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1H NMR spectroscopy를 이용한 수용액 상의 vitamin C와 EGCG의 보존성 분석
목일균 ( Il Kyoon Mok ),엄병헌 ( Byung Hun Um ) 충북대학교 과학교육연구소 2014 과학교육연구논총 Vol.29 No.1
The NMR (nuclear magnetic resonance) techniques were developed for the simultaneous quantitative analysis of L-ascorbic acid (L-ascorbic acid), EGCG (epigallocatechin gallate) and its degradation products in food storage conditions. Several NMR experimental conditions including water-suppression techniques, acquisition (relaxation delay, acquisition time, etc) and processing methods were optimized for quantification of food components. Sampling method with micro NMR-tube was also developed for food components stability study with normal water (H2O) without using deuterium. The quantities of L-ascorbic acid, EGCG and its degradation products were measured by the quantitative NMR method and HPLC analysis method, respectively. The analysis results of the two methods were compared. The NMR method showed the structure of degradation products, which is not possible in HPLC methods. The NMR is quick and simple to use. In stability study of food storage, This modified NMR technique provides simultaneous and quantitative information with chemical structure of food components without time consuming separation procedure and expensive deuterium solvent.
Yang Deng,임주호,Thi Thanh Hanh Nguyen,목일균,Meizi Piao,김도만 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.5
To develop a beverage with high antioxidantcapacity and desirable sensory characteristics, Schisandrachinensis (omija) fruits were added to ale type beer atdifferent time points of the brewing process. The phenoliccompounds contents in beer were found to be dependent atthe moment of the addition of omija fruit. Addition ofomija fruits at the initiation of boiling imparted highestoxidative stability to beer and resulted in highest totalphenolic and flavonoid contents in ale beer (606.82 mgGAE/L and 406.75 mg QE/L, respectively). The amountsof schisandrin, gomisin A and gomisin B in beer were12.10 mg/mL, 3.12 mg/mL and 0.86 mg/mL, respectively. Taken together, it is hypothesized that the addition of omijafruits to traditional brewing process can improve thedevelopment of value-added beer products.
Biological Characterization of Epigallocatechin Gallate Complex with Different Steviol Glucosides
탄한,Nahyun M. Kim,염수청,한송희,곽소형,김성보,박준성,목일균,김도만 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.5
Steviol glucosides (SGs) such as rubusoside (Ru), stevioside (Ste), rebaudioside A (RebA) and stevioside glucosides (SG) are herbal tea sweeteners that enhance the solubility and stability of a number of pharmaceutically important compounds. The complex of epigallocatechin gallate (EGCG) with 10% (w/v) each Ru, Ste, RebA or SG enhanced the water solubility of EGCG over 15 times to 345, 312, 341, or 320 mg/mL, respectively. The 2,2- diphenyl-1-picrylhydrazyl radical scavenging (SC50) activities of EGCG, EGCG-Ru, EGCG-Ste, EGCG-RebA, and EGCGSG in water were 5.88, 6.03, 6.52, 4.89, and 4.23 μg/mL, respectively. EGCGs complexed with different SGs maintained inhibitory activities against human intestinal maltase, human pancreatic α-amylase, and the growth of Streptococcus mutans, Helicobacter pylori, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Clostridium difficile. In glucose tolerance test using C57BL/6 mice, plasma glucose levels in mice treated with EGCG or EGCG-Ste complex were decreased by 9.34%, which was 31.08% lower than those treated with maltose. The efficient and cost-effective EGCG-SGs production method might be applicable to produce water soluble bioactive nutraceuticals in large scale.
Yan Li,Thi Thanh Hanh Nguyen,진주희,임주호,이지연,Meizi Piao,목일균,김도만 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.4
Co-fermentation using yeast (Saccharomycescerevisiae and Pichia kudriavzevii) and the bacteria (Lactobacillusplantarum) as starters isolated from spontaneoussourdough was conducted for the brewing of glucuronicacid (GlcA)-enriched apple cider. The concentration ofGlcA in the apple cider co-fermented for 14 d with commercialS. cerevisiae and L. plantarum was 37.7 ± 1.7 mg/mL while a concentration of 62.8 ± 3.1 mg/mL wasrecorded for fermentation with P. kudriavzevii and L. plantarum, which was higher than the corresponding singleyeast fermentation. The co-fermented apple cider revealedhigher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicalscavenging activity of 171.67 ± 0.79 lg trolox equivalents(TE)/mL using P. kudriavzevii and L. plantarum, comparedto the control (143.89 ± 7.07 lg TE/mL) just using S. cerevisiae. Thus, the co-fermentation of S. cerevisiae andL. plantarum and P. kudriavzevii and L. plantarum provideda new strategy for the development of GlcA-enrichedapple cider with enhanced antioxidant capacity.
Anti-cariogenic Characteristics of Rubusoside
Jeesoo Kim,Thi Thanh Hanh Nguyen,Juhui Jin,Iis Septiana,Gyu-Min Son,Gang-Hee Lee,You-Jin Jung,Dilshad Qureshi,목일균,Kunal Pal,Soo-Yeon Yang,Seong-Bo Kim,Doman Kim 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.2
Streptococcus mutans plays an important role in the development of dental caries in humans by synthesizing adhesive insoluble glucans from sucrose by mutansucrase activity. To explore the anti-cariogenic characteristics of rubusoside (Ru), a natural sweetener component in Rubus suavissimus S. Lee (Rosaceae), we investigated the inhibitory effect of Ru against the activity of mutansucrase and the growth of Streptococcus mutans. Ru (50 mM) showed 97% inhibitory activity against 0.1 U/mL mutansucrase of S. mutans with 500 mM sucrose. It showed competitive inhibition with a Ki value of 1.1 ± 0.2 mM and IC50 of 2.3 mM. Its inhibition activity was due to hydrophobic and hydrogen bonding interactions based on molecular docking analysis. Ru inhibited the growth of S. mutans as a bacteriostatic agent, with MIC and MBC values of 6 mM and 8 mM, respectively. In addition, Ru showed synergistic anti-bacterial activity when it was combined with curcumin. Therefore, Ru is a natural anti-cariogenic agent with antimutansucrase activity and antimicrobial activity against S. mutans.