Otimização da extração de R-ficoeritrina da macroalga marinha vermelha Solieria filiformis (Kutzing) P.W. Gabrielson e sua aplicação como corante natural em alimentos

Abstract

Natural dyes have been increasingly demanded by consumers of industrialized food products, as various artificial dyes have been linked to different adverse reactions to human health. Several natural dyes are already used by the food industry, and phycobiliproteins extracted from cyanobacteria and red algae have been less applied because of the low extraction yield. A species of red algae found in abundance on the Ceará coast and with potential for cultivation in a mariculture system is Solieria filiformis, a renewable source of Rphycoerythrin (R-FE). The R-FE has a red coloration and orange/gold fluorescence. Based on this, the objective of this work was to optimize the extraction and purification efficiency of Rphycoerythrin from S. filiformis red marine macroalga, to characterize its spectroscopic properties at different pHs and its potential as a natural red dye in yoghurt. For this purpose, aqueous extraction followed by protein precipitation with 90% saturation (NH4)βSO4 at -18 °C for 48 hours was obtained to obtain F0-90, which was then subjected to ion exchange chromatography DEAE-Sephacel matrix, where twice the yield of R-FE was obtained than those reported in the literature for the same algal species. The freeze-dried chromatography peak (PIII-DEAE) was solubilized in buffers of different pHs (β to 1β) and the spectroscopic characteristics of the R-FE were stable in the pH range of 5 to 11. The yogurts that received the highest concentrations of F0-90 and PIII-DEAE presented the best classifications for global acceptance, especially when the pigment with the highest purity was used, before commercial yoghurt. It was concluded that the extraction and purification of S. filiformis RFE with a freezing step increases the pigment yield twice, which is stable in the pH range of 5 to 11, and represents an excellent alternative to Artificial dyes, and can be used as a natural dye in yogurt.