Process optimization and ethanol use for obtaining white and red dragon fruit powder by foam mat drying

Area of Science:

• Food Science
• Food Engineering
• Drying Technology

Background:

• Dragon fruit is nutritious but highly perishable.
• Drying extends the shelf life of fruits by reducing moisture content.

Purpose of the Study:

• To optimize foam mat drying for white and red dragon fruit powder.
• To evaluate the impact of ethanol pretreatment and air temperature on drying kinetics.

Main Methods:

• Foam properties (density, stability, porosity, overrun) were optimized.
• Foams underwent ethanol pretreatment and convective drying at 50°C or 70°C.
• Drying kinetics, effective moisture diffusivity (D_eff), and drying rate (DR) were analyzed.

Main Results:

• Optimal foam conditions were determined for both white (26.88 min, 4.12 kg/100kg) and red (23.5 min, 3.44 kg/100kg) dragon fruit.
• Ethanol pretreatment and higher drying temperatures (70°C) resulted in shorter drying times and increased D_eff and DR.
• Foam mat drying is suitable for perishable fruits like dragon fruit.

Conclusions:

• Optimizing foam properties is crucial for successful foam mat drying.
• Ethanol pretreatment and drying air temperature significantly influence drying kinetics.
• Foam mat drying is a viable method for producing dragon fruit powder.