Pectin-decorated magnetite nanoparticles as both iron delivery systems and protective matrices for probiotic bacteria.

GHIBAUDO; GERBINO; COPELLO, GUILLERMO J.; CAMPO DALL' ORTO, VIVIANA; GOMEZ ZAVAGLIA

Sevilla

Congreso; 2nd Food Chemistry Conference: Shaping the Future of Food Quality, Safety, Nutrition and Health. Sevilla, España.; 2019

Food Chemistry (Elsevier)

The goal of this work was to investigate biophysical stability of iron-pectin nanoparticles and analyze the feasibility of using them as delivery systems for the probiotic strain Lactobacillus plantarum CIDCA 83114. Iron oxide (Fe3O4) nanoparticles were synthesized from FeCl2.4H2O/0.5M FeCl3.6H2O, and coated with citrus pectins. Their physico-chemical properties [FTIR, X-ray diffraction (XRD), ζ- potential, particle size, SEM, TEM] and their effect on bacterial stabilization (viability after freezedrying/ storage, stability when exposed to simulated gastro-intestinal conditions) were assessed.XRD indicated the almost exclusive presence of magnetite crystalline phases. FTIR spectra confirmed the adsorption of pectin on magnetite nanoparticles surface. SEM and TEM images evidenced agglomerated nanoparticles, and a morphological surface change after adsorption of pectin. DLS and ζ-potential results proved the solvation of the ionizable groups in the hydrophilic network which induced chain expansion and agglomeration.Iron from nanoparticles demonstrated to be n on-toxic for microorganisms up to 1.00 mg/mL. Simulated saliva and gastric solutions prevented nanoparticles from dissolution. The higher pH of the intestinal conditions (solvated -COO- and Fe-O- groups) facilitated the dispersion and partial dissolution of nanoparticles. Pectins adsorption on magnetite nanoparticles significantly enhanced electrostatic repulsion, which aided the solvation of ionized iron forms. The soluble species diffused out from the aggregates, being detected in the simulated intestinal fluid. Regarding bacterial viability, no decays were observed neither when pectin-decorated nanoparticles were exposed to simulatedfluids nor when stored at 4ºC for 60 days.The main achievement of this work was to engineer a probiotic delivery system based on iron nanoparticles and pectins. Its efficiency for both iron deliver and bacterial stabilization converts it in a functional ingredient contributing to overcome iron deficiency at the population level, with potential applications in the development of functional foods.