Changes of Fagopyrins in Buckwheat Sprout when Exposed to Different Light Sources

Jaecheol Kim,Suna Kim,Keum Taek Hwang 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Buckwheat (Fagopyrum esculentum) sprout (BS) is a healthy food containing various bioactive substances, including fagopyrins (FA). FA can be used for photodynamic therapy as a photosensitizer. This study aims to evaluate the change of FA in buckwheat sprouts when exposed to different light sources (LS). BS were collected on the 7<SUP>th</SUP> day after germination. Collected BS were exposed to different LS (UV-C, 254 nm; UV-B, 312 nm; UV-A, 365 nm; blue (BL), 450 nm; yellow (YL), 590 nm; and red (RL), 660 nm) in an incubator at 25ºC for 1 h or 15 h, or not exposed (NEBS). After exposure to LS, FA in freeze-dried BS were extracted with methanol and analyzed using UPLC-MS/ MS. FA in the BS after exposure to different LS were significantly higher than in the NEBS (P<0.05). When exposed to LS for 1 h or 15 h, the BS exposed to BL contained more FA than the BS exposed to the other LS. FA in the BS exposed to UV lights were significantly less than in the BS exposed to BL, YL, or RL (P<0.05). Among the BS exposed to UV lights for 15 h, the BS exposed to UV-C contained significantly higher FA than the BS exposed to UV-A and B; however, the BS tissue exposed to UV-C was badly damaged.

UPLC-MS/MS를 이용한 배추와 배추김치의 글루코시놀레이트 및 대사체 분석

김재철(Jaecheol Kim),박효순(Hyo Sun Park),황금택(Keum Taek Hwang),문보경(BoKyung Moon),김선아(Suna Kim) 한국식품과학회 2020 한국식품과학회지 Vol.52 No.6

본 연구에서는 부위별 배추와 배추김치에 함유되어 있는 글루코시놀레이트류의 조성을 UPLC-MS/MS를 이용하여 탐색하고, 인돌류 대사체를 MS/MS를 이용하여 분석한 결과, 글루코시놀레이트류는 음이온 모드([M-H]−)에서 검출되었으며, glucobrassicanapin (m/z 386), glucoalyssin (m/z 450), glucobrassicin (m/z 447), 4-methoxyglucobrassicin (m/z 477), neoglucobrassicin (m/z 477)는 MS scan 모드에서, gluconapin (m/z 372→97), progoitrin (m/z 388→97), glucoiberin (m/z 422→97), 4-methoxyglucobrassicin (m/z 477→97), neoglucobrassicin (m/z 477→447)는 MS/MS MRM 모드에서 검출되었다. Glucobrassicin과 같은 인돌기 함유 글루코시놀레이트류들이 대사되어 생성되는 인돌류 대사체로는 ascorbigen (m/z 306→130)과 I3A (m/z 146→118)가 MS/MS MRM ([M+H]+) 모드에서 검출되었다. Ascorbigen은 NKC보다 IPC와 OPC에 유의적으로 많이 함유되어 있었다. I3A는 NKC에 가장 많이 함유되어 있었으나 시료 간 유의적인 차이는 없었다. 본 연구를 통하여 배추와 배추김치에 존재하는 글루코시놀레이트류와 그 대사체인 인돌류 물질을 UPLC-MS/MS를 이용하여 분석할 수 있었다. In this study, we analyzed glucosinolates and their metabolites in the inner and outer parts of napa cabbage (NC; Brassica rapa subsp. pekinensis) and napa cabbage kimchi (NKC) using UPLC-ESI-MS/MS. In the extracts from NC and NKC, glucobrassicanapin (m/z 386), glucoalyssin (m/z 450), glucobrassicin (m/z 447), 4-methoxyglucobrassicin (m/z 477), and neoglucobrassicin (m/z 477) were detected using the MS scan mode ([M-H]−), and gluconapin (m/z 372→97), progoitrin (m/z 388→97), glucoiberin (m/z 422→97), 4-methoxyglucobrassicin (m/z 477→97), and neoglucobrassicin (m/z 477→447) were detected using the MS/MS MRM mode ([M-H]−). Ascorbigen (m/z 306→130) and indole-3-carboxaldehyde (I3A; m/z 146→118), which were metabolites of glucobrassicins, were detected using the MS/MS MRM ([M+H]+) mode. The peak intensities of ascorbigen in the extract from the inner and outer parts of NC were significantly higher than those of the NKC extract (p<0.05); however, there was no significant difference in I3A peak intensity between the NC and NKC extracts.

