Abstract
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).