Notes : The Effect of Carbon Sources on Nisin Z Biosynthesis in Lactococcus Lactis subsp. Lactis A164

( Chan Ick Cheigh ),( Sang Jae Lee ),( Yu Ryang Pyun ),( Duek Jun An ),( Young Sup Hwang ),( Yoo Jin Chung ),( Hoon Park ) 한국미생물 · 생명공학회 2005 Journal of microbiology and biotechnology Vol.15 No.5

Comparison of intense pulsed light- and ultraviolet (UVC)-induced cell damage in <i>Listeria monocytogenes</i> and <i>Escherichia coli</i> O157:H7

Cheigh, Chan-Ick,Park, Mi-Hyun,Chung, Myong-Soo,Shin, Jung-Kue,Park, Young-Seo Elsevier 2012 Food Control Vol.25 No.2

<P><B>Abstract</B></P><P>The purpose of this study was to compare the degree of microbial inactivation and cell damage induced by intense pulsed light (IPL) and short-wavelength ultraviolet (UVC) in <I>Listeria monocytogenes</I> and <I>Escherichia coli</I> O157:H7. The viability of the food-borne pathogens treated with IPL and UVC (254 nm) decreased exponentially with treatment time. Particularly dramatic reductions in <I>L. monocytogenes</I> and <I>E. coli</I> O157:H7 were observed for IPL treatments at energy densities of 376 and 455 W/m<SUP>2</SUP>, with an approximately 7-log reduction for a treatment time of 60–180 s. Also, a 4-log reduction of <I>L. monocytogenes</I> and a 5-log reduction of <I>E. coli</I> O157:H7 were achieved with UVC irradiation for 1200 s. The types and amounts of IPL- and UVC-induced DNA damage in both microorganisms were determined and compared. DNAs from cells irradiated with either IPL or UVC accumulated double-strand breaks (DSBs), single-strand breaks, and cyclobutane pyrimidine dimers, and with a similar pattern; however, more DSBs were detected following UVC than following IPL in both types of microorganism. Transmission electron microscopy observations of IPL- and UVC-induced cell damage clearly indicate that bacterial cell structures were destroyed by IPL treatment but not by UVC treatment.</P> <P><B>Highlights</B></P><P>► Cell damage induced by intense pulsed light (IPL) and UVC irradiation were compared. ► The viability of pathogens decreased exponentially with IPL treatment time. ► More double-strand breaks accumulated in DNA from bacteria treated with IPL than UVC. ► Bacterial cell structures were destroyed by IPL treatment but not by UVC treatment.</P>

Effect of High Pressure Processing on the Microbiological Shelf-life of Beef Patties

( Chan-ick Cheigh ),( You-lee Kang ),( Myong-soo Chung ) 한국산업식품공학회 2018 산업 식품공학 Vol.22 No.2

The purposes of this study was to investigate the effect of high pressure processing (HPP) on a sterilization and microbiological shelf-life of commercial beef patties by varying the pressure level (200, 300, 400, and 500 MPa), treatment time (0-10 min), and storage period (0-16 day at 4℃). The HPP treatment of 200 MPa were ineffective, however the treatment of 300, 400, and 500 MPa reduced the bacterial count by 0.61-1.16, 1.11-1.69, and 2.73-3.86 log (CFU/g), respectively. During 16 days of storage, the viable cell numbers in beef patties treated with 400 and 500 MPa were substantially lower than those in the non-treated control. The control count reached 6.6 log CFU/g after 16 days at 4℃, but after the same storage time, the counts in HPP-treated samples of 400 and 500 MPa were 4.7 and 3.1 log CFU/g, respectively. After an HPP treatment of 200-500 MPa, the pH values were approximately 5.83-6.28. During the 16 days of storage, the pH values in the samples of 400-500 MPa were maintained at initial levels throughout the storage period, regardless of treatment time for HPP.

