The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Jong-whan Rhim - One of the best experts on this subject based on the ideXlab platform.
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fabrication of cellulose nanofiber based functional Color Indicator film incorporated with shikonin extracted from lithospermum erythrorhizon root
Food Hydrocolloids, 2021Co-Authors: Swarup Roy, Jong-whan RhimAbstract:Abstract Cellulose nanofiber (CNF)-based functional films were prepared by adding shikonin extracted from dried roots of gromwell (Lithospermum erythrorhizon) using a solution casting method. The shikonin added CNF film showed distinctive Color changes depending on the pH in the range of 2–12. The shikonin was evenly dispersed in the CNF matrix to form a compatible red Colored film. The addition of shikonin (10%) improved the mechanical properties of the CNF film without significantly affecting the crystal structure, water vapor barrier, and thermal stability properties of the film. The CNF/shikonin composite film showed remarkable ultraviolet blocking properties without much-sacrificing transparency. Besides, the composite film showed potent antimicrobial and antioxidant activities. The CNF-based Color Indicator films with improved physical and functional properties have a high potential for active and intelligent food packaging applications.
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ph responsive Color Indicator films based on methylcellulose chitosan nanofiber and barberry anthocyanins for real time monitoring of meat freshness
International Journal of Biological Macromolecules, 2021Co-Authors: Mahmood Alizadehsani, Milad Tavassoli, Esamil Mohammadian, Ali Ehsani, Gholamreza Jahed Khaniki, Ruchir Priyadarshi, Jong-whan RhimAbstract:Abstract A new pH-responsive Color Indicator film was prepared by blending barberry anthocyanin (BA) with methylcellulose (MC)/chitosan nanofiber (ChNF) composite film. The addition of ChNF and BA increased the mechanical and water barrier properties but reduced the UV–vis light transmittance of the composite film. Anthocyanin showed proper compatibility with the composite film. The Color Indicator film showed an apparent Color change in response to pH changes and ammonia gas, being suitable for indicating the change in food pH, the formation of volatile nitrogen compounds, and food decay. The Color Indicator film changed clearly from reddish-pink to pale peach and finally to yellow when exposed to different pH buffers. However, in response to ammonia vapor, the Color changed from pink to pale green and yellow. Besides, the Color Indicator film exhibited remarkable antioxidant activity. Therefore, the pH-sensing Color Indicator film can be used as a smart Indicator for real-time freshness monitoring of meat and seafood products.
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pH-responsive Color Indicator films based on methylcellulose/chitosan nanofiber and barberry anthocyanins for real-time monitoring of meat freshness.
International journal of biological macromolecules, 2020Co-Authors: Mahmood Alizadeh-sani, Milad Tavassoli, Esamil Mohammadian, Ali Ehsani, Gholamreza Jahed Khaniki, Ruchir Priyadarshi, Jong-whan RhimAbstract:Abstract A new pH-responsive Color Indicator film was prepared by blending barberry anthocyanin (BA) with methylcellulose (MC)/chitosan nanofiber (ChNF) composite film. The addition of ChNF and BA increased the mechanical and water barrier properties but reduced the UV–vis light transmittance of the composite film. Anthocyanin showed proper compatibility with the composite film. The Color Indicator film showed an apparent Color change in response to pH changes and ammonia gas, being suitable for indicating the change in food pH, the formation of volatile nitrogen compounds, and food decay. The Color Indicator film changed clearly from reddish-pink to pale peach and finally to yellow when exposed to different pH buffers. However, in response to ammonia vapor, the Color changed from pink to pale green and yellow. Besides, the Color Indicator film exhibited remarkable antioxidant activity. Therefore, the pH-sensing Color Indicator film can be used as a smart Indicator for real-time freshness monitoring of meat and seafood products.
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Preparation of a shikonin-based pH-sensitive Color Indicator for monitoring the freshness of fish and pork.
Food chemistry, 2020Co-Authors: Parya Ezati, Yeong-ju Bang, Jong-whan RhimAbstract:Abstract A novel intelligent pH-responsive Color Indicator was prepared by adsorbing a natural naphthoquinone pigment, shikonin, onto cellulose paper. FTIR results indicated that shikonin was crosslinked with the cellulose of the Indicator paper. The addition of shikonin increased antioxidant activity, thermal stability, and water resistance properties of the paper. The Indicator changed the Color from red to dark blue, depending on the pH of buffer solutions. Also, the Indicator showed high stability after 4 months of storage and maintained high sensitivity to pH changes. This Indicator was used to monitor fish and pork freshness during storage at room temperature, and the results showed a high correlation between the Color change of the Indicator and the pH change of the sample. The shikonin-adsorbed Indicator with stable and sensitive Color change depending on pH can be used in the intelligent food packaging applications to monitor the quality of packaged food in real-time.
