• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.352-360
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• 2017

This study evaluated the quality characteristics, polyphenolic compounds, and radical scavenging activity of cooked-rice added to commercially available mixed grains. L-value of cooked-rice with various mixed grains decreased compared to that of cooked-white rice; however, a- and b-values increased. Hardness and elasticity of cooked-rice added to various mixed grains were significantly lower in the pressure cooker compared to the electric cooker. There was no significant difference in adhesiveness and stickiness between rice from the electric cooker and pressure cooker. Total polyphenol and flavonoid contents of cooked-rice added to various mixed grains were significantly increased. The average total polyphenol content of cooked-rice added to various mixed grains cooked in an electric cooker and pressure cooker were $16.50{\pm}3.86$ and $15.88{\pm}3.52mg$ gallic acid equivalent /100 g, and flavonoid contents were $1.58{\pm}0.00$ and $1.55{\pm}0.02mg$ catechin equivalents/100 g, respectively. The average of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was $9.27{\pm}2.62$ and $8.72{\pm}2.41mg$ trolox equivalent (TE)/100 g, and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was $22.89{\pm}4.60$ and $23.07{\pm}4.49mg$ TE/100 g for cooked-rice added to various mixed grains cooked in an electric cooker and pressure cooker, respectively. Phenol content and radical scavenging activity of cooked rice was in proportion to the amount of added grains, such as brown rice, colored rice, barley, soybean, and sorghum.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.383-390
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• 2017

Regarding the facts that fat, which is easily oxidized, is one of the major responsible factors affecting the quality of aroma, and polyphenol compounds including chlorogenic acid (CGA) contribute the anti-oxidative activities to coffee, we investigated fat oxidation, conversion of CGA, and changes of anti-oxidative activities according to the degree of roasting and storage of 60 days. We found that the amount of extractable fat by diethyl ether is increased as the coffee beans are roasted longer. Furthermore, the acidity values of the fat are increased from $8.91{\pm}0.16$ to $17.81{\pm}0.11$, and $10.37{\pm}0.27$ to $17.93{\pm}0.09$ in the medium and dark roasted coffee beans, respectively, while it is increased from $4.47{\pm}0.11$ to $11.89{\pm}0.18$ in the green coffee bean after 60 days. The CGA contents in the coffee beans were decreased from $310{\pm}8.2$ to $282{\pm}11.2$, then to $58{\pm}0.0mg$ in 10 gr of the green, medium and dark beans, respectively, and were not changed significantly during the storage period. However, the anti-oxidative activities measured by 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays were not significantly different among the green, medium, and dark coffee beans during the storage period. Furthermore, antioxidant reactive element-luciferase assay showed that biological anti-oxidative activities were increased as coffee beans were more roasted and stored longer. As the total polyphenolic contents in the beans were significantly decreased by roasting, the results suggests that other molecules, such as, Maillard reaction products might play substantial role in anti-oxidative activity and influence cup quality of coffee.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.236-245
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• 2019

Fruit ripening is a genetically programmed process involving a number of biochemical and physiological processes assisted by variations in gene expression and enzyme activities. This process generally affects the phytochemical profile and the bioactive principles in fruits and vegetables. To appraise the variation in bioactive principles of fruits from Rosa rugosa during its ripening process, we analyzed the changes in antioxidant and anti-elastase activities and polyphenolic compounds during the four ripening stages of fruits. Overall, an extract of unripe fruits contained the highest levels of total phenolic and flavonoid contents, radical scavenging activity, reducing power, oxygen radical antioxidant capacity, and elastase inhibitory activity, compared with the extracts of fruits at other stages of ripening. Additionally, we found that the reduction of flavonoid content occurs because of decreased transcriptional levels of genes involved in flavonoid biosynthesis pathway during the ripening process. Based on HPLC analysis, we found that the extract of unripe fruits contained the highest amount of myricetin, caffeic acid, chlorogenic acid, syringic acid, and p-coumaric acid and suggested that the antioxidant and anti-elastase activities of the extract obtained from stage 1, should be mediated by the presence of these compounds. Additionally, we analyzed the interaction sites and patterns between these compounds and elastase using the structure-based molecular docking approach, and suggested that chlorogenic acid strongly interacted with elastase. Together, these findings suggest that the maturity of fruits has profound effects on the pharmaceutical value of R. rugosa.