Antioxidant Dyes And Pigment Extraction Using A Home-Made Pressurized Solvent Extraction System

摘要

Increasing reports of health hazards and toxicity of synthetic colorants are driving the food industry towards application of natural colorants in an increasing number of processed food products. The attention that natural dyes and pigments is getting, is also due to the functional properties attributed to some of these colorants. Although synthetic dyes and/or pigments have lower production costs and greater stability, the number of synthetic additives permitted in developed countries is decreasing every year, in benefits to antioxidant colorants, such as carotenoids and anthocyanins. Commonly, conventional extraction methods are used to extract these compounds from natural sources, nevertheless, these methods are, in general, time and solvent consuming and may promote the degradation of these compounds. In order to overcome these drawbacks short time extraction conditions using environmentally friendly pressurized solvents, such as supercritical carbon dioxide and pressurized ethanol have been successfully used to obtain antioxidant dyes and pigments-rich extracts. The objective of this work was to validate a home-made pressurized solvent extraction system that can be used for Supercritical Fluid Extraction (SFE) and Pressurized Liquid Extraction (PLE) processes, independently. For this, functional colorants sources such as Annatto seeds and Jabuticaba skins were used as model plant materials. Home-made SFE results were compared to those obtained using a commercial SFE using the same processing conditions in order to validate our new system. For establishing the statistical significant differences or similarities between the values of SFE yield, the Tukey’s test was used. A confidence coefficient of 95 % was used for the comparison of all the mean pairs. The anthocyanin content of the Jabuticaba skin extract obtained by PLE method was determined using the pH differential method. The supercritical extracts from Jabuticaba skins previously extracted with pressurized ethanol were fractionated by thin-layer chromatography (TLC).