A continuous production roselle (Hibiscus sabdariffa L.) dryer using solar energy.

There is now an urgent need to consume immediately products in short periods because they can quickly reach the decomposition. The use of solar energy in dehydrated agricultural products is an important element in our days, since through the appropriate use of technology high yields can be achieved in the postharvest products. With the designed and construction of solar dehydrator and using a system thermal control, it is possible to reduce the drying time of roselle (Hibiscus sabdariffa L.) 4 days for 5.098 h on average, with a standard deviation of 1.829. The experimental tests were run under a factorial design 3. The evaluation of the qualitative characteristics is performed by applying the methodology multi-criteria adjusts. This method of analysis compares the functionality of the dryer against other drying systems. The calculation tool is a powerful tool for food dryers that can simulate the drying system before building the prototype. The tool provides reliable results for good decision-making. With this, we obtain the equation that governs the process for drying time; it determines the capacity of the drying process, considering the response of variable final product moisture. The analysis reveals the behavior of the roselle within the tolerance limits of the process; a lower humidity at 11.05% and the higher humidity in 14.64% are obtained to standard deviations. With the experimental run average value is obtained from the final product moisture to 12.84%. A continuous production roselle dryer using solar energy could improve the quality of production and integrate the use of zero energy design in the agricultural sector.