Evaluation of the processes effect of scale-up and encapsulation by electrospinning on the viability of Lactobacillus fermentum K73

Abstract

The global probiotics market is one of the functional food industries that are growing faster. Probiotic production involves several stages from biomass production at bioreactor until encapsulation of the cells. At all stages, the viability, and the ability to tolerate the simulated gastrointestinal conditions must maintain to exerts beneficial effects on the consumers. Hence, the study aimed to evaluate the process of scale-up and encapsulation by electrospinning on the viability of Lactobacillus fermentum K73. A change of scale cultivation at bioreactor was done from 1.3 L to 14 L, oriented in criteria as volumetric oxygen transfer coefficient (kLa) and impeller tip speed. At two scales, the viability was similar at the end of the fermentation, and the percentage of survival undersimulated gastrointestinal conditions was too. Mathematical models were used to calculate the kLaand the impeller tip speed on the 14 L reactor. At the encapsulation by electrospinning, the formulation that maximized the bacterial change cycles after blending and under simulated gastrointestinal conditions was 0.66/0.34. Moreover, the conditions that improve the encapsulation yield during the electrospinning process were 200 g/L of bacteria cultureat the mixture, 2.5 w/w% of soy lecithin, and 7 cm of collector distance. The experimental encapsulation yield at the end of the process was 80.7%, with an experimental error of 7.2%. Also, the SEM micrographs showed theproduction of fibers with beads of gelatin and culture media. The encapsulation improved the viability of the probiotic under simulated gastrointestinal conditions compare to free cells. This work achieved to keep the probiotic viability and the survivalunder simulated gastrointestinal conditions when the fermentation process was scale-up from 1.3 L to 14 L reactors. Lactobacillus fermentum K73 was successfully encapsulated by electrospinning being the producea.