• Journal of the Korean Wood Science and Technology
• /
• v.49 no.1
• /
• pp.23-43
• /
• 2021

In this study, we selected two essential oils, Citrus unshiu and Cinnamomum cassia with superior antioxidant effects from the essential oils of 7 wild plants in South Korea and examined their antimicrobial activity against Candida albicans, which causes dermatitis to identify the antimicrobial components in the essential oils. As a result of measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, SC50 value of the Citrus unshiu essential oil was 0.010 mg/mL, while for the Cinnamomum cassia essential oil, SC50 value was 0.09 mg/mL. In addition, when ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was measured, SC50 value of the Citrus unshiu essential oil was 0.09 mg/mL, while for the Cinnamomum cassia essential oil, it was 0.06 mg/mL, exhibiting high antioxidant activity. For the minimum inhibitory concentration (MIC), the essential oil of Cinnamomum cassia was 1.25 mg/mL and that of Citrus unshiu was 5 mg/mL, demonstrating a high antimicrobial activity of the Cinnamomum cassia essential oil. Through the thin layer chromatography (TLC) bioassay, we assessed the antimicrobial activity against C. albicans according to the fraction components of the two essential oils. Also, by using preparative TLC (prep. TLC), we obtained the active fractions, and by performing GC/MS analysis of the components with the same Rf value, we identified the antimicrobial-active components. As a result, the main components having antioxidant and antimicrobial activities were cinnamyl acetate, eucalyptol, linalool, and citral of the Cinnamomum cassia essential oil and linalool from the Citrus unshiu essential oil. Also, based on the analysis of the fractional components that showed antioxidant and antimicrobial activities in both of the two essential oils, it was found that linalool has antioxidant activity, while cinnamyl acetate, eucalyptol, citral, and geranyl acetate have antioxidant and antimicrobial activities.

• Journal of Food Hygiene and Safety
• /
• v.38 no.4
• /
• pp.211-216
• /
• 2023

A total of 100 commercially available olive oil products were analyzed for 179 pesticide residues using gas chromatography-tandem mass spectrometry (GC/MS/MS). The olive oil samples were mixed with organic solvents, centrifuged and frozen to remove fat, and pesticide residues were analyzed using the "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method. The determination coefficient (R²) of the analysis method used in this study was ≥0.998. The detection limit of the method ranged 0.004-0.006 mg/kg and its quantitative limit ranged 0.012-0.017 mg/kg. The recovery rate (n=5) measured at the level ranging 0.01-0.02, 0.1, and 0.5 mg/kg ranged 66.8-119.5%. The relative standard deviation (RSD) was determined to be ≤5.7%, confirming that this method was suitable for the "Guidelines for Standard Procedures for Preparing Food Test Methods". The results showed that a total of 151 pesticides (including difenoconazole, deltamethrin, oxyfluorfen, kresoxim-methyl, phosmet, pyrimethanil, tebuconazole, and trifloxystrobin) were detected in 64 of the 100 olive oil products. The detection range of these pesticide residues was 0.01-0.30 mg/kg. The percentage acceptable daily intake (%ADI) of the pesticides calculated using ADI and estimated daily intake (EDI) was 0.0001-0.1346, indicating that the detected pesticides were present at safe levels. This study provides basic data for securing the safety of olive oil products by monitoring pesticide residues in commercially available oilve oil products. Collectively, the analysis method used in this study can be used as a method to analyze residual pesticides in edible oils.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.9
• /
• pp.1347-1355
• /
• 2015

In this study, the physicochemical properties, antioxidant capacities, and volatile flavor compounds of oriental melon wine prepared by freeze concentration after heat treatment (HA), ascorbic acid treatment (AAT), and heat and ascorbic acid treatment (HAAT) were investigated. During fermentation period, the melon wine by HAAT showed greater reduction of soluble solids and reducing sugar contents compared to other treatments. In addition, the melon wine treated with HAAT also showed a higher L value and lower browning index compared to other treatments. After aging, free sugar including fructose, and organic acids including citric acid, succinic acid, and malic acid were detected in all samples. For antioxidant activities and contents, HAAT treated wine showed greater antioxidant activities and total phenolic contents than those of others. In GC/MS analysis, a total of 33 volatile flavor compounds were identified. In the principal component analysis of volatile flavor compounds, principal components 1 and 2 represented 88.15% of the whole date distribution and showed opposite tendencies. Taken together, HAAT enhanced the antioxidant activities and sensory properties of oriental melon wine. Moreover, freeze concentration gave the different volatile flavor characteristics in oriental melon wine.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.6
• /
• pp.881-891
• /
• 2003

