• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1523-1528
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• 2006

The optimization of a batch-type quartz crystal microbalance (QCM)-precipitation sensor measuring acetylcholinesterase (AChE) activity was conducted. To covalently bind AChE onto the gold electrode of a QCM surface, glutaraldehyde cross-linking to a cystamine self-assembled monolayer was tried at different cystamine concentrations. At the optimum conditions of the QCM-precipitation sensor, 0.1 M potassium phosphate buffer (pH 8.0), containing 0.01% Tween 80, was used as the reaction buffer, with the enzyme amount of 5 units for immobilization and the substrate concentration of 50 mg/ml. The current biosensor might find a future applicability to the sum parameter detection on organophosphorus and carbamate pesticides.

• Food Science and Biotechnology
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• 제14권4호
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• pp.554-557
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• 2005

As a device for taste sensation, an 8-channel taste evaluation system was prepared and applied for discriminant analysis of marketed liquor. The biomimetic polymer membranes for the system were prepared through a casting procedure by employing polyvinyl chloride, bis (2-ethylhexyl)sebacate as plasticizer and electroactive materials such as valinomycin in the ratio of 33:66:1, and were separately attached over the sensitive area of ion-selective electrodes to construct the corresponding taste sensor array. The sensor array in conjunction with a double junction reference electrode was connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a personal computer via an A/D converter. When the signal data from the sensor array for 3 groups of marketed liquor like Maesilju, Soju and beer were analyzed by principal component analysis after normalization, it was observed that the 1st, 2nd and 3rd principal component were responsible for most of the total data variance, and the analyzed liquor samples were discriminated well in 2 dimensional principal component planes composed of the 1st-2nd and the 1st-3rd principal component.

• Journal of electromagnetic engineering and science
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• 제13권4호
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• pp.208-213
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• 2013

This paper proposes a tag antenna for radio frequency identification (RFID) food system. The RFID tag antenna is designed and fabricated based on the rectangular loop concept used in the UHF band (Korean and Japanese standards, 916.7-923.5MHz). The proposed tag antenna is composed of a radiation patch, sensor tag chip, temperature sensor, oscillator, and battery. We conjugated matching between the tag antenna and the sensor tag using a U-shaped stub. Details of the proposed tag antenna design and the simulated and measured results are presented and discussed.

• Agribusiness and Information Management
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• 제6권2호
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• pp.13-23
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• 2014

The world is in the process of a structural change related to ICT convergence knowledge industries. ICT is leading to the creation of new products and services, and is making our lives more convenient, safer, and more efficient. In advanced countries, many studies have been conducted with the goal of developing new business models converged with ICT, and this is also the case in the food industry. Korea possesses world-leading ICT, and if this ICT is applied to the food industry, a world-class new business model can be developed. The u-Food System, which is in the process of development in Korea, is a next-generation food system that can allow food providers, consumers, and distributors to access various types of information about food products, including traceability, distribution, safety, quality, and freshness, and manage this information. It is a future food system that converges ICT, biotechnology and sensing technology with food. Based on the u-Food System, this paper will introduce the status of current smart quality distribution technologies that converge ICT (such as sensor tag, sensor network, LBS, GIS, and CDMA) with food technologies (such as traceability, quality, distribution management) to manage the safety and quality of fresh food in the distribution process.

• 한국식품위생안전성학회지
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• 제32권6호
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• pp.447-454
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• 2017

본 연구의 목적은 식품 제조 중 표백 및 살균에 사용되는 과산화수소($H_2O_2$)의 잔류 농도 검출에 활용 될 수 있는 유리탄소전극 기반의 바이오센서의 개발이다. 미국 FDA 및 국내 식품의학안전처 등 식품 용 과산화수소(food grade $H_2O_2$)는 국내외적으로 35% $H_2O_2$ 수용액으로 규정한다. 연구에서 개발한 바이오센서는 감응 물질로 사용된 horseradish peroxidase를 graphene oxide와 aniline과 함께 biocomposite를 형성시킨 후 중성 pH에서 본 연구에서 새롭게 개발된 전기화학적 증착법을 수행하여 개발되었다. 센서구조 및 특성 평가를 위하여 SEM, 순환 전압 전류법 등을 수행하였으며 본 연구에서 개발된 바이오센서는 $10-500{\mu}M$ 농도의 $H_2O_2$에 대하여 직선상의 농도 의존적인 반응을 나타내었으며 최저 검출 한계는 $0.12{\mu}M$으로 산출되었다. 본 연구에서 개발된 센서의 전략적 가치는 향후 오징어포, 건어물 등 널리 유통되는 식품 중에 함유된 식품용 $H_2O_2$ 미량을 현장에서 쉽게 분석 할 수 있어서 비용-효과적 측면에서 그 가치가 우수하다는 것을 제시한다.

