• 한국응용과학기술학회지
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• 제40권5호
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• pp.1163-1175
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• 2023

Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α-EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.

• Preventive Nutrition and Food Science
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• 제9권2호
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• pp.167-173
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• 2004

The aim of this study was to investigate the antioxidant effect of medicinal plants used by diabetic patients. Fourteen medicinal plants were selected and antioxidant activity such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, inhibition effect of linoleic acid autoxidation and low density lipoprotein (LDL) oxidation, thiobarbituric acid (TBA) value were measured. The Cornus officinalis had DPPH radical scavenging activity of 84.79%, which was higher than the 78.79% for $\alpha$-tocopherol. Rosa rugosa Thunberg, Pueraria thundergiana Bentham, Artemisia princeps var. orientalis and Sasamorpha purpurascens Nakai also had high values. Extracts with higher DPPH radical scavenging activities had higher total phenol concentrations, and positive correlations between these parameters were found. Inhibitory activities of linoleic acid autoxidation, LDL oxidation and TBA value, used as indices of oxidative stress, were observed in most of the selected medicinal plants. The highest inhibitory activity for TBA value was observed in the extract of Pueraria thundergiana Bentham. Rosa rugosa Thunberg (75.50 %), Sasamorpha purpurascens Nakai (74.00 %), and Cornus officinalis (73.00 %) all had high antioxidant activity against linoleic acid autoxidation, similar to that of $\alpha$-tocopherol. The same 3 plants also had high in inhibitory activity against LDL oxidation. Therefore, we demonstrated that medicinal plants used as folk remedy by diabetic patients had antioxidant activity. Especially, Rosa rugosa Thunberg, Cornus officinalis, Pueraria thundergiana Bentham, Arlemisia princeps var. orientalis, and Sasamorpha purpurascens Nakai had high phenol concentrations which resulted in high values for DPPH radical scavenging. These same plants exhibited high values for inhibitory activities for TBA value, linoleic acid autoxidation and LDL oxidation, indices associated with lipid peroxidation.

• Applied Biological Chemistry
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• 제46권1호
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• pp.32-38
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• 2003

시판되고 있는 두류 13종류의 70% 에탄을 추출물을 제조하여, 이들의 항산화 활성을 환원력, 지질과산화 억제 활성, superoxide radical 소저활성, hydroxyl radical 소거활성, mitomycin C로 유도된 DNA의 산화적 손상에 대한 억제활성을 지표로 조사하였다. 환원력은 예팥, 속피리, 유월콩 및 적두가 높았다. 지질과산화 억제능을 조사한 결과, linoleic acid 자동산화계를 이용한 실험계에서 모든 시료가 억제활성을 보인 반면, 토끼 적혈구막 지질과 산화에 대한 억제활성은 쥐눈이콩과 적두, 속피리에서만 관찰되었다. Superoxide radical 소거활성은 예팥, 나물콩, 적두, 쥐눈이콩에서 높게 나타났으며, hydroxyl radical 소거활성은 속피리, 청태, 예팥과 제비콩에서 높았다. Mitomycin C로 유도된 DNA의 산화적 손상에 대한 억제활성을 조사한 결과, 모든 품종들이 DNA의 산화적 손상을 억제할 수 있었으나, 특히 예팥, 쥐눈이콩, 나물콩, 녹두, 적두의 억제활성이 우수하였다. 이상의 실험결과에서 예팥, 적두, 쥐눈이콩, 속피리가 환원력, 지질과산화 억제, superoxide radical 및 hydroxyl radical 소거활성, DNA의 산화적 손상에 대한 억제활성 둥 항산화활성이 우수한 품종임을 알 수 있었다.

