Optimization of mechanical convective drying parameters for fermented uf-18 cacao beans using response surface methodology

Rick Ryan G. Renegado; Harvey Bryant M. Marquez; Cresencio Pombo Genobiagon Jr.

doi:10.15282/ijame.23.3.2026.8.1044

Authors

Rick Ryan G. Renegado Mechanical Engineering Program, University of Mindanao, Matina Campus, Davao City, Philippines , University of the Philippines Mindanao
Harvey Bryant M. Marquez Mechanical Engineering Program, University of Mindanao, Matina Campus, Davao City, Philippines , University of the Philippines Mindanao
Cresencio Pombo Genobiagon Jr. Mechanical Engineering Program, University of Mindanao, Matina Campus, Davao City, Philippines , University of the Philippines Mindanao https://orcid.org/0000-0003-2491-5793

DOI:

https://doi.org/10.15282/ijame.23.3.2026.8.1044

Keywords:

Dryer, Bean, Drying time, Temperature, Air velocity

Abstract

Mechanical drying is considered an efficient drying technique; however, continuous mechanical drying may compromise flavor and textural properties. This study aimed to create optimized drying parameters of fermented UF-18 cacao beans using a laboratory scale mechanical dryer and Response Surface Methodology (RSM). A central composite design consisting of 20 experiments was conducted within temperature ranges of 29.77 to 80.22 °C, air velocity of 0.5 to 1.5 m/s, and relative humidity of 10 to 20%. Drying time and bean quality were evaluated as response variables. The drying time was a linear function (Adjusted R² = 0.9854, Predicted R² = 0.9783), with temperature as the most significant factor (p < 0.05). Drying at 80.22 °C achieved the shortest drying time of 12 h but resulted in poor quality (score 5). The optimum conditions were at 57.85 °C, air velocity of 0.5 m/s and relative humidity of 10% under intermittent drying with predicted drying time of 34 h and bean quality score of 8.83 with desirability of 0.95.

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