Research Progress of Theaflavins and Thearubigins Found in Black Tea:An Overview

김주신 (사)한국조리학회 2023 한국조리학회지 Vol.29 No.1

The objective of this review is to examine and present the publications related to studies on the major two components of black tea, theaflavins (TFs) and thearubigins (TRs), that contribute to the sensory characteristics and health benefits of black tea and find ways to ensure high quality black tea. This review focuses on the mechanism of how TFs and TRs are formed. These components are formed during fermentation stage of black tea production. TFs and TRs are oxidized polyphenolic non-volatile compounds. During the fermentation phase, the catechins found in fresh tea leaves are turned into TFs and TRs by enzyme-catalyzed reaction of polyphenol oxidase (PPO) and peroxidase (POD). Color, flavor, and mouthfeel of black tea are determined by the oxidized polyphenolic compounds such as TFs and TRs, which show strong bio-functions that are responsible for the health benefits of black tea. TFs are combinations of four compounds called theaflavin (TF1), theaflavin-3-gallate (TF2a), theaflavin-3’- gallate (TF2b), and theaflavin-3-3’-digallate (TF3). They contain a benzotropolone skeleton that is made from co-oxidation of certain pairs of catechins. Meanwhile, TRs are a mixture of heterogeneous phenolic polymers. The concentration of TFs and TRs, formed during fermentation, is determined by the manufacturing parameters for fermentation. It impacts the sensory characteristics and its biological activities for quality desirability of black tea. This review presents basic information on the formation mechanism of TFs and TRs, their sensory characteristics, and their inhibitory effects against diseases. Moreover, this may serve as a guideline for manufacturing high quality black tea.

수용성 모델시스템 내에서의 상업적 γ-Oryzanol의 C-7 산화 콜레스테롤 유도체 생성 저해효과

김주신 한국식품위생안전성학회 2008 한국식품위생안전성학회지 Vol.23 No.1

The inhibition of cholestero γ-oryzanol (0, 50, 100, and 300 pm)was studied in an aqueous model system for 20 h at pH 5.5 and 80C. The inhibition effectiveness of the commercialγ-oryzanol was followed by the retention of cholesterol and the formation of C-7 oxidized cholesterol derivatives(OCDs). Changes in the amount of γ-oryzanol in the aqueous system were determined during cholesterol autoxidation.A method to detect the levels of 7-ketocholesterol, 7α-hydroxycholesterol and 7β-hydroxycholesterol in an aqueousmodel system with γ-oryzanol was developed by using the hexane-ethyl acetate extraction system and high-perfor-mance liquid chromatography. Results showed that the levels of C-7 OCDs in an aqueous dispersion containing 300ppm of γ-oryzanol were not significantly (p>0.05) increased, when compared to other treatments (0, 50, and 100 pm),during the accelerated cholesterol oxidation.

상업적 γ-Oryzanol과 α-Tocopherol 첨가에 따른 냉장 조리 돼지고기의 Warmed-over flavor(WOF)와 7-Ketocholesterol 제어 효과

김주신 한국식품위생안전성학회 2008 한국식품위생안전성학회지 Vol.23 No.1

The oxidative stability of refrigerated precooked pork patties containing commercial γ-oryzanoland α-tocopherol was evaluated. Precooked pork patties containing either γ-oryzanol or α-tocopherol showed higheroxidative stability (p<0.05) during storage at 4C than did the precooked pork patties without the additives (control).The thiobarbituric acid-reactive substances (TBARs) valupatties containing γ-oryzanol or α-tocopherol were lower (p<0.05) than those of the control during refrigerated storage(0, 1, 4, and 8 days). The correlation between TBARs and WOF values was significant (p<0.05). 7-Ketocholesterolcontent was lower (p<0.05) than those of the control during refrigerated storage (0, 6, 12, 18, and 24 days). The cor-relation between TBARs values and 7-ketocholesterol content was also significant (p<0.05).

