Efficacy of the incorporation between self‐encapsulation and cryoprotectants on improving the freeze‐dried survival of probiotic bacteria

• Published in: Journal of applied microbiology Vol. 132; no. 4; pp. 3217 - 3225
• Main Authors: Nguyen, Thi‐Tho, Nguyen, Phu‐Tho, Nguyen, Thi‐To‐Uyen, Nguyen, Thi‐Bich‐Nhu, Bui, Nhi‐Binh, Nguyen, Huu‐Thanh
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.04.2022
• Subjects: Alginates; Alginic acid; Bacteria; Carbon dioxide; Carbon dioxide concentration; Cell viability; Chemical synthesis; Cryoprotectants; Cryoprotective Agents - pharmacology; Cryoprotectors; Drying; Encapsulation; Environmental stress; Extracellular Polymeric Substance Matrix; extracellular polymeric substances; Extracellular polymers; Freeze Drying; Lactobacilli; Lactobacillus acidophilus; Microbial Viability; Microencapsulation; pH effects; Probiotics; Protein folding; stress; Stresses; Survival; Whey; Whey protein; stress; extracellular polymeric substances; freeze-drying; microencapsulation; probiotics
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.15473

Aims This study aimed to improve the viability of probiotic bacteria during freeze‐drying by the combination of self‐encapsulation and cryoprotectants. Methods and Results Lactiplantibacillus plantarum VAL6 and Lactobacillus acidophilus VAR1 were exposed to environmental stresses including temperature, pH and increased CO2 concentration before performing freeze‐drying with the addition of cryoprotectants. The results proved that tested stresses can stimulate the bacteria to synthesize more extracellular polymeric substances to form self‐encapsulation that increases their freeze‐dried viability. In combination with cryoprotectants to form double‐layered microencapsulation, L. plantarum VAL6 stressed at pH 3.5 in combination with whey protein isolate could achieve the highest Improving Cell Viability of 4361‐fold, while L. acidophilus VAR1 stressed at 25oC in combination with alginate gave a maximum Improving Cell Viability of 73.33‐fold. Conclusions The combination of self‐encapsulation and cryoprotectants significantly improves the freeze‐dried viability of probiotics. Significance and Impact of the Study This is the first report that uses environmental stress to stimulate extracellular polymeric substance synthesis for self‐encapsulation formation combined with the addition of cryoprotectants to enhance the freeze‐dried survival of probiotics. This could be a novel approach in improving the viability of probiotic strains for various applications.