Analysis of Environmental Variables During Apple Dehydration

Variability of the solar resource represents a challenge in the solar dehydration of fruits. To control the kinetics of solar dehydration, the behavior of the variables with the greatest impact on fruit dehydration is characterized: ambient temperature, relative humidity, wind speed and irradiance. 876,000 data of these four environmental variables were obtained from a meteorological station located in the city of Guanajuato (Mexico). The data correspond to the dehydration period of 8:00 to 18:00 h during the year 2023. Classified into quartiles and represented in Box-Whiskers diagrams, the data was analyzed in their distribution and symmetry. Experimental tests were carried out for apple dehydration during the four seasons of the year 2023, considering the shrinkage of the fruit (radius and thickness). The impact of environmental variables on the drying kinetics was determined. The shortest drying times of up to 5 h (April), were obtained even when the highest levels of wind speed were recorded (6.65 m/s). Ambient temperature and relative humidity significantly impact drying kinetics, increasing drying times by up to 40 %. This analysis allows standardizing the dehydration process in an indirect solar dehydrator even under variable punctual, monthly and seasonal environmental conditions.