Avaliação de um secador rotatório com recheio de inertes na desidratação do camu-camu (myrciaria dubia)

Abstract

Camu-camu (Myrciaria dubia) is a tropical fruit native to the Amazon region, which has aroused interest due its high content of vitamin C, significantly higher than those found in citric fruits as orange, lemon and acerola. In the same time, a large number of other compounds have also identified in this fruit, such as phenolics and carotenoids, which have a high antioxidant power and are beneficial to health. However the camu-camu fruit is characterized by its high moisture content, which favors bacterial growth and degradation The objective of this work was to evaluate the dehydration of the camu-camu pulp using a rotary drier with inert bed.The equipment stands out due to the feasibility of drying pasty materials and obtaining products directly in the form of powder, which can be used in a variety of applications. A problem that may occur during drying or storage of certain powder foods is the stickiness and compaction, which occur when the particles of the material exhibiting a high cohesion and adhesion to the wall and other structures of the dryers. In order to solve this problem, the effect of adding maltodextrin to the process, which is characterized by promoting greater drying stability by increasing the glass transition temperature of the material, has also been evaluated. The effects of different carrier concentrations (10, 15, 20 and 30%), the drying air temperatures (70, 90 and 110 ° C), the filling degree (21, 28 and 35%) and the velocity of rotation (55, 65 and 75 RPM) on the moisture removal method, the drying yield and the contents of bioactive compounds (total phenolics, total flavonoids, citric acid and ascorbic acid) were studied. The best condition found was at 90°C, 15% maltodextrin concentration, 28% filling degree and 65 RPM rotation, resulting in a drying yield of 55.33%. However, all experiments obtained satisfactory values of final moisture, water activity and bioactive compound contents.