Improved Viability of Probiotics via Microencapsulation in Whey-Protein-Isolate-Octenyl-Succinic-Anhydride-Starch-Complex Coacervates

The aim of this study was to microencapsulate probiotic bacteria (Lactobacillus acidophilus 11073) using whey-protein-isolate (WPI)-octenyl-succinic-anhydride-starch (OSA-starch)-complex coacervates and to investigate the effects on probiotic bacterial viability during spray drying, simulated gastrointestinal digestion, thermal treatment and long-term storage. The optimum mixing ratio and pH for the preparation of WPI-OSA-starch-complex coacervates were determined to be 2:1 and 4.0, respectively. The combination of WPI and OSA starch under these conditions produced microcapsules with smoother surfaces and more compact structures than WPI-OSA starch alone, due to the electrostatic attraction between WPI and OSA starch. As a result, WPI-OSA-starch microcapsules showed significantly (p < 0.05) higher viability (95.94 & PLUSMN; 1.64%) after spray drying and significantly (p < 0.05) better protection during simulated gastrointestinal digestion, heating (65 & DEG;C/30 min and 75 & DEG;C/10 min) and storage (4/25 & DEG;C for 12 weeks) than WPI-OSA-starch microcapsules. These results demonstrated that WPI-OSA-starch-complex coacervates have excellent potential as a novel wall material for probiotic microencapsulation.

Automated summary

The aim of this study was to microencapsulate probiotic bacteria using various materials and investigate their effects on bacterial viability. The combination of whey-protein-isolate and octenyl-succinic-anhydride-starch produced microcapsules with excellent protection during different processes. These findings suggest that this combination has potential as a novel wall material for probiotic microencapsulation.