• Food Engineering Progress
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• v.21 no.3
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• pp.208-214
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• 2017

Proximate analysis and antioxidant activity of cultivated wild Panax ginseng (CWPG) were investigated to provide fundamental information of CWPG with different ages and to increase its industrial application. Proximate analyses of CWPG with different ages were performed. Extraction of CWPG with different ages was carried out using heat-reflux extraction, and their extraction yield, crude saponin content, ginsenoside content, and antioxidant activity were analyzed. Moisture content decreased, but crude fat and crude protein were increased with aging. Extraction yield and crude saponin contents did not show a specific pattern while 5-year-old CWPG revealed the highest extraction yield and crude saponin content. All CWPGs showed typical ginsenoside profiles containing C-K and Rh2 ginsenosides, which are not found in ginseng. The 3-year-old CWPG showed the highest antioxidant activity including total phenolic content, total flavonoid content, and DPPH and ABTS radical scavenging activities. Moreover, 3-year-old CWPG also revealed the highest acidic polysaccharide content. Therefore, these results suggested that 3-year-old CWPG, which is the cheapest, can be used in industrial application due to its high antioxidant activity and acidic polysaccharide content with similar ginsenoside profile compared to 5- and 7-year-old CWPGs.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.165-173
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• 2021

Clematis trichotoma Nakai (CTN) is a broad-leaved vine plant belonging to the family Ranunculus, native to Korea. Young leaves are used as food, and the stem and roots are used as medicinal materials. Antioxidant studies have been reported on the stems of CTN, but no studies have been conducted on the leaves. In this study, a 70% ethanol extract of CTN was prepared and its antioxidant and anti-inflammatory activities were investigated. For measuring the antioxidant activity, five assays (polyphenol and flavonoid content, reducing power, 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity) were performed and CTN showed a concentration-dependent effect in all assays. To investigate the anti-inflammatory activity, we used RAW 264.7 cells. The concentrations (from 31.25 to 250 ㎍/mL) of CTN did not show cytotoxicity. CTN (250 ㎍/mL) inhibited dendritic transformation (34.4%) and also inhibited inflammation as seen by reduced levels of NO (77.4%), IL-6 (85.5%) and TNF-α (41.2%) compared to lipopolysaccharide (LPS). CTN (250 ㎍/mL) also suppressed the expression of the following genes: COX-2 (79.8%), iNOS2 (93.9%), IL-6 (87.6%), and TNF-α (77.3%) compared to LPS. These results demonstrated that CTN has excellent antioxidant and anti-inflammatory activities and can therefore be used as a natural biological resource.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.204-212
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• 2021

Resazurin, an oxidized blue dye, is reduced to resorufin, showing a peak absorbance change and emitting fluorescence due to the metabolic activity of living cells. In this study, the growth of Lactobacillus rhamnosus GG (LGG) and the redox potential of living probiotic bacteria were evaluated based on changes in the absorbance or fluorescence of resazurin. Fluorescence analysis is a more accurate and sensitive method for quantifying viable LGG than the colorimetric absorbance measurement of resazurin change. Fluorescence measurement could detect LGG of 6.5-9.5 log CFU/mL within 30 min with R2=0.99. No significant effect of further reduction of resorufin to dihydroresorufin by LGG was observed. Various probiotics showed different resazurin-reducing activities, and L. kimchicus had the highest reducing activity among the six probiotics tested. These findings suggests that fluorescence measurement in a resazurin-based assay is useful for analyzing bacterial growth and the redox potential of living probiotics.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.305-317
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• 2020