• 한국식품영양과학회지
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• 제32권6호
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• pp.937-941
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• 2003

재래종 적갓(Brassica juncea czerniak et coss)을 주재료로 담금하여 발효시킨 적갓김치(red mustard leaf kimchi, RML kimchi)의 crude anthocyanin(CA) 및 refined anthocyanin(RA) 획분들에 대한 항산화성을 규명하였다. 발효된 적갓김치는 산도 0.72(%), pH 4.6 그리고 crude anthocyanin 함량(건조물기준)은 49.4 mg/g이었다. 동결건조 적갓김치로부터 얻어진 조색소용액 (crude pigment solution)을 계통 추출분획하여 증류수 획분, methanol 획분, TFA-methanol (CA) 획분을 얻었으며, CA 획분을 계속 분획하여 정제된 5개의 정제된 RA 획분(Fr.1, Fr.2, Fr.3, Fr,4, Fr.5)을 얻었다. 이들의 항산화 활성을 linoleic acid의 autoxidation system에서 peroxide formation 억제능과 DPPH($\alpha$, $\alpha$＇-diphenyl-$\beta$-picrylhydrazyl)의 free radical 소거능에 대하여 실험하였다. 그 결과 조색소용액 분획물 중 CA 획분이 항산화능이 높았고, CA 획분으로부터 얻어진 RA 획분 중 Fr.3이 가장 높은 항산화성을 보였다. 특히 Fr.3은 적갓김치의 대표적인 anthocyanin이었고 항산화 활성은 $\alpha$-tocopherel보다는 낮았으나 그것에 접근하는 유사한 특성을 보였다. 그리고 그 활성은 지질의 과산화 억제능과 수소공여성에서 다같이 비슷한 수준의 항산화성을 보였다.

• Applied Biological Chemistry
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• 제47권1호
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• pp.61-66
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• 2004

신선찰거대배아미, 화청거대배아미 및 남풍거대배아미 등 거대배 돌연변이 계통 쌀 3종류 및 일반미의 70% 에탄올 추출물을 제조하여, 이들의 항산화 활성 및 항변이원성을 비교 검정하였다. 거대배아미 추출물의 항산화 활성은 DPPH radical 및 Fenton 반응에 의해서 유도되는 hydroxy radical의 소거활성, hypoxanthine/xanthine oxidase system에서 생성되는 활성산소종인 superoxide radical의 소거활성, linoleic acid자동산화에 대한 지질 과산화 억제활성 및 토끼 적혈구 막지질의 과산화 억제활성 둥으로써 검정하였으며, 항변이원성은 E. coli PQ 37 균주를 사용하여 화학적 변이원 mitomycin C에 대한 변이원성 억제효과를 SOS chromotest에 의해서 검정하였다. 일반미 품종에 비해서 거대배아미 품종의 항산화 활성 및 항변이원성이 모두 높았으며, 거대배아미 품종 중에서는 남풍거대배아미가 가장 효과적인 경향이 있었다. 남풍거대배아미의 DPPH radical, superoxide radical과 hydroxyl radical 소거활성, 그리고 지질과산화 억제활성은 일반미보다 각각 2.3배, 3.3배, 1.7배 및 2.5배 정도까지 더 높았다.

• 대한화장품학회지
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• 제23권3호
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• pp.101-107
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• 1997

Phellinus linteus was artificially cultivated in kangwon province in Korea. The air-dried phellinus linteus was frozen in liquid nitrogen tank and powdered in jar. 10g of the powder was extracted with each 200g of ethanol, methanol, distilled water and 1,3-butylene glycol/distilled water 4 hours under refluxing and then the liquidextract was concentrated under reduced pressure. As a result of analysis by high performance liquid chromatography and thin layer chromarography, many kinds of sugar and flavonoids were detected. Also we knew that phellinus linteus' extract had a strong UV-ray absorption. In the efficacy test for applying to cosmetics, free radical scavenging effect was confirmed. As a result, 2% of sample was the most potent inhibitory effect and the free radical savenging activity, was 0.31%. This is more effective than any other meterial. In the test of antioxidative activity against lipid autoxidation, phellinus linteus' extract had a good effect by 46% while vitamine E was 42.3%. The immunological activity of phellinus linteus was showed through the activation of macrophage cell. Actually, phellinus linteus activated macrophage function of 1.1-1.8 times including nitrite production compared to control. The whitening effect of phellinus linteus was showed through the inhibition of tyrosinase activity, melanin biosynthesis of S. bikiniensis and B-16 melanoma cells. Phellinus linteus' extract was showed strong mushroom tyrosinase inhibitory activity with IC50 value of 0.5% and inhibited melanin biosynthesis with 28mm inhibition zone at 0.005%/paper disc in S. bikinniensis, a bacterium used as an indicator organism in this work. Also it inhibited melanin biosynthesis in B-16 melanoma cells with a minimum inhibitory concentration of 0.134%.