반응표면분석법을 이용한 차가버섯(Inonotus obliquus)의 생리활성물질 최적 추출조건 탐색

김재철(Jaecheol Kim),이해창(Haechang Yi),이기욱(Kiuk Lee),황금택(Keum Taek Hwang),유기춘(Gichun Yoo) 한국식품과학회 2015 한국식품과학회지 Vol.47 No.2

본 연구에서는 차가버섯(Inonotus obliquus)의 유효성분과 항산화능이 최대가 되는 추출물의 제조를 위하여 반응표면분석법을 이용하여 최적 추출조건을 탐색하였다. 추출 수율, 총 폴리페놀 함량, 항산화능(ABTS 자유 라디칼 소거능, ORAC), β-1,3-glucan 함량의 총 다섯 가지 반응변수에서 유의적인 이차 회귀식을 얻었고, 반응표면그래프와 등고선도를 통하여 최적 추출조건을 예측하였다. 각 반응변수에 따른 최적 추출조건은 추출 수율에서 50% (v/v), 88.7℃, 14.5 h, 총 폴리페놀 함량에서 9.2%, 92.7℃, 14.5 h, ABTS free radical scavanging activity에서 50.8%, 92.7℃, 14.5 h, ORAC에서 9.2%, 92.7℃, 1.5 h, β-1,3-glucan 함량에서 90.8%, 92.7℃, 1.5 h으로 예측되었다. 각 반응변수의 예측 최대추출조건에서 실제 실험을 실행하여 예측 값과 비교해본 결과, 상대오차는 0.4-12.5%였다. 각 반응 변수에서 유의적인 이차 회귀식을 얻었으며, 예측 값과 실험 값의 오차가 크지 않아 반응표면모델이 최적 추출조건을 예측하는데 적합하다고 판단하였으며, 다섯 가지 반응 변수를 통합하는 최적 추출조건은 81.4%, 92.7℃, 14.5 h으로 예측하였다. 본 연구는 주로 열수추출물의 형태로 유통되는 차가버섯 추출물의 품질 개선을 위하여 에탄올 용매를 포함한 최적 추출조건을 설정하였고, 구체적인 추출 수율과 생리활성물질 함량 및 항산화능이 최대가 되는 추출조건을 제시하였다. This study determined the optimum extraction conditions based on five response variables (yield, total phenolics, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavanging activity, oxygen radical absorbance capacity (ORAC), and β-1,3-glucan content) in chaga mushroom (Inonotus obliquus) using the response surface methodology, where three independent variables (ethanol concentration, extraction temperature, and extraction time) were optimized using a central composite design. The optimum ethanol concentration, extraction temperature, and extraction time were 50% (w/w), 88.7℃, and 14.5 h; 9.2%, 92.7℃, and 14.5 h; 50.8%, 92.7℃, and 14.5 h; 9.2%, 92.7℃, and 1.5 h; and 90.8%, 92.7℃, and 1.5 h for yield, total phenolics, ABTS, ORAC, and β-1,3-glucan content, respectively. The predicted values of the response variables were compared with those of the extracts under the optimal extraction conditions to verify the models. The optimum extraction condition for the five response variables as predicted to be 81.4% ethanol at 92.7℃ for 14.5 h.

항공기 전자전 전방 안테나 배치 통합 연구

오재철(Jaecheol Oh),서홍은(Hongeun Seo),황광연(Kwangyoun Hwang),신항철(Hancheol Shin) 항공우주시스템공학회 2017 항공우주시스템공학회 학술대회 발표집 Vol.2017 No.4

Variation in phenolic content, flavonoid content, and antioxidant capacities of radish sprouts (Raphnus sativus) exposed to red and blue light-emitting diodes during cultivation

Christopher Chen,Jaecheol Kim,Keum Taek Hwang 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Radish (Raphnus sativus) sprouts are well known for their considerable amount of phenolic compounds. This study aimed to investigate the effect of blue and red LEDs on the phenolic content and antioxidant capacities in radish sprouts. The radish seeds were germinated in darkness and cultivated under red or blue LED (12 h of darkness+12 h of LED exposure per day). Sprouts were collected on the 4th and 7th days after germination and extracted with 70% methanol to evaluate total phenolic content (TPC), total flavonoid content (TFC), and DPPH and ABTS free radical scavenging activities. The radish sprouts cultivated under red LED contained the highest TFC (120±7.7 mg quercetin equivalent/100 g dry weight) (p<0.05), but there were no significant differences (P>0.05) between the both LED groups. DPPH and ABTS free radical scavenging activities of the red LED group were significantly higher (73.2±3.2% and 99.8 ± 0.02 % respectively) than the other groups on the 4th day after germination (P<0.05). It is suggested that exposure of radish sprouts to red LED might increase the phenolic contents, contributing to their higher antioxidant activities.

