New Method for Fingerprinting Probiotics by Physico-chemical Approaches

Nowadays, there is a growing interest in probiotics owing to their high potential therapeutic and preventive health effects. These beneficial microorganisms are natural, relatively safe, and can be incorporated in food (dairy products, meats, beverages, supplements) and non-food products (cosmetics, drugs, and so on). As existing microorganisms since many centuries, both scientists and industries are only trying today to discover and better understand their roles, behaviors, mechanisms, and functionalities, which have been proved to beneficial for human, animal and plant species. However, the quality of probiotic products depends on many factors such as, the properties of each individual strain and its proportion in mixed products, the viable probiotic dose, and other selective ingredients like prebiotics and protectant agents incorporated into the formulation. Several strategies have been employed for generating and ensuring high-quality profitable products through different methods and techniques. Most of them are based on biological, biochemical and/or physiological methods. Nevertheless, physico-chemical approaches appear very attractive, but less exploited for characterizing and controlling microorganism qualities and performances. It particularly consists in characterizing probiotic products in terms of thermal, surface and colloidal properties, which could be correlated to probiotic viability and functionalities. In this communication, a new method for fingerprinting probiotics at the solid state is described and illustrated. It consists in coupling simultaneously the thermogravimetry and differential scanning calorimetry techniques for generating specific thermal data related to the material phase decomposition and transition (temperatures, rates, mass losses, enthalpies, etc.) for both single and multiple strains, belonging to the main probiotic classes which includes bacteria (Lactobacilli, Bifidobacteria, Streptococcus, Bacillus) and yeasts (Saccharomyces). Such an approach has been successfully relevant for discriminating high concentrated multistrain-based formulation samples of identical brand but from different production sites.