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 degrees C. In contrast, the lowest viability of encapsulated and free probiotics was observed at 20 degrees 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.

Automated summary

The study showed that the highest powder production yield was obtained at lower voltage and WPI/Lac ratio. The viability of free and encapsulated L. acidophilus was influenced by storage temperatures, with the highest viability observed at 4 degrees C. The optimized electrosprayed capsules were spherical, round, and smooth, with an average size distribution of 435 nm.