Drying (dehydration) of fruits and vegetables may be achieved with small investments and many high quality products may be obtained that are not prone to spoilage. Drying is the simplest and most natural way of all procedures for food conservation, by which food freshness is preserved given that most of free water is extracted from it. Lower level of water content slows down respiration rate, enzyme reactions and overall velocity of spoilage, due to which products become more durable for keeping and much easier and cheaper for storing and transport. Though it is possible to dry all kinds of bioproducts, not all dried products are of high quality and taste after dehydration.
Drying may be carried out naturally on the sun (direct drying on the sun) or ventilation and heat may be added in order to accelerate drying process (electro, gas or diesel drying plants). Solar drying is the cheapest method, and it can be applied if the weather is dry and warm during products gathering. However, it is the slowest method and often results in products of lower overall quality. Pretreatments, such as blanching and plunging into solution of ascorbic acid prior to drying, assists that losses of nutrients, colour, taste and flavour are reduced, which occurs during drying process. The dried products may be improved during drying by adding e.g. some spices to vegetables or sweetening fruits with sugar or honey.