As the demand for the monitoring of VOCs increases, various unpowered colorimetric sensors are being developed, but the performance evaluation method of the developed sensors has not been systematically established. In this study, the device, experimental process, and data calculation methods for the performance evaluation of the colorimetric sensors were proposed. An aluminum chamber (70W× 128 L × 40 mm H) was designed to expose the sensor to a constant concentration of VOCs. In addition, an experimental apparatus was devised to evaluate the effect of environmental factors (temperature and humidity) affecting the ability of the sensor to detect VOCs. To calculate the color change value of the sensor corresponding to the concentration of VOCs, the ‘peak wavelength method’ that analyzes the wavelength of the highest intensity for high-concentration VOCs and the ‘spectral centroid method’ using a weighted arithmetic average for low-concentration VOCs were used. As a result of evaluating the ability of the colorimetric sensor to detect VOCs, which was made of polydimethylsiloxane (PMDS) by the method proposed in this study, the wavelength change values (bandgap shift) of the sensor for 1,000 ppm of benzene, toluene, oxylene, and acetone were 0.898 nm, 2.304 nm, 5.775 nm, and 0.249 nm, respectively. The precision was calculated by repeatedly measuring the sensing ability of the sensor 5 times for each type of VOCs. The precision of the sensor responses to benzene, toluene, o-xylene, and acetone were 15.23%, 7.84%, 4.14%, and 30.00% RSD, respectively. The method proposed in this study can be used to evaluate the performance of various types of VOCs colorimetric sensors.

This study examined the bioactive compound content and the antioxidant activities of bitter melon (Momordica charantia Linn.) leaves. The content of vitamin C, beta-carotene, and total carotenoids was 69.77, 45.68, and 65.08 mg/100 g, respectively. To investigate the antioxidant capacity, bitter melon leaves were extracted using various concentrations of ethanol (60, 80, or 100%). Highest content of total polyphenols (18.07 mg gallic acid equivalent/g) and flavonoids (4.53 mg cathechin equivalent/g) was found in the 100% ethanolic extract of the leaves (E100). Also, the E100 extract showed the highest levels of 2,2'azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and α-α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging activities. Reducing power was also the highest (39.21 mg Trolox equivalent/g) in E100 extract. The E100 extract effectively inhibited lipid peroxidation by 91.45% compared to the control group. Also, the E100 extract showed a cytoprotective effect against oxidative stress in HepG2 cells and decreased the generation of intracellular reactive oxygen species. These results suggest that bitter melon leaves could be regarded as a potential source of natural antioxidants.

본 연구에서는 기능성 화장품의 소재로서의 금전초(Lysimachia christinae Hance)의 항산화와 항주름 효과를 조사하였다. 최근 천연물의 주름 개선 개발의 연구가 지속적인 관심을 받고 있어 본 연구를 통해 활성산소종(reactive oxygen species, ROS) 생성과 pro-collagen 합성 및 MMPs의 연관성에 대해 알아보았다. 금전초는 70% 에탄올(LcHE)과 열수(LcHW)로 각각 추출하여 실험을 진행하였다. HaCaT cells에서 LcHE가 LcHW보다 ROS 저해효능이 더 우수하고 세포독성 결과 250 μg/mL 농도 까지 독성을 보이지 않아 LcHE를 선택하여 주름 개선 소재연구를 진행하였다. pro-collagen 합성실험을 통하여 UVB에 의해 감소된 type-1 pro-collagen의 합성 활성을 유의미하게 확인하였다. Western blot 실험을 통하여 피부세포에서 UVB에 의해 유도된 MMPs 중 MMP-1 -3 -9의 증가를 억제함을 확인하였으며, Real time PCR을 통하여 상위단계인 mRNA levels에서도 MMP-1, MMP-2, MMP-3, MMP-9의 mRNA levels가 농도 의존적으로 유의미한 감소를 보여 추출물의 효능을 확인하였다. 위의 실험결과에 따라 UVB에 의한 주름생성과 피부 광노화를 효과적으로 예방할 수 있는 화장품의 천연소재로서의 이용이 기대된다.

