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Food Processes (food + process)
Terms modified by Food Processes Selected AbstractsJOURNAL of FOOD PROCESSING and PRESERVATION SEP 2000 Vol-24.4. DEVELOPMENT of A PROCESS FOR DETECTING NONTHERMAL EFFECTS of MICROWAVE ENERGY ON MICROORGANISMS AT LOW TEMPERATURE,JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2000MICHAEL KOZEMPEL We developed an experimental process capable of isolating thermal and nonthermal effects of microwave energy relative to the destruction of microorganisms at low temperature. the concept combines instantaneous energy input to the food system by microwaves with rapid removal of thermal energy. the process used a double tube heat exchanger inside a continuous microwave dryer. the outer tube was transparent to microwaves, whereas the inner tube was stainless steel and was used for cooling the system. the microwave energy, 5,6 kW power, was absorbed by the process fluid in the annulus. the cooling water flowing in the inner tube removed the thermal energy from the process fluid to control temperature at or below 45C. the process was at turbulent flow to assure a uniform temperature and dwell time. There were no detected nonthermal effects from microwave energy for yeast, Pediococcus sp., Escherichia coli, Listeria innocua, or Enterobacter aerogenes in various test fluids, such as water, liquid egg, beer, apple juice, apple cider, and tomato juice. [source] Estimation of Kinetic Parameters for Nonisothermal Food ProcessesJOURNAL OF FOOD SCIENCE, Issue 3 2003K.D. Dolan ABSTRACT This work deals with the hypothesis that kinetic parameters for nonisothermal processes can be reliably obtained using a 1-step method. Parameters were estimated for 3 typical processes: (1) no residence time distribution (RTD), (2) first-order reaction with RTD, and (3) nth-order reaction with RTD. When nonisothermal processes were approximated isothermally, k and ,E were underestimated 80% to 3 orders of magnitude, and 30% to 1 order of magnitude, respectively. Reaction order was overestimated by up to 0.81. Therefore, accounting for thermal history and RTD is critical to obtain accurate estimates of kinetic parameters. The 1-step method was also used to solve for equivalent isothermal temperatures and times for an arbitrary nonisothermal process. [source] Heat transfer during microwave combination heating: Computational modeling and MRI experimentsAICHE JOURNAL, Issue 9 2010Vineet Rakesh Abstract Combination of heating modes such as microwaves, convection, and radiant heating can be used to realistically achieve the quality and safety needed for cooking processes and, at the same time, make the processes faster. Physics-based computational modeling used in conjunction with MRI experimentation can be used to obtain critical understanding of combination heating. The objectives were to: (1) formulate a fully coupled electromagnetics - heat transfer model, (2) use magnetic resonance imaging (MRI) experiments to determine the 3D spatial and temporal variation of temperatures and validate the numerical model, (3) use the insight gained from the model and experiments to understand the combination heating process and to optimize it. The different factors that affect heating patterns during combination heating such as the type of heating modes used, placement of sample, and microwave cycling were considered. Objective functions were defined and minimized for design and optimization. The use of such techniques can lead to greater control and automation of combination heating process benefitting the food process and product developers immensely. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] Comparative study of nine Lactobacillus fermentum bacteriophagesJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2001R. Foschino Aims:,To investigate the basic properties of six temperate and three virulent phages, active on Lactobacillus fermentum, on the basis of morphology, host ranges, protein composition and genome characterization. Methods and Results:,All phages belonged to the Siphoviridae family; two of them showed prolate heads. The host ranges of seven phages contained a common group of strains. SDS-PAGE protein profiles, restriction analysis of DNA and Southern blot hybridization revealed a high degree of homology between four temperate phages; partial homologies were also detected among virulent and temperate phages. Clustering derived from host range analysis was not related to the results of the DNA hybridizations. Conclusions:,The phages investigated have common characteristics with other known phages active on the genus Lactobacillus. Sensitivity to viral infection is apparently enhanced by the presence of a resident prophage. Significance and Impact of the Study:,These relationships contribute