Response surface methodology for optimizing osmotic dehydration of papaya slices

Abstract:

Osmotic dehydration is defined as the partial removal of water from plant tissues by immersion in a hypertonic solution, and it has emerged as an energy-efficient pre-treatment step for producing intermediate-moisture fruit products. This research applied Response Surface Methodology (RSM) with a Central Composite Design (CCD) to optimise osmotic dehydration conditions for papaya (Carica papaya L. cv. Red Lady) slices. Three independent variables sucrose concentration (30-60 °Brix), solution temperature (40-60 °C), and immersion time (2-6 hours) were investigated for their effects on water loss, solid gain, and overall mass loss. Experiments were carried out at the Sierra Madre Institute of Organic Agriculture, Colima, between February and July 2023. Second-order polynomial models fitted to each response showed high coefficients of determination (R² = 0.94-0.97). The optimal conditions identified were 48.3 °Brix, 52.1 °C, and 4.2 hours, yielding a predicted water loss of 38.6%, solid gain of 9.4%, and mass loss of 29.2%. Validation experiments confirmed the predictions within ±4.1% error. These optimised parameters offer papaya processors a reliable starting point for pilot-scale osmotic dehydration.