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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Evaluation and modeling of a microwave-assisted unit for continuous flow pasteurization of liquid foods: Residence time distribution, time-temperature history, and integrated lethality

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Author(s):
Siguemoto, Erica Sayuri [1] ; Pires, Marcos Neves [1] ; Funcia, Eduardo dos Santos [1] ; Wilhelms Gut, Jorge Andrey [1, 2]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Escola Politecn, Dept Chem Engn, BR-05508010 Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, FoRC Food Res Ctr, Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF FOOD PROCESS ENGINEERING; v. 41, n. 8 DEC 2018.
Web of Science Citations: 1
Abstract

Focused microwave heaters have potential to replace heat exchangers in continuous flow pasteurization of liquid foods. The objective of this work was to evaluate a pilot scale unit used for microwave assisted pasteurization of low viscosity liquid foods in order to model the heat transfer and residence time distribution (RTD) to, subsequently, predict the average time-temperature history and estimate the level of heat treatment of the process and contributions from each step. RTD data using water showed that it was possible to assume plug-flow (negligible axial dispersion). Heat transfer experiments using water provided heat transfer coefficients as functions of Reynolds number and microwave power absorption. Mathematical modeling was used to determine the temperature distribution along the product path, and results were validated. Integrated lethality calculated from the time-temperature histories (pasteurization at 70 degrees C) revealed the contribution of each process step. Results showed that focused microwave heating provided the necessary temperature increase in a very short time, with a lethality contribution of only 0.7% as compared to 59-68% when using only the conventional heat exchanger. The methods described can be useful for the evaluation of other continuous flow pasteurization units processing low viscosity liquid foods. Practical applicationsThe mathematical modeling approach and experimental methods presented herein can be used for the analysis of continuous flow pasteurization systems based on tubular heat exchangers and with low axial dispersion (plug flow), providing temperature and lethality distribution along the product path, showing the contribution from each section on inactivation. Specifically for the equipment used in the experiments, the obtained heat transfer and resident time distribution parameters will be useful to study the processing of low viscosity foods such as fruit juices and nectars on ongoing works from the group. (AU)

FAPESP's process: 16/24265-1 - Study and modelling of enzyme inactivation in the processing of green coconut water and orange juice by ohmic and dielectric heating
Grantee:Eduardo dos Santos Funcia
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 14/06026-4 - Study of continuous-flow microwave thermal processing of cloudy apple juice
Grantee:Érica Sayuri Siguemoto
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 15/20113-0 - Study on continuous processing apple juice using focused microwave technology
Grantee:Marcos Neves Pires
Support Opportunities: Scholarships in Brazil - Scientific Initiation
FAPESP's process: 14/25179-6 - Study of enzyme inactivation in the processing of green coconut water by focused microwave technology
Grantee:Eduardo dos Santos Funcia
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 13/07914-8 - FoRC - Food Research Center
Grantee:Bernadette Dora Gombossy de Melo Franco
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC