Secagem de Spirulina platensis: análise das técnicas de leito de jorro e camada delgada.

by de Oliveira, Elizangela Gonçalves

Abstract (Summary)
Microalgae Spirulina platensis have been commercialized and studied by its nutritional potential because of its elevated content of proteins, pro-vitamins and fatty acids unsaturated; and also for present therapeutic potential in some diseases treatment. In order to preserve Spirulina after harvest and to vary its incorporation in food, it has to be submitted of a drying operation. The general aim of this study was to analyze the drying of the microalgae Spirulina platensis in thin layer and spouted bed. Having as specific aims to evaluate the temperature influence, sample load, spouted bed geometric and concentrations of suspension in functional properties and c-phycocyanin content at dry biomass in thin layer and spouted bed. Raw material used was given by Biochemical Engineering Laboratory/FURG, obtained from ?Lagoa Mangueira? situated in the south of ?Rio Grande do Sul?. The biomass was filtered and pressed until moisture of 76% for thin layer experiment, for spouted bed Spirulina was diluted at different concentrations. The microalgae was dry in a discontinuous drier of trays with perpendicular air flow at temperatures of 50-60°C and load in tray of 4-6kg/m2. It was used the conical spouted bed (CSB) and jet spouted bed (JSB), with suspension feed rate of 0,4 kg/ of inert, circulation rate of 1,8 and out temperature of ± 70°C. It were evaluated the protein solubility in water and acid, ?in vitro? digestibility and c-phycocyanin content of Spirulina in natura and after drying. Results show that thin layer drying of Spirulina platensis with perpendicular air flow occurred during the falling-rate period, not showing constant-rate period. For the solubility in acid the temperature and sample load were significant, being that the best work region was 60°C and 4kg/m2. The spouted bed dryer had a stable behavior, not showing collapse at operational conditions. The suspension concentration of Spirulina 5% shows better results than the protein solubility in water and the in vitro digestibility. Both techniques of drying show a similar increasing at the water solubility. The spouted bed dryer (CSB) show a highest recuperation of c-phycocyanin when compared to the dry product in thin layer.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Susana Juliano Kalil; Luiz Antonio de Almeida Pinto; Antônio Carlos Luz Lisboa; Jorge Alberto Vieira da Costa

School:Fundação Universidade Federal do Rio Grande

School Location:Brazil

Source Type:Master's Thesis

Keywords:Spirulina platensis drying spouted bed thin layer


Date of Publication:03/20/2006

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