연구본문 : 흑미강으로부터 유용 폴리페놀 및 플라보노이드의 추출효율 증진을 위한 아임계수의 효과

최찬익 ( Chan Ick Cheigh ),정은영 ( Eun Young Chung ),고민정 ( Min Jung Ko ),조상우 ( Sang Woo Cho ),장판식 ( Pahn Shick Chang ),박영서 ( Young Seo Park ),이경아 ( Kyoung Ah Lee ),백현동 ( Hyun Dong Paik ),김기태 ( Kee Tae Kim 한국산업식품공학회 2010 산업 식품공학 Vol.14 No.4

본 연구에서는 흑미의 가공부산물인 흑미강으로부터 기능성 polyphenol 및 flavonoid가 새로운 추출방법인 아임계 추출법을 통해 추출되었고, 열수(80℃), 에탄올, 설탕용액을 이용한 기존 추출법과의 추출효율이 비교 분석되었다. 건조된 흑미강 시료로부터 polyphenols(35.06±1.28 mg QE/g dried material) 및 flavonoids(7.08±0.31 mg QE/g dried material)에 대한 최대 수율이 아임계 추출법(190℃, 1300 psi, 10 min)을 통해 획득되었으며, 이것은 기존 추출법 가운데 가장 높은 수율을 보인 에탄올 추출법을 통한 polyphenols(2.98±0.74mg QE/g dried material) 및 flavonoids(0.58±0.21mg QE/g dried material) 수율 대비 11.77배와 12.21배 이상 더 높은 것이었다. 추출방법에 따른 흑미강 추출물의 항산화 활성은 에탄올 추출물에서 가장 높게 관찰되었다. 그러나 흑미강 시료 1 g 당 획득된 추출물의 건조중량차이 비교를 통해서 얻어진 건조 흑미강 1 g 당 함유된 항산화 성분의 상대수율(relative yield, %)은 최적조건(190℃, 1,300 psi, 10 min)의 아임계 추출법을 통해 획득된 추출물에서 가장 높았으며, 이것은 에탄올 추출물의 항산화 성분 상대수율에 비해 대략 11.53배 이상 더 높은 것이다. 이상의 결과들은 아임계 추출법이 흑미강으로부터 기능성 polyphenols 및 flavonoids를 추출하는데 매우 적합한 방법임을 설명하고 있으며, 유기용매 추출법을 포함한 기존의 전통적 추출법에 대한 매우 효과적인 대안임을 제시하고 있다. The extraction of polyphenol and flavonoid from black rice bran was performed by diverse extraction methods using the sugar solution, ethanol, hot water (80℃), and by subcritical water extraction (SWE) method. By SWE under operating conditions of 190℃, 1,300 psi, and 10 min, the maximum yields of total polyphenolic compounds (35.06±1.28 mg quercetin equivalent (QE)/g dried material and flavonoids (7.08±0.31 mg QE/g dried material) could be obtained. These results were over 11.77- and 12.21-fold higher than those of the ethanol extraction, which showed the highest extraction efficiency among tested conventional methods in total polyphenols (2.98±0.74 mg QE/g dried material) and flavonoids (0.58±0.21 mg QE/g dried material), respectively. Though the highest antioxidant activity (87.14±1.14%) was observed at the dried extract obtained from ethanol method, the relative antioxidant activity per 1 g dried black rice bran by SWE (190℃, 10 min) was over 11.53-fold higher than that by the ethanol extraction.

