Aims:Probiotics are living microorganism, when administrated in sufficient quantity can exert beneficial effect to the host. This study focused on the microencapsulation by co-extrusion to increase the viability of Lactobacillus plantarum 299v (Lp299v) in gastrointestinal conditions, and its storage stability in kuini juice at refrigerated (4 °C) and ambient temperature (25 °C).

Methodology and results:Lp99v was encapsulated with 1.5% w/v sodium alginate and chitosan coating (0.1% w/v) and yielded a microencapsulation efficiency of 97.71%. The Lp299v microbeads produced were spherical in shape and exhibited a mean microbeads size of 618.75 ± 25.85 µm. Acid and bile tolerance of both free and encapsulated Lp299v were tested in simulated gastric juice (SGJ) for 2 h and in simulated intestinal juice (SIJ) for 4 h, respectively. The encapsulated Lp299v maintained above 108 CFU/mL after exposure to artificial gastrointestinal juice, whereas a significant loss of viability was observed in the free cells. The storage stability of encapsulated Lp299v in kuini juice was determined during 4 weeks of storage at 4 °C and 25 °C. Results showed that encapsulated Lp299v was capable to remain viable (107 CFU/mL) for at least 4 weeks in a refrigerated condition. However, free Lp299v did not survived under both refrigerated and ambient temperature as the storage period extended.

Conclusion, significance and impact of study:Lp299v entrapped in chitosan-coated alginate microbeads produced by co-extrusion method is able to enhance the viability of Lp299v above the minimum recommended level in harsh environment (gastrointestinal conditions and low pH of kuini juice).