to the explanation for the origin of phage infection in food processes where Lact. fermentum is involved, such as sourdough fermentation. [source] Comparative proteome approach to characterize the high-pressure stress response of Lactobacillus sanfranciscensis DSM 20451TPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 6 2006Sebastian Hörmann Abstract High hydrostatic pressure (HHP) exerts diverse effects on microorganisms, leading to stress response and cell death. While inactivation of microorganisms by lethal HHP is well investigated in the context of food preservation and the hygienic safety of minimal food processes, sublethal HHP stress response and its effect on adaptation and cross-protection is less understood. In this study, the HHP stress response of Lactobacillus sanfranciscensis was characterized and compared with cold, heat, salt, acid and starvation stress at the proteome level by using 2-DE so as to provide insight into general versus specific stress responses. Sixteen proteins were found to be affected by HHP and were identified by using N-terminal amino acid sequencing and MS. Only one slightly increased protein was specific to the HHP response and showed homology to a clp protease. The other proteins were influenced by most of the investigated stresses in a similar way as HHP. The highest similarity in the HHP proteome was found to be with cold- and NaCl-stressed cells, with 11,overlapping proteins. At the proteome level, L.,sanfranciscensis appears to use overlapping subsets of stress-inducible proteins rather than stereotype responses. Our data suggest that a specific pressure response does not exist in this bacteria. [source] Anwendungen der Magnetresonanz zur Untersuchung von Wasser-, Temperatur- und Porenverteilung bei lebensmittelverfahrenstechnischen ProzessenCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 4 2004M. Regier Dr.-Ing. Abstract Es werden verschiedene Methoden der kernmagnetischen Resonanz (NMR) und ihrer Anwendung zur Bestimmung von Wasser-, Temperaturverteilungen und Selbstdiffusionskoeffizienten im Verlauf von Prozessen im Bereich der Lebensmittelverfahrenstechnik vorgestellt. Ausgehend von den physikalischen Grundlagen der Magnetresonanz werden verschiedene Anwendungen gezeigt, die das Potenzial besitzen, zum tieferen Verständnis der verfahrenstechnischen Prozesse beizutragen: Beispielhaft wird die Bestimmung von Wasserverteilungen bei der Rehydratation von getrockneten Proben, die Ermittlung von Temperaturverteilungen bei der Mikrowellenerwärmung und von beobachtungszeitabhängigen Selbstdiffusionskoeffizienten bei der Mikrowellen-Vakuumtrocknung gezeigt. Letztere können dazu genutzt werden, um weitere Aussagen über die innere Gewebestruktur wie Tortuosität und Porenradien zu erlangen. Applications of Magnetic Resonance for Investigating Water-, Temperature- and Poredistributions in Food Process Engineering Various methods of nuclear magnetic resonance (NMR) and their application for determinig water- and temperature distributions as well as self diffusion coefficients during food processing operations are presented. Starting from the physical basics of the magnetic resonance, various NMR applications are shown, which may contribute to a more comprehensive understanding of the food processes: Presented examples are the determination of water distributions during the rehydration of dried samples, of temperature distributions during a microwave heating process and of self diffusion coefficients during microwave vacuum drying. These observation time dependent self diffusion coefficients may be used to receive further information about the internal tissue structure, like tortuosity and pore radii. [source] Food Process Engineering: The Last 25 Years and Challenges AheadCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 2 2003S. Bruin ABSTRACT In the first part of this contribution, an overview is given of some of the main developments in food process engineering in the last 25 years of the 20th century. This overview is, of course, colored by the personal experience of the authors, but a sincere effort was made to maintain a general perspective. Topics that will be briefly discussed are: progress in understanding how to control food microstructure formation during processing, separation processes, conversion processes and stabilization processes, progress in flavor technology and understanding of flavor retention during processing and release. In the 2nd part, in our view, the most exiting future developments are briefly discussed. The major items here are: processing requirements for functional foods, integrated process design approaches, application of novel,fields'in food processes,,precision'processing, supply chain approaches to food manufacturing, and more. [source] | |||||||||||||||||||