Encapsulation of Lactobacillus casei ATCC 393 in alginate capsules for probiotic fermented milk production

Abstract

The aim of the present study was to investigate encapsulation of probiotic Lactobacillus casei ATCC 393 on alginates using the extrusion technique and to evaluate cell survival under simulated gastrointestinal conditions and during fermented milk production and storage at 4 degrees C for up to four weeks. Encapsulation of probiotic bacteria led to significantly higher viabilities compared to free cells under simulated gastrointestinal conditions, as well as after storage for 28 days in fermented milk (7.13 log cfu g(-1)). In addition, the effect of encapsulated L. casei ATCC 393 cells on aroma volatile compounds formation during milk fermentation was studied using the SPME GC/MS technique. The fermented milks presented improved aroma, containing characteristic compounds produced usually by L. casei in fermented dairy products. The results showed that the alginate matrix has a great potential as encapsulation material for probiotics and application of the encapsulated cells in fermented dairy products may result in effective maintenance of cell survival during refrigerated storage and improvement of sensory characteristics. From an economical point of view and under certain conditions, the application of encapsulated probiotic cells is a sustainable process for the production of fermented milk.