균근성 버섯이란 외생균근(ectomycorrhizae)이 수목의 뿌리에 침입하여 균투 (fungal sheath), 세포 간 균사(hyphae)와 하티그망(hartig net)을 만들어 기주 식물과 공생하며 사는 절대생물영양성(obligate biotroph) 고등균류임 균근성 버섯을 만드는 버섯류로는 주로 담자균류이며 대부분의 겉씨식물과 일 부의 속씨식물과 공생하는 것으로 알려짐 국내 야생버섯 중 균근성 버섯은 약 35%를 차지하며 국내에서 잘 알려진 균근 성 버섯으로는 송이, 능이, 싸리버섯, 꾀꼬리버섯, 달걀버섯 등이 있음 본 연구에서는 국내 자생하는 균근성 버섯의 생리활성 분석을 통하여 우수한 자원을 발굴함과 동시에 토종 버섯자원을 이용한 새로운 천연물 유래 생리활 성 물질로 활용하기 위한 기초자료를 제시하고자 함

The extracts of four species of ectomycorrhizal mushrooms—Cantharellus cinnabarinus (OK1247), Lactarius parallelus (OK1264), Tricholoma matsutake (OK1282), and Ramaria botrytis (OK1283)—were prepared to determine their antioxidant activities and nutritional properties. R. botrytis extract displayed the highest 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (33.8%), ferric reducing antioxidant power (0.38), reducing power (0.35), total polyphenol (13.83 mg gallic acid equivalent/g), and flavonoid contents (2.56 mg quercetin equivalent/g). L. parallelus extract displayed the highest nitrite scavenging activity. Analysis of amino acid contents revealed that C. cinnabarinus extract had the highest total amino acid (1,046.1 mg/kg) and essential amino acid (404.9 mg/kg) contents, while R. botrytis extract had the lowest total amino acid (708.3 mg/kg) and essential amino acid (247.3 mg/kg) contents. Among the amino acid components detected in the four ectomycorrhizal mushrooms, cysteine was the most abundant, accounting for 14.3~20.7%, followed by phenylalanine, which accounted for 9.5 ~13.4% of all amino acids. In summary, the antioxidant activities were the highest in R. botrytis extract, and the amino acid content was the highest in C. cinnabarinus extract, among the four ectomycorrhizal mushrooms.

본 연구는 귀리의 겨, 겉껍질 및 잎을 에탄올로 추출한 후 항산화 및 항균활성을 조사하였으며, 추출물을 유화형 돈육 소시지에 적용하였을 때 품질 및 저장성에 미치는 영향을 알아보기 위하여 수행하였다. 귀리의 잎 추출물(OLE)의 총 페놀함량(145.99ug CAE/mg), ABTS 라디칼 소거 활성(35.07%) 및 FRAP 활성(32.77ug Fe2+/mg)은 다른 부위에 비해 유의적으로 높게 나타났다(p<0.05). 항균 활성 측정결과 모든 부위의 추출물에서 Staphylococcus aureus, Streptococcus pneumonia과 Escherichia coli에 대해서 활성을 보이지 않았으나, OLE 및 귀리 겨 추출물은 Klebsiella pneumonia에 대해서는 120μg/disk이상에서 활성을 보였으며, OLE가 귀리 겨 추출물보다 동일 농도에서 유의적으로 높은 활성을 나타내었다(p<0.05). OLE를 유화형 돈육 소시지에 첨가하였을 때, 0.025% 첨가구에서 pH, 조직감 및 관능적 특성에 유의적인 영향을 미치지 않았다. 하지만 저장 14일차에 모든 첨가구에서 지방산화(TBARS), volatile basic nitrogen (VBN), 총균수가 대조구보다 유의적으로 낮게 측정되었다(p<0.05). 본 실험결과 OLE는 높은 항산화 활성을 보였으며, 유화형 돈육 소시지 제품에 적용하였을 때 지방산화를 지연시켰고, 총균수의 저하를 가져왔기 때문에 천연 보존제로서 좋은 첨가제로 사료된다.

