• Journal of Bio-Environment Control
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• v.33 no.3
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• pp.129-138
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• 2024

This study was conducted to determine the differences in bioactive compounds and antioxidant activity according to the ripening stage of tomato fruits with different skin colors. The tomato samples used three tomato cultivars distinguished by their skin colors as yellow, black, and red at the mature stage. Tomato samples were analyzed for soluble sugars, lycopene, ascorbic acid, polyphenols, and antioxidant activity after being harvested at green, breaker, turning, and mature. The major sugars in tomato fruits are fructose and glucose. The content of fructose and glucose in yellow tomatoes gradually increased during the ripening stages. However, red and black tomatoes, their levels exhibited an initial increase at the breaker points, followed by a period of relative constancy. The lycopene contents in fruits of all skin colors showed a significant increase during ripening stages. The highest content of lycopene was observed at the mature stage in red tomato fruits. Differential patterns in the accumulation of ascorbic acid between yellow and black or red tomato fruits were detected during the entire ripening stages. In yellow tomato fruit, the content of ascorbic acid remained consistently low throughout the ripening stages. Ascorbic acid content in black tomato fruits significantly increased to 2,249 mg·kg^-1 of tomato fruits at the mature stage, while in red tomato fruits, it gradually increased to 3,529 mg·kg^-1 of fruits at the mature stage. Quercitrin content in tomato fruits gradually decreased during the ripening stages. In yellow tomato fruits, the ABTS radical scavenging activity abruptly increased at the turning stages, while in black and red tomato fruits, it gradually increased according to the ripening stages. The DPPH radical scavenging activity in tomato fruits significantly increased at the turning stages.

• Journal of Life Science
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• v.33 no.2
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• pp.115-128
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• 2023

The fruit of Vaccinum oldhami was separated and purified to obtain the compounds chlorogenic acid (CA), quercetin (QT), and quercitrin (QR). The electron-donating abilities of CA, QT, and QR at 1,000 ㎍/ml were 91.9%, 89.9%, and 77.4%, respectively QT and QR showed 99.5% and 91.4% ABTS⁺ radical scavenging ability at a 1,000 ㎍/ml concentration, respectively, and CA showed a 95% ability or higher at 100 ㎍/ml. Regarding tyrosinase inhibitory activity, CA, QT, and QR exhibited 29.5%, 34.7%, and 23.7% efficacy, respectively, at 1,000 ㎍/ml. Regarding the cell viability for melanoma cells (B16F10) assessed through MTT assay, CA, QT, and QR showed cell a viability of 80% or more at 100 ㎍/ml. To measure the deterrent of protein expression, CA affected TRP-1 and TRP-2 in accordance with increases in concentration. The protein expression inhibition rate of QT was excellent for TRP-1, TRP-2, and tyrosinase. CA was confirmed to have an excellent mRNA expression inhibitory effect against MITF, and the amount of mRNA expression of TRP-1, TRP-2, and tyrosinase decreased with an increase in the CA concentration. As the concentration of QT increased, the mRNA expression of MITF, TRP-2, and tyrosinase decreased. QR decreased the amount of mRNA as the QR concentration increased. The excellent antioxidant and whitening effects of CA, QT, and QR were thus confirmed.