• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.317-323
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• 1994

Nine plant foods (persimmon leaf, perilla seed, Chinese quince, ginger root, walnut, mugwort leaf, arrowroot, buckwheat and sorghum) rich in phenolic substances were examined for their effects on the digestive enzymes, food-poisoning bacteria and mutagenicity/antimutagenicity by Ames test. Among tested samples, Chinese quince significantly inhibited the $\alpha-amylase$ activity (97%), exhibiting an uncompetitive inhibition type. Protease activity was inhibited by Chinese quince (86%), persimmon leaf (51%) and mugwort leaf (20%), in which mugwort extract exhibited a noncompetitive type. Lipase was activated >50% by all samples. The inhibition of $\alpha-amylase$ was highly correlated with the content of condensed tannin (r=0.89) and the inhibition of protease, with total phenolic content (r=0.84). Total phenolies fraction of tested samples showed the growth inhibition toward E. coli. Streptococcus faecalis and Salmonella enteritidis, in which the effect of perilla, sorghum and arrowroot was the highest for E. coli. Standard phenolics and food samples did not show any mutagenicity toward Salmonella typhimurium TA98 and TA100. Tannic acid inhibited the mutation of the two strains by benzo[a]pyrene whereas total phenolics fractions of Chinese quince and walnut exhibited antimutagenicity to a lesser extent.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.264-270
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• 2021

In the present study, the total polyphenol and flavonoid contents, radical scavenging ability, and reducing power of ethanol extracts and fractions from Rubus coreanus Miq. were assessed in order to determine the antioxidant activity. The total polyphenol contents in the 70% ethanol extract and ethyl acetate fraction were 238.46 mg gallic acid equivalents (GAE)/g and 413.59 mg GAE/g, respectively; these values were higher than those in the other fractions (p < 0.05). In addition, the total flavonoid content was as high as 52.83 mg quercetin equivalents (QE)/g in the ethyl acetate fraction (p < 0.05). With regard to DPPH and ABTS radical scavenging activities, the RC₅₀ values of the ethyl acetate fraction were 3.95 and 6.25 ㎍/mL, respectively, indicating that the scavenging activity was similar to that of ascorbic acid (control) (p < 0.05). Moreover, in the FRAP assay performed to assess the reducing power, the ethyl acetate fraction showed high activity (p < 0.05). In summary, the present findings confirmed that the ethyl acetate fraction of the R. coreanus Miq. 70% ethanol extract had high polyphenol and flavonoid contents and excellent antioxidant properties. Therefore, it was confirmed that the ethyl acetate fraction of the mugwort 70% ethanol extract had high polyphenol and flavonoid content and excellent antioxidant effect.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.178-184
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• 1996

Dryfilm method by using 3M Petrifilm$^{TM}$ has been examined to replace conventional agar method for isolation of microorganisms from foods. The objectives of the present study were to evaluate suitability of dryfilm method as a microbial isolation method and to determine the effect of antimicrobial agent on dryfilm for isolation of microorganisms from foods. Five different foods, milk, ground beef, fishery surimi, Takju and wheat flour were used to isolate the natural microflora in foods and the inoculated Escheri chia coli. Standard method agar (SMA, Difco) and Petrifilm$^{TM}$ aerobic count (PAC, 3M) were used to isolate total microorganisms from foods. Violet red bile agar (VRBA), brilliant green lactose bile (BGLB) broth and Petrifilm$^{TM}$ coliform count (PCC, 3M) were used to isolate coliforms from foods. E. coli broth (EC broth) and Petrifilm$^{TM}$ E. coli count (PEC, 3M) were used to isolate E. coli from foods. Acidified potato dextrose agar (APDA) and Petrifilm$^{TM}$ yeast & mold count (PYMC, 3M) were used to isolate yeasts and molds from foods. Total aerobic plate counts isolated from five different foods by SMA and PAC (3M) were riot significantly different each other at P<0.05 level and were highly correlated each other ($\geq$0.96). Mugwort extract as an antimicrobial agent did not affect microbial enumeratiion of Dryfilm. Significantly higher number of coliform colonies were formed on VRBA than PCC (3M) from ground beef, but they were not significantly different in coliform colonies from milk samples. PCC (3M) and BGLB were not significantly different for enumeration of coliforms in milk and beef samples. Significantly higher number of E. coli were isolated by EC broth than PEC from ground beef, but these were not significontly different for enumeration of E. coli from milk. Yeast and mold counts isolated from Takju and wheat flour by APDA and PYMC (3M) were not significantly different at P<0.05 level. These data indicate that dryfilm method by using 3M Petrifilm$^{TM}$ can be successively used as an alternative to conventional agar method for enumeration of microorganisms in various foods.

• Food Science and Preservation
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• v.24 no.2
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• pp.196-205
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• 2017

This study was conducted to increase the functionality of Korean traditional beverage, Sikhye. The Sikhye were prepared by supplementation up to 20% of Seomaeyaksuk extract (SE) and saccharification for five hours (h). During the saccharification, turbidity of SE-added Sikhye (SES) was the highest at two hours of saccharification and then lowered gradually. L vlaue of SES did not show significant difference feduring saccharification, and both a and b value of Sikhye were increased as saccharification time passed and SE addition ratio was increased. The pH before saccharification was not significantly different by SE addition ratio but it was increased to 5.68-5.73 at 5 h saccharification. Soluble solid, total sugar and reducing sugar contents were enhanced as saccharification time and SE addition ratio were increased. The total phenolic compounds contents and DPPH radical scavenging activity showed a similar trend by saccharification time and SE addition. In sensory test, the evaluations of 5% SES and control were not significant different, but 20% SES group showed significant lower evaluation than other groups because strong color and mugwort flavor. From all of these results, physicochemical characteristics and antioxidant activity of SES was improved by SE addition but sensory characteristics was lower. Acceptable addition ratio of SE in Sikhye is determined to be within 15%.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.272-279
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• 2003

