• Plant Biotechnology Reports
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• v.5 no.1
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• pp.79-88
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• 2011

Vitis vinifera cv. Koshu is a traditional grape cultivar that has been grown for centuries in Japan. The Koshu grape has pink-colored skin and Koshu wines have slight astringency. We demonstrated for the first time the characterization of hydroxycinnamic acids, flavan-3-ols, and flavonoids in Koshu grape using high-performance liquid chromatography and liquid chromatography-mass spectrometry. The gross weight of phenolic compounds excluding anthocyanins and proanthocyanidins in Koshu grape at harvest was higher than those in Sauvignon Blanc, Chardonnay, and Merlot grapes. In addition, hydroxycinnamic acid and monomeric flavonol contents in Koshu grape were also higher than those in the other grape cultivars. Transcription analysis of cinnamic acid 4-hydroxylase, p-coumarate 3-hydroxylase, caffeate methyltransferase, and flavonol synthase genes indicated high accumulation of hydroxycinnamic acids and flavonols in Koshu grape skin compared with the other cultivars. These findings obtained by chemical and molecular approaches partially explained the phenolic characteristics and the peculiar astringency of Koshu grape.

• Nutrition Research and Practice
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• v.6 no.4
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• pp.286-293
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• 2012

Resveratrol (3,4,5-trihydroxy-trans-stilbene), a phytoalexin found in grape skin, grape products, and peanuts as well as red wine, has been reported to have various biological and pharmacological properties. The purpose of this study was to investigate the anti-obesity effect of resveratrol-amplified grape skin extracts on adipocytes. The anti-obesity effects of grape skin extracts were investigated by measuring proliferation and differentiation in 3T3-L1 cells. The effect of grape skin ethanol extracts on cell proliferation was detected by the MTS assay. The morphological changes and degree of adipogenesis of preadipocyte 3T3-L1 cells were measured by Oil Red-O staining assay. Treatment with extracts of resveratrol-amplified grape skin decreased lipid accumulation and glycerol-3-phosphate dehydrogenase activity without affecting 3T3-L1 cell viability. Grape skin extract treatment resulted in significantly attenuated expression of key adipogenic transcription factors, including peroxisome proliferator-activated receptor, CCAAT/enhancer-binding proteins, and their target genes (FAS, aP2, SCD-1, and LPL). These results indicate that resveratrol-amplified grape skin extracts may be useful for preventing obesity by regulating lipid metabolism.

• Nutrition Research and Practice
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• v.6 no.1
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• pp.3-8
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• 2012

Polyphenol-rich grape seeds have a beneficial effect on human health. The present study was performed to investigate the effects of grape seeds on antioxidant activities in rats. Male Sprague-Dawley rats were randomly divided into a control diet group (C), a high-fat diet group (HF), a 5% grape seed-supplemented control diet group (G), and a 5% grape seed-supplemented high-fat diet group (HG). Dietary supplementation with grape seeds reduced serum concentrations of lipid peroxides compared with those in the C and HF groups. The hepatic level of lipid peroxides decreased significantly in the grape seed groups compared with that in the C and HF groups. Superoxide dismutase activity in the G group increased significantly compared with that in the C group. Catalase activity tended to be higher by feeding grape seeds. The grape seed diet increased glutathione peroxidase activity in the C group. Glutathione-S-transferase activity increased significantly in the G group compared with that in the C group. Hepatic content of total glutathione increased significantly in the HG group but decreased significantly in the HF group. The ratio of reduced glutathione and oxidized glutathione increased by feeding the grape seed diet. Total vitamin A concentration was significantly higher in HG group than in other groups. Liver tocopherol content of the G and HG groups was significantly higher than that of the control groups. These results suggest that dietary supplementation with grape seeds is beneficial for suppressing lipid peroxidation in high fat-fed rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1813-1818
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• 2015

