• Journal of the East Asian Society of Dietary Life
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• v.23 no.3
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• pp.320-331
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• 2013

Omija, the major material of omigalsu, has liver protective and antioxidant effects, while mung bean has detoxification effects. A series of studies were conducted to standardize the traditional recipe for omigalsu to develop traditional functional drinks made from Omija extract and mung bean juice. Study 1 was designed to determine the optimal conditions for Omija extraction and mung bean juice. A higher water temperature and longer immersion time was associated with higher, free sugar and organic acid contents of omija extract; however, sensory evaluation revealed that the optimal extraction conditions for the highest acceptability, proper taste and red tone were $23^{\circ}C$ and 18 hrs of immersion. Conversely, the pH of the mung bean juice produced by varying the immersion time (5 hr, 11 hr, 17 hr) was found to be neutral, containing small levels of organic acid and free sugar, and showing a yellow tone. The results of the sensory evaluation also showed that the optimal conditions for taste, flavor and yellowness of mung bean juice was 5-hour-long immersion. Study 2 was designed to determine the optimum mixing ratio of omigalsu concentrate. Sensory evaluation revealed that the contents of sugar and total free sugar were highest when the mixing ratio among omija extract, mung bean juice and sugar was 1:1:20%, indicating that these conditions produced the most attractive color and highest overall acceptability. Study 3 was designed to determine the optimum dilution magnification for omigalsu. Sensory evaluation during summer revealed that the omigalsu produced by mixing 54 g of omigalsu concentrate into 200 cc water of $4^{\circ}C$ or $80^{\circ}C$ was most preferred, while during winter. Overall, the optimum dilution magnification for omigalsu was 4.7~5.4.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.101-108
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• 2014

This study was conducted in order to compare the biological activities of water extracts and sugar immersion extracts of green pepper (Capsicum annuum L.), purslane (Portulaca oleracea L.) and shiitake (Lentinula edodes (Berk.) Pegler) by measuring total polyphenol and flavonoid contents, antioxidant activities and inhibitory effects on ${\alpha}$-amylase and ${\alpha}$-glucosidase. The contents of total polyphenols and flavonoids were higher in water extracts than in sugar immersion extracts. The anti-oxidative activities of water and sugar immersion extracts were measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay and reducing power assay. All extracts scavenged radicals in a concentration-dependent manner, and water extracts showed stronger radical scavenging activity and reducing power than sugar immersion extract. However, they all exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, the two types of extracts exhibited low ${\alpha}$-glucosidase inhibitory activities, although the activity of sugar immersion extracts were 2-fold higher than that of water extracts. ${\alpha}$-Amylase inhibitory action was not observed for any of the extracts. Finally, by cytotoxicity test, we confirmed that sugar immersion extracts were safer than water extracts. These results indicate that water extracts and sugar immersion extracts of green pepper, purslane and shiitake have different advantages in terms of their antioxidant and anti-diabetic effects, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.3
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• pp.368-375
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• 2008

This study examined the physico-chemical properties of omija extracts that were manufactured using various water temperatures($0^{\circ}C$, $23^{\circ}C$, $70^{\circ}C$) and immersion times(12 hrs, 18 hrs, 24 hrs). The results were as follows: The pH levels of the extracts ranged from 2.86 to 2.95: however, there were no significant differences between the samples according to the various water temperatures and immersion times. The total organic acid contents of the samples ranged from 1.87 to 2.57%, and included citric acid, malic acid, and succinic acid at levels of $1.11{\sim}1.54%$, 0.49{\sim}0.66%$, and $0.25{\sim}0.38%$, respectively. As the immersion time and water temp. is erature increased the level of total organic acid significantly increased(p<0.01). The sugar contents of samples ranged from 3.01 to 3.90% brix, and did not show significant differences according to the immersion times at the different water temperatures(0, 23, $70^{\circ}C$). The Omija extract that was immersed in water for 24 hrs. at $70^{\circ}C$ had a significantly higher(p<0.05) sugar content than the other samples. The total free sugar contents of samples ranged from 0.714 to 0.833%, and included glucose, fructose, and sucrose at levels of $0.37{\sim}0.42%$, 0.34{\sim}0.41%$, and $0.003{\sim}0.004%$, respectively. The Omija extract that was immersed in water for 18 hrs. at $70^{\circ}C$ water had a significantly higher(p<0.05) total free sugar content than the other samples. The lightness, redness, and yellowness values of the samples were in ranges of $49.09{\sim}58.25$, 62.37{\sim}67.34$, and $19.76{\sim}24.57$, respectively; therefore, red was the predominant color of the extracts. Overall, as the immersion time and water temperatures increased is, lightness significantly decreased and redness significantly increased(p<0.001).