The Experts below are selected from a list of 213 Experts worldwide ranked by ideXlab platform
Paula Teixeira - One of the best experts on this subject based on the ideXlab platform.
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non Thermal approach to listeria monocytogenes inactivation in milk the combined effect of high pressure pediocin pa 1 and bacteriophage p100
Food Microbiology, 2020Co-Authors: Norton Komora, Claudia Maciel, Carlos A Pinto, Vânia Ferreira, Teresa R S Brandao, Jorge A Saraiva, Sonia Marilia Castro, Paula TeixeiraAbstract:Abstract Non-Thermal Food Processing and replacement of chemical additives by natural antimicrobials are promising trends in the Food industry. The objective of the present work was to evaluate the effect of a process which combines mild high hydrostatic pressure – HHP (200 and 300 MPa, 5 min, 10 °C), phage Listex™ P100 and the bacteriocin pediocin PA-1 as a new non-Thermal process for destruction of Listeria monocytogenes (104 CFU mL−1 or 107 CFU mL−1) in milk. For inoculum levels of 104 CFU mL−1, HHP combined with phage P100 eliminated L. monocytogenes immediately after pressurization. When L. monocytogenes was inoculated at levels of 107 CFU mL−1, a synergistic effect between phage P100, pediocin PA-1 and HHP (300 MPa) on the inactivation of L. monocytogenes was observed during storage of milk at 4 °C. For non-pressure treated samples inoculated with phage or pediocin or both, L. monocytogenes counts decreased immediately after biocontrol application, but regrowth was observed in a few samples during storage. Phage particles were stable during refrigerated storage for seven days while pediocin PA-1 remained stable only during three days. Further studies will have to be performed to validate the findings of this work in specific applications (e.g. production of raw milk cheese).
Hans-ulrich Humpf - One of the best experts on this subject based on the ideXlab platform.
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Thermal stability of T-2 and HT-2 toxins during biscuit- and crunchy muesli-making and roasting
Food additives & contaminants. Part A Chemistry analysis control exposure & risk assessment, 2018Co-Authors: Henning Sören Kuchenbuch, Stefanie Becker, Mareike Schulz, Benedikt Cramer, Hans-ulrich HumpfAbstract:The mycotoxins T-2 and HT-2 toxin are frequently occurring Food contaminants which are produced by Fusarium species. Humans and animals are mainly exposed to these substances by the consumption of contaminated oats, maize and wheat. For the production of crunchy muesli, bread and bakery products, these cereals undergo multiple Processing steps, including baking, roasting and extrusion cooking. However, the influence of Food Processing on T-2 and HT-2 toxin levels is to date poorly understood. Thus, the effects of baking and roasting on both mycotoxins were evaluated during biscuit-, crunchy muesli- and toasted oat flakes-production under precise variation of various parameters: heating time and temperature as well as recipe formulation were varied in the range they are applied in the Food Processing industry. Therefore, oatmeal or flaked oats were artificially contaminated individually with both toxins and processed at the laboratory scale. T-2 toxin generally showed a higher degradation rate than HT-2 toxin. During biscuit-making up to 45% of T-2 toxin and 20% of HT-2 toxin were Thermally degraded, showing a dependency on water content, baking time and temperature. The preparation of crunchy muesli yielded no significant toxin degradation which is probably due to the low temperatures applied. Roasting led to a degradation of 32% of T-2 toxin and 24% of HT-2 toxin. Taken together, both mycotoxins are partially degraded during Thermal Food Processing; the degradation rates are influenced by the Food composition and Processing parameters.
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impact of mechanical and Thermal energies on the degradation of t 2 and ht 2 toxins during extrusion cooking of oat flour
Journal of Agricultural and Food Chemistry, 2017Co-Authors: Henning Soren Schmidt, Stefanie Becker, Benedikt Cramer, Hans-ulrich HumpfAbstract:The type A trichothecenes T-2 toxin (T-2) and HT-2 toxin (HT-2) are naturally occurring toxic Food contaminants, with the highest concentrations found in contaminated oats. The influence of Thermal Food Processing on these toxins is poorly understood, and only a few publications address the degradation rates. Therefore, we systematically investigated the degradation of T-2 and HT-2 during both laboratory and industrial-scale extrusion cooking of oats. Extrusion cooking under laboratory conditions was performed with oats fortified with T-2 or HT-2 as well as with naturally contaminated oat flour dust. The experiments were designed according to industrial conditions in terms of temperature, water content, pressure, residence time, and oat content. Flour mixtures containing naturally contaminated oats were used for industrial-scale Processing. Degradation rates under laboratory conditions were up to 59.6 ± 1.51 and 47.2 ± 0.53% for T-2 and HT-2, respectively, in fortified extrudates but were decreased to 35....
