• 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.

• Journal of Dairy Science and Biotechnology
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• 제33권2호
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• pp.119-127
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• 2015

낙농 미생물학에서 사용하는 주요 분석 방법들에 대한 지속적인 개정이 요구되어지고 있는 것이 사실이다. 현재 이용 가능한 자료들을 바탕으로 균주의 생리 및 대사 특성을 더 깊이 이해할 수 있으며, LAB와 probiotic 생리적 상태를 측정할 수 있는 기술을 개발할 수 있다. 예를 들어, 고유 균주의 생화학 반응으로부터 얻은 생물학적 생리학적 지식을 바탕으로 발색형광배지(chromogenic media)의 개발이 가능하다. 이 기술은 오랫동안 사용되어온 한천 배지보다 사용법이 간단하며, 미생물을 제어할 수 있다. 유망한 유동세포계수법(flow cytometry, FC) 기술은 우유, 요구르트, 그 외 발효 유제품의 혼합 배양의 분석에 뛰어나다. 이 기술은 공정 과정 중에 또는 생산품의 유통 기한 관리에 사용될 수 있지만, 이 기술을 사용하기 위해서는 우유 단백질에 의해서 생성되는 인공 산물을 방지하기 위해 최적화 되어야 한다. 또한 유동세포계수법(flow cytometry, FC)은 정량 한계가 높기 때문에, 현재 사용하고 있는 탐침(probe)은 종 또는 속이 아닌 표적 세포 구성을 분석한다. 따라서 유동세포계수법(flow cytometry, FC)은 특정 물질의 계수보다는 생리적 상태를 측정에 더 적합한 기술이라고 볼 수 있다. Omics 자료를 통해 생리적 상태를 더 신속하게 측정할 수 있는 핵심적인 생체지표 확인이 가능해졌다. PCR은 이미 식품매개 병원균 및 부패균의 검출에 일상적으로 사용되고 있다. 이 기술은 더욱 나아가 발효균 및 probiotic 박테리아 검출에도 사용되어 핵산 추출, PCR 과정, 자료 해석을 표준화 시킬 수 있으며, 또한 다른 기술에 비해 PCR은 표적 발효 균주를 더 신속하게 선택하며, 공정 과정을 최적상태로 유지시킬 수 있을 것이다. LAB와 probiotic의 적응성 및 생리적 상태의 연구에 필요한 기준, 특허품, 상업화된 신속분석장치(kit)는 아직까지 개발되지 않았다. 본 총설 논문에서는 여러 가지 기술을 검토함으로써 이 모든 기술에는 2가지 주요한 요인이 있다. 첫 번째는 낙농업 산업의 특정 요구에 따른 방법의 평가이며, 두 번째는 공식적인 기준에 따른 검증이다. 사실상 식품매개 병원균의 특성 분석에 사용될 수 있는 표준법이 개발되고 검증되었지만, LAB, probiotic 등의 박테리아 분석에 있어서 표준화된 방법과 진단산업과의 연관성이 부족한 것이 사실이다. 낙농 업계에 의해서 수행되어진 품질관리의 양을 고려해 볼 때 이것은 매우 중요하게 인식되어야 할 부분이다.

• 분석과학
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• 제33권5호
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• pp.209-214
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• 2020

This study has been carried out to develop a standard method for quantifying of 3 permitted artificial sweeteners (including sodium saccharine, aspartame, acesulfame potassium) contained in foods by HPLC-DAD. A simple and rapid sample pretreatment method was used to remove fat and protein from the test solution with Carrez clearing regent precipitant know to be effective for protein and fat removal. The artificial sweeteners in the test solution purified through sample pretreatment were detected by high performance liquid chromatograph using a Reverse phase C18 column (5 ㎛, 4.6 × 250 mm). The simultaneous quantitative test of 3 kinds of artificial sweeteners can be effectively performed on the high fat emulsified foods containing a large amount of fat. Using the established simultaneous quantitative test method, artificial sweeteners were tested in foods such as dairy products, snacks and chocolate. The results calibration curve showed good linearity with high regression coefficients and the result of recovery test showed satisfactory recoveries within 80~110 %.

• 한국축산식품학회지
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• 제40권5호
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• pp.734-745
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• 2020

Commercially sterilized ultra high temperature (UHT) milk was manufactured at different homogenization pressures (20, 25, and 30 MPa), and changes in fat particle size, mechanical stress-induced fat aggregation, plasmin activity, and lipid oxidation were monitored during ambient storage of the UHT milk for up to 16 wk. The particle sizes of milk fat globules were significantly decreased as homogenization pressure increased from 20 to 30 MPa (p<0.05). The presence of mechanical stress-induced fat aggregates in milk produced at 20 MPa was significantly higher than for UHT milk produced at either 25 or 30 MPa. This difference was maintained all throughout the storage. There were no significant differences in plasmin activity, trichloroacetic acid (12%, w/v) soluble peptides, and the extent of lipid oxidation. Based on these results, an increase of homogenization pressure from 20 (the typical homogenization pressure employed in the Korea dairy industry) to 25-30 MPa significantly decreased mechanical stress-induced fat aggregation without affecting susceptibility to lipid oxidation during storage.

