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Shim S.D.,Dongguk University | Jung S.W.,Dongguk University | Jung S.W.,Center for Intelligent Agro Food Packaging | Lee S.J.,Dongguk University | Lee S.J.,Center for Intelligent Agro Food Packaging
Mathematical Problems in Engineering | Year: 2013

Prediction of the quality of packaged foods using a colorimetric time temperature integrator (TTI) is affected by the types of kinetic models for the TTIs and the associated food qualities. Several types of kinetic models were applied for the TTI color change (four types) and food microbial growth (three types). To evaluate the prediction, a virtual experiment data of the food microbial growth were mathematically created by using the relevant kinetic models. In addition to the kinetic models, two types of temperature-dependent models (Arrhenius and square root models) were used in the calculation. Among the four types of TTIs, M2-3510 or S type for Pseudomonas spp. and M type for Listeria monocytogenes and Escherichia coli showed the least erroneous results. Overall, a suitable TTI could be selected for each food microorganism, based on the prediction accuracy. © 2013 Soo Dong Shim et al.


Kim Y.A.,Dongguk University | Kim Y.A.,Center for Intelligent Agro Food Packaging | Jung S.W.,Dongguk University | Jung S.W.,Center for Intelligent Agro Food Packaging | And 5 more authors.
Korean Journal for Food Science of Animal Resources | Year: 2012

The predictive ability for off-flavor development and quality change of ground beef was evaluated using a microbial time temperature indicator (TTI). Quality indices such as off-flavor detection (OFD) time, color, pH, volatile basic nitrogen (VBN), aerobic mesophilic bacteria (AMB) counts, and lactic acid bacteria (LAB) counts were measured during storage at 5, 10, 15, and 25oC, respectively. Arrhenius activation energies (Ea) were estimated for temperature dependence. The Ea values for TTI response (changes in titratable acidity (TA)), VBN, AMB counts, LAB counts, and freshness, which is defined based on OFD time for quality indices of ground beef, were 106.22 kJ/mol, 58.98 kJ/mol, 110.35 kJ/mol, 116.65 kJ/ mol, and 92.73 kJ/mol, respectively. The Ea of microbial TTI was found to be closer to those of the AMB counts, LAB counts, and freshness. Therefore, AMB counts, LAB counts, and freshness could be predicted accurately by the microbial TTI response due to their Ea similarity. The microbial TTI exhibited consistent relationships between its TA change and corresponding quality indices, such as AMB counts, LAB counts, and freshness, regardless of storage temperature. Conclusively, the results established that the developed microbial TTI can be used in intelligent packaging technology for representing some selected quality indices of ground beef.


Mijanur Rahman A.T.M.,Dongguk University | Mijanur Rahman A.T.M.,Center for Intelligent Agro Food Packaging | Jung S.W.,Dongguk University | Jung S.W.,Center for Intelligent Agro Food Packaging | And 6 more authors.
Food Science and Biotechnology | Year: 2013

In the present study, a new microbial TTI system was developed based on encapsulation techniques. TTI response (color change) was evaluated by using primarily the CIELab coordinates which were further used for the conversion into the secondary and tertiary variables and finally compared all the variables to choose the best ones for calculation of activation energy (Ea) quickly and accurately. In order to select the best variables for calculating the Ea, 95% confidence interval was also used. Primary variable a* exhibited the best linearity, narrowest 95% confidence interval and simplicity in interpretation of the color-developing reaction. Ea of the developed microbial TTIs ranged from 57.28 to 110.23 kJ/mol and maintains a consistent performance similar to that of other microbial and nonmicrobial TTIs which are commercially available. Therefore, it can be concluded that this new microbial TTI system can be used effectively in the food industry for monitoring food quality. © 2013 The Korean Society of Food Science and Technology and Springer Science+Business Media Dordrecht.


Choi D.Y.,Dongguk University | Choi D.Y.,Center for Intelligent Agro Food Packaging | Jung S.W.,Dongguk University | Jung S.W.,Center for Intelligent Agro Food Packaging | And 4 more authors.
Packaging Technology and Science | Year: 2014

Screen printing method was employed to produce microbial time temperature indicators (TTI). Bio-pastes containing lactic acid bacteria loaded Ca-alginate microparticles (LCAMs) and suitable for printing on polymer films have been produced. Through a spray-solidification method, polysaccharide gel microparticles allowed for the efficient encapsulation of the lactic acid bacteria, which chromatically induced a colour change in the pH indicator. As the alginate concentration of LCAMs increased, the size of the microparticles decreased. The average diameter of LCAMs ranged from (1.67 ± 0.15) × 103 to (2.93 ± 0.31) × 103 nm. For the evaluation of bio-pastes, the contact angles and lactic acid production properties were determined. Lower contact angles were obtained with decreasing pullulan concentration, indicating the increase in wettability for printing. The curve of lactic acid production by alginate immobilized cells was determined to take place as a zero-order reaction favourable to TTI colour change. Visibility of TTIs was greatly improved at microencapsulation sites. As the size of the LCAMs was decreased, the visibility was found to be improved. The Arrhenius activation energy (Ea) of CIFP009-based TTI was 117 kJ/mol. The results show that the developed manufacturing method would be used for an industrialized, simple and low-cost manufacturing method for microbial TTIs. Copyright © 2013 John Wiley & Sons, Ltd.


Jung S.W.,Dongguk University | Jung S.W.,Center for Intelligent Agro Food Packaging | Mijanur Rahman A.T.M.,Dongguk University | Mijanur Rahman A.T.M.,Center for Intelligent Agro Food Packaging | And 2 more authors.
Food Science and Biotechnology | Year: 2015

Ten strains of psychrotrophic Weissella species from imitation crab sticks (ICSs) were isolated and characterized to develop a microbial-based time temperature integrator (TTI). The strains were selected according to their hemolytic activity, gram staining, and catalase reaction. All the strains grew well in modified imitation crab (MIC) broth at 5 and 15°C. Significant acid production, an associated drop in pH values, and a color change were observed in most of the strains after 7-days of incubation at both temperatures. Furthermore, the strains produced a time-temperature dependent color change due to the production of lactic acid. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the ten strains belonged to the genus Weissella. © 2015, The Korean Society of Food Science and Technology and Springer Science+Business Media Dordrecht.

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