Commercial ${\gamma}$-Oryzanol Inhibits the Formation of C-7 Oxidized Cholesterol Derivatives (OCDs) in an Aqueous Model System during Cholesterol Autoxidation

김주신,Kim, Joo-Shin The Korean Society of Food Hygiene and Safety 2008 한국식품위생안전성학회지 Vol.23 No.1

The inhibition of cholesterol autoxidation by commercial ${\gamma}$-Oryzanol (0, 50, 100, and 300 ppm) was studied in an aqueous model system for 20 h at pH 5.5 and $80^{\circ}C$. The inhibition effectiveness of the commercial ${\gamma}$-Oryzanol was followed by the retention of cholesterol and the formation of C-7 oxidized cholesterol derivatives (OCDs). Changes in the amount of ${\gamma}$-Oryzanol in the aqueous system were determined during cholesterol autoxidation. A method to detect the levels of 7-ketocholesterol, $7{\alpha}$-hydroxycholesterol and $7{\beta}$-hydroxycholesterol in an aqueous model system with ${\gamma}$-Oryzanol was developed by using the hexane-ethyl acetate extraction system and high-performance liquid chromatography. Results showed that the levels of C-7 OCDs in an aqueous dispersion containing 300 ppm of ${\gamma}$-Oryzanol were not significantly (p>0.05) increased, when compared to other treatments (0, 50, and 100 ppm), during the accelerated cholesterol oxidation. 미강 추출 상업용 유통 감마오리자놀의 콜레스테롤 자동산화에 의한 C-7 산화 콜레스테롤 유도체 생성 저해 효과가 수용성 모델 시스템을 이용하여 검토되었다. C-7 콜레스테롤 산화 유도체 (C-7 oxidized cholesterol derivatives: C-7 OCDs) 생성을 위해 콜레스테롤과 감마오리자놀이 분산된 수용성 모델시스템은 구리이온을 촉매로 pH 5.5와 $80^{\circ}C$의 가혹 조건에서 20시간 동안 반응되었다. 산화 유도 기간에 따른 C-7콜레스테롤 산화 유도체 (7-ketocholesterol, 7{\alpha}$-hydroxy-cholesterol과 7b-hydroxycholesterol)의 생성 정도와 감마오리자놀 및 콜레스테롤 변화 추이 정도가 핵산과 에틸아세테이트를 이용한 용매 추출법과 고속 액체크로마토그래프 (high-performance liquid chromatography) 테크닉을 이용 정량적으로 분석되었다. 분석 결과 콜레스테롤 산화 유도 기간에 따른 7-ketocholesterol 생성비율은 7-hydroxycholesterol 이성체 (${\alpha}$-형:${\beta}$-형) 대비 약 2:1의 비율로 생성되었으며, 7-hyoxycholesterol 이성체에 있어서는 ${\alpha}$-형 대비 ${\beta}$-형의 생성 정도가 약 1:2의 비율로 나타났고, 총 C-7 산화콜레스테롤의 생성은 상대적인 고농도(300 ppm) 감마오리자놀 처리 모델 시스템에서 효과적으로 저해되었다.

Flavonoids, an Overview: Chemical Structures, Dietary Sources, and Biological Properties

김주신 한국산업식품공학회 2020 산업 식품공학 Vol.24 No.3

Flavonoids are a group of plant polyphenol secondary metabolites, which widely exist in plant systems. Recently, flavonoids from plant-based sources have been gaining more interest due to their versatile biological activities. The biological activities of flavonoids are dependent upon their chemical structures, which in turn rely on their structural class, level of hydroxylation, substitution pattern, connection position, existence of C2=C3 double bond, and level of polymerization. Flavonoids are considered nutraceuticals in diet. They help prevent many chronic and degenerative illnesses through various biological activities, such as free radical scavenging, anti-lipid peroxidation, and xanthine oxidase inhibition, as well as their anti-inflammatory, antimicrobial, and anti-cancer activities. The goal of the present review is to evaluate flavonoids’ chemical structural features and their biological activities as they relate to preventing chronic diseases affecting human health, and further navigate the relationship between the chemical structure and their biological function.

