Effects of polymerised whey protein-based microencapsulation on survivability of Lactobacillus acidophilus LA-5 and physiochemical properties of yoghurt

Abstract

Lactobacillus acidophilus LA-5 has poor survivability in yoghurts. This study aims to microencapsulate L. acidophilus LA-5 using polymerised whey protein as wall material and evaluate its survivability and effects on physiochemical properties of yoghurts. The microencapsulation yield was 92.90% and average beads size was 744 μm. Microencapsulated L. acidophilus LA-5 showed higher survival at simulated gastrointestinal conditions. Microencapsulated L. acidophilus LA-5 had improved survivability (∼10⁶ cfu/mL) than free cells (∼10⁴ cfu/mL) after digesting by simulated intestinal juice (6 h) in yoghurts during 10-week storage. Microencapsulated L. acidophilus LA-5 improved the firmness and protein content and decreased the spontaneous whey separation and synaeresis of yoghurts significantly (p < 0.01). Changes in pH and free microorganism population of yoghurts during storage were not affected by adding microencapsulated L. acidophilus LA-5. Microencapsulation of L. acidophilus LA-5 using polymerised whey protein as wall material improved its survivability and the physiochemical properties of the yoghurt.

Keywords:

• Lactobacillus acidophilus LA-5
• whey protein
• microencapsulation
• survivability
• cow/goat milk yoghurt

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors would like to thank the Ministry of Science and Technology of China (Project# 2013BAD18B07) for financial support of this project.