oils, among which com oil was more efficient than soybean and rice bran oils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.367-375
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• 2013

The rice bran, a by-product of rice milling process, is well known for various functional components, such as tocopherol, tocotrienol, ${\gamma}$-oryzanol, carrying antioxidant activities. This study was conducted to investigate the antioxidant components and antioxidant activities in rice bran of different Korean rice cultivars. The 8 isomers of vitamin E, ${\gamma}$-oryzanol, flavonoids, and polyphenolics in rice bran from 16 Korean premium and high quality rice cultivars were quantified. DPPH and ABTS radical scavenging activities and reducing power of the ethanol extracts of rice bran were measured. 'Hopum' showed the highest total vitamin E content, $221.47{\mu}g/g$ among the cultivars, and 'Hanseol' showed the lowest content. The rice bran showed different compositions of ${\alpha}-$, ${\beta}-$, ${\gamma}-$, ${\delta}-$ tocopherol and tocotrienol among rice cultivars. The antioxidant contents were also different by cultivar; the ${\gamma}$-oryzanol contents ranged from 1.99 mg/g (Unkwang) to 4.30 mg/g (Chilbo), the polyphenol contents ranged from 427.22 mg gallic acid eq./100 g (Odaebyeo) to 775.80 mg gallic acid eq./100 g (Hopum). 'Hopum' also had the highest DPPH and ABTS free radical scavenging activities, 9.82% and 187.5 AEAC mg/100 g, respectively. In vitro, the rice bran extracts from 'Hopum' had significantly higher antioxidant activities than that of other cultivars.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.933-940
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• 2015

The objective of this study was to determine quality changes in seed germination rates and lipid components in Japonica and Tongil (indica/japonica) type brown rices with different tocol composition during storage. Moisture content, seed germination rate, crude lipid content, fat acidity, tocol content, free fatty acid composition of brown rice and pH of milled rice were measured to evaluate their quality after storage. Seed germination rates of stored Japonica and Tongil type brown rices were decreased by 22.4% and 59.7%, respectively, after 8 weeks of storage. The fat acidity of Japonica rice was significantly (p<0.05) higher than that of Tongil type brown rices after storage. The major tocol homologue of Tongil type was ${\gamma}-tocotrienol$, whereas, major tocol homologues of Japonica brown rices were ${\alpha}-tocopherol$ and ${\alpha}-tocotrienol$ throughout the entire storage period.