저온스팀 열처리 방식에 따른 감자의 전처리 특성

최찬익(Chan-Ick Cheigh) 한국식품과학회 2014 한국식품과학회지 Vol.46 No.5

본 연구는 최근 매우 우수한 가열 매체로 인정받고 있는 저온스팀(soft steam) 열처리 공정의 natural convection (NC) 방식과 forced convection-boiler (FC-b) 및 forced convection-fan (FC-f) 방식을 이용하여 처리온도(60, 70, 80℃) 및 시간(0-60분)에 따른 감자의 전처리 특성을 비교 평가하고자 하였다. 스팀처리 방식에 따른 가열실 내부의 온도변화와 감자 내·외부의 온도변화, 감자의 cook value, ascorbic aicd 및 수분의 함량과 중량감소율의 변화를 관찰한 결과, 모든 처리조건에서 FC-b 및 FC-f의 강제대류 방식에 비해 자연대류의 NC 방식이 이들 전처리 특성에 대해 우수한 결과를 나타냄을 확인할 수 있었다. 따라서, 본 연구의 결과들은 감자의 가공 및 전처리를 위해 현재 사용되고 있는 기존의 열처리 공정에 대한 대안으로써 NC 방식 스팀처리의 높은 효율성 및 산업적 적용에 대한 가능성을 제시하고 있다. This study aimed to investigate the effects of various soft steam treatments, namely, forced convection-boiler, forced convection-fan, and natural convection, on the pretreatment characteristics of potatoes. In this study, potatoes were exposed to various cooking conditions, including steaming method, treatment time (0-60 min), and temperature (60, 70, 80℃). Then, changes in temperature, cook value, ascorbic acid content, moisture content, and weight loss in the fresh and steam-treated samples were measured and evaluated. The results clearly showed that natural convective steaming was superior to other treatments in terms of heating characteristics, cook value (FC-b: 46.4±1.7, FC-f: 21.8±1.1, NC: 52.1±1.9 min at 80℃), ascorbic acid content (FC-b: 36.5±2.7, FC-f: 28.5±2.9, NC: 48.2%±2.5% at 80oC), moisture retention (FCb: 74.6±0.8, FC-f: 71.5±0.5, NC: 77.6%±0.4% for 60 min at 80oC), and weight loss (FC-b: 13.9±0.8, FC-f: 15.6±0.6, NC: 10.6%±0.7% for 60 min at 80℃) for thermally processed potatoes.

스팀 열처리 방식에 따른 채소류의 품질 특성

최찬익 ( Chan Ick Cheigh ),이진희 ( Jin Hee Lee ),정명수 ( Myong Soo Chung ) 한국식품영양학회 2011 韓國食品營養學會誌 Vol.24 No.3

Thermally processed vegetables have long been considered to have lower nutritional values compared to fresh produce. This consideration is based on the fact that ascorbic acid(vitamin C) or other thermolabile compounds may lose their activity due to oxidation or by consequence of leaching into the water during home cooking or industrial processing, such as by blanching. In this study, major agricultural products such as carrots, broccoli, and potatoes were exposed to steam treatments of different types. Then, changes in color and levels of ascorbic acid, carotene, and moisture in the fresh and steam processed vegetable samples were measured and evaluated. The results clearly showed that steam-processing using a natural convection type method was superior to the other treatments in terms of quality, including color and nutrient retention, among all the vegetables tested.

아임계수를 이용한 사과 과피 플라보노이드의 효율적 추출 및 항산화 활성 평가

최찬익 ( Chan Ick Cheigh ),유서연 ( Seo Yeon Yoo ),정명수 ( Myong Soo Chung ) 한국식품영양학회 2011 韓國食品營養學會誌 Vol.24 No.3

The effect of subcritical water for the extraction of total polyphenols and flavonoids from apple peel was investigated, and then the antioxidant activity of the extracts was estimated. Maximum yields of total polyphenolic compounds(36.4±1.9 mg quercetin equivalent(QE)/g dried material) and flavonoids(9.9±0.8 ㎎ QE/g dried material) were obtained by subcritical water extraction(SWE) with operating conditions of 190℃, 1,300 psi, and 20 min. Furthermore, the highest antioxidant activity(76.1±1.1%) was observed in the extract obtained from SWE using the same conditions. The flavonoids from the SWE of apple peel were compared to three conventional extraction methods in terms of their extraction efficiency and antioxidant activity. The SWE was significantly more effective than hot water (90℃), methanol, and ethanol extraction for flavonoid yield by 4.7-, 2.2-, and 1.3-fold, respectively, and for antioxidant activity by 11.0-, 4.9, and 2.8-fold, respectively.

