Survivability of free and microencapsulated Lactobacillus plantarum with alginate and resistant starch in simulated gastrointestinal conditions.

摘要

The main objective of this study was to examine survivability of free and microencapsulated Lactobacillus plantarum PTCC 1058 with alginate and resistant starch in simulated gastrointestinal conditions. Mixtures of sodium alginate (2% w/v) and resistant starch (2% w/v) were prepared and pure bacterial mass (1% v/v) was added into the mixture. Then microcapsules were prepared by the use of emulsion method. Mean size of beads was 19.87+or-1.49 micro m obtained by the Scanning Electron Microscopy (SEM). The survivability of free and encapsulated cells of L. plantarum was examined in 0.6% (w/v) bile salt solution (pH 8.25), simulated gastric juice (pH 1.55) and simulated intestinal juice with and without 0.6% (w/v) bile salt (pH 7.43) by incubation at 37 degrees C with 50 rpm mechanical tension for 120 min. Survivability was investigated every 30 min by pour plate culture in MRS agar and incubation at 37 degrees C for 72 h. All of the stages were carried out with triplicate trials. Encapsulated L. plantarum could reach to the colon by the viable count of 6.48 and 7.23 log CFU/ml live cells, respectively, at the presence and absence of bile salts in the intestinal juice, whereas, free bacteria could reach to the colon by 4.6 log CFU/ml live cells which is not sufficient for its probiotic function. Statistical analyses with ANOVA and independent t-test showed that the survivability of encapsulated bacteria was significantly higher than that of free bacteria (P<0.05). It is concluded that microencapsulation of L. plantarum with calcium alginate and resistant starch can effectively protect these bacteria against gastrointestinal adverse conditions.