Cucurbita moschata와 Cassia seed에서 유래한 흡착제에 관한 연구

김주신,한상수,김형민,김재백 圓光大學校 藥品硏究所 1988 藥品硏究所報 Vol.3 No.1

Adsorption of metal ions (Ag^+, Co^2+, Zn^2+) in water by leaves of Cucurbita moschata, and adsorption of cholic acid, cholesterol in aqueous solution by Cassia seed were investigated. Adsorption rate was evaluated under the condition of variation in each stirring time, pH and concentration of adsorbate. The result is as follows; Formalin treated leaves of Cucurbita moschata was evaluated useful scavenger of metal ions. Also to compare with nontreated Cassia seed. formalin treated Cassis seed has the larger adsorption capacity constant. Adsorption of silver, cobalt and zinc ion by the formalin treated leaves of Cucurbita moschata roughly follows a Freundlich Isotherms in the experimental concentration range(5-200㎍/ml). Adsorption of cholic acid cholesterol by Cassia seed followed a Freundilich Isotherm equation.

Closed Hydroponic Nutrient Solution Management Using Multiple Water Sources

김주신,김학진,강민석,김동욱,조우재,장재경 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.2

Purpose A properly ion-balanced nutrient solution is vital for plant growth. However, when reusing a nutrient solution, the nutrient balance is likely to fl uctuate and become unsuitable for irrigation. Ionic imbalance problems that cause plant growth disorders in nutrient solutions can be minimized if the nutrient concentration of the various water sources can be determined and considered when making the nutrient solution. In this study, a closed hydroponic nutrient management algorithm for multiple water sources was developed. Methods The concentrations of NO 3 − , K + , and Ca 2+ ions in the nutrient solution and various water sources were measured in real time and calculated to automatically replenish insuffi cient ions. For this purpose, ion-selective electrodes (ISEs) were selected for the determination of NO 3 − , K + , and Ca 2+ ion concentrations and eight stock solutions for individual salt replenishment. Results Performance tests were conducted to verify the developed system’s ability to maintain NO 3 − , K + , and Ca 2+ ion concentrations at their target values. The nutrient solution dosing accuracy obtained in the stepwise management test was evaluated using root mean square error (RMSE). In addition, long-term performance evaluation of the developed algorithm was validated while growing lettuce using the closed nutrient fi lm technique (NFT). The long-term accuracy of the developed system was RMSE 60.6, 21.0, and 9.86 mg/L for the NO 3 − , K + , and Ca 2+ ions, respectively. Conclusion The results of this study showed nutrient management using multiple water sources by applying three diff erent ISE sensors, NO 3 − , K + , and Ca 2+ . With the further development of ISE technology, it would be possible to control all six macronutrients in the nutrient solution.

결명자에 의한 수용액중 Cholic acid 및 cholesterol흡착에 관한 연구

김주신,김재백 圓光大學校 藥品硏究所 1991 藥品硏究所報 Vol.6 No.1

Adsorption rate of cholic acid and cholesterol in aqueous solution by Cassia seed was investigated. Adsorption rate of the defatted seeds, the methanol treated seeds after defat and formalin treated seeds was evaluated under the various conditions such as stirring time, concentration of cholic acid and cholesterol, pH and ionic strength. Stirring time at 60 minutes was suitable for this experiments. The maximal adsorption rate of each adsorbent was presented at pH 8.0 and the ionic strength was not significantly affcted. Adsorption rate of chokic acid and cholesterol by methanol by methanol treated seeds after defat was higher than defatted seeds. In formalin treated residue(defatted seeds, methanol treated seeds after defat), adsorption rate of cholic acid and cholesterol was increased but wasn't significantly varied in methanol treated seeds after defat. Adsorption of cholic acid and cholesterol by acssia seed could be significantly established by Freundlich's isotherm equation.

