• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.28-33
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• 2001

During storage of 45°Bx cloudy and 72°Bx clear apple juice concentrates for up to 16 weeks at 4$\^{C}$ , -3$\^{C}$ and -15$\^{C}$ respectively, the changes of viable microbial counts, physicochemical properties were investigated and the correlation between the physicochemical properties were determined. During storage for up to 16 weeks, any viable microbes were not found in 45°Bx cloudy apple juice concentrate stored at -3 and -15$\^{C}$ and in 72° Bx clear stored at all three temperature. There were little change in pH and tillable acidity except 45°Bx cloudy apple juice concentrate stored at -4$\^{C}$ . As longer storage time and higher storage temperature, was shown higher redness of color(a value) and alcohol soluble color(ASC) in common. Vitamin C contents were more rapid decreased proportionally to time and temperature of storage. The high correlation coefficients were shown of 0.957∼0.967 between redness and ASC and -0.936∼ -0.864 between redness and vitamin C contents of apple juice concentrate during storage.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.235-239
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• 1999

During storage of $45^{\circ}Bx$ cloudy, $50^{\circ}Bx\;and\;72^{\circ}Bx$ clear apple juice concentrates for 18 months, the changes in microbial counts and physicochemical properties were investigated. Little viable microbial counts were detected in $50^{\circ}Bx\;and\;72^{\circ}Bx$ clear concentrates during all storage time and a few in $45^{\circ}Bx$ cloudy concentrates during the only first storage stage. In all three concentrates, any changes were not found in pH and titrable acidity. But Hunter L values were decreased and a, b values were increased. Alcohol soluble color(ASC) were increased and vitamin C contents rapidly decreased, especially during the first three months. The contents and compositions of free sugars were showed a little change. It seemed that the change in ASC was more closely related with that of vitamin C contents than that of reducing sugar contents.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1484-1487
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• 1998

Superoxide dismutase (SOD)-like activities of sixteen kinds of fruits, vegetable juice and commercial concentrates were measured by pyrogallol autoxidation method. The changes in SOD-like activity by heat treatment and the increase in SOD-like activity of apple juice mixed with fruits and vegetables were investigated. SOD-like activity of broccoli juice was 41.7%, the highest value among tested sample. SOD-like activities of strawberry juice, carrot concentrate, kiwi juice, radish juice and apple juice were 30.2, 30.0, 27.6, 26.7, 24.1 and 14.6%, respectively. SOD-like activity was increased generally after heat treatment at $95^{\circ}C$ until 20 min. SOD-like activity of apple juice was increased $20{\sim}35%$ by mixing with 20% of carrot concentrate, kiwi juice, strawberry juice, broccoli juice, respectively and particularly was increased 48% by mixing with 20% of raddish juice.