This study investigated that change of the nutrients (including fatty acids, amino acids, and minerals) and total phenolic (TP), total flavonoid (TF), and isoflavone contents and antioxidant activities during the storage of soybean leaves containing high isoflavone contents at 5, 25, and 55 ℃ for 180 days. The contents of free amino acids were increased from 1313.81 mg/100 g at 0 day to 1776.15, 1693.93 and 1551.18 mg/100 g at 5, 25, and 55 ℃ storage for 180 days, respectively, but the values of fatty acids were little unchanged. The contents of minerals were detected from 51.65 mg/100 g (0 day) to 49.93 (5 ℃), 50.20 (25 ℃), and 61.21 (55 ℃) mg/100 g at 180 days, respectively. The levels of total isoflavones did not change during the storage periods. In case of storage at 55 ℃, the contents of glycosides (1347.78→2195.13 ㎍/g) and aglycones (342.79→480.61 ㎍/g) increased during storage, while the levels of malonylglycosides (2209.22→1289.48 ㎍/g) decreased. Also, the TP and TF contents were slightly increased from 9.31 and 8.61 mg/g at 0 day to 9.97 and 9.3 mg/g at 180 days, corresponding to the radical scavenging activities of 2,2-diphenyl-1-picrydrazyl, 2,4,6-azino-bis (3-ethylbenzthiazoline-6-sulphnoic acid), and hydroxyl increased from 30.91, 55.98 and 23.27% from 37.10, 62.54, and 30.95%, respectively.

• Journal of Life Science
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• v.30 no.12
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• pp.1042-1053
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• 2020

The physicochemical properties, antioxidant activity, color value, sensory evaluation, and sinigrin content of chicken breast jerky supplemented with Dolsan leaf mustard powder (DLMP) were evaluated over a period of 120 days. The control groups contained no DLMP, and the product groups contained 0.04 g (S-1, S-3) and 0.3 g (S-2, S-4) of DLMP. These samples were stored at 25℃ and 60℃ and then compared. The pH changes decreased at 25℃ and 60℃ over the storage period, with S-1 maintaining the highest pH value over the course of the experiment. The acid and peroxide values increased at room temperature and 60℃ but were better controlled in the DLMP-containing groups. Overall, the antioxidant activity of these products decreased during storage; the most marked reduction was observed in the control group, and the greatest activity was retained in S-2 and S-4. Hardness and gumminess were higher in the S-2 and S-4 groups and thus correlated with increased DLMP concentration. Sinigrin content also increased with increasing DLMP concentration. Product color remained similar at days 0 and 120 but underwent daily fluctuations over the course of the 120-day storage period. Sensory evaluation scores for color, flavor, taste, texture, and overall acceptability were highest for the S-2 and S-4 groups stored at 25℃. This suggests that higher concentrations of DLMP were more effective at retaining good quality characteristics for fried chicken breast jerky. This was facilitated by its suppression, which decreased changes in textural and color properties while increasing the antioxidant activity of these products.

• Food Engineering Progress
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• v.22 no.4
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• pp.328-336
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• 2018

The aim of this study was to investigate the effect of pretreatments on quality of frozen peach. Pretreatments including steam blanching, water blanching, high pressure, and osmotic dehydration were applied to two varieties (Daeokgye and Hwangdo). Pretreated peaches were frozen and thawed at $-20^{\circ}C$ and $5^{\circ}C$, respectively. Steam blanching and osmotic dehydration with ascorbic acid reduced ${\Delta}E$ values without change of pH and acidity. Osmotic dehydration with sucrose decreased drip loss and increased brix. Freezing/thawing resulted in an increase of maximum force, while maximum force decreased with increasing time of steam and water blanching. Furthermore, osmotic dehydration with calcium chloride increased maximum force. High pressure decreased maximum force of Daeokgye and increased that of Hwangdo compared with non-treatment. Total polyphenol content, DPPH radical scavenging activity, and ABTS radical scavenging activity were improved by pretreatment including steam blanching, blanching, and osmotic dehydration with ascorbic acid.

• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.692-701
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• 2020

Centella asiatica (CA) has been widely used as herbal plants. It is a valuable resources. The aim of the present study was to evaluate physiological activities of solvent extracts from CA cultivated in Chungju, Korea (Good tiger care). After preparing water (cold-water, CA-WE; hot-water, CA-HWE) and EtOH extracts (50% EtOH, CA-50E; 70% EtOH, CA-70E), their total polyphenol, flavonoid, and triterpenoid contents, and anti-oxidant activities, and anti-inflammatory activities were examined and compared. CA-70E showed the most potent anti-oxidant activity based on ABTS radical scavenging activity and reducing ability assays, while CA-50E and CA-70E showed the highest DPPH radical scavenging activity. Among major triterpenoid glycosides present in CA, madecassoside and asiaticoside contents were found to be the highest in CA-70E, and madecassic acid and asiatic acid were the highest in CA-50E. In LPS-stimulated RAW 264.7 cells, CA-70E showed the highest TNF-α inhibitory activity, although CA-50E and CA-70E similarly inhibited nitric oxide production. Ethanol extracts significantly inhibited IL-6 and IL-8 production more than water extracts using TNF-α/IFN-γ-stimulated HaCaT cells, indicating its better inhibitory against skin inflammation. Therefore, Chungju-CA EtOH extract, especially 70% EtOH extract, has high physiologically active ingredients and potent anti-oxidant and anti-inflammatory activities, suggesting its industrial application as a functional material.

• Journal of Food Hygiene and Safety
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• v.36 no.4
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• pp.353-362
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• 2021

Ecklonia stolonifera, which belongs to the family Laminariaceae, is an edible perennial brown marine alga that is widely distributed, and is rich in polyphenols, including dieckol. Here, we investigated the radical scavenging activities of E. stolonifera extract (ESE) using various in vitro models. We further evaluated the effect of ESE on the cholesterol secretion inhibition activity in HepG2 cells, as well as the hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase activity. Our results showed that the total phenol, total flavonoid, and dieckol contents of ESE were 9.64±0.04 mg GAE/g, 2.72±0.08 mg RE/g and 27.42±0.66 mg/g, respectively. The antioxidant activity of ESE increased in a dose-dependent manner. In addition, the ESE inhibited cholesterol secretion from HepG2 cells with anti-HMG-CoA reductase activity. These results suggested that ESE possesses antioxidant and anti-cholesterol activities, and can therefore be used as a preclinical bioresource for development of health functional foods.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.171-178
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• 2022

In this study, the quality characteristics of rice cookies supplemented with different types of insect powder (Tenebrio molitor, Protaetia brevitarsis, and Gryllus bimaculatus) were assessed according to the quantity of insect powder used (0, 1, 2.5, 5, and 7.5 g). No significant differences were observed in rice cookie densities or water content. The pH value and spread factor decreased with increasing insect powder content (p<0.05); however, a significant increase was observed in the loss rate (p<0.05). Crude ash, crude fat, and crude protein content significantly increased with higher concentrations of insect powder (p<0.05). Moreover, lightness and yellowness decreased, whereas redness increased with higher insect powder concentrations (p<0.05). Hardness significantly decreased, whereas the antioxidant capacities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals increased with higher insect powder concentrations (p<0.05). Finally, insect powder can prove a valuable resource in rice cookie production, considering its nutritional value, consumer preference, and antioxidant properties.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.257-263
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• 2022

Various dietary pigments are added to processed foods to improve their sensory and commercial properties. In this study, autoclave sterilization (121℃ for 15 min at 15 psi) was performed on 34 food pigments, and changes in their color stability and antioxidant activity were analyzed. The autoclaving process drastically reduced the peak color intensities of water-soluble paprika and beet red (BR) by ~90%. Turmeric oleoresin (TO), water-soluble β-carotene, and grape skin color were also unstable and showed a remaining color intensity of 45-60%. The colors of all the synthetic pigments tested were stable under this process. The scavenging activities of BR and paprika against ABTS, DPPH, and AAPH radicals decreased significantly, whereas those of TO were enhanced after the autoclaving treatment. The results suggest that the chemical and bioactive properties of certain dietary pigments are affected by the autoclaving process, and this phenomenon should be considered during food processing.