• 한국식품과학회지
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• 제29권6호
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• pp.1075-1081
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• 1997

L-Glutamate를 간편하고 단시간에 측정할 수 있는 glutamate sensor를 개발하기 위하여, glutamate oxidase를 여러 가지 membranes에 고정화 시키는데 적합한 조건과. 그 결과로 얻은 효소 membranes의 특성, 개발한 glutamate sensor의 반응특성 및 glutamate sensor의 정확성을 조사하였다. Glutamate oxidase를 membranes에 고정화 하는데 GA 0.25%, BSA 0.3 mg, 효소 사용량 2.0 units이상이 적당하였다. 고정화 효소의 최적 pH는 6.5이었고, chitosan membrane을 사상한 경우 가장 효소활성이 높았다. 그러나 저장 안정성이나 반응시간 등을 고려하여 preactivated nylon에 고정화시킨 효소 membrane을 glutamate sensor 개발에 사용하였다. Glutamate oxidase를 선택한 membrane에 고정화시켜 효소와 glutamate의 반응산물인 암모니아가 nonactin membrane을 이용한 암모니움이온 전극에 의하여 측정되도록 효소 sensor를 구성하였으며, sensor의 반응시간은 약 2분이었다. Preactivated membrane에 고정화된 효소는 $4^{circ}C$에서 2개월간 저장중 안정한 활성을 보였으며, 이를 사용한 glutamate sensor로 약 250회 측정할 때 까지 활성에 별 변화가 없었다, 개발된 glutamate sensor의 glutamate 측정 농도범위는 $0.1{\sim}5\;mM$ 이었다. Glutamate sensor를 체더 치즈중의 L-glutamate 측정에 응용한 결과는 HPLC로 분석한 결과와 높은 상관관계가 있어, 정확성이 인정되었다.

• 한국식품과학회지
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• 제27권2호
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• pp.266-269
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• 1995

알코올 함량을 보다 신속하고 정확하게 측정하고자, 알코올 센서를 사용하였다. Alcohol oxidase를 glutaraldehyde로 nylon net에 고정화시킨 다음 산소전극에 연결하여 기질과의 반응에서 소모되는 용존산소 소비량의 변화를 용존산소측정기로 측정하여 알코올을 정량하였다. 알코올 센서의 최적조건에서 시판되는 각종 주류를 측정해 본 결과, 각각 맥주는 $4{\sim}5%$, 저알코올성 음료는 0.71%, 포도주는 10.06%, 청주는 16.12%, 소주는 25.71%, 탁주는 6.18%로 정량되었으며, 이는 가스 크로마토그래피로 측정한 값과 좋은 상관관계를 가졌다.

• 한국식품과학회지
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• 제22권6호
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• pp.686-689
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• 1990

김치의 발효상태를 monitoring할 수 있는 압력측정 sensor와 감시장치를 설계, 제작하였다. 본 시스템은 밀폐형 발효관(31.5 ml)과 strain gauge 타입의 압력 sensor, 741 Op. Amp.와 ADC0809를 사용하여 제작한 신호가공 장치로 구성하였으며 퍼스널 컴퓨터와 접속하여 사용하였다. 배추김치는 플라스틱 용기에 담가 $25^{\circ}C$와 $30^{\circ}C$에서 발효시켰으며 발효상태는 김치를 넣은 발효관으로 monitoring하였다. 압력곡선 형태의 김치발효 곡선을 얻을 수 있었으며 이는 2단 압력증가 양식을 갖는 김치숙성 곡선을 보여주었다.

• 센서학회지
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• 제29권5호
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• pp.293-302
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• 2020

Food safety has emerged as a growing concern for human health in recent times. Consuming contaminated food may lead to serious health problems, and therefore, a system for monitoring food freshness that is both non-detrimental to the quality of food and highly accurate is required to ensure that only high-quality fresh food packages are provided to the customers. This paper proposes a method to monitor and detect food quality using a compact smart sensor tag. The smart tag is composed of three ultra-low-power sensors, which monitor four major indicators of food freshness: temperature, humidity, and the concentrations of ammonia and hydrogen sulfide gases. An RF energy scavenging circuit is integrated into the smart sensor tag to harvest energy from radio waves at a high frequency of 13.56 MHz to supply sufficient power to the tag. Experimental results show that the proposed energy harvester can efficiently obtain energy at a distance of approximately 40 cm from a 4 W reader. In addition, the proposed smart sensor tag can operate without any battery, thereby eliminating the requirement of frequent battery replacement and consequently decreasing the cost. Meanwhile, the freshness of preserved pork is continuously monitored under two conditions--room temperature and refrigerator temperature--both of which are the most common temperatures under which food is generally stored. The food-monitoring experiments are conducted over a period of one week using the proposed battery-less tag. Based on the experimental results, the food assessment is classified into four categories: fresh, normal, low, and spoiled.

• 센서학회지
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• 제6권6호
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• pp.437-444
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• 1997

A potentiometric L-lysine-selective sensor is described for the direct determination of lysine. The sensor system is based on a carbon dioxide gas sensing electrode and an L-lysine decarboxylase immobilized to CNBr-activated sepharose 4B. A highly selective L-lysine sensor has been prepared with immobilizing enzyme slurry put into reaction buffer solution. The optimum conditions for the measurement were evaluated by various experiments. This sensor exhibits a linear response to L-lysine concentrations from $10^{-4}M$ to $10^{-1}M$. Response time of this lysine sensor is shorter than 30secs and the immobilized enzyme slurry is stable over one year.