Grape seed extract (GSE) was added to grape seed oil to improve the oxidative stability of the grape seed oil during storage. To measure the oxidative stability of grape seed oil, peroxide value, acid value, and conjugated diene value were measured, and changes in browning, vitamin E, fatty acid composition, and polyphenol content of oil were examined. In the case of grape seed oil with GSE, peroxide value, acid value, and conjugated diene value were lower than those of grape seed oil. The magnitude of increase in absorbance of grape seed oil with GSE was less than that of additive-free grape seed oil, whereas the magnitude of decrease in vitamin E isomers in grape seed oil with GSE was less than that of grape seed oil with no additive. Changes in fatty acid composition were also similar. However, polyphenol contents showed the greatest reduction in grape seed oil containing GSE. GSE contributes to the oxidation stability of grape seed oil, but the antioxidant capacity of GSE was lower than that of butylated hydroxytoluene.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.168-174
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• 2005

This study was carried out to investigate the feeding effect of wild grape wine by-products on pork qualities. The chemical composition, volatile basic nitrogen, thiobarbituric acid reactive substances and pH were not significantly different between control and wild grape pork, but the cholesterol and roast loss of wild grape polk. were lower than those of the control, and 1l1e salt soluble protein extractability of the control was lower than that of the wild grape pork. The Hunter's $a^{\ast}$ and $b^{\ast}$ value of wild grape polk. meat were higher than the control, the $a^{\ast}$ value of wild grape polk. meat was higher than the control, but the $L^{\ast}$ value of meat and fat were not significantly different between control and wild grape pork. The cohesiveness, gumminess and chewiness of control(respectively $66.2\%$ 428kg and 189g) were higher than wild grape polk. (respectively $61.4\%$ 357 kg and 154 g). The total amino acid composition of polk. were not significantly different between control and wild grape wine, The glutamic acid, leucine, arginine and aspartic acid were major amino acids in control and wild grape pork. The arachidonic acid $(C_{20:4})$, EPA $(C_{20:5})$ and DHA $(C_{22:6})$ of wild grape polk. were higher than those of the control. The taste (p<0.001), aroma (p<0.05), flavor (p<0.001), juiciness (p<0.01) and palatability (p<0.01) of wild grape polk. were higher than those of the control, but the texture between control and wild grape polk. were not significantly different.

• Journal of Applied Biological Chemistry
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• v.42 no.4
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• pp.175-179
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• 1999

Grape seed oil was extracted using different preparatory treatments as follows: (1) grinding, (2) grinding and roasting, (3) grinding and wet- roasting, (4) grinding, roasting, and wet-roasting, and (5) grinding, wet-roasting, and wet-roasting. The highest antioxidant activity was obtained from the sample with the method (2). Initial states of oxidation were similar except method (1) that showed more oxidized state, being P.O.V.8. Acid values were observed in the range from 1.42 to 1.89. The lowest acid value was found as 1.42 in method (1) and those of others were somewhat higher, indicating that heating process of roasting produced some free fatty acids. From the results of sensory evaluation, the best odor and taste were obtained from the methods (2) and (3). Repetitive procedure of wet-roasting, like method 5, caused some loss of flavor components and decrease in the sensory evaluation score. Addition of grape seed oil (method 2) to soybean and perilla oil at the level of 20% retained considerable antioxidant activities as much as 4.3 and 5 times, respectively, than 100% soybean or perilla oil stored for 12 weeks. When soybean or perilla oil was mixed with 20% grape seed oils, P.O.V. decreased to half of that of unmixed oils.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.616-623
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• 2004

Fermentation characteristics of rice-grape wine with different mixing ratios of rice and grape, rice one vs. grape five (Exp.1), rice two vs. grape five (Exp.2), rice five vs. grape five (Exp.3), and rice five and grape two (Exp.4), were investigated. Final alcohol contents of Exp.4, Exp.3, Exp.2, and Exp.1 were 18.4, 16.0, 14.9, and 12.9%, respectively. Final alcohol content increased with increasing amount of rice. Acidity of four experiments ranged pH 3.4-3.92, and total acidity was 0.52-0.74%. Exp.4, Exp.3, Exp.2, and Exp.1 gave a values of 8.76, 12.77, 12.88, and 23.96, respectively. When different mixing methods were applied to Exp.1, the resulting final alcohol contents of Exp.6 (grape musts periodically added after rice fermentation), Exp.7 (rice and grape simultaneously added and fermented), and Exp.8 (rice added after grape must fermentation) were 2.3-3.2% Bower than that of Exp.1 (grape must added after rice fermentation), and total acidity was 0.72-0.74%. Sensory evaluation comparing conventional red wine and rice-grape wine of Exp.1 showed rice-grape wine was preferred in taste.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.462-468
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• 1998