Performance Counter Monitor를 이용한 머신 러닝 기반 캐시 부채널 공격 탐지

황종배(Jongbae Hwang),배대현(Daehyeon Bae),하재철(Jaecheol Ha) 한국정보보호학회 2020 정보보호학회논문지 Vol.30 No.6

최근 마이크로 아키텍처의 취약점을 이용하여 내부의 비밀 정보를 노출시키는 캐시 부채널 공격들이 제안되었다. 캐시 부채널 공격 중 Flush+Reload 공격은 높은 해상도와 낮은 노이즈 특성으로 인해 여러 악의적 응용 공격에 활용되고 있다. 본 논문에서는 CPU 캐시 활동을 관측할 수 있는 PCM(Performance Counter Monitor) 기능을 이용하여 캐시 기반 부채널 공격을 찾아낼 수 있는 탐지기를 구현하였다. 특히, Spectre 공격과 AES 암호 연산 중 비밀 키 추출 공격이 발생했을 때를 가정하여 PCM 카운터 값의 변화를 관측하였다. 실험 결과, PCM의 4가지 카운터 특성이 캐시 부채널 공격에 크게 반응함을 확인하였고, SVM(Support Vector Machine). RF(Random Forest), MLP(Multi Level Perceptron)와 같은 머신 러닝 기반 검출기를 통해 높은 정확도로 캐시 부채널 공격을 탐지할 수 있었다. Recently, several cache side channel attacks have been proposed to extract secret information by exploiting design flaws of the microarchitecture. The Flush+Reload attack, one of the cache side channel attack, can be applied to malicious application attacks due to its properties of high resolution and low noise. In this paper, we proposed a detection system, which detects the cache-based attacks using the PCM(Performance Counter Monitor) for monitoring CPU cache activity. Especially, we observed the variation of each counter value of PCM in case of two kinds of attacks, Spectre attack and secret recovering attack during AES encryption. As a result, we found that four hardware counters were sensitive to cache side channel attacks. Our detector based on machine learning including SVM(Support Vector Machine), RF(Random Forest) and MLP(Multi Level Perceptron) can detect the cache side channel attacks with high detection accuracy.

가열 처리한 더덕 열수추출물의 이화학 및 관능 특성

안수지(Susie Ahn),김재철(Jaecheol Kim),조현노(Hyunnho Cho),박선영(Sun Young Park),황금택(Keum Taek Hwang) 한국식품과학회 2016 한국식품과학회지 Vol.48 No.2

본 연구에서는 더덕 껍질의 활용도를 높이고 식품소재, 특히 차원료로서의 가능성을 제시하기 위하여 더덕을 껍질과 육질로 나누어 가열 처리한 더덕으로부터 열수추출물을 제조하여 이화학 및 관능 특성을 비교하였다. 더덕 열수추출물의 pH는 껍질이 육질보다 낮았고(p<0.05), 색도는 볶은 껍질과 육질의 L값이 낮고 b값이 높았다(p<0.05). 총당 함량은 껍질의 경우에 증건군이 볶음군보다 많았으나(p<0.05), 환원당 함량은 껍질의 경우에 열풍건조군이, 육질의 경우에 대조군이 많았다. 조 사포닌 함량은 대조군 육질, 볶은 육질, 열풍건조한 육질에 많았다(p>0.05). 껍질의 열수추출물이 육질의 열수추출물보다 총 폴리페놀 함량이 많고 DPPH 라디칼 소거능도 높았다(p<0.05). 더덕 분말을 차로 만들어 관능검사한 결과, 더덕 껍질로 만든 차는 향과 전반적 기호도에서 더덕 육질로 만든 차와 유의적 차이가 없었다(p>0.05). 결론적으로 대부분 폐기물 처리되는 더덕 껍질은 육질보다 총 폴리페놀 함량이 많고 산화방지 활성이 뛰어났으며, 더덕 껍질 차의 향과 전반적 기호도가 더덕 육질로 만든 차와 유사한 관능 특성을 가지고 있으므로 차의 재료로 활용할 수 있을 것으로 기대한다. In this study, the physicochemical and sensory characteristics of hot water extracts of Codonopsis lanceolata root skin (RS) and root flesh (RF) subjected to different heat treatments were analyzed to determine whether C. lanceolata RS can be used as a tea material. C. lanceolata RS and RF were roasted, hot-air dried (HDS and HDF, respectively), or steamed and hot-air dried (SHDS and SHDF, respectively). The heat-treated samples were extracted with hot water (90℃) for 90 min. The hot water extracts of RS and RF had lower L-values and higher b-values than the other samples. The RS extracts had significantly higher polyphenol content and DPPH radical scavenging activities than RF samples. In the sensory evaluation, the color acceptability of the teas made from CS, HDS, and SHDS were found to be significantly different from those of the teas made from their respective flesh samples. The results suggest that the hot water extract of the C. lanceolata RS can be utilized as a tea material.