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fate of deoxynivalenol and deoxynivalenol 3 glucoside during cereal based Thermal Food Processing a review study
Mycotoxin Research, 2017Co-Authors: Kamil Kuca, Hans-ulrich Humpf, Blanka Klimova, Benedikt CramerAbstract:Deoxynivalenol (DON), the most commonly occurring trichothecene in nature, may affect animal and human health through causing diarrhea, vomiting, gastrointestinal inflammation, and immunomodulation. DON-3-glucoside (DON-3G) as a major plant metabolite of the mycotoxin is another "emerging" Food safety issue in recent years. Humans may experience potential health risks by consuming DON-contaminated Food products. Thus, it is crucial for human and animal health to study also the degradation of DON and DON-3G during Thermal Food Processing. Baking, boiling, steaming, frying, and extrusion cooking are commonly used during Thermal Food Processing and have promising effects on the reduction of mycotoxins in Food. For DON, however, the observed effects of these methods, as reported in numerous studies, are ambiguous and do not present a clear picture with regard to reduction or transformation. This review summarized the influence of Thermal Processing on the stability of DON and the formation of degradation/conversion products. Besides this, also a release of DON and DON-3G from Food matrix as well as the release of DON from DON-3G during Processing is discussed. In addition, some conflicting findings as reported from the studies on Thermal Processing as well as cause-effect relationships of the different Thermal procedures are explored. Finally, the potential toxic profiles of DON degradation products are discussed as well when data are available.
Xiaojian Zheng - One of the best experts on this subject based on the ideXlab platform.
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the inactivation kinetics of polyphenol oxidase and peroxidase in bayberry juice during Thermal and ultrasound treatments
Innovative Food Science and Emerging Technologies, 2018Co-Authors: Yongling Wang, Xiaojian ZhengAbstract:Abstract Ultrasound is recognized as a non-conventional Processing technology for Food preservation and quality improvement. Effects of Thermal and ultrasound treatment on the inactivation kinetics of polyphenol oxidase (PPO) and peroxidase (POD) in bayberry juice were studied. Whether cooling with ice bath during ultrasound treatment was conducted to separate effects of heat and cavitation effects. In all processes, the inactivation kinetics of PPO and POD followed a first-order model (R 2 = 0.864–0.997).The D T value during Thermal inactivation varied from 151.99 to 6.23 min for PPO and the corresponding Z T values and activation energy (E a ) were 13.16 °C and 166.77 kJ/mol, while those parameters of POD were 298.26–7.08 min, 14.25 °C and 153.49 kJ/mol, respectively. The ultrasound (US) inactivation rate constants (k) for PPO ranged from 0.0556 min − 1 to 0.8878 min − 1 with the corresponding D values of 41.44–2.59 min and Z UI values of 312.50 W/cm 2 . However, the k value of PPO during ultrasound with cooling (USC) decreased to 0.0412–0.3268 min − 1 , while the D and Z UI values increased to 55.92–7.05 min and 432.90 W/cm 2 , indicating that the heat brought out during ultrasound treatment significantly enhanced the inactivation kinetics of PPO. The inactivation rates of POD by US treatment were also higher than those by USC at the same ultrasound intensity and time. In addition, the kinetic parameters for POD by US and USC treatment were lower than those of PPO, inferring its more sonication resistant. Industrial relevance Ultrasound is a non-Thermal Food Processing method for microorganism and enzyme inactivation, as well as quality maintenance. Attractive color is one of the most important quality attribute of bayberry products and strongly affects the consumer acceptance and preference. A key role in color degradation in berry fruit products is attributed to enzymatic browning of phenolic compounds which mainly related to PPO and POD. Therefore, the inactivation of PPO and POD is necessary for better color retention and shelf life increasing. This study would provide technical support for PPO and POD inactivation of ultrasound technique in bayberry juices Processing.
