A coupled ODE-diffusion modeling framework for removing organic contaminants in crops using a simple household method

Area of Science:

• Food safety
• Environmental chemistry
• Chemical engineering

Background:

• Organic contaminants in fresh crops pose significant human health risks.
• Effective removal methods are crucial for mitigating these risks.
• Water soaking is a common household method for cleaning produce.

Purpose of the Study:

• To develop a diffusion-based model for estimating organic contaminant removal efficiency in fresh crops using water soaking.
• To identify key factors influencing contaminant removal.
• To provide a theoretical framework for optimizing washing protocols.

Main Methods:

• A diffusion-based model framework was developed.
• The model incorporates diffusion coefficients and octanol-water partition coefficients (Kow) of contaminants.
• Crop macro-properties (e.g., surface area) and contaminant properties were analyzed.

Main Results:

• Removal efficiency (RF) shows an inverse-exponential relationship with log Kow, limiting removal for high log Kow chemicals.
• Chemical diffusion coefficients in water influence kinetic removal rates.
• Crop macro-properties, like surface area interacting with water, have a greater impact than micro-properties or contaminant physiochemical properties.

Conclusions:

• The model provides insights into the thermodynamic and kinetic limitations of contaminant removal by water soaking.
• Refreshing the water during soaking can significantly improve removal efficiency, especially for persistent contaminants.
• The findings suggest optimizing washing protocols by considering crop surface characteristics and contaminant properties.