Human beings have been using natural products since the dawn of time. Plants growing wild in nature or cultivated as crops are still the prime ingredients in many drugs, beverages, flavors, and cosmetics. GEA Niro's comprehensive product range covers most of the required steps for processing leaves, herbs, and other plant material, for example into extracts and then further into powders or granulates.
Extracts are generally concentrated forms of natural substances obtained by treating crude material containing these substances with an appropriate solvent such as water, alcohol, or another organic solvent. This process can successfully be performed in the GEA Niro continuous extraction plant CONTEX™.
The CONTEX™ unit operates in the counter-current extraction principle featuring an inclined trough surrounded by heat transfer jackets for temperature control of the process. The raw material (solids) enters the lower end of the trough and is transported upwards by two heliocoidal conveyors. The solids are therefore transported in a gentle spiral movement, which gives ideal counter-current plug-flow extraction conditions.
Spray drying is by definition the transformation of feed from a fluid state into a dried form (either powder or granulate), by spraying the feed into a hot drying medium. Air is used in case of water and nitrogen if an organic solvent is used.
Prior to spray drying, the extract normally needs to be concentrated and in most cases formulated with carbohydrates as carrier and with water soluble gums in order to form a protective en-capsulated surface film around each particle.