Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/102881
Type: Artigo de evento
Title: Analysis Of Freeze Drying And Microwave Vacuum Drying Processes For Retinol Concentration
Author: Koroishi E.T.
Boss E.A.
Maciel Filho R.
Abstract: Vitamin A (retinol) and derivatives (retinyl esters, retinoic acid, retinaldehyde), are of great commercial potential in cosmetics and pharmaceuticals such as skin care products. Vitamin A is necessary for maintenance of healthy epithelial tissue and can prevent the inception or progress of skin cancers by stimulating normal cell differentiation. Deficiency of vitamin A is usually accompanied by a number of severe diseases. The preformed vitamin A (retinol) is found in foods of the animal source. The vegetables are vitamin A source under carotenoids form that will be converted to vitamin A in the organism. The retinol is a pure form of the vitamin A. The retinol, alcohol of the vitamin A is the most active of the retinoids. Retinol is used as an antiwrinkle in the cosmetics industry. It is a hydrophobic vitamin A compound that exerts a potent influence on cell differentiation, proliferation, homeostasis, and development. To facilitate the formulation of the some products, the retinol needs to be in concentrated form. However, due to sensibility of the retinol to temperature, conventional methods can not be adequate. In this work, the retinol drying was studied, using the freeze drying process and microwave vacuum drying with the goal to reduce the water tenor, that is to say, to increase the retinol concentration, and consequently to increase the shelf life. Freeze drying is a drying process, where the water or aqueous substance is removed from frozen solution through sublimation. In this process the water passes direct from the solid phase to vapor phase. In order to do that, it is necessary that the sublimation temperature zone be bellow the triple point. The aim of the freeze drying process is to conserve the product, reducing the activity water. This process guarantees the preservation of the original product characteristics. Due to the absence of solvent and the low temperature required for the process, most of deterioration and microbiological reactions are stopped which gives a final product of excellent quality. The microwave vacuum drying can be considered as an interesting alternative front to conventional drying to offer a brief time of the material exposition. Some foods are being processed with this technique, such as concentration of the fruit juice, teas and instants coffee and in vegetables drying. In microwave vacuum dryers, as with conventional microwave equipment, the heat needed for drying is generated by the absorption of electromagnetic radiation by the molecules of the substance to be dried. The energy is transformed into kinetic energy, especially by water. The increase in kinetic energy makes the molecules vibrate more intensively. This process is followed by a temperature increase and evaporation of water.In this work, it was built a drying curve to verify the necessary time for drying the retinol. It was applied a factorial design to analyze the effects of the variables in processes, to know, freeze-drying. The results show the potential of such techniques to achieve the product with the required quality.
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Rights: fechado
Identifier DOI: 
Address: http://www.scopus.com/inward/record.url?eid=2-s2.0-34748850733&partnerID=40&md5=54c867a50fe3cdad873232331b905c9b
Date Issue: 2006
Appears in Collections:Unicamp - Artigos e Outros Documentos

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