편이었다. 미량성분으로는 K이 다량으로 존재하였고, 2단계 발효로 제조된 포도식초는 포도양파식초 보다K, Na, Cu함량이 높게 나타났다. ^x Grape vinegar (A) and grape onion vinegar(B) added (3% of onion juice) were produced through two stages of fermentation(alcohol fermentation and acetic acid fermentation) to increase the grape's use. Grape wine which contained 5.6% alcohol was produced on the 3rd day of first stage. Then through the second stages, grape vinegar, of which total acidity was 5.37% was produced. The quality of (A) and ( B) which was produced through the two stages of fermentation was compared with the traditional grape vinegar (C, D) in the market. The content of sugar in (D) was a little higher such as 5.4 $^{\circ}$Brix than others. That of (A) and (B) was 5.13, 4.98 $^{\circ}$Brix respectively. The content of remaining alcohol in (C) was high such as 0.23% comparatively. But there was no remaining alcohol in (A) and (B). The content of acetic acid was 4.3~5.3% as a major organic acid of vinegars. The content of tartaric acid was 340.0 in (A), 315.7 in (B), 322.6 in (C) and 391.7mg% in (D). The content of lactic acid was distinctly high such as 277.4mg% in (D) There were differences such as 9.2~15.5mg% in the content of total free amino acids among grape vinegars. (D) contained 15.5mg% of total free amino acid and (B) also highly such as 12.0mg%. Potassium was high in grape vinegars. The content of potassium, sodium and copper was higher in (A) than (B).

• Korean Journal of Organic Agriculture
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• v.9 no.3
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• pp.73-83
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• 2001

The qualities of the rice straw, black locust and orchardgrass silage added with grape pomace were investigated in this study and the amount of grape pomace added in different treatments were 0, 20, 40 and 50%, respectively. Crude protein contents of rice straw(6.5-10.6%) and orchardgrass silage(13.2-14.8%) added with grape pomace were significantly higher(p<0.05) than that of 100% rice straw(5.3%) and orchard grass silage(12.8%), however the crude protein contents(14.9-15.6%) of black locust silage in supplementation were lower than that of 100% black locust silage(16.3%). With higher amount of addition of grape pomade to rice straw, black locust and orchardgrass silages, ADF, NDF and crude ash contents decreased significantly(p<0.75). Moisture contents decreased according to the higher proportion of grape pomace in the rice straw silages, but increased according to the higher proportion of grape pomace in the black locust and orchardgrass silage. Values of pH in 20∼60% addition of grape pomace in rice straw(4.0∼4.2), black locust(4.1∼4.3) and orchardgrass silages(4.2∼4.4) were lower than that of 100% in rice straw(4.6), black locust(5.4) and orchardgrass silages(4.7). The contents of acetic acid and total volatile fatty acid significantly increased according to higher levels of addition of grape pomace compared to the respective values of silage. However the contents of lactic acid in supplementation of grape pomace were lower than that of 100% black locust silage.

• The Korean Journal of Food And Nutrition
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• v.12 no.2
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• pp.150-155
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• 1999

The possibility of grape seeds as industrial resources was tested by analyzing various chemical proper-ties of their oils from seven different species. The range of crude oil content of the grape seeds was 26.0-32.0% showing the highest content in Steuden, Mean individual fatty acid contents in the grape seeds were lioleic (70.75%) oleic (18.48%) stearic (2.01%) and palmitic (8.45%) acids. Stearic acid was low in Jingyu and high oleic acid was found in Fugiminori compared with other grape strains. Total lipirds were consisted of nutral lipid (87.25%) glycolipid(4.68%) and phospholipid *8.06%) Content of crude proteins was approximatery 11.2% with some variation between strains. Total sugar content was 2.35~5.63$\mu$g/mg with reducing sugar 3.20$\mu$g/mg. Mean saponification value of crude oils was 186.3mg.KOH.oil Antioxidant activity of grape seed oils was better than that of sesame oil resulting in the hi-oils and sesame oil after heat treatment at 18$0^{\circ}C$.