Dehydration of green banana to obtain flour: physical, chemical, functional and microstructure properties analysis during process and storage

Abstract

The preparation of food materials needs the application of efficient and cheap methods with ever higher quality required by the consumers.Convective drying with hot air and this technique in combination with other methods allow to produce a dried product which maintains (sometimes even improves) the nutritional, functional, taste and flavour properties. At the same time, the energy requirements and environmental pollutions are reduced. The use of dehydration processes allows no have to use a complex infrastructure of freezing.The design of industrial driers and the global processes design along with the characterization of processed and final dried foodstuffs (flour) need the knowledge and study of mass and heat properties of transport. These properties show dependence with temperature, composition, texture and rheology of the material.Unriped banana (Musa cavendishii, Var. Nanicão), which has high resistant starch content and large surplus production in Brazil, will be submitted to different dehydration process with aim to obtain unripe banana flour with high quality parameter (resistant starch amount preserved) indicating a functional food. The evolution of physico-chemical, functional and microstructure properties during the process carried out by specific tests. Simultaneously, the mass and heat transfers modelling of the material need the correlation of all these properties with the temperature and furthermore to relate the experimental determination of mass and heat properties of transport (conductivity and diffusivity). (AU)