동결속도 및 저장온도가 취반된 쌀의 노화도, 조직감 및 미세구조에 미치는 영향

최성길,이철,Choi, Sung-Gil,Rhee, Chul 한국식품과학회 1995 한국식품과학회지 Vol.27 No.5

Cooked rices were frozen at four different rates(3, 5, 7 and 12 hr) of maximum ice crystal formation zone and stored at $-20^{\circ}C\;and\;-70^{\circ}C$ for 3 months. Freezing rate, storage temperature and storage period all affected the degree of retrogradation of cooked rice. As the maximum ice crystal formation zone increased from 3 hrs to 12 hrs, the degree of retrogradation of cooked rice increased from 14.9% to 40.0%. Further retrogradation occurred during the freezing storage and cooked rice stored at $-20^{\circ}C$ retrograded faster than that held at $-70^{\circ}C$. The hardness and adhesiveness of frozen cooked rice thawed in $40^{\circ}C$ water were measured. Hardness of the frozen cooked rice was higher than that of non-frozen sample and was higher at lower freezing rate. However, the hardness of cooked rice decreased after 3 months of storage. On the other hand, the adhesiveness decreased during the freezing processing, and adhesiveness decreased more rapidly at a higher freezing rate. However, the adhesiveness of cooked rice increased after 3 months of the storage, and the level of decrease was higher at $-70^{\circ}C$ than at $-20^{\circ}C$. After 3 months of storage, ice crystal size of frozen cooked rice became larger by recrystalization than that of frozen sample prior to storage. Microstructure of cooked rice was damaged by ice crystal formation and its growth when observed by scanning electron microscope. 본 연구는 동결속도 및 동결저장온도가 취반된 쌀의 이화학적 특성에 미치는 영향을 살펴보고자, 단열재를 이용하여 최대 빙결정 형성신간이 3시간, 5시간, 7시간 그리고 12시간인 동결속도로 24시간 동안 동결하였고, 동결된 시료는 각각 $-20^{\circ}C$와 $-70^{\circ}C$의 냉동고에서 3개월간 저장하여 동결저장동안에 각 시료의 노화도 그리고 조직감의 변화를 조사하였다. 동결된 쌀밥의 미세구조 및 표면구조는 빙결정을 동결치환에 의해 제거한후 scanning electron microscopy(SEM)으로 관찰하였다. 취반된 쌀의 노화도는 동결속도, 동결저장온도, 저장기간에 따라 큰 영향을 받아 최대 빙결정 형성시간이 3시간에서 12시간으로 길어짐에 따라 노화도는 14.85%에서 40.00%로 증가하였고, 동결된 쌀밥의 동결저장 중 노화도는 $-20^{\circ}C$에서 저장한 것이 $-70^{\circ}C$의 경우보다 노화된 정도로 크고, 빠른 진행을 보였다. 동결된 시료를 해동한 후의 경도는 동결시키지 않은 대조구와 비교할 때 크게 증가하였으며, 또한 동결속도가 늦어질수록 더 큰 증가를 보였다. 하지만, 3개월간 저장한 후에는 경도가 다시 감소하였다. 한편, 부착성은 대조구와 비교하여 24시간 동안 동결된 쌀밥에서는 감소하였으며 3개월간 저장한 후에는 다시 증가하는 경향을 보였다. 동결된 취반된 쌀의 빙결정의 크기는 동결속도가 늦어짐에 따라 커졌고 그 수는 상대적으로 적었다. 또한 3개월간 저장한 후에는 얼음의 재결정화에 의해 시료의 빙결정은 더욱 커져 취반된 쌀의 구조가 많이 파손되었음을 확인할 수 있었다. 결론적으로 최대빙결정형성시간을 단축하여 취반된 쌀을 동결시키는 것과 낮은 온도에서 저장하는 것이 빙결정의 형성과 성장에 따른 전분의 노화와 조직감의 변화를 억제할 수 있다고 판단되었다.

