Synthesis and characterization of nano and microparticles of biopolymers for food packaging applications

Abstract

The main aim of this thesis is the preparation and characterization of nano and microparticles of selected biopolymers addressed for food packaging and active food packaging applications. Two biopolymers have been selected for the nano and microparticles preparations: poly(3-hydroxybutyrate-co-3- hydroxyvalerate) (PHBV) and starch. The results for the PHBV showed spherical porous particles with wide variety of size distribution depending on the selected techniques and the procedure conditions. Starches from different botanical origins were used for preparing starch nanoparticles and starch/quercetin nanoparticles using the nanoprecipitation technique. The loading capacity, the release profile of the quercetin from the nanoparticles and therefore the antioxidant activity changed by changing the starch origin. Starch microparticles with donut-shaped morphology were prepared from starches of two different botanical origins and then loaded to thermoplastic starch (TPS) films. The TPS loaded with microparticles showed better thermal stability, less water vapour and oxygen transmission rates. The donut-shaped microparticles were also used as a carrier for quercetin within TPS films. The quercetin kept releasing during 4 to 11 days depending on the starch origin. The produced nano and microparticles provide many possibilities for improving some properties of the biopolymeric packaging films with the capacity for active delivery function for reasonable periods.