Development of Lactobacillus acidophilus LA5-loaded whey protein isolate/lactose bionanocomposite powder by electrospraying: A strategy for entrapment.

This study aimed to investigate the effect of voltage (6, 9, and 12 kV) and whey protein isolate (WPI) to lactose (Lac) ratio (3:1, 4:1, and 5:1) on the fabrication of Lactobacillus acidophilus LA5-loaded bionanocomposite powder by the electrospraying method. The highest powder production yield obtained at the lowest value of voltage and WPI/Lac ratio. The entrapment efficiency increased with increasing voltage and decreasing WPI/Lac ratio. After 28 days of storage, respectively a significant and non-significant reduction in the viability of free and encapsulated L. acidophilus was observed. The highest viability of encapsulated and free probiotics was observed at 4 °C. In contrast, the lowest viability of encapsulated and free probiotics was observed at 20 °C. The morphology of the optimized electrosprayed capsules was spherical, round, and smooth. The average size distribution of the electrosprayed capsules was 435 nm. The results of FTIR showed that probiotic bacteria were loaded within the optimized bionanocomposite powder. Investigating the thermograms of the optimized electrosprayed particles and pure powder of WPI and Lac showed that the glass transition temperature of the electrosprayed particles with L. acidophilus was near to that of its polymeric materials. [Display omitted] • L. acidophilus LA5 was loaded successfully in WPI/lactose bionanocomposite powder by electrospraying. • The viability of the loaded L. acidophilus LA5 was studied at −18, 4 and 20 °C during 28 days. • The SEM images of the electrosprayed capsules optimized were spherical, round, similar, and smooth. • The FTIR showed it was possible to establish physical and chemical bonds between probiotic bacteria and used polymers. [ABSTRACT FROM AUTHOR]