Bacterial viability retention in probiotic foods: a review

Probiotics offer substantial health benefits, leading to their increased consumption in various food products. The viability of probiotics is a critical factor that influences the nutritional and therapeutic efficacy of these foods. However, as probiotics often lose viability during production and oral administration, effective preservation and encapsulation technologies are needed to overcome this challenge. This review elucidates the diverse sources and incorporation strategies of probiotics, while systematically analyzing the effects of water transformation (ice front velocity, glass transition temperature, and collapse temperature), processing conditions (food matrix, temperature, and dissolved oxygen), and gastrointestinal challenges (gastric fluid, digestive enzymes, and bile salts) on probiotic viability. Effective strategies to strengthen probiotic viability encompass three primary domains: fermentation processes, production techniques, and encapsulation methods. Specifically, these include meticulous fermentation control (nitrogen sources, lipids, and carbon sources), pre-stress treatments (pre-cooling, heat shock, NaCl stress, and acid stress), optimized lyoprotectant selection (carbohydrates, proteins, and polyols), synergistic freeze-drying technologies (infrared technology, spray drying, and microwave), bulk encapsulation approaches (polysaccharide or protein-based microencapsulation), and single-cell encapsulation methods (self-assembly and surface functionalization). Despite these advancements, targeting specific probiotics and food matrices remains challenging, necessitating further research to enhance probiotic viability.