Paenibacillus polymyxa is a plant growth-promoting rhizobacterium (PGPR) which can be used for biological control of plant diseases. Several bacterial strains were isolated from rotten roots of Korean ginseng (Panax ginseng C. A. Meyer) that were in storage. These strains were identified as P. polymyxa, based on a RAPD analysis using a P. polymyxa-specific primer, cultural and physiological characteristics, an analysis utilizing the Biolog system, gas chromatography of fatty acid methyl esters (GC-FAME), and the 16S rDNA sequence analysis. These strains were found to cause the rot in stored ginseng roots. Twenty-six P. polymyxa strains, including twenty GBR strains, were phylogenetically classified into two groups according to the ERIC and BOX-PCR analyses and 16S rDNA sequencing, and the resulting groupings systematized to the degrees of virulence of each strain in causing root rot. In particular, highly virulent GBR strains clustered together, and this group may be considered as subspecies or biovar. The virulence of the strains seemed to be related to their starch hydrolysis enzyme activity, but not their cellulase or hemicellulase activity, since strains with reduced or no starch-hydrolytic activity showed little or no virulence. Artificial inoculation of the highly virulent strain GBR-1 onto the root surfaces of Korean ginseng resulted in small brown lesions which were sunken and confined to the outer portion of the root. Ginseng root discs inoculated in vitro or two-year-old roots grown in soil drenched with the inoculum developed significant rot only when the inoculum density was $10^{6}-10^{7}$ or more colony-forming units (CFU) per ml. These results suggest that P. polymyxa might induce ginseng root rot if their population levels are high. Based on these results, it is recommended that the concentration of P. polymyxa should be monitored, when it is used as a biocontrol agent of ginseng, especially in the treatment of stored roots.

• Microbiology and Biotechnology Letters
• /
• v.44 no.3
• /
• pp.400-407
• /
• 2016

A unicellular green alga, Chlorella vulgaris KNUA027, was isolated from the roots of Panax ginseng seedlings and its biotechnological potential was investigated. The results of GC/MS analysis showed that C. vulgaris KNUA027 was rich in nutritionally important polyunsaturated fatty acids (PUFAs) such as alpha-linolenic acid (C_18:3 ω3, 45.8%, 50.8 mg/g) and hexadecatrienoic acid (C_16:3 ω3, 11.8%, 13.1 mg/g). Therefore, this Korean indigenous microalga may have potential as a source of omega-3 PUFAs. It was also found that the saturated palmitic acid (C_16:0, 37.1%, 41.2 mg/g), which is suitable for biodiesel production, was one of the major fatty acids produced by strain KNUA027. The proximate analysis showed that the volatile matter content was 88.5%, and the ultimate analysis indicated that the higher heating value was 19.8 MJ/kg. Therefore, the results from this research with C. vulgaris KNUA027 may provide the basis for the production of microalgae-based biofuels and biomass feedstock.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.5
• /
• pp.925-932
• /
• 2017

Changes in the metabolite profiles of Lactobacillus sakei and its growth media, based on different culture times (0, 6, 12, and 24 h), were investigated using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS with partial least squares discriminant analysis, in order to understand the growth characteristics of this organism. Cell and media samples of L. sakei were significantly separated on PLS-DA score plots. Cell and media metabolites, including sugars, amino acids, and organic acids, were identified as major metabolites contributing to the difference among samples. The alteration of cell and media metabolites during cell growth was strongly associated with energy production. Glucose, fructose, carnitine, tryptophan, and malic acid in the growth media were used as primary energy sources during the initial growth stage, but after the exhaustion of these energy sources, L. sakei could utilize other sources such as trehalose, citric acid, and lysine in the cell. The change in the levels of these energy sources was inversely similar to the energy production, especially ATP. Based on these identified metabolites, the metabolomic pathway associated with energy production through lactic acid fermentation was proposed. Although further studies are required, these results suggest that MS-based metabolomic analysis might be a useful tool for understanding the growth characteristics of L. sakei, the most important bacterium associated with meat and vegetable fermentation, during growth.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.3
• /
• pp.350-359
• /
• 2016

We performed fast pyrolysis of empty fruit bunch (EFB) in the range of temperature from $400{\sim}550^{\circ}C$ and 1.3 s of residence time. The effect of temperature on the yields and physicochemical properties of pyrolytic products were also studied. Elemental and component analysis of EFB showed that the large amount of potassium (ca. 8400 ppm) presents in the feedstock. Thermogravimetric analysis suggested that the potassium in the feedstock catalyzed degradation of cellulose. The yield of bio-oil increased with increasing temperature in the range of temperature from $400{\sim}500^{\circ}C$, while that of gas and biochar decreased and showed monotonous change each with increasing temperature. When the EFB was pyrolyzed at $550^{\circ}C$, the yield of bio-oil and char decreased while that of gas increased. Water content of the bio-oils obtained at different temperatures was 20~30% and their total acid number were less than 100 mg KOH/g oil. Viscosity of the bio-oils was 11 cSt (centistoke), and heating value varied from 15 to 17 MJ/kg. Using GC/MS analysis, 27 chemical compounds which were classified into two groups (cellulose-derived and lignin-derived) were identified. Remarkably the concentration of phenol was approximately 25% based on entire chemical compounds.