To determine optimal fermentation period of wild vegetables mixed with black sugar without microorganisms during plant extract fermentation food processing, changes in chemical components, quality characteristics of the fermented broth, and physiological functionality during fermentation period were investigated. pH and $^{\circ}Bx$ of fermented broths decreased gradually during fermentation period. Except persimmon leaf, viscosity of fermented broths of wild vegetables decreased after 3 months fermentation period. Amylase activity increased to $167{\sim}800%$ of its initial level after 6 months fermentation period, and invertase activity decreased by $60{\sim}170$ units after 1 month fermentation. No significant level of cellulase activity was observed. In the sensory evaluation test, inherent flavors and tastes of the wild vegetable decreased during the fermentation period, while those of others gradually increased. Overall acceptability was the highest after 3 months fermentation. Content of total phenolic compounds and electron-donating ability were highest after 3 to 4 months fermentation period, and decreased thereafter. Except Mugwort, tyrosinase inhibitory activity was found in all fermented broths. SOD-like activities were $23.0{\sim}25.1$ and $27.0{\sim}29.2%$ in fermentation broths of acacia flower and persimmon leaf, respectively, and were maintained throughout the fermentation period. Based on these results, fermentation period of 3 to 4 months was determined to be appropriate for plant extract fermentation food processing.

• Food Science and Preservation
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• v.22 no.3
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• pp.399-407
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• 2015

Sumaeyaksuk (Artemisia Argyi H.) is one of the original mugwort spices in Namhae-gun, Korea. This study was conducted to investigate the physicochemical characteristics and biological activities of water extracts from dried and aging Sumaeyaksuk samples during the May-July harvest season. One (SD) was dried under shade for 12 days, while the other (AD) was aged for 7 days at $60^{\circ}C$ and then roasted for 220 minutes at over $90^{\circ}C$. Glucose was solely detected as a free sugar, and its SD and AD content were $0.42{\pm}0.02{\sim}0.43{\pm}0.01g/100g$, and $0.41{\pm}0.02{\sim}0.47{\pm}0.04g/100g$, respectively. The total phenolic contents of SD were $1.85{\pm}0.09{\sim}3.45{\pm}0.14g/100g$, which were higher than those of AD ($1.29{\pm}0.08{\sim}2.90{\pm}0.08g/100g$). The antioxidant activities of the water extract powder from each Sumaeyaksuk were assessed by different in vitro methods, such as the DPPH and ABTS radical scavenging activity, FRAP, and decoloration prevention activity in ${\beta}$-carotene linoleic system. The DPPH and ABTS radical scavenging activity of AD extract were significantly higher than those of the SD extract (p<0.05). Moreover, at the concentrations of 31.25, 62.5, 125, 250, $500{\mu}g/mL$, the FRAP of the SD-May extract showed $1.67{\pm}0.58{\sim}489.90{\pm}7.59{\mu}M$, while the AD-July extract showed $9.70{\pm}1.07{\sim}590.40{\pm}7.45{\mu}M$. The ${\beta}$-carotene decoloration prevention activity of the SD-May and AD-July extracts were $25.53{\pm}2.85{\sim}81.43{\pm}2.56%$, $35.98{\pm}2.22{\sim}79.00{\pm}1.42%$, respectively. Based on these results, the extracts of SD-May and AD-July were promising as a functional food source due to their high antioxidant activites.

• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.373-390
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• 2015

This study investigated the effect of coated feed using mixed oil on rumen fermentation characteristics. Two experiments were conducted based on materials that were mixed. First, cashew nut and soybean oils were mixed with white mineral oil. And second, different plant extracts were mixed with white mineral oil. At first experiment, inclusion levels of mixed oil on diet (0.03%, 0.1%, 0.5%) were applied as variables. A coated diet was fermented with rumen inoculum according to in vitro rumen fermentation and its parameters were investigated. In the result of first experiment, no negative effects on rumen pH were found. Significantly decreased dry matter digestibility was detected at 0.5% treatment (P<0.05). Total gas productions in control and 0.03% were significantly greater than those of others (P<0.05). Significantly reduced methane productions were found in all treatments compared to the control (P<0.05). Inclusion of mixed oil did not affect on ammonia production. Total volatile fatty acid production was also not influenced by coating with mixed oils. Rumen fermentation parameters were greatly changed according to introduced plant extracts at second experiment. The significantly lowest and greatest ammonia productions were found at treatments with Ixeris dentata and Plantago asiatica, respectively (P<0.05). The significantly greatest acetate and propionate productions were detected at treatments with Crucuma longa and Zizyphus vulgaris 1, respectively (P<0.05). All treatments, except Chrysanthemum idicum, Euyale ferox seed, Moringa leaf and fruit and Zizyphus vulgaris 1, showed significantly increased total volatile fatty acid production compared to the control (P<0.05). Only Paeonia lactiflora showed significantly lesser gas production than the control (P<0.05). In methane production, Ceramium, Zizyphus, Paeonia, Agrimonia, Torilis, Mugwort, Foeniculum, Euphorbia, Taraxacum, Artemisia, Momordica, Curcuma and Moringa reduced methane significantly compared to the control (P<0.05).