• Journal of Photoscience
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• v.8 no.1
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• pp.13-17
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• 2001

Cucumber leaves subjected to light chilling stress exhibit a preferential inactivation of photosystem(PS) I relative to PSII, resulting in the photoinhibition of photosynthesis. In light chilled cucumber leaves, Cu/Zn-Superoxide dismutase(SOD) is regarded as a primary target of the light chilling stress and its inactivation is closely related to the increased production of reactive oxygen species. In the present study, we further explored that inactivation of PSI in cucumber leaves is not a light chilling specific, but general to various oxidative stresses. Oxidative stress in cucumber leaves was induced by treatment of methylviologen(MV), a producer of reactive oxygen species in chloroplasts. MV treatment decreased the maximal photosynthetic O$_2$ evolution, resulting in the photoinhibition of photosynthesis. The photoinhibition of photosynthesis was attributable to the decline in PSI functionality determined in vivo by monitoring absorption changes around 820 nm. In addition, MV treatment inactivated both antioxidant enzymes Cu-Zn-superoxide dismutase and ascorbate peroxidase known sensitive to reactive oxygen species. From these results, we suggest that chloroplast antioxidant enzymes are the primary targets of photooxidative stress, followed by subsequent inactivation of PSI.

• Journal of the Korean Society of Food Culture
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• v.29 no.6
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• pp.615-622
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• 2014

This study investigated the antioxidative properties of Yangha Buds (Zingiber Mioga R) and quality characteristics of Korean steamed-rice cake, Sulgidduk, prepared with Yangha Buds juice. Antioxidative activities were measured based on DPPH radical and ABTS radical scavenging activities, total phenol content, and total flavonoid content in Yangha Buds (water extract and juice). Sulgidduk was prepared by adding Yangha buds at concentrations of 0, 1, 2, 3, and 4% of juice. To analyze quality characteristics, proximate composition, color, texture profiles, and sensory evaluations were measured. As content of Yangha buds juice increased, L-value significantly decreased while a-value and b-value increased (p<0.05). For texture profiles, control group scored higher score for hardness as compared to groups added with Yangha buds juice. Springiness, chewiness, and adhesiveness were not significantly different among the groups. In the sensory evaluation, samples containing 3% Yangha buds juice showed better results for attitude. Based on these results, we suggest that Yangha buds are a good ingredient for increasing consumer acceptability and functionality of Sulgidduk.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.92-100
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• 2013

This study investigated the quality and antioxidative properties of a Korean fried rice cake, Gaeseong-Juak (doughnut of waxy rice) added with Prunus yedoensis Matsumura (PYM) extract, vitamin C and BHT. Gaeseong-Juak was prepared by adding PYM extract at 0, 0.5, 1, and 2% of waxy rice powder. The moisture contents of Gaeseong-juak added with PYM extract varied between 17.50% and 21.70%. Among the samples, the lowest moisture content was 2% Gaeseong-juak added with PYM extract. The contents of the samples obtained from crude protein, crude fat, crude ash were 4.47~4.73, 11.15~12.50, and 0.73~0.82%, respectively. The as the content of PYM extract increased, L-values significantly decreased while a-value and b-value significantly increased (p<0.001). The texture profile analysis of the Gaeseong-Juak was not significantly different at the samples. In the sensory test, the sample containing 0.5% PYM extract obtained good scores. The antioxidative effect of the Gaeseong-Juak significantly increased as the addition level increased, compared to the original Gaeseong-Juak (p<0.001). From these results, we suggest that PYM is a good ingredient for increasing the consumer acceptability and the functionality of Gaeseong-Juak.

