Modeling and Optimization of Drying Rate and Quality Parameters of Dried Osmo-Pretreated Green Bell Pepper (Capsicum annuum)

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Faculty Physical Sciences and Faculty of Life Sciences, University of Ilorin, Nigeria.


A study on modeling and optimization of osmotic dehydration and drying of green bell pepper was carried out. Five levels of osmotic process durations (60 min, 90 min, 120 min, 150 min and 180 min) and five levels of osmotic solution concentrations (5% (w/w), 10% (w/w), 15% (w/w), 20% (w/w) and 25% (w/w) as input parameters were used. Design Expert 8.0.3 version was used to design the experiment in order to get all possible combinations of durations and concentrations. After pretreating all samples of fresh green pepper in hypertonic osmotic solution concentrations of NaCl for the required durations, they were all dried at 50˚C in a fabricated cabinet dryer. The following output parameters were modeled and optimized with Design Expert 8.0.3 version: drying rate, vitamin C, crude protein, crude fibre, fat, ash content, water loss, solid gain, shrinkage and rehydration ratio. Ten (10) model equations, one for each of the output parameters were developed, and checked for adequacy and validity. All developed model equations were found to present functional relationships between input and output parameters. Hence, all developed model equations can be used as reliable tools for estimating, predicting and conducting analysis of the process. Best optimized results were selected based on desirability (0 - 1). Drying rate (maximized), vitamin C (maximized), crude protein (maximized), crude fibre (maximized), fat (maximized), ash content (minimized), water loss (maximized), solid gain (maximized), shrinkage (minimized) and rehydration ratio (maximized) got desirability of 0.889, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 0.85, 0.734 and 0.868 respectively.



modeling, optimization, osmotic dehydration, drying, green bell pepper