• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.35-41
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• 2019

The sensory characteristics of eight commercial ready-to-drink (RTD) cold brew coffees were compared by descriptive analysis. The cold brew coffee samples were analyzed for hunter color values, brown color, turbidity, pH, titratable acidity, soluble solids, total phenolic content, and chlorogenic acid content. Three appearances, nine aroma, five flavor/taste, and four texture/mouth-feel related sensory attributes were evaluated by a panel of nine judges. The results of three-way analysis of variance of descriptive data showed that all sensory attributes except "fruit" aroma, "dark chocolate" aroma, "bitter" aroma, and "sweet" taste had significant differences among the samples (p<0.05). Based on the principal component analysis (PCA) of the descriptive data, the samples were primarily separated by first and second principal components, which accounted for 81.78% of the total variance among the samples with high intensities of "nutty aroma", "grain aroma", and "grain taste" versus "earth aroma", "sour aroma", "sour taste", "astringent", "smoothness", and "residual". In the correlation analysis of sensory terms and physicochemical parameters, titratable acidity and soluble solids showed significant positive correlations with earth aroma and smoothness characteristics.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.64-68
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• 2019

To utilize soybean leaf, which is a waste product in soybean production, as a value-added food material, this study aimed to investgate the extraction efficiency of isoflavone from soybean leaf and to characterize physicochemical properties of the extract. Maximum isoflavone content of $59.74{\pm}4.54mg/l$ was obtained from soybean leaf extracted at $90^{\circ}C$ for 12 h. DPPH (1,1-diphenyl-2-pricylhydrazyl) radical-scavenging activity and total polyphenol contents reached maximum levels of $67.26{\pm}3.64%$ and $1,688.68{\pm}97.37{\mu}g/ml$ chlorogenic acid equivalent, respectively. Based on the contents of isoflavone and total polyphenol, and DPPH radical-scavenging activity, optimum extraction conditions for soybean leaf using water as solvent were $90^{\circ}C$ and 12 h.

• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.327-333
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• 2023

This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.25-25
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• 2022

피부 노화는 피부와 피부 지지층 등의 광범위한 퇴행 과정을 말한다. 피부 노화의 원인은 흡연, 공해, 스트레스 등이 있지만, 그 중에서도 자외선(ultra violet, UV) 조사가 가장 큰 요인으로 꼽힌다. 반복적인 자외선 조사에 의해 진행되는 피부노화를 광노화라고 하며 그 가장 큰 특징으로는 콜라겐 섬유와 엘라스틴의 감소로 야기되는 주름을 들 수 있다. 본 연구에서는 제주에서 채집한 바위수국의 추출물 및 분획물의 항산화 및 자외선으로 인한 피부노화 예방(anti-photoaging) 효능을 확인하고, 활성물질을 분리하여 광노화 예방 효능과 그 메커니즘을 확인하였다. 실험에 사용된 바위수국은 범의귀과의 덩굴성 식물로 바위면이나 나무줄기 등에 붙어서 자라며, 한국(제주, 울릉도)과 일본에 분포한다. 바위수국 추출물과 분획물에서 총 페놀 함량. 총 플라보이드 함량, DPPH 및 ABTS 라디칼소거 활성의 항산화 실험 결과, 부탄올과 에틸아세테이트 분획층에서 강력한 항산화 활성이 관찰되었다. 또한 UVA를 조사한 인간 진피 섬유아세포 (human dermal fibroblast, HDF)데 대한 콜라겐 분해효소인 matrix metalloproteinase-1(MMP-1) 생성 억제 활성을 확인한 결과, 부탄올 분획층이 세포 생장 저해 없이 가장 우수한 효능이 확인되었다. 따라서 부탄올 분획층에서 주요 성분 분리 실험을 수행하여 총 4개의 화합물을 분리하였다; Chlorogenic acid (1), Quercetin-3-O-glucosyl-(1-2)-rhamnoside (2), Quercetin-3-O-xylosyl-(1-2)-rhamnoside (3), Quercitrin (4). 분리한 4개의 물질의 MMP-1 생성 억제 활성을 비교한 결과 화합물 2가 세포독성 없이 MMP-1 생성 억제 효능이 우수하였고, 이후 화합물 2의 광노화 예방 효능과 그 메커니즘을 확인하였다. 화합물 2는 MMP-1의 생성을 억제할 뿐만 아니라 procollagen type I의 생성을 증가시켰으며, MMP-1 생성에 관여하는 mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) 신호전달경로를 하향 조절하며, 콜라겐 생성과 관련된 Transforming growth factor-β (TGF-β)/Smad 신호전달경로를 상향 조절하여 UVA에 의한 광노화 예방에 효능을 나타내었다. 이러한 결과들을 바탕으로, 바위수국은 항노화(anti-aging) 기능성 화장품 및 이너뷰티 기능성 식품 소재로 개발이 가능할 것으로 기대된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.487-496
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• 2013