난용성 의약품인 Erythromycin 및 그 유도체의 용출특성과 생체이용성의 상관성에 관한 연구

김주신,함성호,한상수,고건일,김재백 圓光大學校 藥品硏究所 1988 藥品硏究所報 Vol.3 No.1

An evaluation of erythromycin and it's derivatives on factors concerning absorption characteristics was conducted. Dissolution characteristics and stability of them were evaluated in six test solutions of the different acidity concerning gastrointestinal acidity. And stability test was carried out at the same time with the dissolution test. The bioavailability of erythromycin stearate was investigated in gastric acidity controlled rabbits. Dissolution rate of erythomycin was still more rapid than that of its derivatives vis all test solutions, and dissolution rates them were presented as the apparent first order rate. But the stability of erythromycin stearate was significantly diminished by lowering pH in all test solutions, while erythromycin estolate showed the available stability through all test solutions. Rabbit with low acidity showed significantly higher Cpmax and AUC than rabbits with high acidity after oral adminstration of erythromycin stearate.

생활자원회수센터의 재활용품 반입량 및 선별량 분석을 통한 개선방안검토

김주신,박성민,양경아,배재근 한국폐기물자원순환학회(구 한국폐기물학회) 2016 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2016 No.-

가정에서 분리배출되는 재활용품은 지자체관리영역에서 수집운반되어 생활자원회수센터로 반입되는 영역(단독주택)과 민간재활용업체에 의하여 수집운반되어 자원화되는 체계로 반입되는 영역(공동주택)으로 분류가 가능하다. 현재 우리나라 폐기물 통계중에서 가장 신뢰하기 어려운 것이 재활용품의 분리배출 및 처리량이며, 통계산출방법에 문제가 있는 것으로 지적되고 있다. 본 연구에서는 S시의 S구를 대상으로 재활용품의 수거시스템상에서 수거량 및 밀도, 분리배출된 재활용품의 원단위, 재활용선별장 반입량 및 선별되어진 물질 비율을 분석하여 재활용품 통계와 재활용선별체계 내에서 관련 제도 및 정책의 개선방안에 대하여 검토하였다. 먼저 반입되는 차량별 적제용량 대비 적제량을 분석하여 적제밀도를 조사한 결과, 지역별, 차량별 차이가 있었으나, 적제평균밀도는 0.196ton/㎥로 실측되었으며, 업체별 수거지역에 수거대상세대의 인구수를 구하여 수거량으로 원단위를 산출한 결과, 원단위가 0.086∼0.143kg/입.일의 량의 범위로 보였으며, 평균 0.109kg/인.일을 보였다. 이 량은 현재 집계되고 있는 폐기물통계와는 많은 차이가 있는 것으로 확인되었다. 또한 반입되는 재활용품의 겉보기 밀도를 조사한 결과, 종류별 차이가 컸으며, 아주 낮은 값을 보여주고 있다(표 1). 또한 선별장에 반입되는 재활용품 량에 대하여 회수율을 조사한 결과, 45%정도의 유가물 회수가 있었으며, 55%는 잔재물로 처리되고 있었다. 즉 단록주택 구역은 사전에 유가물이 추출되어 재활용이 불가능한 물질의 반입이 많은 것으로 확인되었다. 잔재물로서 배출되는 폐기물의 성상을 조사한 결과, 건조중량비로 종이류가 20%, pet 18%, PS류 14%, 섬유류 15%, 포장재 pp 13.5%, 유리병 12.33%, 포장재필름 1.6%의 비율로서 시설의 개선 및 인력투입을 증가시키는 것에 의하여 선별장내에서 유가물 선별율을 향상시키는 것이 가능한 것으로 확인되었으며. 잔재물내에 가연성폐기물비율이 높아 고형연료로서의 가치가 확인되었다.