Evaluation of the drying kinetics of a cidra snack impregnated with coffee leaf extract

Fruit, vegetables and vegetable extracts have a very reduced lifespan under environmental conditions, because some compounds degrade easily and the amount of moisture present in them makes it difficult to retain some biochemical and sensory properties over time for consumption and storage; Therefore, more cost-effective alternatives such as vacuum impregnation and refractance window drying (VR) techniques are sought which favour the preservation of physico-chemical and nutritional characteristics of food. The aim of this research was to evaluate the refractance window drying kinetics of a cidra snack impregnated with vacuum coffee leaf extract. Vacuum (IV) impregnated 2 mm thick circular sheets of citron with a 1.5% solution of coffee leaf extract for 30 min, then the sheets dried by the refractance window (VR) technique at a temperature of 70°C in a Mylar membrane. Drying kinetics were performed up to constant weight by measuring the moisture ratio (MR) in kg H2O/kg ss every 10 min. The kinetics results showed that the equilibrium point was in a time of 1.8 hours (110 min) when reaching a mass of 0.0012 kg. At this point of equilibrium the snack presented a moisture percentage of 0%, allowing its preservation for a long time. To conclude, the combination of cidra and coffee leaf extract represents an alternative for the conservation of bioactive components, such as phenolic compounds, antioxidant activity, among others.