Carbon Dioxide and Oxygen Gas Sensors-Possible Application for Monitoring Quality, Freshness, and Safety of Agricultural and Food Products with Emphasis on Importance of Analytical Signals and Their Transformation

Xiangpeng Meng,김세훈,pradeep puligundla,고상훈 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.6

Intelligent packaging technologies are rapidly gaininginterest in the agriculture and food industries. Intelligent packagingfor agricultural and food products has great potential to improvethe shelf life and safety of agricultural and food products apartfrom its basic functions of keeping the products clean andprotecting against unwanted physical and chemical changes. Intelligent packaging components are not limited to radiofrequency identification (RFID) sensors, time-temperature indicators,ripeness indicators, and biosensors. Carbon dioxide, oxygen gassensors and nanobiosensor can be used for real-time monitoring offreshness or quality for agricultural and food products. In thisreview, details of different sensors that are primarily used forcarbon dioxide or oxygen gas sensing and their possible potentialto be incorporated into agricultural and food packaging forproduct quality monitoring are discussed. In addition, specialemphasis is placed on detailing the importance of analyticalsignals and their transformation, because these aspects play crucialrole in monitoring the quality and freshness of agricultural andfood products via intelligent packaging systems. Signal transducerscontribute to the establishment of communication between theproduct quality sensor and the communication components suchas RFID sensors in smart packaging systems by converting asignal in one form of energy to another form.

Carbon Dioxide and Oxygen Gas Sensors-Possible Application for Monitoring Quality, Freshness, and Safety of Agricultural and Food Products with Emphasis on Importance of Analytical Signals and Their Transformation

Meng, Xiangpeng,Kim, Saehoon,Puligundla, Pradeep,Ko, Sanghoon 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.6

Intelligent packaging technologies are rapidly gaining interest in the agriculture and food industries. Intelligent packaging for agricultural and food products has great potential to improve the shelf life and safety of agricultural and food products apart from its basic functions of keeping the products clean and protecting against unwanted physical and chemical changes. Intelligent packaging components are not limited to radio frequency identification (RFID) sensors, time-temperature indicators, ripeness indicators, and biosensors. Carbon dioxide, oxygen gas sensors and nanobiosensor can be used for real-time monitoring of freshness or quality for agricultural and food products. In this review, details of different sensors that are primarily used for carbon dioxide or oxygen gas sensing and their possible potential to be incorporated into agricultural and food packaging for product quality monitoring are discussed. In addition, special emphasis is placed on detailing the importance of analytical signals and their transformation, because these aspects play crucial role in monitoring the quality and freshness of agricultural and food products via intelligent packaging systems. Signal transducers contribute to the establishment of communication between the product quality sensor and the communication components such as RFID sensors in smart packaging systems by converting a signal in one form of energy to another form.

An Irreversible Ripeness Indicator to Monitor the CO2 Concentration in the Headspace of Packaged Kimchi during Storage

Xiangpeng Meng,이규호,강태영,고상훈 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.1

An irreversible chitosan-based indicator has been developed to monitor the kimchi quality corresponding to the partial pressure of CO2 gas in the packaging headspace. For this, 0.3% (w/v) solutions of chitosan and the Coomassie Brilliant Blue dye (BB) were mixed at volume ratios of 10:1, 10:2, and 10:5 to yield BB-incorporated chitosanbased CO2 indicators. A greater CO2 accumulation was observed for kimchi samples stored at 25oC than those stored at 15oC. Acidity measurements indicated optimal consumer satisfaction at 1 and 3 days (when the transparency measurements for the developed indicators were approximately 20%) for kimchi samples stored at 15 and 25oC, respectively. A Pearson correlation analysis revealed that the indicator transparency correlated well with several parameters used to indicate the kimchi quality.

Application of Iron Oxide as a pHdependent Indicator for Improving the Nutritional Quality

( Xiangpeng Meng ),( Jina Ryu ),( Bumsik Kim ),( Sanghoon Ko ) 한국임상영양학회 2016 Clinical Nutrition Research Vol.5 No.3

Acid food indicators can be used as pH indicators for evaluating the quality and freshness of fermented products during the full course of distribution. Iron oxide particles are hardly suspended in water, but partially or completely agglomerated. The agglomeration degree of the iron oxide particles depends on the pH. The pH-dependent particle agglomeration or dispersion can be useful for monitoring the acidity of food. The zeta potential of iron oxide showed a decreasing trend as the pH increased from 2 to 8, while the point of zero charge (PZC) was observed around at pH 6.0-7.0. These results suggested that the size of the iron oxide particles was affected by the change in pH levels. As a result, the particle sizes of iron oxide were smaller at lower pH than at neutral pH. In addition, agglomeration of the iron oxide particles increased as the pH increased from 2 to 7. In the time-dependent aggregation test, the average particle size was 730.4 nm and 1,340.3 nm at pH 2 and 7, respectively. These properties of iron oxide particles can be used to develop an ideal acid indicator for food pH and to monitor food quality, besides a colorant or nutrient for nutrition enhancement and sensory promotion in food industry.

포장식품의 이산화탄소 농도 검출을 위한 키토산 현탁액의 지시능 향상

맹상붕 ( Xiangpeng Meng ),정준호 ( Junho Jung ),고상훈 ( Sanghoon Ko ) 한국산업식품공학회 2016 산업 식품공학 Vol.20 No.3

The purposes of this study are to develop a chitosan suspension for the carbon dioxide (CO₂) concentration indication of packaged food and to investigate the changes in the CO₂ indication corresponding to 2-amino-2-methylpropan- 1-ol (AMP) or 2-aminoethanol (monoethanolamine, MEA) addition. Chitosan suspension was prepared by adding chitosan (0.1, 0.2, and 0.4%) to distilled water and subsequently the pH of the suspension was adjusted to 7.0 after the addition of AMP or MEA. Changes in the pH and the turbidity of the chitosan suspension were measured over time under exposure in a normal atmosphere or 100% carbon dioxide environment. The pH of the chitosan suspension exposed at 100% carbon dioxide environment decreased rapidly up to approximately 6.3 in the initial CO₂ exposure. The transmittance values of 0.1 and 0.2% chitosan suspensions with 5% AMP increased from 32 to 99% and from 19 to 86%, respectively. The addition of 5% AMP improved the visual indication performance of the chitosan suspension since it increased significantly the width of the transmittance value before and after CO₂ exposure. The chitosan suspension with AMP has a potential to be used as a quality indicator of the packaged foods which produce carbon dioxide during storage and distribution.

A Dye-incorporated Chitosan-based CO2 Indicator for Monitoring of Food Quality Focusing on Makgeolli Quality during Storage

이규호,Xiangpeng Meng,강태영,고상훈 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.3

A chitosan-based CO2 indicator that exhibits a prominent visual change depending on different CO2 levels was developed. The partial pressure of CO2 in the headspace of food packaging can be considered as a quality indicator of makgeolli. For fabrication of a CO2 indicator, 0.3% brilliant blue (BB) was incorporated into chitosan dissolved in a 0.1 M HCl solution, and the pH was subsequently adjusted to 7.0. At the beginning of makgeolli storage, the indicator was opaque because chitosan is insoluble at pH 7.0. With an increase in the CO2 level in the packaging headspace during fermentation, the indicator developed transparency due to dissolution at lower pH values caused by CO2. BB dye encapsulated in flocculated chitosan particles was released. The transparency of the indicator was correlated with the makgeolli quality attribute of titratable acidity over the storage time.