Development of microwave applicator for continuous thermal processing of liquid foods

• Grant number: 23/13161-4
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2023
• End date: November 30, 2025
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Jorge Andrey Wilhelms Gut
• Grantee: Jorge Andrey Wilhelms Gut
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Carmen Cecilia Tadini ; Edmilson Renato de Castro ; Eduardo Victor dos Santos Pouzada ; Renata Borges do Nascimento

Abstract

The electrification of industrial heating processes, associated with the use of renewable and clean sources of electrical energy, has the potential to reduce emissions and increase energy efficiency. Microwave irradiation is one of the electro-technologies available and this project contemplates its use in the food industry, but specifically in the continuous thermal processing of liquid foods, such as juices, pulps and milk. Such processing aims to inactivate microorganisms and enzymes and heat exchangers are used for continuous flow heating. The objective is to develop, build and test a microwave applicator for the efficient heating of fluid foods. Rapid volumetric heating by microwaves, without the use of superheated surfaces, reduces nutritional and quality losses, in addition to allowing the efficient use of clean energy. However, designing a cavity for continuous flow heating is a complex task as it involves coupling between electromagnetism, flow and heating. Main challenges are the homogeneity of heating, which can compromise the safety of the product and energy efficiency in absorbing power. To address this challenge, multiphysics numerical simulation will be used to model a multimode cavity operating at 2.45 GHz. Improving the volumetric power distribution will be sought through the use of unconventional geometries in investigating the coupling between generator and load. The prototype will be built and connected to the microwave transmission line, power monitoring instrumentation and a thermal processing line (feed pump, retention tube, chiller and chilled water generator). Tests will be carried out with a model food to validate and refine the model, before moving on to practical application with a real food. The cavity design is subject to intellectual property protection and the technology developed can benefit small and medium-sized producers, in addition to contributing to scientific advancement in this field of knowledge. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RUSSO, GUILHERME; GUT, JORGE A. W.; BOLDOR, DORIN. Multiphysics modeling and validation of a microwave applicator with a three-stub tuner for the continuous flow pasteurization of fruit juices with low reflection. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS, v. 9, p. 14-pg., 2025-03-26. (23/13161-4, 13/07914-8)