LISBÔA, C. G. C.; http://lattes.cnpq.br/0842189903365114; LISBÔA, Cícera Gomes Cavalcante de.
Resumo:
The potato yacon (Smallanthus sonchifolia) is originally from the Andes and was brought
to Brazil for cultivation. It became popularly known as the diet potato because it is rich in
fructooligosaccharides (FOS) and inulin. These constituents have a beneficial effect on
health because they have low caloric value and contribute to reducing cholesterol and
glucose. The objective of this work was to dry the yacon potato in a cylindrical format in a
fixed bed dryer at different temperatures (50, 60 and 70 ºC) and drying air velocities (1.0,
1.5 And 2.0 m/s). The yacon potato in natura was characterized regarding its physical,
chemical and physicochemical parameters. The Page, Henderson & Pabis, and Two terms
diffusion approximation models were adjusted to the drying kinetics data, and the
shrinkage coefficient and effective diffusivity were determined. The dry yacon potato was
characterized physically, chemically and physico-chemically and its moisture adsorption
isotherms were determined at 25 °C and adjusting the GAB, Oswin and Peleg models to
the experimental data. Potato yacon in natura has been found to have low acidity and starch
content, and is a source of antioxidants and minerals. The temperature and the drying air
velocity influenced the effective diffusivity and the shrinkage, resulting in an increase in
these measurements with the increase of these parameters. The dry samples showed low
water activity, increased sugar concentration, phenolic compounds and antioxidant
capacity, as well as a tendency for browning during drying. It was found that the GAB,
Oswin and Peleg models can be used to estimate the moisture adsorption isotherms and
were classified as type II and III.