Effect Of Microencapsulation And Coating On The Survivability Of Lactobacilli Probiotics In Yogurt And Gastrointestinal Conditions

Abstract

Microencapsulation of probiotics is an efficient way that can improve the viability rate of them in dairy products like yogurt as well as in lumen tract conditions. The viability of free and microencapsulated forms of Lactobacillus rhamnosus and Lactobacillus acidophilus were evaluated in yogurt and under simulated gastrointestinal conditions. Microencapsulation and double coating process carried out by alginate-chitosan and Eudragit S100 nanoparticles and by the extrusion method. Bacterial count (cfu g-1) of L. acidophilus reduced from 7.0×108to 4.2×106in day 0 and in day 42 in yogurt containing free bacteria, while the bacterial count of microencapsulated bacterium showed a reduction from 3.3×107to 2.5×107. Microencapsulation of L. rhamnosus could also increase the viability of this bacterium; 3.2×109to 5.8×106bacterial count by reduction of free-form storage, and 7.6×109to 3.4×108bacterial count by reduction of microencapsulated form in 42 days. On day 14 (first day of bacterial count in gastrointestinal condition) L. acidophilus count was 1.3×103and 5.0×107which reached 2.0×100and 2.8×104on day 42 in free and microencapsulated forms respectively. The bacterial count of L. rhamnosus decreased from 1.2×103to 5.0×100in free form, and from 2.5×107to 2.8×104in microencapsulated one. The results of this study suggest that this method of microencapsulation can improve the viability of L. rhamnosus and L. acidophilus in yogurt and in the simulated human gastrointestinal tract.