GC/MS를 이용한 사육수 중 유기염소계농약의 분석법 개발

최성길 ( Sung Gil Choi ),김종환 ( Jong Hwan Kim ),안지영 ( Ji Young An ),서종수 ( Jong Su Seo ) 한국환경농학회 2013 한국환경농학회 학술대회집 Vol.2013 No.-

This study was conducted to develop the analytical method of 14 organochlorine pesticides (Aldrin, Dieldrin, Endrin, g-chlordane, a-chlordane, p,p`-DDT, o,p`-DDT, p,p`-DDE, p,p`-DDD, Heptachlor, Heptachlor isomer-A, Heptachlor isomer-B, Mirex, Hexachlorobenzene)by GC/MS in dilution water applied tobioconcentration test.Pyrene-d10 was used as internal standard.From the full scan spectra of total ion chromatography (TIC), precursor ions of each 14 organochlorine pesticides were selected as Aldrin (m/z 263), Dieldrin (m/z 263), Endrin (m/z 263), g-chlordane (m/z 375), a-chlordane (m/z 375), p,p`-DDT (m/z 235), o,p`-DDT (m/z 235), p,p`-DDE (m/z 246), p,p`-DDD (m/z 235), Heptachlor (m/z 100), Heptachlor isomer-A (183), Heptachlor isomer-B (m/z 353), Mirex (m/z 272), Hexachlorobenzene (m/z 284). In recovery or linearity test, the 14 organochlorine pesticides and internal standard were added to 500 mL of water (HPLC grade) to be 0.01∼0.5 ng/mL and 20ng/mL, respectively and extracted with 50 mL of dichloromethane. The extraction process was performed with three repetition. The organic layer combined through the sodium sulfate was evaporated under reduced pressure just to dryness. The residue was dissolved with 5 mL of acetone and aliquot (1 μL) wasanalyzed with GC/MS-selected ion monitoring (SIM). The allcalibration curves showed the good linearity (>0.99) in the range of 1.0∼50.0 ng/mL. This method showed MLOQs (Method limit of quantitations)of 0.05 ng/mL for 14 organochlorine pesticides.This method could be used as a determination of 14 organochlorine pesticides in dilution water to conduct thebioconcentration test.

안드로이드에서 개인정보 유출을 방지하기 위한 실시간 감시 기법

최성길(Sung-Gil Choi),전서현(Suh H. Cheon) 한국정보과학회 2013 한국정보과학회 학술발표논문집 Vol.2013 No.6

매실추출물이 발효유제품의 Shelf-Life에 미치는 영향

최성길 ( Sung Gil Choi ),오병태 ( Byung Tae Oh ),박우포 ( Woo Po Park ),이승철 ( Seung Cheol Lee ),조성환 ( Sung Hwan Cho ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2006 한국식품저장유통학회지 Vol.13 No.3

국내 시판 블루베리와 라즈베리의 영양성분 분석 및 항산화 활성

정창호(Chang-Ho Jeong),최성길(Sung-Gil Choi),허호진(Ho Jin Heo) 한국식품영양과학회 2008 한국식품영양과학회지 Vol.37 No.11

