Project, manufacturing and evaluation of a pilot multipurpose equipment destined to study microwave applications to food processing

• Grant number: 14/14435-1
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2014
• End date: November 30, 2016
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Antonio Marsaioli Junior
• Grantee: Antonio Marsaioli Junior
• Host Institution: Instituto de Tecnologia de Alimentos (ITAL). Agência Paulista de Tecnologia dos Agronegócios (APTA). Campinas , SP, Brazil
• City of the host institution: Campinas
• Associated researchers: Maria Isabel Berto ; Michele Nehemy Berteli

Abstract

Scientific community as well as industry have been focusing attention more and more on applications of microwave technology. Examples of microwave uses in processes of food industries are numerous: drying, defrosting, blanching, pasteurization and sterilization, extraction, enzyme inactivation, among others. More recently microwaves are being associated to the technology of non-thermal plasma generation, with potential applications against contaminating microorganisms of foods. During dielectric heating, the electric field distribution inside a cavity occurs derived from a multimodal propagation, caused by a number of reflections coming from the cavity metallic walls. That is an undesirable feature associated to the microwave heating, because multiple reflections generate volumetrically regions with standing waves of different electrical field intensities, resulting in a non-uniform product heating. The objective of this study is the design of a multipurpose processing and drying microwave system (3kW & 2.45 GHz), with a cavity of hexagonal prismatic geometry designed to homogenize the different electrical field intensities, and followed by its manufacturing, testing and evaluation. A similar study was already successfully developed in the Microwave Laboratory - LMA/GEPC/ITAL, although related to a lab scale microwave applicator (700 W & 5.8 GHz). The present project being submitted will permit studying innovative microwave technologies at an industrial frequency (2.45 GHz), making possible to extrapolate the experimental data to the food processing industry. Additionally, it is predicted the study of plasma generated by microwaves, by means of a different disposition of the microwave provision system, such as to be transformed into a standing mono-mode universal applicator, inside the waveguide. Plasmas, differently from traditional thermal processes, are capable of inactivating microorganisms, including bacterial spores, at either room or moderately elevated temperatures, for short periods. (AU)

Filed patent(s) as a result of this research project