• Journal of the Korean Society of Food Culture
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• v.32 no.4
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• pp.295-302
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• 2017

The aim of this study was to analyze the functional components of five cultivars of 'Mugunghwa (Hibiscus syriacus L.)' for the development of 'Mugunghwa'-added foods. There were five varieties, namely, Hibiscus syriacus 'Hwanhee' (HH), Hibiscus syriacus 'Samchulli' (SC), Hibiscus syriacus 'Harmony' (HM), Hibiscus syriacus 'Baekgu' (BG), and Hibiscus sabdariffa L (HB). Of the five varieties tested, HH extract showed the highest total phenolic content (131.85 GAE mg/g), DPPH free radical scavenging activity (95.18%), and anthocyanin and sugar contents. The sensory quality of powders from each Hibiscus variety was evaluated, and it was found that overall palatability decreased in the order: HH, SC, HB, HM, and BG. Thus, addition of Hibiscus variety, which has excellent functionality and palatability, to foods confers an extra element of Korean history and culture, which is expected to improve the marketability of various food products.

• Mycobiology
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• v.39 no.2
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• pp.109-112
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• 2011

Vitis hybrid (Sheridan)-Robus coreanus red wine was vinified by fermentation of a mixture of Vitis hybrid and Robus coreanus must at $25^{\circ}C$ for 10 days. The Vitis hybrid-Robus coreanus red wine had ethanol contents of 10.9%. It had high antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity of 57.8% and antioxidant activity of 64.8%. Changes in the physicochemical properties and functionality of the Vitis hybrid-Robus coreanus red wine was investigated during a post-fermentation period of three months. The ACE inhibitory activity of the red wine increased as the post-fermentation period prolonged, and showed the highest ACE inhibitory activity of 70.4% 60 days post-fermentation. However, the antioxidant activity declined significantly to 47.2% during the post-fermentation period of 60 days. In terms of sensory evaluation, the Vitis hybrid-Robus coreanus red wine had the best acceptability 60 days post-fermentation.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.383-389
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• 2016

Purpose: This study was conducted to evaluate the effect of rehydration and subsequent heating at high temperature on the pigments and antioxidants of dried samnamul (Aruncus dioicus) and daraesoon (Actinidia arguta). Methods: Rehydration included 16 h-soaking in cold water, and 30 min-boiling and 1 h-infusion in water. Rehydrated samnamul and daraesoon were heated at $180^{\circ}C$ for 10 or 20 min with or without perilla oil addition (10%) for cooking. Pigments and antioxidants were determined by HPLC and spectrophotometry. Results: Rehydration caused decreases in pigment and polyphenol contents, but increase in tocopherol content. Cooking by heating without addition of perilla oil resulted in increases in chlorophyll and carotenoid contents, but decreases in polyphenol and tocopherol contents. Decrease in tocopherol content by heating at $180^{\circ}C$ was reversed by the addition of perilla oil. Conclusion: This study strongly suggested that cooking of samnamul and daraesoon at $180^{\circ}C$ with perilla oil could improve color, texture, and potential health functionality by recovering the loss of antioxidants and pigments with antioxidant activity.

• Journal of the Korean Dietetic Association
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• v.25 no.4
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• pp.281-294
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• 2019

The objective of this study was to develop fermented vegetable juices that possess antidiabetic and antioxidant activities. Lactobacillus plantarum MKHA15 (MKHA15) and Leuconostoc mesenteroides MKSR (MKSR) were applied to ferment onion, cabbage, and tomato juices at $37^{\circ}C$ and $30^{\circ}C$ for 72 h, respectively, and their functionality was tested using the 12 h hour-fermented juice by MKHA15, and 48 h hour-fermented juice by MKSR. Inhibition of ${\alpha}$-glucosidase activity was observed in all fermented juices. The onion juice fermented by MKHA15 showed significantly higher ${\alpha}$-glucosidase inhibition activity compared to other juices. All juices showed more than 70% inhibition of ${\alpha}$-amylase activity. The DPPH radical scavenging activity of onion juice fermented by MKSR showed significantly lower activity than cabbage and tomato juices; however, no difference was observed between the types of starter cultures. The SOD-like activity of cabbage juice fermented by MKSR was the highest among the fermented juices. The juices fermented by MKHA15 showed higher reducing power than those by MKSR. Therefore, we believe that cabbage, onion and tomato juice fermented by MKHA15 and MKSR would be useful in probiotic juices, as they possess antidiabetic and antioxidant activities.

