Aims: Probiotics are claimed to confer many health effects upon consumption. However, the survivability of probiotic under the harsh conditions in the gastrointestinal tract has been a challenge. This study aimed to improve the survivability of Lactobacillus rhamnosus GG under gastrointestinal condition through co-extrusion microencapsulation and the addition of black bean extract. Methodology and results: Optimization was carried out on wall material formulation, types of pectin (low and high methoxyl pectin) and alginate: pectin ratio (2:1 and 3:1), and black bean extract concentration (0 to 1% w/v) to produce capsules with desired properties. The effect of L. rhamnosus GG microencapsulation with and without black bean extract on its survivability under simulated gastrointestinal conditions was also investigated. The optimal formulation that gives the highest microencapsulation efficiency (86.17%) was low methoxyl pectin, alginate: pectin ratio at 3:1, and 0.5% (w/v) of black bean extract. The inclusion of black bean extract into L. rhamnosus GG microencapsulation showed no significant effect (p >0.05) on the capsule diameter, with a mean diameter of 715.44 µm and a high microencapsulation efficiency of 97.4%. The viability of encapsulated L. rhamnosus GG increased with black bean extract after 6 h of sequential digestion with the final viable cell count of 12.47 log10 CFU/mL, which meet the minimum requirement of 10^6-10^7 log10 CFU/mL viable cells. Conclusion, significance and impact of study The high microencapsulation efficiency and survivability through sequential digestion showed that the optimized encapsulated L. rhamnosus GG with black bean extract has the potential to be a value-added ingredient in food application.
Lacticaseibacillus rhamnosus ; Alginates ; Phaseolus