국내 시판되는 블루베리와 라즈베리의 영양성분 및 항산화 활성에 대하여 조사하였다. 블루베리와 라즈베리 각각의 일반성분은 수분 10.47%와 22.67%, 조단백질 2.66%와 2.64%, 조지방 2.04%와 1.67%, 가용성물질소물 81.36%와 70.19%, 조섬유 1.48%와 0.85% 및 회분 1.99%와 1.98%였다. 총페놀화합물 함량은 라즈베리(5.340 ㎎/g)보다 블루베리(9.028 ㎎/g)가 높게 나타났다. 블루베리와 라즈베리의 주요 무기성분은 Ca(451.34 and 97.48 ㎎/100 g), K(355.40 and 215.20 ㎎/100 g), P(321.10 and 294.04 ㎎/100 g) 및 Na(137.58 and 137.67 ㎎/100 g)이었다. 블루베리와 라즈베리의 총아미노산 함량은 각각 2,011.44 ㎎/100 g과 2,098.82 ㎎/100 g이었으며, 주요 아미노산으로는 glutamic acid, aspartic acid 및 leucine이었다. 블루베리와 라즈베리 80% 메탄올 추출물의 DPPH 및 ABTS radical 소거활성을 측정한 결과 농도 5 ㎎/mL에서 각각 88.67%와 62.77%, 76.34%와 30.53%의 소거활성을 보였다. 블루베리와 라즈베리 80% 메탄올 추출물의 환원력을 이용한 항산화 활성은 농도의존적인 경향을 보였으며, β-carotene-linoleate와 FTC method를 이용한 항산화활성은 블루베리가 라즈베리보다 2배 높은 활성을 보였다. The nutritional compositions and antioxidative activities of Korean commercial blueberry and raspberry were investigated. The proximate compositions were 10.47% and 22.67% in moisture, 2.66% and 2.64% in crude protein, 2.04% and 1.67% in crude fat, 81.36% and 70.19% in nitrogen free extracts, 1.48% and 0.85% in crude fiber, and 1.99% and 1.98% in ash of blueberry and raspberry, respectively. Total phenolics content were higher in blueberry (9.028 ㎎/g) than in raspberry (5.340 ㎎/g). Major elements of blueberry and raspberry were Ca (451.34 and 97.48 ㎎/100 g), K (355.40 and 215.20 mg/100 g), P (321.10 and 294.04 ㎎/100 g), and Na (137.58 and 137.67 ㎎/100 g). The total amino acid contents of blueberry and raspberry were 2,011.44 ㎎/100 g and 2,098.82 ㎎/100 g, respectively. Amino acid were mainly composed of glutamic acid, aspartic acid and leucine. The DPPH and ABTS radical scavenging activities of the 80% methanol extract from blueberry and raspberry were 88.67% and 62.77%, 76.34% and 30.53% at a concentration of 5 ㎎/mL. The 80% methanol extract from blueberry and raspberry showed considerable antioxidative activity against reducing power in dose-dependent manner. Antioxidative activities using β-carotene-linoleate and FTC method were twice higher in blueberry than raspberry.

살구 중 Flonicamid 및 그 대사산물의 잔류특성 연구

김영진 ( Yeong-jin Kim ),최성길 ( Sung-gil Choi ),권영상 ( Young-sang Kwon ),이경민 ( Gyung-min Lee ),김종환 ( Jong-hwan Kim ) 한국환경농학회 2020 한국환경농학회 학술대회집 Vol.2020 No.-

This study was conducted to investigate residual characteristics of Flonicamid and metabolites among minor crop apricots, evaluate safety and use them as data for expanding the registration of pesticides. The test pesticide was harvested after diluting Flonicamid 10 % water dispersible granule (WG) 2,000 fold and spraying it from 50 days before harvest to 7 days before harvest. 10mL of acetonitrile containing 5% acetic acid was added to 10g ± 0.05g of homogenized sample, and after shaking for 10 minutes, a sample was extracted by adding a QuEChERS (Original)kit. The extracted sample was analyzed for Flonicamid, metabolites TFNA, and TFNG using LC-MS/MS. Standard calibration curves were made by matrix matched standards and their correlation coefficients were higher than 0.99. The method limit of quantitation (MLOQ) was each 0.02 mg/kg for Flonicamid and metabolite TFNA, TFNG. Average recovery rates of Flonicamid, metabolites TFNA, and TFNG were 89.2-110.2 %, 91.4-103.8 %, and 95.8-113.6 %, respectively. The converion residue amounts of Flonicamid at 50-40 DAT (days after treatment) were 0.12- 0.15 mg/kg, 40-30 DAT were 0.16-0.17 mg/kg, 30-21 DAT were 0.10-0,11 mg/kg, 21-14 DAT were 0.11-0.15 mg/kg, 14-7 DAT were 0.11-0.21 mg/kg, respectively. Residual concentration of Flonicamid in the crop was increased as spraying more closer to harvest day. The percentage of estimate daily intake(%EDI) compared to ADI based on the residual amount of Flonicamid in apricots from 0.0018% to 0.0034%. The %ADI was considered safe at less than 10%.