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CMC and CNF-based alizarin incorporated reversible pH-responsive Color Indicator films.
Carbohydrate polymers, 2020Co-Authors: Parya Ezati, Jong-whan Rhim, Mehran Moradi, Hossein Tajik, Rahim MolaeiAbstract:Abstract Smart Color-changing Indicator films were prepared using two different types of cellulose (CMC and CNF) and pH-sensitive dye, alizarin. pH-responsive Color Indicator films were produced by ionization and deprotonation of hydroxyl groups of alizarin phenolic compounds. The X-ray diffraction pattern of the Color Indicator film showed a new weak diffraction peak at 2θ = 13°, indicating the semi-crystalline character of alizarin. The Indicator film showed UV–vis light screening properties and radical scavenging activity with enhanced thermal stability. The Indicator film showed a distinct Color change of alizarin from yellow to purple in the pH range of 2−12. In addition, the Color Indicator film showed stable and reversible Color changes even after repeated changes in environmental pH. The pH-responsive Color Indicator films are likely to be used as an acid or base gas sensor due to the rapid response and reversible Color change to the pH change in the packaging environment.
Isao Karube - One of the best experts on this subject based on the ideXlab platform.
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a spectrophotometric biochemical oxygen demand determination method using 2 6 dichlorophenolindophenol as the redox Color Indicator and the eukaryote saccharomyces cerevisiae
Analytical Biochemistry, 2007Co-Authors: Hideaki Nakamura, Isao Karube, Shun Kobayashi, Yu Hirata, Kyota Suzuki, Yotaro MogiAbstract:A method to determine the spectrophotometric biochemical oxygen demand (BOD(sp)) was studied with high sensitivity and reproducibility by employing 2,6-dichlorophenolindophenol (DCIP) as a redox Color Indicator, the yeast Saccharomyces cerevisiae, and a temperature-controlling system providing a three-consecutive-stir unit. The absorbance of DCIP decreased due to the metabolism of organic substances in aqueous samples by S. cerevisiae. Under optimum conditions, a calibration curve for glucose glutamic acid concentration between 1.1 and 22mg O(2) L(-1) (r=0.988, six points, n=3) was obtained when the incubation mixture was incubated for 10min at 30 degrees C. The reproducibility of the optical responses in the calibration curve was 1.77% (average of relative standard deviations; RSD(av)). Subsequently, the characterization of this method was studied. The optical responses to pure organic substances and the influence of chloride ions, artificial seawater, and heavy metal ions on the sensor response were investigated before use with real samples. Measurements of real samples using river water were performed and compared with those obtained using the BOD(5) method. Finally, stable responses were obtained for 36 days when the yeast cell suspension was stored at 4 degrees C (response reduction, 89%; RSD(av) value for 9 testing days, 8.4%).
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A simple and highly repeatable Colorimetric toxicity assay method using 2,6-dichlorophenolindophenol as the redox Color Indicator and whole eukaryote cells.
Analytical and bioanalytical chemistry, 2007Co-Authors: Hideaki Nakamura, Shun Kobayashi, Yu Hirata, Kyota Suzuki, Yotaro Mogi, T. Hirayama, Isao KarubeAbstract:A simple and highly reproducible toxicity assay method was studied by employing 2,6-dichlorophenolindophenol (DCIP) as a redox Color Indicator, baker’s yeast Saccharomyces cerevisiae, and a thermostable three-consecutive-stir unit. The absorbance of DCIP was decreased by increasing the metabolism activity of S. cerevisiae to intake glucose as an organic substance. By optimizing the measurement conditions, we obtained highly sensitive responses to glucose between 0.75 and 30 mg/L (eight points, n = 3) with an incubation time of the reaction mixture of 10 min at 30 °C. An excellent value of 1.15% was obtained as the average of the repeatability from eight points. Next, for the characterization of this method, we investigated the influence on the Colorimetric response of dissolved substances, such as inorganic ions and surfactants, in natural water. Furthermore, the Colorimetric responses to several toxicants were examined using Cu2+, Mn2+, Zn2+, Cr3+, and Fe3+ as heavy-metal ions and simazine as an agricultural chemical. As a result, notable Colorimetric responses were obtained for Cu2+ and Mn2+ at several concentrations, and the results were compared with those obtained using river water as a real sample. In the stability test, responses to 30 mg/L glucose were obtained for 28 days when the yeast cell suspension was stored at 4 °C (response reduction, 43.9%; average of the relative standard deviation for nine testing days, 22.7%; average of repeatability, 1.01%).
