Encapsulation of Lactobacillus plantarum ATCC 8014 and Pediococcus acidilactici ATCC 8042 in a freeze-dried alginate-gum arabic system and its in vitro testing under gastrointestinal conditions

Abstract

The aim of this study was to investigate the viability of Pediococcus acidilactici ATCC 8042 and Lactobacillus plantarum ATCC 8014 in a freeze-dried capsules system prepared with sodium alginate and gum arabic using the extrusion technique. The capsules made with alginate 2% (w/v)/gum arabic 2% (w/v) showed higher hardness (7.12 ± 0.71 N), with highly cohesive (0.81 ± 0.02) and elastic (0.99 ± 0.00) features on the Texture Profile Analysis (TPA), as well as higher sphericity with 1.75 ± 0.12 mm y 1.73 ± 0.13 mm diameter axes and regularity in their surface by Scanning Electron Microscopy (SEM). The use of skimmed milk at 10% as a cryoprotector in the freeze-drying process allowed the obtention of high viability percentages (88% a 96%) for both strains. Best results of viability for P. acidilactici encapsulated was with the use of alginate 2% (w/v)/gum arabic 2% (w/v) (92%±2.65), and L. plantarum with the use of alginate 2% (w/v) (84.71%±10.33) during the gastrointestinal environment challenge.

Keywords: Encapsulation; extrusion; freeze-drying; gum arabic; probiotics; sodium alginate.