Agradecimentos: The authors acknowledge the financial support received from FAPESP – São Paulo - Brazil for the financial support (Process numbers 2007/58017-5, 2011/06083-0, 2017/18109-0, and 2019/07744–1). This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Financial code 001, Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq, Brazil (Process numbers 140700/2017-0, 140710/2015-9, 154160/2018-0, 140283/2013- and 307168/2016-6). Aureliano Agostinho Dias Meirelles thanks CAPES – Brazil for the Ph.D. fellowship. Ana Letícia Rodrigues Costa Lelis thanks the financial support FAPESP (process number 2020/02313–0). Juliane Viganó thanks the financial support of FAPESP (process number 2020/15774–5). Rosiane Lopes Cunha thanks CNPq – Brazil (CNPq 307168/2016–6) for the productivity grant Ver menos

Abstract: Carrying lipophilic compounds protection within alginate microgels is a challenge, mainly due to the necessary oil-core matrix. Based on this demand, this study aimed to evaluate the use of glass microfluidic devices to produce emulsion-filled alginate microgels and understand the effect of process variables on microgels size and polydispersity. Firstly, stable and monodisperse size-distributed oil microdroplets were formed by preparing an oil-in-water (O/W) emulsion using high shear followed by ultrasound. The continuous aqueous phase was composed of Na-alginate, cellulose nanocrystals and ultrafine calcium carbonate. Sunflower oil composed the emulsion oil phase (10%, w/w). Secondly, oil-in-water-in-oil (O/W/O) emulsions were formed within microfluidics devices to obtain emulsion-filled hydrogel particles. The previously produced O/W emulsion was introduced as the dispersed phase into a continuous phase containing sunflower oil, PGPR and acetic acid. The aqueous phase was gelled by internal gelation, promoting the alginate network. Monodisperse particle size distribution was observed, with a coefficient of variation lower than 6% and mean size ranging from 259 to 526 µm. Microgels size was influenced by the viscosity of O/W emulsion and the phases flow rates. Our results show the potential of microfluidic processes for producing microgels and filled microgels to encapsulate lipophilic compounds Ver menos