Nisin quantification by ELISA allows the modeling of its apparent diffusion coefficient in model cheeses

Area of Science:

• Food Science
• Biochemistry
• Chemical Engineering

Background:

• Solute diffusion is crucial for enzymatic reactions during cheese ripening.
• Limited data exists on peptide diffusion in cheese compared to salt.
• Nisin, a bacteriocin peptide, plays a role in cheese properties.

Purpose of the Study:

• To quantify the apparent diffusion coefficients of nisin in model cheeses.
• To investigate the effect of cheese composition (gelatin addition) on peptide diffusion.
• To establish a foundation for understanding peptide transport in cheese.

Main Methods:

• Utilized a profile concentration device for nisin migration studies.
• Employed a specifically developed enzyme-linked immunosorbent assay (ELISA) for nisin quantification.
• Modeled apparent diffusion coefficients using Fick's law.

Main Results:

• The average apparent diffusion coefficient for nisin in ultrafiltered (UF) cheese was 49.5 μm²/s.
• Adding 10% gelatin to the UF retentate reduced the nisin diffusion coefficient to 34.4 μm²/s.
• Differences in cheese macrostructure and microstructure correlated with diffusion rates.

Conclusions:

• This study presents the first apparent diffusion coefficients for a peptide in cheese.
• Cheese composition and microstructure significantly influence the diffusion of small solutes like peptides.
• Findings support the hypothesis that structural properties affect peptide mobility in cheese.