Microencapsulation the natural dye annatto: an analysis of the efficiency of cashew gum as material wall.

• Autor(a) principal: Luana Guabiraba Mendes
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFC
• Texto Completo: http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8488
• topic: Bixina,MicroencapsulaÃÃo, Goma do cajueiro e estabilidade; Bixin, microencapsulation, cashew gum and stability; CIENCIA E TECNOLOGIA DE ALIMENTOS

In practice, some natural dyes, such as bixin present technological difficulties of use, hindering their application in the food industry. Microencapsulation can improve this situation by increasing their stability and making their incorporation in food systems possible without losing their properties. The objective of this research was to microencapsulate the natural dye annatto, using cashew gum as wall material, applying the freeze-drying and spray drying processes, to characterize the microcapsules obtained according to morphological and physico-chemical properties as well as to determine the effectiveness of the microencapsulation by quantification of the total bixin and surface bixin. Gum arabic was used as wall material, the reference for comparison. Thus, three formulations were prepared as follows: annatto colorant / cashew gum (U-GC) 4:1 w / w of annatto colorant / gum arabic (GA-U) 4:1 m / m of annatto colorant / cashew gum / gum arabic and (1:1) 4:1 m / m (U-GCA). The suspensions, which had been previously prepared, were also characterized in terms physical and chemical analyses. In colorimetric evaluation the stability of the microencapsulated pigment was studied, at a room temperature of 25 Â C Â 2 Â C in the presence and absence of light for 40 days storage in two situations, that is dissolved in buffer solution pH 4.0 and in powder form. In the three formulated suspensions , there were no major differences between the pH and colorimetric analyses, but the suspension viscosity cashew gum / dye annatto, resulted in lower viscosity (0.01746 Â 0.000) at the same concentrations of solids. The microcapsules produced by atomization also showed predominantly irregularly shaped circular and toothed surfaces, and lyophilization, show indefinite shapes and sizes vary widely. All the microspheres proved soluble in water. Microcapsules prepared with gum arabic and gum cajuerio / gum arabic (1:1) showed the best efficiency in the microencapsulation, 43.14 and 31.21%, respectivelyand this confers greater stability to the bixin during exposure to light and storage in the dark. The different formulations resulted in different concentrations of microencapsulated annatto dye, with the gum arabic being the most efficient and the cashew gum the least efficient in terms of lyophilization and spray drying. There was a greater total degradation of bixin, about 65.79% and the surface bixin, about 60.52%, in the microcapsules stored under light incidence at 25 Â C Â 2ÂC, demonstrating the detrimental effect of light on the dye annatto. The microencapsulation method by means of lyophilization is the one which led to the lowest levels of degradation of encapsulated bixin. Among the parameters used and the concentration and methods of microencapsulation employed, cashew gum, on its own, is not presented as an effective wall material. However, its mixture with gum arabic provided promising results, which favors making use of this material (U-GCA) in the food industry and in other technological sectors such as cosmetics and pharmaceuticals.