Nisin:Carboxymethylcellulose polyion complex (PIC) nanoparticles. Preparation and antimicrobial activity

Area of Science:

• Food Science and Technology
• Biotechnology
• Materials Science

Background:

• Nisin, a natural antimicrobial peptide, is effective against Gram-positive bacteria but degrades when interacting with food components.
• There is a need for improved formulations to enhance nisin's stability and efficacy as a food preservative.

Purpose of the Study:

• To investigate the use of Carboxymethylcellulose (CMC) for protecting nisin and extending its antimicrobial activity.
• To optimize nisin:CMC nanoparticle formulations for enhanced encapsulation and stability.

Main Methods:

• Optimization of nisin:CMC ratio, pH, and CMC degree of substitution for nanoparticle formation.
• Characterization of nanoparticle size, charge, and encapsulation efficiency.
• Evaluation of the antimicrobial activity of nisin:CMC nanoparticles against Staphylococcus aureus in milk.

Main Results:

• Optimized formulations achieved over 60% w/w nisin loading and approximately 90% encapsulation efficiency.
• Nisin:CMC nanoparticles demonstrated significant inhibition of Staphylococcus aureus growth in milk.
• Effective inhibition was achieved at one-tenth the concentration of nisin typically used in dairy products.

Conclusions:

• Nisin:CMC nanoparticles offer a stable and effective platform for nisin delivery as a food preservative.
• The affordability of CMC and simplicity of preparation make these nanoparticles a promising alternative for food pathogen control.
• This approach enhances nisin's antimicrobial efficacy, potentially leading to improved food safety and reduced preservative usage.