• The Korean Journal of Food And Nutrition
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• v.33 no.1
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• pp.17-26
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• 2020

This study was conducted to evaluate the functionality of fermented black garlic extracts under various conditions. Black garlic powder was prepared by aging for 0~72 hours at 80℃ depending on relative humidity (RH). It showed the highest antioxidant effects among the samples; the total antioxidant activity of black garlic powders at RH 75%, 84%, and 90% for 72 hours was increased 31.9 times, 28.2 times, and 22.6 times compared with that of the fresh garlic powder, respectively. Also, the alliin content was gradually decreased. S-ally-L-cysteine and S-ethyl-cysteine levels were increased; the highest values were 495.9 ㎍/g and 1,769.7 ㎍/g after aging for 72 hours at RH 75%. Aspartate transaminase (AST) and alanine transaminase (ALT) levels were increased following high fat diet feeding, but the rise was obviously reduced by administration of black garlic extract. The total cholesterol, LDL/VLDL-cholesterol, and triglyceride contents in serum were significantly lower in methionine and choline deficient (MCD) diet treatment groups than in the positive control group. The concentration was increased following the intake of black garlic and fermented black garlic extracts. Therefore, black garlic extracts could be an ideal material as a dietary supplement in healthy functional foods to improve the effects on fatty liver.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.681-688
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• 2013

This work is aimed to increase knowledge of the functional exopolysaccharide (EPS) from lactic acid bacteria (LAB) in makgeolli, a Korean fermented rice wine. Among LAB strains isolated from makgeolli, strain M76 was selected as a functional strain producing a bioactive EPS, based on its antioxidative activity on the DPPH radical. The 16S rRNA gene sequencing analysis showed a high sequence similarity (99.0%) with P. acidilactici, but had different biochemical properties with the already known P. acidilactici type strains in the aspect of carbohydrates utilization. The obtained P. acidilactici M76 produced a soluble EPS above 2 g/l. One-step chromatography using gel filtration after ethanol precipitation from the supernatant of P. acidilactici M76 was enough to obtain purified EPS with a single peak, showing a molecular mass of approximately 67 kDa. Componential and structural analyses of EPS by TLC, HPLC, and FT-IR indicated that the EPS is a glucan, consisting of glucose units. The purified EPS had antioxidant activity on the DPPH radical of 45.8% at a concentration of 1 mg/ml. The purified EPS also showed proliferative effect on the pancreatic RIN-m5F cell line and remarkable protection activity on alloxan-induced cytotoxicity. This potent antioxidant and antidiabetic EPS by LAB in makgeolli may contribute to understanding the functionality of makgeolli.

• Journal of the Korean Society of Food Culture
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• v.29 no.1
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• pp.111-118
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• 2014

Cedrela sinensis is a Korean traditional wild herb found especially in the southern provinces of Korea. This study investigated the effects of Cedrela sinensis powder on the antioxidant activities and quality characteristics of bread. Bread was prepared with different amounts of Cedrela sinensis powder (at ratios of 0, 1, 2, and 3% of total flour quantity). The results showed that the dough pH, moisture, and fermentation tension levels decreased as Cedrela sinensis powder content increased. Bread volume and specific volume decreased (p<0.01) with an increasing amount of Cedrela sinensis powder (Bread weight increased (p<0.001)). As Cedrela sinensis powder content increased, color 'a' value decreased, and 'b' value increased. Sensory parameters such as color (p<0.01), flavor (p<0.01), appearance (p<0.001), taste, softness (p<0.05), and overall quality (p<0.01) of bread containing 2% Cedrela sinensis powder were measured. Total phenol contents and DPPH free radical scavenging activity of bread significantly increased with increasing Cedrela sinensis powder content (p<0.001). Based on these results, we suggest that Cedrela sinensis can be used for increasing the consumer acceptability and functionality of bread.