선형구동기와 기어를 적용한 해치구동장치의 설계 및 해석

이원석(Wonseok Lee),신재철(Jaecheol Shin),황찬오(Chanoh Hwang) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

Analysis of Polyphenols in Black Raspberry by LC-ESI-QTOF/MS and HPLC

Sun Young Park,Jaecheol Kim,Mashhadi Abolghasem Fatemeh,Keum Taek Hwang 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Black raspberry (Rubus occidentalis; BR) has a considerable amount of polyphenols, which have been known to have protective activities against oxidative stress and inflammation. This study aims to identify and quantify polyphenols in BR using liquid chromatography coupled with electrospray-ionization triple quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS) and high-performance liquid chromatography (HPLC). BR polyphenols were fractionated into non-anthocyanin polyphenol fraction (NAF) and anthocyanin fraction (AF) by liquid-liquid extraction. The NAF and AF were analyzed using LC-ESI-QTOF/MS and HPLC. Aconitic acid, pyrogallol, protocatechuic acid, quercitrin, corilagin, 2-pyridylacetic acid, 2,4-dihydroxyacetophenone, p-coumaric acid, phlorizin, epicatechin, kaempferol-3-rutinoside, madecassic acid, ellagic acid, quercetin-3-glucuronide, and quercetin-3-rutinoside were detected in the NAF. Among them, epicatechin was the most (105 ± 9.7 mg/100 g, dry weight). Cyanidin-3-rutinoside and cyanidin-3-xylosylrutinoside were identified in trhe AF. Cyanidin-3-rutinoside was the most (278 ± 16.1 mg/100 g, dry weight) among anthocyanins in BR.

블록 암호 ARIA에 대한 Flush+Reload 캐시 부채널 공격

배대현(Daehyeon Bae),황종배(Jongbae Hwang),하재철(Jaecheol Ha) 한국정보보호학회 2020 정보보호학회논문지 Vol.30 No.6

하나의 서버 시스템에 여러 운영체제를 사용하거나 사용자간 메모리를 공유하는 클라우드 환경에서 공격자는 캐시 부채널 공격을 통해 비밀 정보를 유출할 수 있다. 본 논문에서는 국내 표준 블록 암호 알고리즘인 ARIA를 사전 연산 테이블 기반 최적화 기법을 이용해 구현할 경우, 캐시 부채널 공격의 일종인 Flush+Reload 공격이 적용되는 것을 확인하였다. ARIA-128을 대상으로 한 Ubuntu 환경에서의 실험 결과, Flush+Reload 공격을 통해 16바이트의 마지막 라운드 키를 찾을 수 있었으며 나아가 마지막 라운드 키와 첫 번째 라운드 키를 이용하면 마스터 키를 찾을 수 있음을 증명하였다. Since the server system in the cloud environments can simultaneously operate multiple OS and commonly share the memory space between users, an adversary can recover some secret information using cache side-channel attacks. In this paper, the Flush+Reload attack, a kind of cache side-channel attacks, is applied to the optimized precomputation table implementation of Korea block cipher standard ARIA. As an experimental result of attack on ARIA-128 implemented in Ubuntu environment, we show that the adversary can extract the 16 bytes last round key through Flush+Reload attack. Furthermore, the master key of ARIA can be revealed from last and first round key used in an encryption processing.