Strategies for production of lipid particles in fluidized bed

Author(s)

Bruna Barbon Paulo

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2017-03-10

Examining board members

Ana Silvia Prata; Izabela Dutra Alvim; Marcello Nitz

• Advisor: Ana Silvia Prata; Almerindo Domingues Ferreira

Abstract

Phase Change Materials (PCMs) are used for thermal energy storage, and if incorporated in food packaging, they can increase the thermal capacity and keep the product at the desired temperature. However, its application is still limited, due to the volumetric variation that occurs during the solid-liquid phase transition, and implies losses and may damage the surface where they are applied. The production of PCMs in particulate form and the subsequent coating in fluidized bed may be an efficient alternative to broad their application, despite the susceptibility of these materials to change phase with the process. Due to the little knowledge about the use of the fluidized bed for this purpose, it is interesting to use material with high melting point in order to establish bases for further expansion of the use of the technology for other materials. Carnauba wax is a lipid of vegetable origin and has been studied as a potential PCM because of its high heat of fusion and melting point. In this way, this work had two challenges: the structuring of the carnauba wax in the particulate form and its coating in fluidized bed. The structuring of the carnauba wax particles was performed using the cold extrusion and dripping techniques. The particles produced were characterized for the physical and thermal properties that are important for fluidization. Despite the similar physical and thermal characteristics of the particles, the extrusion technique was significantly more advantageous, since it presented a high rate of production of particles with easy control of temperature and cleaning. The coating of the carnauba wax particles was performed under the set thermos-fluid dynamics conditions, and the polysaccharides sodium alginate, gum arabic, chitosan and maltodextrin were used as candidates for coating material. The selection of such materials was based on the adhesive and rheological properties, and subsequently validated in coating tests. The adhesive property was evaluated based on the contact angle obtained between the carnauba wax and the coating material candidates. Suspensions containing sodium alginate and Eudragit® L30-D55 showed the lowest contact angle ('theta' ¿=40 °), and low viscosity, and they were able to restrain the volumetric particle variation of the particles (coating efficiency = 55%) when exposed to heating at 100 °C for at least one hour (AU)

• FAPESP's process: 15/11629-2 - Strategies for producing lipidic particles using fluidized bed
• Grantee: Bruna Barbon Paulo
• Support Opportunities: Scholarships in Brazil - Master