Kombucha Fermentation With Dried Starter Cultures: A Strategy for Microbial Stabilization via Spray and Freeze Drying

Area of Science:

• Food Science and Technology
• Microbiology
• Fermentation Science

Background:

• Kombucha production faces challenges in reproducibility and scalability due to variable microbial consortia.
• Standardizing kombucha starter cultures is crucial for consistent product quality and industrial application.

Purpose of the Study:

• To evaluate the impact of spray drying (SD) and freeze drying (FD) on kombucha starter culture viability and metabolic activity.
• To assess the efficacy of maltodextrin (MD) and gum Arabic (GA) as drying carriers for kombucha cultures.
• To determine the fermentation performance and physicochemical properties of dried kombucha starter cultures.

Main Methods:

• Kombucha starter cultures were dried using SD and FD with MD and GA as carriers.
• Physicochemical properties (moisture, water activity, solubility) of dried cultures were analyzed.
• Fermentation performance, including acetic acid, ethanol, and total phenolic content, was evaluated.
• Microbial viability was assessed through cell count reductions.

Main Results:

• Dried cultures showed favorable physicochemical properties (low moisture, reduced water activity, high solubility).
• Gum Arabic (GA) effectively protected microbial viability during drying, with minimal cell count reduction (<1 log CFU/mL) in GA-SD and GA-FD treatments.
• Freeze-dried cultures resulted in higher total phenolic content and enhanced antioxidant activity in the final kombucha beverage.
• Maltodextrin-spray drying (MD-SD) treatment showed the lowest acetic acid concentration, indicating potential thermal damage.

Conclusions:

• Spray drying and freeze drying are feasible methods for producing stable kombucha starter cultures.
• Gum Arabic is a superior carrier for preserving microbial viability compared to maltodextrin.
• Dried kombucha starter cultures offer a promising solution for microbial stabilization and standardization in industrial kombucha production.