Chitosan-glucose derivative as effective wall material for probiotic yeasts microencapsulation.

Area of Science:

• Biomaterials Science
• Food Science and Technology
• Microbiology

Background:

• Chitosan is a widely used biopolymer, but its native form may exhibit limitations for specific applications.
• Probiotic yeast encapsulation requires protective materials that maintain viability and functionality.
• The Maillard reaction offers a method to modify biopolymers like chitosan.

Purpose of the Study:

• To synthesize and characterize a chitosan-glucose derivative (ChG) via the Maillard reaction.
• To evaluate the antioxidant, cytotoxic, and antimicrobial properties of the synthesized ChG.
• To assess the efficacy of ChG as a wall material for spray-dried microencapsulation of the probiotic yeast *K. marxianus* VM004.

Main Methods:

• Synthesis of ChG using the Maillard reaction.
• Characterization of ChG using FT-IR, 1H NMR, and SLS to determine structure, deacetylation degree (DD), and molecular weight (Mw).
• Evaluation of antioxidant, cytotoxic, and antimicrobial activities of ChG.
• Microencapsulation of *K. marxianus* VM004 using ChG as a wall material via spray drying.
• Characterization of microcapsules for encapsulation efficiency, morphology, gastrointestinal tolerance, and storage stability.

Main Results:

• The Maillard reaction yielded a ChG derivative with lower molecular weight and deacetylation degree but enhanced antioxidant activity compared to native chitosan.
• The synthesized ChG was non-cytotoxic.
• ChG microcapsules containing *K. marxianus* VM004 demonstrated high encapsulation efficiency (>57%).
• Microcapsules exhibited improved tolerance to simulated gastrointestinal conditions and enhanced storage stability.

Conclusions:

• The chitosan-glucose derivative (ChG) synthesized via the Maillard reaction possesses favorable antioxidant and non-cytotoxic properties.
• ChG is an effective wall material for microencapsulating probiotic yeast *K. marxianus* VM004.
• ChG microcapsules provide enhanced protection to probiotic yeast, improving their stability and survival under challenging conditions, indicating potential for functional food applications.