ALEXANDRE, H. V.; http://lattes.cnpq.br/8167891826960360; ALEXANDRE, Hofsky Vieira.
Resumen:
Growing concerns with the environment have been mobilizing several segments of the
market. Countless government offices and industries are preparing to employ an
environmental politics that reduces negative impacts on nature. After they are
generated, industrial residues need appropriate disposal for they create potential
environmental problems and represent loss of raw materials and energy. Brazil is the
largest producer of pineapple in South America and one of the largest in the world. The
fruit is the marketable part of the plant; however, this portion represents only 23% of
the plant total, while the remaining (formed by stem, leaves, peel, crowns and shafts) is
considered agricultural residue and has not been properly used, thus, resulting in
economic loss. The objective of this work was to study the drying of enriched pineapple
residues (peel and crowns) by using Saccharomyces cerevisiae yeast in static bed in fine
layer. In natura and enriched residues characterization consisted of the determination of
moisture content, total titratable acidity, pH, ashes and organic matter, soluble solids
(oBrix), neutral detergent fiber (NDF), acid detergent fiber (ADF), pectin, total reducer
sugars (RS; TS), Dried matter and Rude protein. Desorption isotherms of in natura and
enriched residues were determined in order to know the values of balance humidity,
obtained through the gravimetric static method, at temperatures that ranged from 25 to
40 °C. The best fittings to data of desorption isotherms of humidity of in natura and
enriched residues were obtained by using the GAB model. In the study of drying
kinetics the methodology of factorial experimental planning 22 was used, which
assessed temperature and air speed influences in the respouses: moisture content after
120 and 60 minutes for peel and crown, respectively, and protein of dried residue.
Drying experiments were carried out with temperature varying from 40 to 60 °C and air
speed from 0,8 to 1,8 m.s-1. According to data analyses, drying kinetics happened in the
period of decreasing rate. The experimental data were adjusted to Page, Henderson &
Pabis, and Lewis’ models, and the three represented experimental data satisfactorily.
Influence of the variable temperature was verified only for the respouses variable
humidity; no statistically significant influence of drying air speed was observed.