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The inactivation kinetics of polyphenol oxidase and peroxidase in bayberry juice during Thermal and ultrasound treatments
Innovative Food Science & Emerging Technologies, 2018Co-Authors: Xiamin Cao, Yongling Wang, Chunfang Cai, Xiaojian ZhengAbstract:Abstract Ultrasound is recognized as a non-conventional Processing technology for Food preservation and quality improvement. Effects of Thermal and ultrasound treatment on the inactivation kinetics of polyphenol oxidase (PPO) and peroxidase (POD) in bayberry juice were studied. Whether cooling with ice bath during ultrasound treatment was conducted to separate effects of heat and cavitation effects. In all processes, the inactivation kinetics of PPO and POD followed a first-order model (R 2 = 0.864–0.997).The D T value during Thermal inactivation varied from 151.99 to 6.23 min for PPO and the corresponding Z T values and activation energy (E a ) were 13.16 °C and 166.77 kJ/mol, while those parameters of POD were 298.26–7.08 min, 14.25 °C and 153.49 kJ/mol, respectively. The ultrasound (US) inactivation rate constants (k) for PPO ranged from 0.0556 min − 1 to 0.8878 min − 1 with the corresponding D values of 41.44–2.59 min and Z UI values of 312.50 W/cm 2 . However, the k value of PPO during ultrasound with cooling (USC) decreased to 0.0412–0.3268 min − 1 , while the D and Z UI values increased to 55.92–7.05 min and 432.90 W/cm 2 , indicating that the heat brought out during ultrasound treatment significantly enhanced the inactivation kinetics of PPO. The inactivation rates of POD by US treatment were also higher than those by USC at the same ultrasound intensity and time. In addition, the kinetic parameters for POD by US and USC treatment were lower than those of PPO, inferring its more sonication resistant. Industrial relevance Ultrasound is a non-Thermal Food Processing method for microorganism and enzyme inactivation, as well as quality maintenance. Attractive color is one of the most important quality attribute of bayberry products and strongly affects the consumer acceptance and preference. A key role in color degradation in berry fruit products is attributed to enzymatic browning of phenolic compounds which mainly related to PPO and POD. Therefore, the inactivation of PPO and POD is necessary for better color retention and shelf life increasing. This study would provide technical support for PPO and POD inactivation of ultrasound technique in bayberry juices Processing.
Norton Komora - One of the best experts on this subject based on the ideXlab platform.
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non Thermal approach to listeria monocytogenes inactivation in milk the combined effect of high pressure pediocin pa 1 and bacteriophage p100
Food Microbiology, 2020Co-Authors: Norton Komora, Claudia Maciel, Carlos A Pinto, Vânia Ferreira, Teresa R S Brandao, Jorge A Saraiva, Sonia Marilia Castro, Paula TeixeiraAbstract:Abstract Non-Thermal Food Processing and replacement of chemical additives by natural antimicrobials are promising trends in the Food industry. The objective of the present work was to evaluate the effect of a process which combines mild high hydrostatic pressure – HHP (200 and 300 MPa, 5 min, 10 °C), phage Listex™ P100 and the bacteriocin pediocin PA-1 as a new non-Thermal process for destruction of Listeria monocytogenes (104 CFU mL−1 or 107 CFU mL−1) in milk. For inoculum levels of 104 CFU mL−1, HHP combined with phage P100 eliminated L. monocytogenes immediately after pressurization. When L. monocytogenes was inoculated at levels of 107 CFU mL−1, a synergistic effect between phage P100, pediocin PA-1 and HHP (300 MPa) on the inactivation of L. monocytogenes was observed during storage of milk at 4 °C. For non-pressure treated samples inoculated with phage or pediocin or both, L. monocytogenes counts decreased immediately after biocontrol application, but regrowth was observed in a few samples during storage. Phage particles were stable during refrigerated storage for seven days while pediocin PA-1 remained stable only during three days. Further studies will have to be performed to validate the findings of this work in specific applications (e.g. production of raw milk cheese).
Kei Eguchi - One of the best experts on this subject based on the ideXlab platform.
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modification of cockcroft walton based high voltage multipliers with 220 v and 50 hz input for non Thermal Food Processing apparatus
Sustainability, 2020Co-Authors: Anurak Jaiwanglok, Kei Eguchi, Krit Smerpitak, Amphawan JulsereewongAbstract:A design of high-voltage multipliers to generate underwater shockwaves is one of the most important factors for successfully providing non-Thermal Food Processing in a cost-effective manner. To be capable of fully utilizing the Cockcroft–Walton-based high-voltage multipliers for underwater shockwave generation, this paper presents a topological modification of three interesting design approaches in bipolar structure for 220 V and 50 Hz AC input to generate more than 3.5 kV DC output within short time periods. In addition to Cockcroft–Walton multipliers (CWMs), the first modified scheme employs a positive full-wave rectifier (FWR) and positive voltage multiplier block (VMB), the second modified scheme employs positive/negative half-wave rectifiers (HWRs), and the last modified scheme employs a switched-capacitor AC-AC converter. To comparatively analyze their performances, the digitally controlled operations of the modified realization schemes as well as their electrical characteristic estimation based on a four-terminal equivalent model are described in detail. The effectiveness of three modified circuit configurations and the correctness of the given theoretical analysis are verified through SPICE (Simulation Program with Integrated Circuit Emphasis) simulation results. The formulas achieved from theoretical estimation are particularly useful when designing the proposed high-voltage multipliers (HVMs) because good agreement between the theoretical and simulation results can be achieved.