추출방법에 따른 감귤 과피 유래 Flavonoid의 추출효율 및 항산화 효과에 대한 비교

최찬익 ( Chan Ick Cheigh ),정원근 ( Won Guen Jung ),정은영 ( Eun Young Chung ),고민정 ( Min Jung Ko ),조상우 ( Sang Woo Cho ),이재환 ( Jae Hwan Lee ),장판식 ( Pahn Shick Chang ),박영서 ( Young Seo Park ),백현동 ( Hyun Dong Paik 한국산업식품공학회 2010 산업 식품공학 Vol.14 No.2

본 연구에서는 감귤 과피 가공부산물로부터 기능성 polyphenol 및 flavonoid가 새로운 추출방법인 아임계 추출법을 통해 추출되었고, 열수(80oC), 에탄올, 설탕용액을 이용한 기존 추출법과의 추출효율이 비교 분석되었다. 건조된 감귤 과피로부터 총 polyphenol(27.25±1.33mg QE/g DCP) 및 flavonoid(7.31±0.41mg QE/g DCP)에 대한 최대수율이 아임계 추출법(190°C, 1300 psi, 10 min)을 통해 획득되었으며, 이것은 기존 추출법 가운데 가장 높은 수율을 보인 에탄올 추출법을 통한 총 polyphenol(3.79±0.73mg QE/g DCP) 및 flavonoid(0.86±0.27mg QE/g DCP) 수율 대비 7.2배와 8.5배 이상 더 높은 것이었다. 추출방법에 따른 감귤 과피 추출물의 항산화 활성은 큰 차이를 나타내지 않았으나, 이러한 결과는 건조 감귤 과피 1g 당 아임계 추출법(190oC, 1300 psi, 10 min)에 의한 항산화 성분의 상대 수율(relative yield, %)이 다른 추출방법을 통해 획득된 것보다 대략 9.5배 이상 더 높다는 것을 설명하는 결과로, 아임계 추출법이 기존의 전통적 추출법에 비하여 감귤 과피의 기능성 polyphenol 및 flavonoid를 추출하는데 매우 적합한 방법임을 제시하고 있다. The extraction of polyphenol and flavonoid from citrus peel was performed by the ethanol, sugar, hot water (80oC), and subcritical water extraction methods. The maximum yields of total polyphenolic compounds (27.25±1.33mg QE/g DCP, QE and DCP indicate quercetin equivalent and dried citrus peel, respectively) and flavonoids (7.31±0.41mg QE/g DCP) were obtained by subcritical water extraction (SWE) with operating conditions of 190oC, 1300 psi, and 10 min. The yields by SWE were over 7.2-, and 8.5-fold higher than those of total polyphenols (3.79±0.73mg QE/g DCP) and flavonoids (0.86±0.27mg QE/g DCP) obtained using the ethanol extraction, which showed the highest extraction efficiency among tested conventional methods, respectively. Antioxidant activities of extracts obtained by different methods showed no significant differences. However, the relative antioxidant yield per 1 g dried citrus peel by SWE (190oC, 10 min) was over 9.5-fold higher than that by the ethanol extraction.

Inactivation Mechanism of Bacillus subtilis Spores by Ethanol Extract of Torilis japonica Fruit

Won-Il Cho,Chan-Ick Cheigh,You-Jung Choi,Jeong-Yoon Jeong,Jun-Bong Choi,Kangpyo Lee,Seok Cheol Cho,Yu-Ryang Pyun,Myong-Soo Chung 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.2

To confirm the antimicobial mechanism of Torilis japonica, antimicrobial profile was observed on various spore conditions by combining 0.1% (3 mM) torilin with antimicrobial activity and 0.27% water fraction with germinants. A 75% ethanol extract of T. japonica fruit reduced Bacillus subtilis ATCC 6633 spore counts by 3 log cycles and reduced the vegetative cells to undetectable level (by about 6 log cycles) (both in terms of CFU/㎖). Further fractionating the ethanol extract into n-hexane and water fractions revealed that the former reduced the spore count by 1 log cycle whereas the latter had no effect. The antimicrobial active compound was isolated and purified from the hexane layer, and identified as torilin (C₂₂H₃₂O?). The water fraction of the ethanol layer did not show antimicrobial activity, whereas the antimicrobial effect of 0.1% (3 mM) torilin was significantly enhanced in the presence of the water fraction (0.27%). This result can be explained by synergistic effects of the water fraction containing considerable amounts of germinants such as L-alanine and K? ions that triggered germination.

Characterization of a bacteriocin , brevicin 101 produced by Lactobacillus brevis A101 isolated from Kimchi

Hak Jong Choi,Chan Ick Cheigh,Seong Bo Kim,Yu Ryang Pyun 한국식품과학회 1999 한국식품과학회 학술대회 Vol.1999 No.1