한국산 골드키위의 화학성분 및 항산화 활성

정창호,이원재,배송환,최성길,Jeong, Chang-Ho,Lee, Won-Jae,Bae, Song-Hwan,Choi, Sung-Gil 한국식품영양과학회 2007 한국식품영양과학회지 Vol.36 No.7

한국산 골드키위를 기능성 식품 재료 및 가공품을 개발하기 위한 기초자료로 활용하기 위하여 화학성분 및 항산화활성을 조사하였다. 골드키위의 pH 4.43${\pm}$0.16, 당도 17.01${\pm}$0.04$^{\circ}Brix$ 및 총산도 0.82${\pm}$0.02%이었으며, L값 49.80${\pm}$0.24, a값 -6.79${\pm}$0.02 및 b값 19.72${\pm}$0.18로 나타났다 일반성분은 수분 78.62${\pm}$2.26%, 조단백 1.34${\pm}$0.25%, 조지방 0.70${\pm}$0.06%, 조섬유 1.99${\pm}$0.13%, 조회분 0.99${\pm}$0.26% 및 가용성 무질소물 16.36${\pm}$1.23%이었다. 무기성분은 Na, Ca 및 K으로 그 함량은 각각 21.50${\pm}$1.58 mg%, 23.84${\pm}$2.10 mg% 및 265.86${\pm}$5.00 mg%였다. 골드키위에 함유되어 있는 유리당으로는 sucrose(1.04${\pm}$0.18%), glucose(2.17${\pm}$0.21%) 및 fructose(1.86${\pm}$0.11%)였으며, 가장 많이 함유되어 있는 아미노산은 glutamic acid(86.51${\pm}$5.58 mg%)였고, 가장 낮은 아미노산으로는 tyrosine(15.00${\pm}$4.91 mg%)이었다. 유기산은 quinic acid(6.65${\pm}$0.21 mg/g), malic acid(1.62${\pm}$0.13 mg/g) 및 citric acid(4.82${\pm}$0.21 mg/g)가 함유되어 있었으며, 비타민 C 함량과 총페놀 함량은 각각 0.27${\pm}$0.06 mg/g 및 0.047${\pm}$0.002 mg/g이었다. 골드키위 물추출물 농도 25 mg/mL일 때 86.87%의 DPPH radical 소거활성을 보였으며, 환원력은 1.96으로 나타났고, linoleic acid를 이용한 지질과산화 억제활성은 농도의존적인 경향을 보였다. The chemical components and antioxidative activity of Korean gold kiwifruit were investigated. The values of pH, soluble solid and total acidity were 4.43${\pm}$0.16, 17.01${\pm}$0.04$^{\circ}Brix$, and 0.082${\pm}$0.02%, respectively. Hunter L, a, and b values were 49.80${\pm}$0.24, -6.79${\pm}$0.02, and 19.72${\pm}$0.18 value, respectively. Proximate compositions were as follows; moisture 78.62${\pm}$2.26%, crude protein 1.34${\pm}$0.25%, crude lipid 0.70${\pm}$0.06%, crude fiber 1.99${\pm}$0.13%, crude ash 0.99${\pm}$0.26%, and carbohydrate 16.36${\pm}$1.23%, respectively. Mineral elements were K 265.86${\pm}$5.00, P 71.82${\pm}$29.18, and Ca 23.84${\pm}$2.10 mg%, respectively. Free sugar compositions were sucrose (1.04${\pm}$0.18%), glucose (2.17${\pm}$0.21%) and fructose (1.86${\pm}$0.11%). Amino acid contents of Korean gold kiwifruit was very rich in glutamic acid 86.51 ${\pm}$5.58 mg/100 g and deficient in tyrosine 15.00${\pm}$4.91 mg/100 g. Organic acid compositions were quinic acid (6.65${\pm}$0.21 mg/g), malic acid (1.62${\pm}$0.13 mg/g) and citric acid (4.82${\pm}$0.21 mg/g). Contents of ascorbic acid and total phenols were 0.27${\pm}$0.06 mg/g and 0.047${\pm}$0.002 mg/g, respectively. The DPPH radical scavenging activity and reducing power of the water extract from Korean gold kiwifruit was 86.87% and 1.96 at a concentration of 25 mg/mL. The water extract showed considerable antioxidative activity against linoleic acid autoxidation in a dose-dependent manner.