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Reduction of Inrush Current in a Shockwave Non-Thermal Food Processing System Using an Exponential Clock Pulse Generator
Sustainability, 2020Co-Authors: Kei Eguchi, Farzin Asadi, Akira Shibata, Hiroto Abe, Ichirou OotaAbstract:Recently, shockwave Food Processing is drawing much attention as a low-cost non-Thermal Food process technique. In shockwave non-Thermal Food Processing, underwater shockwaves are generated by a high voltage generator. Therefore, high inrush currents and high voltage stress on circuit components significantly reduce the reliability and life expectancy of the circuit. However, to the best of our knowledge, stress reduction techniques and their experimental verification have not been studied yet in the shockwave non-Thermal Food Processing system. In this paper, we propose a stress reduction technique for the shockwave non-Thermal Food Processing system and investigate the effectiveness of the proposed technique experimentally. To achieve high reliability and life expectancy, a new high voltage multiplier with an exponential clock pulse generator is proposed for the shockwave non-Thermal Food Processing system. By slowing down the rate at which the capacitors charge in the high voltage multiplier, the exponential clock pulse generator significantly reduces the inrush current. Furthermore, to perform shockwave non-Thermal Food Processing continuously at a lower voltage level, we present a new electrode with a reset mechanism for wire electric discharge (WED), where a square-shaped metal wire swings on a hinge in the proposed electrode. The proposed electrode enables not only shockwave generation at a lower voltage level but also continuous non-Thermal Food Processing, because the square-shaped metal wire is not melted in the WED process. To confirm the validity of the proposed techniques, some experiments are performed regarding the laboratory prototype of the shockwave non-Thermal Food Processing system. In the performed experiments, reduction of inrush currents and effective Food Processing are confirmed.
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An Efficient Non-Thermal Food Processing System by Underwater Shockwaves Using Two Pairs of Restoration Electrodes
2019 5th International Conference on Engineering Applied Sciences and Technology (ICEAST), 2019Co-Authors: Hiroto Abe, Kei EguchiAbstract:Non-Thermal Food Processing systems using underwater shockwaves can process only a part of the Food at once. In order to process several parts of the Food at once, we propose an efficient non-Thermal Food Processing system using two pairs of restoration electrodes. The difference between the proposed and conventional systems is the number of electrode pairs, the shape of electrodes, and the use of thin wires. By placing two pairs of electrodes across a target Food, underwater shockwaves destroy the target Food from both sides. Therefore, both sides of the target Food are processed at once. Also, a hole is formed in one electrode and a square-shaped thin wire penetrates through the hole. Further, an insulator is attached to the electrode with the hole. By using the thin wire, the energy for generating the underwater shockwaves can be reduced. Also, the thin wire returns to the original position after discharging process, which makes it possible discharge continuously. In experiments, we processed an apple as the target Food by using the proposed and conventional systems, and compared the results by measuring the flesh firmness of the apple. By using the proposed method, the Processing range of apples can be expanded, and the softness equivalent to the conventional method can be realized.
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Experimental Study of a Non-Thermal Food Processing System Using a Series-Connected Bipolar Voltage Multiplier with Multiple Electrodes
The Proceedings of the 5th International Conference on Industrial Application Engineering 2017, 2017Co-Authors: Kei Eguchi, Kanji Abe, Ryo Ogata, Ichirou OotaAbstract:To provide nutritious and fresh processed Foods at low cost, non-Thermal Food Processing utilizing an underwater shockwave is one of the most promising methods. In the non-Thermal Food Processing system, a high voltage multiplier is the vital component to generate the underwater shockwave. In this paper, an experimental study is conducted concerning a non-Thermal Food Processing system using a series-connected bipolar voltage multiplier with multiple electrodes. In the proposed system, a target Food is destroyed from both sides by underwater shockwaves. Therefore, unlike conventional systems, the proposed system can soften the whole flesh of target Foods effectively. Furthermore, owing to the series-connected bipolar topology, the proposed multiplier can achieve not only higher operation speed but also higher step-up gain than conventional multipliers. Therefore, the proposed system can process the target Food at high speed. The feasibility of the proposed system is clarified by experiments.
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Study on Non-Thermal Food Processing Utilizing an Underwater Shockwave
Indian Journal of Science and Technology, 2017Co-Authors: Kanji Abe, Ryo Ogata, Kei Eguchi, Krit Smerpitak, Sawai PongswatdAbstract:In this paper, a novel non-Thermal Food Processing system utilizing an underwater shockwave is proposed to process Food at high speed. In the non-Thermal Food Processing, target Foods are crushed by an underwater shockwave generated by a high voltage. Unlike conventional non-Thermal Food Processing systems, the proposed system has a high voltage multiplier which can generate the underwater shockwave at high speed. Therefore, the proposed system can achieve a high production capacity. The validity of the proposed high voltage multiplier is confirmed by the Simulation Program with Integrated Circuit Emphasis (SPICE) simulation. Furthermore, the feasibility of the proposed system is verified by demonstrating the proposed system by the experiments. In the experiments, an apple is softened by discharging 3.5kV stepped-up voltage.