Thermal analysis as screening technique to assess spray-drying process of encapsulated yacon juice

Yacon is a plant from Andean region (South America) whence it has spread to other countries. It produces roots with high content of fructooligosaccharides, inulin, some phenolic compounds among others substances. With sweet taste and low-energetic value, these roots are considered prebiotic food due to some medicinal properties. The encapsulation process via spray drying was used in this work from a pilot plant with aim to obtain a juice from this root (YJ). Solid whey (W) and maltodextrin (MD) was added in different ratios. Optimisation conditions were determined, and the best encapsulation process was YJ with MD: W ratio 80: 20, which results are in agreement with those obtained by thermogravimetry/derivative thermogravimetry, differential scanning calorimetry and confirmed by field emission gun scanning electron microscopy. Thus, thermoanalytical techniques are important tools that can be used in quality control of industrial encapsulation process.