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A simple, multiple simultaneous spectrophotometric method for BOD determination using dcip as the redox Color Indicator
Analytical Letters, 2002Co-Authors: Nobuyuki Yoshida, Scott Mcniven, Takashi Morita, Hideaki Nakamura, Isao KarubeAbstract:ABSTRACT Especially in the analysis of environmental samples, it is necessary to perform rapid, simple and multiple analyses because it highly desirable to determine the results quickly as well as to analyze numerous samples simultaneously. We use 2,6-dichlorophenolindophenol (DCIP) as a redox Color Indicator for the Biochemical Oxygen Demand (BOD) determination in this report. The absorbance of DCIP decreases due to the metabolism of organic substances in aqueous samples by Pseudomonas fluoresens biovar V. Our technique using a microplate reader is able to measure 96 samples simultaneously. Thus real samples, blanks, standards and replicates can be determined concurrently, ensuring the accuracy of this method. The process requires approximately 20 min per determination, compared with 5 days for the standard BOD method. This method gives a linear response (r 2 = 0.943) to OECD synthetic sewage samples from 50 to 430 mg L −1.
Parya Ezati - One of the best experts on this subject based on the ideXlab platform.
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Preparation of a shikonin-based pH-sensitive Color Indicator for monitoring the freshness of fish and pork.
Food chemistry, 2020Co-Authors: Parya Ezati, Yeong-ju Bang, Jong-whan RhimAbstract:Abstract A novel intelligent pH-responsive Color Indicator was prepared by adsorbing a natural naphthoquinone pigment, shikonin, onto cellulose paper. FTIR results indicated that shikonin was crosslinked with the cellulose of the Indicator paper. The addition of shikonin increased antioxidant activity, thermal stability, and water resistance properties of the paper. The Indicator changed the Color from red to dark blue, depending on the pH of buffer solutions. Also, the Indicator showed high stability after 4 months of storage and maintained high sensitivity to pH changes. This Indicator was used to monitor fish and pork freshness during storage at room temperature, and the results showed a high correlation between the Color change of the Indicator and the pH change of the sample. The shikonin-adsorbed Indicator with stable and sensitive Color change depending on pH can be used in the intelligent food packaging applications to monitor the quality of packaged food in real-time.
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CMC and CNF-based alizarin incorporated reversible pH-responsive Color Indicator films.
Carbohydrate polymers, 2020Co-Authors: Parya Ezati, Jong-whan Rhim, Mehran Moradi, Hossein Tajik, Rahim MolaeiAbstract:Abstract Smart Color-changing Indicator films were prepared using two different types of cellulose (CMC and CNF) and pH-sensitive dye, alizarin. pH-responsive Color Indicator films were produced by ionization and deprotonation of hydroxyl groups of alizarin phenolic compounds. The X-ray diffraction pattern of the Color Indicator film showed a new weak diffraction peak at 2θ = 13°, indicating the semi-crystalline character of alizarin. The Indicator film showed UV–vis light screening properties and radical scavenging activity with enhanced thermal stability. The Indicator film showed a distinct Color change of alizarin from yellow to purple in the pH range of 2−12. In addition, the Color Indicator film showed stable and reversible Color changes even after repeated changes in environmental pH. The pH-responsive Color Indicator films are likely to be used as an acid or base gas sensor due to the rapid response and reversible Color change to the pH change in the packaging environment.
Philip T Feldsine - One of the best experts on this subject based on the ideXlab platform.
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Enumeration of total coliforms and E. coli in foods by the SimPlate coliform and E. coli Color Indicator method and conventional culture methods: collaborative study.
Journal of AOAC International, 2005Co-Authors: Philip T Feldsine, Andrew H Lienau, Nerie H. Roa, Shannon T. GreenAbstract:The relative effectiveness of the SimPlate® Coliform and E. coli Color Indicator (CEc-CI) method was compared to the AOAC 3-tube Most Probable Number (MPN) methods for enumerating and confirming coliforms and Escherichia coli in foods (966.23 and 966.24). In this study, test portions were prepared and analyzed according to the conditions stated in both the AOAC methods and SimPlate directions for use. Six food types were artificially contaminated with coliform bacteria and E. coli: frozen burritos, frozen broccoli, fluid pasteurized milk, whole almond nut meats, cheese, and powdered cake mix. Method comparisons were conducted. Overall, the SimPlate method demonstrated
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Enumeration of total aerobic microorganisms in foods by SimPlate Total Plate Count-Color Indicator methods and conventional culture methods: collaborative study.
