• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.3
• /
• pp.333-338
• /
• 2008

The tea has traditionally been used as a foodstuff by unique flavor, however recently not only the diversity of consumer demands but also the public interest in unique favorite and functional aspects have increased. It has been also reported that the main components contained in the leaves of tea (Camellia sinensis) include total nitrogen, free amino acids, polyphenols, and fiber, of which catechin has powerful bioactive effect such as anti-cancer, anti-aging, and anti-diabetic. (-)-Epigallocatechin gallate (EGCG) which is a major phenolic constituent of green tea extract has received considerable attention for a variety of important bioactivities. This study was carried out to obtain useful information for tea breeding programs, and to investigate the concentration of quality and functional related components in Korean indigenous tea germplasms. Korean indigenous tea lines were classified into three groups of sprout time, i.e, early, medium and late sprout time, and the ratio were 20%, 43% and 37%, respectively. There was a difference in characteristics among these Korean indigenous tea lines, leaf width of those ranged from 19.8 to 75 mm, leaf length was 35.5-160.0 mm, and leaf area was $660-8,400\;mm^2$. Experimental data on chlorophyll content (SPAD value) of Korean indigenous tea genetic resources ranged from 51.3 to 82.3. The concentrations of the total nitrogen, total free amino acids, and theanine were ranged 4.18-6.07%, 2.87-4.58%, and 1.64-2.66%, respectively. Also, catechin concentration showed from 11.54 to 15.07%, and concentration of caffeine was 2.82-4.23%. These results indicated indicated that it is possible to select elite lines with high concentration of quality related components and low concentration of caffeine from Korean domestic tea germplasms.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.52 no.4
• /
• pp.447-452
• /
• 2007

This experiment was conducted to enhance the colored potatoes utilization and to determine the biological activity of colored potato extracts. In order to understand the factors responsible for the potent antioxidant and antihypertensive ability of colored potatoes, it has been evaluated for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the 1,1-diphenyl-2-picryl hydrazyl free radical generating system. There were significant differences of antioxidant activities in $50{\mu}g/mL$ extracts treatment among different colored potatoes. About two-fold higher radical scavenging activity was found in 'Daegwan 1-102', 'Daegwan 1-104' and 'Jasim' compared to that in 'Superior'. Based on the flesh color tested, potatoes with purple tuber showed higher radical scavenging activity than red potatoes, while white potato showed the lowest radical scavenging activity. The ability of 80% ethanol extracts from colored potatoes to influence the inhibitory activity of angiotensin converting enzyme(ACE) and xanthine oxidase(XOase) has also been investigated. Expect 'Jasim', the high levels of inhibition activity of xanthine oxidase in two colored potatoes such as 'Daegwan 1-102' and 'Daegwan 1-104' were highly correlated to $IC_{50}$ values of ACE inhibition activity. The various therapeutic benefit claims in the new functional medicinal usage of colored potatoes ascribed to the phenolic compounds and anthocyanin. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of free radical scavengers and anti-hypertentive agent.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.1
• /
• pp.75-84
• /
• 2008

Colored potatoes are an excellent source of dietary polyphenols including anthocyanins. Generally, anthocyanins from fruits and vegetables exhibit anti-carcinogenesis and anti-cancer properties in vitro test. This experiment was conducted to know the effects of colored potato extracts contained anthocyanins on antimutagenic activity and anticancer activity to six human cancer cell lines containing LNCaP (androgen-dependent) prostate cancer cells. Extracts of three colored potatoes ('Hongyoung', 'Jayoung' and 'Jasim') and the white potato ('Superior') cultivars were used in this study. The extracts of three colored potatoes inhibited the mutagenicities induced by direct mutagen such as 4-nitro-quinoline-1-oxide (4-NQO) and another indirect mutagens of bezo(a)pyrene (BaP). Also, the extracts of 'Hoyoung' and 'Jayoung' showed higher antimutagenic activity than 'Jasim' and 'Superior' against to direct or indirect mutagen on both strains of TA98 and TA100. The activity of growth-inhibitory of extract of four potato cultivars were screened by SRB (sulphorhodamine B) method on diverse human cancer cells representing different types of cancers. Among the extract of four potato cultivars, the extract of 'Jasim' showed moderate inhibition on proliferation of LNCaP, ACHN and MOLT-4F cells and did not inhibit the proliferation of other cancer cells. On the other hand, extract of 'Superior' did not inhibit the proliferation of any tested cancer cell lines. However, the extracts of 'Hongyoung and Jayoung' inhibited the proliferation of cancer cells with $GI_{50}$ values ranging from 2.5 to $30\;{\mu}g/mL$. On the basis of the $GI_{50}$ values, it is clear that LNCaP cells were more sensitive to extracts of colored potato cultivars than other cancer cells. The extract of 'Jayoung' at $30\;{\mu}g/mL$ were more active and inhibited cell proliferation, and induced apoptosis in LNCaP cells. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of antimutagenic and anticancer agent.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.1
• /
• pp.110-117
• /
• 2008

Soybeans (Glycine max) with a black seed coat have been widely utilized as food source and as a medicinal herbs in Korea. The pigmentation in the seed coat of black soybean is due to accumulate anthocyanins in the epidermis palisade layer. The anthocyanin content and composition of the black soybean seed coat are considered as a standard. of quality evaluation of black soybean. The main objective of this study was to investigate the optimal condition for an extraction method of anthocyanins and compare anthocyanin quantity and composition within black soybean varieties and germplasms. In the test of extraction solvent, absorbance at 530 nm and Hunter's a value were increased as increasing the concentration of MeOH, but Hunter's Land b values were the exact opposite of absorbance and Hunter's a values. There was no significant difference for anthocyanin contents from 1% HCl - $H_2O$ to 1% HCl - 80% MeOH. In the aspects of anthocyanin contents and HPLC peak resolution, 1% HCl - 20% MeOH extraction solution was the most suitable solvent. Among the 5 kinds of extraction method using 1% HCl - 20% MeOH solution, the anthocyanin contents of room temperature extraction at 72 h was the highest among the methods. High extraction temperature, sonication and reflux method influenced on the decrease of anthocyanin contents because of breakdown of anthocyanins. There was no significant difference for extraction time between 12 h and 24 h. However, the optimal extraction condition were at room temperature for 12 h. The anthocyanin contents in seed coats of black soybean were determined on the basis of HPLC peak area at 530 nm. Ten black soybean varieties and germplasms were tested with optimal conditions founded in this study. On the basis of antocyanin component, these can be classified into three groups; C3G, C3G + D3G and C3G + D3G + Pt3G. The total anthocyanin content in seed coats ranged from 1.58 to 10.62 mg/g of seed. The total anthocyanin content of the variety "Geomjeongol" was about 7 times higher than that of variety "Heugchong". Information for extraction method and diversity in antocyanin of soybean seed coats can be used for future research for germplasm evaluation and development of high quality black soybean varieties.