• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.478-483
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• 1999

This study was conducted to investigate functional properties of 70% acetone extract in different parts of two potato varieties. 'Superior' and 'Atlantic' potato were processed by following method. Potatoes are washed, peeled, sliced and steamed before hot air drying for flesh and peel powder. Hunter's L and b values of flesh powder from blanched 'Superior' potato were higher than flesh powder from fresh 'Superior' potato. Discoloration of 'Superior' potato was inhibited by steam blanching. Contents of total polyphenol and chlorogenic acid in the 70% acetone extract of 'Superior' potato were higher than those of 'Atlantic' potato paticularly in the blanched flesh and peel. But flavonoid was not detected in flesh extract. The phenolic concentration was not decreased by the heat treatment. The nitritescavenging and electron donating ability was greatest at the tuber peel including the skin and cortex tissue 1mm beneath the skin. From the above results browning reaction and polyphenol contents in different parts of potato slices were dependent on cutivars. Peels contained more polyphenols than those from the flesh. The results indicate that potato peel extract of steam blanched plus hot air dried potato tuber showed the effectiveness as a natural nitrite scavenger and antioxidant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.879-884
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• 2009

Allium tuberosum Rotter (Liliaceae, Chinese chives) is a perennial herb of which leaves are used for food. This study investigated the effect of pretreatment on quality of dehydrated Chinese chives. Chinese chives was blanched at $80^{\circ}C$ for 20 sec, followed by drying at $70^{\circ}C$, $80^{\circ}C$, $100^{\circ}C$, or drying at $100^{\circ}C$ for 30 min and subsequent drying at $70^{\circ}C$, or $100^{\circ}C$ for 60 min and subsequent drying at $70^{\circ}C$. Optimum drying temperature and time was $100^{\circ}C$ for 30 min and subsequent drying at $70^{\circ}C$, or $100^{\circ}C$ for 60 min and subsequent drying at $70^{\circ}C$. These conditions were shortened time for dehydration and showed smaller decrease than others in Hunter color L, a, b. Dehydrated Chinese chives showed a constant decrease in greenness with storage, probably due to destruction of chlorophyll by light. In the measurement of Hunter color L, a, b, these conditions showed smaller decrease than others in Hunter color for 15 week storage. Chlorophyll content and SOD (superoxide dismutase)-like activity in that condition was higher than others. It was assumed that a phenolic compound that forms its thermostable activity. The fitness of drying models was conducted in order to explain reducing chlorophyll loss and SOD (superoxide dismutase)-like activity loss. Based upon the chlorophyll content, SOD-like activity, and retention of green color of the vegetable, optimum drying conditions was $100^{\circ}C$ for 30 min followed by $100^{\circ}C$ for 30 min and subsequent drying at $70^{\circ}C$, or $100^{\circ}C$ for 60 min and subsequent drying at $70^{\circ}C$.

• Food Science and Preservation
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• v.30 no.4
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• pp.654-662
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• 2023

The Aster glehni extract has many therapeutic and medicinal values. Therefore, it is essential to set appropriate conditions for enzyme treatment to efficiently extract A. glehni. In this study, changes in the quality of A. glehni extract depending on the concentration and time of enzyme treatment was investigated to increase its effective utilization. Compared to the control, the pH of the extract of A. glehni its soluble solid content increased with the enzyme treatment. The color of the A. glehni extract changed from green-yellow to reddish-yellow with the increase in treatment duration. The fructose and sucrose contents of the extract were the highest at 7.73% and 6.78%, respectively, in the control group without the enzyme treatment. Glucose and maltose contents were 6.91% and 4.44% in the C group (3.2% enzyme concentration and 60 min for enzyme treatment), respectively. Total polyphenol content, which shows antioxidant activity, was the highest at 7.38 mg GAE/g in the E group (1.6% of enzyme concentration and 120 min for enzyme treatment). 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) showed the highest radical scavenging activity in the C group (3.2% of enzyme concentration and 60 min for enzyme treatment). These results enable setting appropriate conditions of enzyme treatment in terms of enzyme concentration and time for the production of dry powders using A. glehni extract.