Journal of AOAC International, 2003Co-Authors: Philip T Feldsine, Stephanie C. Leung, Andrew H Lienau, Linda A. Mui, Townsend David EAbstract:The relative efficacy of the SimPlate Total Plate Count-Color Indicator (TPC-CI) method (SimPlate 35 degrees C) was compared with the AOAC Official Method 966.23 (AOAC 35 degrees C) for enumeration of total aerobic microorganisms in foods. The SimPlate TPC-CI method, incubated at 30 degrees C (SimPlate 30 degrees C), was also compared with the International Organization for Standardization (ISO) 4833 method (ISO 30 degrees C). Six food types were analyzed: ground black pepper, flour, nut meats, frozen hamburger patties, frozen fruits, and fresh vegetables. All foods tested were naturally contaminated. Nineteen laboratories throughout North America and Europe participated in the study. Three method comparisons were conducted. In general, there was
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Enumeration of total yeasts and molds in foods by the SimPlate Yeast and Mold-Color Indicator method and conventional culture methods: collaborative study.
Journal of AOAC International, 2003Co-Authors: Philip T Feldsine, Stephanie C. Leung, Andrew H Lienau, Linda A. MuiAbstract:The relative effectiveness of the SimPlate Yeast and Mold-Color Indicator method (Y&M-CI) was compared to the U.S. Food and Drug Administra- tion's (FDA) Bacteriological Analytical Manual (BAM) method and the proposed International Or- ganization for Standardization (ISO) method, ISO/CD 21527, for enumerating yeasts and molds in foods. Test portions were prepared and incu- bated according to the conditions stated in both the BAM and ISO methods. Six food types were an- alyzed: frozen corn dogs, nut meats, frozen fruits, cake mix, cereal, and fresh cheese. Nut meats, frozen fruits, and fresh cheese were naturally con- taminated. All other foods were artificially contami- nated with either a yeast or mold. Seventeen labo- ratories throughout North America and Europe participated in the study. Three method compari- sons were conducted. In general, there was
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enumeration of total aerobic microorganisms in foods by simplate total plate count Color Indicator methods and conventional culture methods collaborative study
Journal of AOAC International, 2003Co-Authors: Philip T Feldsine, Stephanie C. Leung, Andrew H Lienau, Linda A. Mui, David E TownsendAbstract:The relative efficacy of the SimPlate Total Plate Count-Color Indicator (TPC-CI) method (SimPlate 35 degrees C) was compared with the AOAC Official Method 966.23 (AOAC 35 degrees C) for enumeration of total aerobic microorganisms in foods. The SimPlate TPC-CI method, incubated at 30 degrees C (SimPlate 30 degrees C), was also compared with the International Organization for Standardization (ISO) 4833 method (ISO 30 degrees C). Six food types were analyzed: ground black pepper, flour, nut meats, frozen hamburger patties, frozen fruits, and fresh vegetables. All foods tested were naturally contaminated. Nineteen laboratories throughout North America and Europe participated in the study. Three method comparisons were conducted. In general, there was <0.3 mean log count difference in recovery among the SimPlate methods and their corresponding reference methods. Mean log counts between the 2 reference methods were also very similar. Repeatability (Sr) and reproducibility (SR) standard deviations were similar among the 3 method comparisons. The SimPlate method (35 degrees C) and the AOAC method were comparable for enumerating total aerobic microorganisms in foods. Similarly, the SimPlate method (30 degrees C) was comparable to the ISO method when samples were prepared and incubated according to the ISO method.
S. Memon - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the SimPlate yeast and mould Color Indicator to the BAM method for quantification of fungi in naturally-contaminated foods
Food Control, 2011Co-Authors: V.h. Tournas, J. Rivera Calo, S. MemonAbstract:Abstract A total of 260 samples from six food groups (grains and grain products, tree nuts, dried fruits, fresh produce, fruit juice, and dairy products) were tested for levels of fungal contamination using the SimPlate Yeast and Mould Color Indicator (YM-CI) and the FDA official (BAM) method. Results showed that the SimPlate, in most cases, gave higher yeast and mould (YM) counts than the FDA (reference) method. Statistical analysis of the data (paired t-test) revealed that there were significant differences (α = 0.05) between the two methods for several foods tested. The SimPlate was easy to use, saved time during sample preparation and inoculation and gave results faster than the reference method. Some difficulties were encountered when spreading moulds were present.