Formulation, spray-drying and physicochemical characterization of functional powders loaded with chia seed oil and prepared by complex coacervation

BORDÓN, MARÍA GABRIELA; PAREDES, ALEJANDRO J.; CAMACHO, NAHUEL MATÍAS; PENCI, MARÍA CECILIA; GONZÁLEZ, AGUSTÍN; PALMA, SANTIAGO DANIEL; RIBOTTA, PABLO DANIEL; MARTINEZ, MARCELA LILIAN

POWDER TECHNOLOGY

ELSEVIER SCIENCE SA

Año: 2021 vol. 391 p. 479 - 493

0032-5910

In this research, complex coacervation between soy protein isolate (SPI) and gum arabic (GA) constituted a preliminary step for developing chia oil (CO)-in-water emulsions suitable for subsequent spray-drying. The contributions of total biopolymer concentration, SPI-GA ratio w/w and ionic strength on coacervate yield (CY) were quantified through a 3×6×4 factorial design. The SPI-GA ratios that gave the highest CY values (1-1 and 2-1) were selected to prepare emulsions and blank dispersions (devoid of CO). The preparation process included four well-defined sequential steps: high speed homogenization, high pressure homogenization, complex coacervation and a carrier addition (maltodextrin). The emulsification step, the SPI-GA ratio and the presence of CO had a significant effect (p ≤ 0.05) on ζ-Potential, apparent viscosity, structural recovery of the systems, gel strength and cross-linking. The microencapsulation process preserved the quality of CO (2.18 ± 0.01 h), as reflected by enhanced oxidative stability indices (around three times higher than bulk CO, 5.65?6.84 h) and non-significant changes in α-Linolenic acid after spray-drying and in-vitro digestion processes (60?66.53%, relative abundance). In addition, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) helped corroborate the stability of CO within the powders´ structure. Finally, different characteristics of powders were significantly influenced (p ≤ 0.05) by the presence of CO, especially the color, flowability and sorption-dependent properties: the monolayer content (Wm) and the bulk moisture diffusivity.