• 한국식품영양학회지
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• 제22권3호
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• pp.367-376
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• 2009

This study aimed to determine the antioxidant and antibacterial effects of solvent extracts from Scutellaria baicalensis. The S. baicalensis was successively extracted with 5 kinds of solvents. The obtained samples were as follows; hexan fraction (IPK-1), chloroform fraction(IPK-2), ethyl acetate fraction(IPK-3), butanol fraction(IPK-4), and water fraction(IPK-5). These extracts were determined to process antibacterial effects using a paper disc method against 18 species of human pathogenic bacteria, antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl(DPPH) method and inhibiting ability of linoleic acid autoxidation. Extracts of S. baicalensis has shown selective antibacterial effects on various strains of bacteria. Ethyl acetate fraction(IPK-3) showed the highest antimicrobial activity against selective bacteria, such as Staphylococcus aureus 285, S. aureus 503. In antioxidant activity test, free radical scavenger activity of IPK-3 fraction was 92% compared with BHA at the same concentration, while lipid peroxidation inhibition was 48%. These results suggest that IPK-3 fraction of S. baicalensis could be suitable in development of antimicrobial and antioxidant agents.

• Journal of Applied Biological Chemistry
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• 제52권4호
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• pp.174-179
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• 2009

목초액, 죽초액 및 왕겨초액을 포함한 시판 중인 19종의 탄화초액이 가지는 기능성을 DPPH 라디칼에 대한 전자공여활성과 $Fe^{3+}$인 ferricyanide에 대한 환원력, linoleic acid의 자동산화를 억제하는 지질과산화 억제활성, LPS 자극에 의한 생쥐 대식세포주 RAW264.7세포의 NO생산에 대한 억제활성 및 탄화초액 처리에 의한 RAW264.7세포의 세포독성을 중심으로 평가하였다. 실험 결과, 탄화원료에 관계없이 정제도가 떨어지는 탄화초액의 경우, 전자공여활성, 환원력, 지질과산화 억제활성 및 NO 생성 억제활성을 포함한 항산화활성과 세포독성은 모두가 높게 나타났다. 반면, 피부이상 치료용이나 목욕용 정제 탄화액의 경우, 세포독성은 낮지만 전반적인 항산화활성도 낮았고, 특히 염증 유발에 중요한 분자인 NO의 생성을 억제하는 활성도 낮게 나타났다. 19종의 탄화초액 중에서는 왕겨초액이 NO 생성 억제활성을 포함한 항산화활성이 높을 뿐 아니라 세포독성이 낮은 기능성이 뛰어난 탄화초액임이 관찰되었다.

• 한국식품영양과학회지
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• 제33권2호
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• pp.249-254
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• 2004

MM에 여러 가지 버섯균을 7일 동안 액체배양하고 균사를 제거한 배양물에 대한 항산화성에 관한 연구를 수행하였다. 시료(1 mg)를 275 $\mu$mol linoleic acid가 함유된 배양액에첨 가하고 shaking incubator(200 rpm, 4$0^{\circ}C$)에 16일 동안 배양하면서 생성된 POV와 MA의 함량의 조사하였다. 이 결과를 BM에 서 배양한 버섯균사체배양물과 BMM 자체의 POV 및 MA 생성 결과와 비교하였다. AB-BMM과 HE-BMM의 항산화능이 다른 버섯균사체 배양물이나 BMM보다 우수하였다. 따라서 이 연구결과는 뽕나무는 버섯균사체액체배양물의 항산화성을 증가시켰고, AB -BMM 및 HE-BMM은 항산화물로 활용할 수 있음을 의미한다.