• Journal of Dairy Science and Biotechnology
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• 제31권2호
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• pp.165-170
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• 2013

Milk and dairy products are not only excellent foods for humans, providing plentiful varied nutrients, but are also a good medium for detrimental food-borne pathogens. Although the food safety field has stabilized due to standardization of food processing, such as the hazard analysis critical control point (HACCP), outbreaks and cases caused by food-borne pathogens still occur at high rates. In approximately 30% of cases, the disease-causing pathogenic organism is undetermined. Recently, a biosensor was developed that has a simple and fast response and overcomes the problems of conventional methods such as cultivation, immuno-assay, polymerase chain reaction, and microarray. Due to the high selectivity and sensitivity of optical biosensors, it is a suitable method for the immediate detection of food-borne pathogens in milk and dairy products.

• 대한영양사협회학술지
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• 제21권4호
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• pp.280-290
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• 2015

Diet is closely related to an economic level, but few studies have reported on the relationship between the economic level and eating habits, especially in college students. Therefore, this study was conducted to clarify differences in eating habits with a focus on processed foods according to allowance level in college students. This study was a cross-sectional survey of 500 college students using a questionnaire. The questionnaire consisted of general characteristics, eating behaviors, purchase of processed foods, and preference and intake frequency of processed foods. All subjects were classified based on monthly allowance: less than \300,000 (n=149), \300,000~400,000 (n=177), and more than \400,000 (n=124). All survey results were comparatively analyzed among the spending money groups. As the level of spending money of the subjects increased, the rate of skipping meals, eating out, and unbalanced diet increased (P<0.05). The reason for consuming processed foods was because they are easy to prepare. The factor considered the most when buying processed foods was price. However, these results showed no significant difference according to level of spending money. As spending money increased preference for retort, convenience, canned, and bottled foods significantly increased. Intake frequency of dairy products was lower, and the frequency of processed foods was significantly higher with more spending money. This study found that a higher level of monthly allowance in college students, was associated with higher rate of skipping meals, eating out, and unbalanced diet, and the preference and intake frequency of processed foods were also high. These results suggest that spending money level in college students, as an economic indicator, is relevant to intake of processed foods.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2006년도 한국약용작물학회 공동춘계학술발표회
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• pp.400-401
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• 2006

• 축산식품과학과 산업
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• 제5권2호
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• pp.42-49
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• 2016

• Journal of Dairy Science and Biotechnology
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• 제28권2호
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• pp.31-39
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• 2010

Lactic acid bacteria (LAB) are typical probiotic microbes which are used in various industries including fermented foods, feed additives, and pharmaceuticals. The purpose of this study was to compare the ability of antioxidative activities of 23 strains of LAB isolated from cheese, kimchi, yogurt, and etc. LAB were tested for antioxidative activities such as 2,2'- azino-bis(3-ethyl-benzothiazoline-6-sulphonic acid) (ABTS) radical scavenging abilities and superoxide dismutase (SOD)-like ability. Antioxidative activities were examined different media such as MRS, M17, and 10% skim milk. Culture supernatant in M17 medium showed a higher antioxidative activity than these in MRS and 10% skim milk. Comparison of ABTS radical scavenging ability by the LAB showed a wide variation with a range from 9~93% and SOD-like ability of LAB ranged from 70~78%, respectively. Therfore, some of LAB can play important roles in the protection for oxidative stress and CPP-producing activity of LAB may be a promising material for application in the dairy industry.

• Journal of Dairy Science and Biotechnology
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• 제37권4호
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• pp.213-222
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• 2019

Milk and dairy products are the high value foods for the elderly population. In particular, fermented milk is the best source of calcium for people in the specific age group of over 79 years. It provides a good source of protein. Regular exercise and active lifestyle are recommended to slow down the muscle loss. However, exercising without proper nutrient intake is simply not sufficient at this age. Milk and dairy products provide the iron and protein content required for effective exercise-assisted growth. Milk nutrients have the advantage of being produced in various food forms, such as liquid, semi-solid, and powder types. Fat-soluble vitamins such as retinol and vitamin K can be encapsulated using various technologies for milk and dairy products. Using the encapsulation method, spray drying and fluidized-bed coating have been used for adding the micro-nutrients to the food. Microencapsulation technology is being applied in case of the fermented dairy products too. In particular, various wall materials are being developed to enhance the viability of probiotics. In the near future, advanced high-efficiency technologies that can effectively nourish the dairy products with nutrients will be developed to produce targeted high-nutrition value food for the elderly.