The diversity and characterization of microorganisms isolated from the soil around several ranches in Korea were confirmed in this study. To isolate halophilic microorganisms, the marine agar medium was basically used and cultivated at 37℃ for several days. After single colony isolation, a total of 116 pure colonies were isolated and phylogenetic analysis was carried out based on the result of 16S rDNA sequencing, indicating that isolated strains were divided into 4 phyla, 23 families, 30 genera and 51 species. To confirm whether isolated strain can be a candidate for the fermentation of diverse food ingredients, amylase, lipase, and protease enzyme assays were performed individually, showing that 92 strains possessed at least one enzyme activity. Especially 4 strains, identified to Jonesia quinghaiensis (isolate name: JSF 19-2), Halomonas alkaliantarctica (isolate name: JSF 21), Bacillus velezensis (isolate name: NWFY-36), and Staphylococcus capitis subsp. urealyticus (isolate name: MSY-5), showed all enzyme activity tested. Moreover, 17 strains showed the ability for auxin production. This result indicated that isolated strains have shown the possibility of the application for the food and feed industries. Therefore, this study has contributed to securing domestic biological resources and the improvement of hydrolytic enzyme activity by using isolated strains.

This research confirmed the diversity and characterization of halophilic microorganisms isolated from the various solar salterns, collected on the inside and outside of the country. To isolate strains, the marine agar medium was basically used and cultivated at 37oC for several days aerobically. After single colony isolation, a totally of 230 pure colonies were isolated and phylogenetic analysis was carried out based on the result of 16S rDNA sequencing, indicating that isolated strains were divided into 4 phyla, 12 families, 27 genera and 64 species. Firmicutes phylum, the main phyletic group, comprised 89.6% with 3 families, 17 genera and 52 species of Bacillaceae, Staphylococcaceae and Carnobacteriaceae. To confirm whether isolated strain can produce industrially useful enzyme or not, amylase, lipase, and protease enzyme assays were performed individually, showing that 177 strains possessed at least one enzyme activity. Especially 17 strains showed all enzyme activity tested. This result indicated that isolated strains have shown the possibility of the industrial application. Therefore, this study has contributed to securing domestic genetic resources and the expansion of scientific knowledge of the halophilic microorganisms community in solar salterns.

In this research, a simulation program is developed in order to investigate non steady-state cornering performance of 6WD/6WS special-purpose vehicles. 6WD vehicles are believed to have good performance on off-the-road maneuvering and to have fail-safe capabilities. But the cornering performances of 6WS vehicles are not well understood in the related literature. In this study, 6WD/6WS vehicles are modeled as a 18 DOF system which includes non-linear vehicle dynamics, tire models, and kinematic effects. Then the vehicle model is constructed into a simulation program using the MATLAB/SIMULINK so that input/output and vehicle parameters can be changed easily with the modulated approach. Cornering performance of the 6WS vehicle is analyzed for brake steering and pivoting, respectively. Simulation results show that cornering performance depends on the middle-wheel steering as well as front/rear wheel steering. In addition, a new 6WS control law is proposed in order to minimize the sideslip angle. Lane change simulation results demonstrate the advantage of 6WS vehicles with the proposed control law.

In this paper, quality properties and antioxidant capacity of cooked black carrot has been studied. Five different cooking methods have been applied: microwave (45 sec), boiling (100℃, 14 min), steaming (100℃, 20 min), sous vide (75℃, 80 min), sous-vide (95℃, 30 min). The color value was slightly different (p<0.05), the boiling method was the highest in L-value and Sous vide 75℃ method was the lowest. The steaming method indicated the highest a-value at 5.50. The b-value was significantly different between the samples (p<0.05). The microwave method was the highest at 3.49 while the sous vide 95℃ method was the lowest at －0.34. No significant difference was observed between the samples when only the moisture content results were considered. The highest pH was observed in samples cooked using the boiling method. The softening (%) was higher when the cooking water was in contact with samples and it was dependent on the temperatures. In addition, this study shows that not only temperature but also cooking time and cooking media are very crucial in the preparation and cooking of black carrot to prevent the loss of the antioxidant compound. In conclusion, the comparison of the quality characteristics and antioxidant properties of black carrots indicated that the most appropriate cooking method is sous-vide method.