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The drying process of vegetable species is a widely used technique for food conservation. The process requires large amounts of energy and it is responsible for the emission of pollutants to the environment. Therefore, many investigations have been made in order to improve the energy aspects of the process. It is very common that the effect of temperature and drying air mass-flow rate on the drying process are included in research but the effect of the turbulence level has not been studied yet. In this paper, the effect of the drying air turbulence level, temperature and mass-flow rate in the drying time, efficiency and energy consumption involved in the drying process of three types of chilies are studied. Under the conditions studied the turbulence level is the most influential factor in the drying process, followed by drying temperature. Also, the energy invested in increasing the turbulence level is very advantageous.

The drying process of vegetables is a widely used technique for food conservation. However, this process can be expensive, and the cost highly depends on the ventilation, drying temperature and drying characteristics of the chillies. The contribution of this new study was to obtain the drying kinetics parameters of two different types of Mexican Capsicum annuum (Puya and Mulato) and model it at different temperatures with two different ventilation levels. The aim of this study is to provide a method to analyse the cost of the drying process by studying its drying kinetics parameters. The experimental results were fitted to Weibull distribution and Newton’s model, obtaining an adequate numerical fit at different drying temperatures. The Weibull distribution demonstrates to be a better fit than Newton’s model. Drying kinetics parameters were also studied by a diffusive model with effective diffusivity. The effect of temperature on the diffusivity was described by the Arrhenius equation with activation energy of 49.7 kJ mol−1 for Puya and 24.1 kJ mol−1 for Mulato. The ventilation effect on chilli drying kinetics parameters was qualitatively assessed. As expected, the ventilation effect improved the drying rate and reduced the drying time, and consequently the cost of the drying process was reduced. In addition, a new method is presented to evaluate the cost of the drying process considering the kinetic parameters obtained. This new method allows evaluating the cost of the drying process in a simple way and with little experimental work. Consequently, it is possible to greatly reduce the cost of the drying process.