Green coffee beans (CB, Indonesian Mandheling) were fermented with three kinds of mushrooms (Phellinus linteus, PL; Hericium erinaceum, HE; Ganoderma lucidum, GL) or two kinds of mycelia from molds (Monascus purpureus, MP; Monascus ruber, MR) using solid-state culture to enhance physiological activity. After the roasting of fermented green coffee beans, roasted coffees were extracted with a hot-water decoction or 95% ethanol reflux. Yields from hot water extracts (HW, 17.7~25.3%) were higher than those from ethanolic extracts (EE, 9.5~12.2%). Hot-water extracts of roasted coffees from green coffee beans fermented with two molds (MP-CB-HW and MR-CB-HW) showed higher total polyphenols, flavonoids, and DPPH free radical scavenging activity than roasted coffees from non-fermented (CB-HW) or fermented green coffee beans with the three mycelia from mushrooms. MR-CB-HW also had the most potent macrophage stimulating and mitogenic activity (1.32 and 1.40-fold of CB-HW, respectively). In addition, MP-CB-EE and MR-CB-EE did not show any cytotoxicity to the RAW 264.7 cell at a concentration of $100{\mu}g/mL$, and these extracts significantly inhibited nitric oxide (NO) production from the LPS-stimulated RAW 264.7 cell line (38.6 and 37.0% of the LPS-treated group). Meanwhile, the chlorogenic acid concentrations of MP-CB-HW or MR-CB-HW highly increased (to 76.21 or $76.73{\mu}g/mL$, respectively), but caffeine concentrations were not affected by solid-state fermentation. In conclusion, the physiological activities of roasted coffees were enhanced by the solid-state culture of green coffee beans with M. purpureus or M. ruber, suggesting that these roasted coffees could possibly serve industrial applications as functional coffee beverages.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.533-538
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• 2013

Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's food. Potatoes were first introduced into Europe in the 16th century and Korea in the early 19th century. In the nutritional aspects, potatoes contain abundant vitamins and minerals, as well as an assortment of phytochemicals such as carotenoids and natural phenols. Chlorogenic acid constitutes up to 90% of potato natural phenols. Due to the high content of potato functional compounds, it has known that potatoes are effective in the prevention of various human diseases. Recently, color-fleshed potatoes 'Hongyoung' and 'Jayoung' were developed by RDA, and it has reported that they have high content of anthocyanin. Additionally they show higher radical scavenging activity compared to white or yellow fleshed potatoes. So it will be expected that the consumption of color-fleshed potatoes grandually increase by pre-peeled potatoes and color potato chips. This study was conducted to enhance the peel of color-fleshed potatoes utilization and to determine the biological activity of peel of color-fleshed potatoes extract. The anti-inflammatory effects on ethanol extract and its solvent fraction were also evaluated. The anti-inflammatory activities of $CHCl_3$ fraction was evaluated for inhibitory activities against lipopolysacchride(LPS) induced nitric oxide(NO) and prostaglandin $E_2(PGE_2)$ production as well as inducible nitric oxide synthase(iNOS) and cyclo oxygenase-2(COX-2) protein expressions in RAW264.7 cell lines. The fraction inhibitory activity for both tests with $IC_{50}$ values showed in the ranges of $25{\sim}50{\mu}g/ml$. This result revealed that $CHCl_3$ fraction of Jayoung's peel is expected to be good candidate for development into source of anti-inflammatory agent.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.232-239
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• 2012

A laboratory experiment was conducted to determine the content of phenolics and flavonoids, antioxidant activity and cytotoxicity from methanol extracts of different plant parts of $T.$ $officinale$ F. H. Wigg. Total phenolics [mg chlorogenic acid equivalents (FAE) $kg^{-1}$ DW] was highest in flower extracts (72.0 mg $kg^{-1}$), followed by leaf, root, and stalk extracts of $T.$ $officinale$ ($p$ < 0.05). The result of total flavonoid level [mg naringin equivalents $kg^{-1}$ DW] had same tendency to differential total phenolics contents among plant parts, but showed lower ranges of amount. The antioxidant activity of the methanol extracts from all the plant parts dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was highest in flower extracts ($IC_{50}$ value = 624.3 mg $kg^{-1}$ ), and followed by leaf, root, and stalk extracts of $T.$ $officinale$ ($p$ < 0.05). By means of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, cell viability of Calu-6 for human pulmonary carcinoma and SNU-601 for human gastric carcinoma showed the lowest $IC_{50}$ value in the flower extracts ($IC_{50}$ value = 85.7 and 311.4 mg $kg^{-1}$, respectively), indicating the highest cytotoxicity. The results suggested that total phenolics content and total flavonoids level in different plant parts of $T.$ $officinale$ were highly correlated with antioxidative ($r^2$=0.7280 to 0.9971) or with cytotoxic activities ($r^2$=0.5795 to 0.9515).

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.198-204
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• 1988

This study was aimed at obtaining elementary data on enzymatic browning of potato and potato products and examining the inhibitory method of browning. Therefore, we extracted polyphenol oxidase from potatoes(Solanum tubersum L.), and investigates its general properties and inhibiting effects of its activity with the different concentrations of sulfites($Na_2S_2O_4,\;Na_2SO_3{\cdot}7H_2O,\;NaHSO_3$). The optimum pH and temperature of polyphenol oxidase were observed to be 6.5 and $37^{\circ}C$ respectively. The polyphenol oxidase at PH5 was very stable, and the activity of polyphenol oxidase between pH $5.0{\sim}9.0$ was estimated to be relatively high, showing $72{\sim}75%$ of its activity at pH5. The polyphenol oxidase was very stable when heated at $40^{\circ}C$ for one hour, and almost 50% of enzyme activity was decreased when heated at $70^{\circ}C$ for twelve minutes. At 0.1mM concentrating of sulfites the relative activity of polyphenol oxidase was 98% in all the three cases of sulfites. Thus sulfites at 0.1mM concentration was found to have little inhibiting effect on polyphenol oxidase activity. At 1mM concentration of sulfites $NaHSO_3$ showed the lowest 36% relative activity among the three. At 5mM concentration of sulfites, the relative activity of $Na_2SO_3{\cdot}7H_2O$ was the lowest 14%.