• Preventive Nutrition and Food Science
• /
• v.17 no.3
• /
• pp.184-191
• /
• 2012

The purpose of this study was to investigate the fatty acid profiles in 18 soybean cultivars grown in Korea. A total of eleven fatty acids were identified in the sample set, which was comprised of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1, ${\omega}7$), stearic (C18:0), oleic (C18:1, ${\omega}9$), linoleic (C18:2, ${\omega}6$), linolenic (C18:3, ${\omega}3$), arachidic (C20:0), gondoic (C20:1, ${\omega}9$), behenic (C22:0), and lignoceric (C24:0) acids by gas-liquid chromatography with flame ionization detector (GC-FID). Based on their color, yellow-, black-, brown-, and green-colored cultivars were denoted. Correlation coefficients (r) between the nine major fatty acids identified (two trace fatty acids, myristic and palmitoleic, were not included in the study) were generated and revealed an inverse association between oleic and linoleic acids (r=-0.94, p<0.05), while stearic acid was positively correlated to arachidic acid (r=0.72, p<0.05). Principal component analysis (PCA) of the fatty acid data yielded four significant principal components (PCs; i.e., eigenvalues>1), which together account for 81.49% of the total variance in the data set; with PC1 contributing 28.16% of the total. Eigen analysis of the correlation matrix loadings of the four significant PCs revealed that PC1 was mainly contributed to by oleic, linoleic, and gondoic acids, PC2 by stearic, linolenic and arachidic acids, PC3 by behenic and lignoceric acids, and PC4 by palmitic acid. The score plots generated between PC1-PC2 and PC3-PC4 segregated soybean cultivars based on fatty acid composition.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.40 no.1
• /
• pp.37-44
• /
• 2014

Preservatives such as paraben, phenoxyethanol, and chlorphene are commonly used in cosmetics thanks to cheap price and good antiseptic effect. Recently, consumers' concerns about their possible toxicity and skin irritation forced them to be replaced with straight 1,2-alkanediols. However, as the alkanediols may also irritate skin, limited amount of them should be used in cosmetics. Three 1,2-alkanediols including 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol in cosmetics were analyzed simultaneously by gas chromatogrphy with flame ionization detector. As a result of method validation, the specificity was confirmed by the calibration curves of 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol showing good linearity correlation coefficient of above 0.999 over the concentration range of $100{\sim}1,200{\mu}g/g$. The limit of detection (LOD) and quantification (LOQ) of 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol were 31, 40, and $19{\mu}g/g$ and 98, 108, and $57{\mu}g/g$, respectively. The precision (Repeatability) of the amount in cosmetics showed less than 2.0%. Relative Standard Deviation (% RSD) and the Accuracy (% recovery) of the amount in cosmetics showed 99.3 ~ 103.3, 99.4 ~ 106.7, 97.5 ~ 107.3% respectively. As a result, simultaneous analysis of antimicrobial three 1,2-alkanediols in cosmetics were possible. This method can be utilized in accurate quantitative analysis of 1,2-alkanediols in cosmetics.

• Korean Journal of Food Science and Technology
• /
• v.45 no.2
• /
• pp.142-147
• /
• 2013

This study was conducted to evaluate and compare new beer (NB) with market beers, e.g., New castle brown ale (NC), Victoria bitter (VB), and Coopers pale ale (CP) using physicochemical parameters. In addition, pattern recognition analyses were carried out using an electronic nose based on mass spectrometry (MS-E nose) and an electronic tongue (E-tongue) for differentiation of the different types of beer. The measured alcohol content of NB was 4.37%. NB was not significantly different compared with other types of beer with regard to bitterness unit, color, and polyphenol content (p<0.05). On the basis of the flavor pattern determined by the MS-E nose, NB was separated by DF1 (first score from discriminant function analysis), while NC, VB, and CP were located in the same group. The result of the E-tongue showed that the different samples could be clearly discriminated; NB was less sour. It was suggested that the discriminant function analysis (DFA) given by the MS-E nose and E-tongue could be used for evaluations during new product development. Furthermore, because of its simplicity, it might be possible to use the validated method for the evaluation of beer.