A Comprehensive Review of Preservation Techniques for Probiotic Lactic Acid Bacteria: Focus on Cryopreservation and Lyophilization

Abstract

Lactic acid bacteria (LAB) are crucial for food fermentation and offer nutritional and health benefits, particularly as probiotics. However, maintaining their viability and functionality during processing and storage remains a significant challenge. This comprehensive review examines the effectiveness, benefits, and limitations of cryopreservation and lyophilization techniques for preserving probiotic LAB strains. Cryopreservation involves storing biological materials at ultra-low temperatures to prolong viability, whereas lyophilization removes water through sublimation, enabling room temperature storage and easier transportation. The survival of LAB during these processes is influenced by factors such as the bacterial strain, cultivation conditions, cryoprotectants, and processing parameters. Cryoprotectants such as trehalose and lactose provide additional protection against stress-induced damage. Despite these advancements, further research is needed to develop strain-specific preservation protocols, enhance probiotic survivability in the gastrointestinal tract, and improve cost efficiency for large-scale applications. Challenges include differences between strains, maintenance of probiotic stability and functionality over time, and making these methods practical and cost-effective for industrial use. By identifying research gaps, this review aims to guide future studies to optimize LAB preservation techniques and ensure their sustained efficacy for health benefits and industrial utilization. Overcoming these challenges is essential for the effective incorporation of probiotics into functional foods and their broader use in promoting human health.