LC-MS를 이용한 황금추출물의 항균물질 검색

김영록 ( Young Rok Kim ),최성길 ( Sung Gil Choi ),조성환 ( Sung Hwan Cho ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2005 한국식품저장유통학회지 Vol.12 No.4

분말녹차 추출물의 항산화 활성에 미치는 수분활성도 및 저장온도의 효과

최귀남 ( Gwi Nam Choi ),정창호 ( Chang Ho Jeong ),김지혜 ( Ji Hye Kim ),곽지현 ( Ji Hyun Kwak ),신영희 ( Young Hee Shin ),이승철 ( Seung Cheol Lee ),조성환 ( Sung Hwan Cho ),최성길 ( Sung Gil Choi ),허호진 ( Ho Jin Heo ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2009 한국식품저장유통학회지 Vol.16 No.3

풋고추 농약다성분분석 정도관리용 분석표준물질 개발

김종환(Jong-Hwan Kim),최성길(Sung-Gil Choi),오영곤(Young-Gon Oh),권영상(Young-Sang Kwon),홍수명(Su-Myeong Hong),성문현(Mun-Hyun Sung),이세자(Se-Ja Lee),황선영(Sun-Young Hwang),서종수(Jong-Su Seo) 한국농약과학회 2016 농약과학회지 Vol.20 No.3

This study was to develop the analytical reference material of green-pepper for multi-residue analysis of pesticides. According to the ISO Guide 35, ISO Guide 13528 and EURL-PT protocol, the homogeneity, stability, assigned value and uncertainty were calculated to assess if it was suitable to be used as the proficiency test or quality control. The values of the within-bottle standard variation (s<SUB>wb</SUB>) and the between-bottle standard variation (s<SUB>bb</SUB>) were 1.7~3.7% of assigned value according to the requirement of the ISO guide 35. And, the uncertainty (u<SUP>*</SUP><SUB>bb</SUB>) due to inhomogeneity was 0.8~1.1% for all pesticides. The storage stabilities of ten-pesticides at various conditions were assessed. For all target pesticides, the slop (b<SUB>1</SUB>) values were smaller than the corresponding values of [t<SUB>0.95,n-2</SUB>×s(b<SUB>1</SUB>)] specified by the ISO guide 35, indicating that there were no statistically significant decreases in the concentration of the target pesticides when the analytical reference material was stored at room temperature (20~30℃) for 7 days, freezing (-20℃) for 30 days and deep freezer (-80℃. except for bifenthrin, fenpropathrin) for 245 days. For proficiency test by using it developed by Korea Institute of Toxicology, inter-lab test was performed with eight organization performing the residual pesticide analysis. We found that there were some different results among them. Some were assessed as questionable or unacceptable for two pesticides and one organization didn’t analyze the six pesticides. From these results, this green-pepper analytical reference material containing ten-pesticides could be used as a tool for the proficiency test to improve the reliability or consistency for pesticide residue’s results.