Smelling Peppers and Pout Submitted to Convective Drying: Mathematical Modeling, Thermodynamic Properties and...

Area of Science:

• Food Science and Technology
• Agricultural Engineering
• Biophysics

Background:

• Pepper (Capsicum spp.) fruits are highly perishable, necessitating effective preservation methods to extend their shelf life.
• Traditional preservation techniques are crucial for maintaining the quality, flavor, and pungency of peppers for culinary use.
• Understanding the drying process is key to developing value-added pepper products.

Purpose of the Study:

• To mathematically model the drying kinetics of smelling peppers and pout peppers (Capsicum chinense).
• To determine the thermodynamic properties associated with the pepper drying process.
• To investigate the impact of drying temperature on the proximal composition and energy value of peppers.

Main Methods:

• Whole peppers (Capsicum chinense) were dried in a forced air circulation oven at temperatures ranging from 50°C to 80°C.
• Ten mathematical models were fitted to the experimental drying data; the Midilli model showed the best fit.
• Effective diffusivities were calculated using the Arrhenius equation, and thermodynamic properties were analyzed.

Main Results:

• The Midilli model best described the drying kinetics for both pepper varieties across the studied temperatures.
• Effective diffusivities followed an Arrhenius relationship, with activation energies of 31.01 kJ·mol⁻¹ for smelling pepper and 30.11 kJ·mol⁻¹ for pout pepper.
• Increased drying temperature led to reduced water content and macronutrient concentrations, consequently increasing the energy value of the pepper powder.

Conclusions:

• The drying process for these peppers is non-spontaneous, characterized by positive enthalpy and Gibbs free energy, and negative entropy.
• Drying significantly alters the proximal composition, concentrating nutrients and increasing the energy value of the final product.
• The resulting pepper powders offer a viable alternative for industrial applications, serving as a new condiment or ingredient in food product formulation.