Evaluation of modified starch and rice protein concentrate as wall materials on the microencapsulation of flaxseed oil by freeze-drying

• Published in: Food science & technology 2021-04, Vol.140, p.110760, Article 110760
• Main Authors: Perrechil, Fabiana, Louzi, Vitor César, Alves da Silva Paiva, Lidia, Valentin Natal, Gabriela Santos, Braga, Matheus Boeira
• Format: Article
• Language: English
• Subjects: Encapsulation; Flaxseed oil; Freeze-dryer; Modified starch; Plant protein
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2020.110760

The aim of this work was to study functional formulations composed of flaxseed oil, rice protein concentrate (RPC), and modified starch and the characterization of the powder obtained by the freeze-drying process. Powders were characterized by encapsulation efficiency (ϒ), physical properties, differential scanning calorimetry (DSC), and infrared spectroscopy using the Fourier Transform (FTIR) analysis. RPC showed a poor emulsifying property (emulsifying activity index of 1.15 m2/g), resulting in powders with low encapsulation efficiency (less than 1%). The increase of modified starch content led to an increase in the ϒ (12.9–90.6%), and in the temperature and intensity of the endothermic peaks of the powders analyzed by DSC. Also, the increase of modified starch content resulted in particles with a porous structure and with a lower amount of oil droplets on the surface. The powders produced with mixtures of RPC and modified starch showed low values of moisture content (less than 5.5%), and hygroscopicity (less than 0.1065 kg/kg), and average values of bulk density of 0.2113 g/cm3, packed bulk density of 0.3178 g/cm3 and particle mean diameter of 42.36 μm. The product developed could be classified as a hypoallergenic particulate, rich in polyunsaturated fatty acids (PUFAs) and essential amino acids. [Display omitted] •Development of a hypoallergenic powder food product enriched in ω-3 PUFA.•Rice protein and modified starch were applied as adjuvants for the flaxseed oil encapsulation.•Structure and thermal characterization of powder analyzed by FTIR and DSC.•The increase of modified starch content led to an increase in the powder stability.