Spraying of natural dyes by spray drying

Abstract

In this work, the conditions for the extraction of dyes from the seeds of achiote (Bixa orellana), and avocado (Persea gratisima Goerin), from the peel of the banana hartón (Musa paradisiaca), and from the leaves of common fern (Pteridium aquilinum), are determined. With the help of statistical experimental designs the best conditions for the extraction parameters are determined.
In order to obtain the powdered dyes, using a different process from the high temperature drying, an spray dryer is constructed according to a previous study in which the components of the equipment were selected and the blueprints for the construction were drawn. In this project some modifi cations are introduced in agreement with limitations of the unit operations lab. The constructed spray dryer has capacity to evaporate up to fi ve liters of water per hour.
The dyes are tested to dye textile fi ber like cotton and nylon, and the Icontec Norms are applied to the colored materials to verify that their characteristics are over the standard requirements of the norm. Some initial tests with nutritional products are made, but it is necessary to deepen in this area to have the security that they don’t have unhealthy effects on human beings.