Effect of drying methods on Lactobacillus Rhamnosus GG microcapsules prepared using the complex coacervation method

Area of Science:

• Food Science and Technology
• Microbiology
• Biotechnology

Background:

• Lactobacillus rhamnosus GG (LGG) is a beneficial probiotic with limited stability, necessitating methods to enhance its survival and efficacy.
• Microencapsulation is a promising strategy to protect LGG from inactivation and prolong its physiological benefits.
• The choice of drying method significantly impacts the properties and stability of microencapsulated probiotics.

Purpose of the Study:

• To evaluate the physical properties and stability of Lactobacillus rhamnosus GG (LGG) microcapsules prepared using complex coacervation and dried by spray or vacuum freeze drying.
• To compare the resistance of spray-dried and vacuum freeze-dried LGG microcapsules to simulated gastrointestinal conditions, bile salts, and storage.
• To provide insights into selecting optimal drying methods for LGG microcapsule preparation and application.

Main Methods:

• Lactobacillus rhamnosus GG (LGG) microcapsules were prepared via complex coacervation.
• Microcapsules were dried using spray drying and vacuum freeze drying techniques.
• Physical properties, encapsulation efficiency, water content, and survival rates under simulated gastrointestinal conditions, bile salt exposure, and various storage conditions were assessed.

Main Results:

• Both spray and vacuum freeze drying yielded LGG microcapsules with low water content (<2.80%) and high encapsulation efficiency (>93.21%).
• Microencapsulated LGG demonstrated high survival rates (>96%) under simulated gastrointestinal conditions.
• Spray-dried LGG microcapsules exhibited superior resistance to bile salts (110.89% higher survival) and better stability under low water activity compared to vacuum freeze-dried counterparts.
• Both methods showed good LGG survival after 8 weeks at -18°C, with minimal loss at 4°C and 25°C.

Conclusions:

• Spray drying and vacuum freeze drying are viable methods for producing stable Lactobacillus rhamnosus GG (LGG) microcapsules.
• Spray drying appears to be a more advantageous method for enhancing LGG microcapsule stability against bile salts and low water activity.
• Understanding the impact of drying methods is crucial for optimizing LGG microcapsule formulation for improved probiotic applications.