Effect of drying methods (electrospraying, freeze drying and spray drying) on survival and viability of microencapsulated Lactobacillus rhamnosus ATCC 7469

Electrospraying, freeze and spray drying were used to microencapsulate Lactobacillus rhamnosus ATCC 7469 in whey protein isolate (WPI), whey protein isolate + inulin (WPI + IN) or whey protein isolate + inulin + Persian gum (WPI + IN + PG) matrixes. Physical properties, survivability, cell injuries and resistance to simulated gastrointestinal condition of L. rhamnosus ATCC 7469 microcapsules were examined. Cell damage evaluation showed that electrospray was more injurious to L. rhamnosus ATCC 7469 cells in comparison with other two methods, also Persian gum had the most protecting effect against cell damaging agents. The viability of encapsulated cells decreased from 10.60-10.97 log cfu/g in the first week to 8.72-10.78 log cfu/g in the last week of storage. Freeze drying and electrospraying showed the lowest and highest loss in cell survival during storage, respectively. Results showed the superiority of freeze-dried microcapsules to prolong L. rhamnosus ATCC 7469 survival when exposed to digestive system conditions.