Brazil is one of the greatest producers of castor bean, which has more than 700 industrial applications and is being cogitated as the main source for the Biodiesel production in Brazil and abroad. This utilization will cause an exaggerated increase in the castor cake production, one of the by-products of the oil extration. The alergenic proteins, presents in the castor cake are isoforms of 2S albumins. Two of these forms, Ric c 1 and Ric c 3, had already been sequenced and had determined its biological characteristics. In this work we developed a methodology to inactivate the alergenic epítopes of these proteins. The pool of 2S albumins and three synthetic peptides, P0 and P3, presents respectively, in the large and small chains of Ric c 1; and P5, present in the large chain of Ric c 3, were submitted at different chemical modifications, with triethylamine, with calcium hydroxide and with Woodward`s Reagent K, that was more efficient. The samples were reacted with WRK in different concentrations (250, 100, 25 and 37,5 mM); times (5 minutes, 3 and 12 hours) and temperatures (25 ºC, 40 ºC or 100 ºC). The carried modifications were analysed by High Performance Liquid Chromatography (reverse phase), by masses spectrometry (for the peptides)and by the mast cell degranulation assays.The peptides P3 and P5 and the pool of 2S albumins treated with WRK 250 mM, for three hours, followed by heating at 100 ºC for thirty minutes, presented the best ones results. The chromatographic profiles and the absorption spectrums of treated polypeptides were different from the native samples. This chemical treatment reduced the mast cells degranulation from 70% ("pool" of 2S albumins), 61% (P3) and 57% (P5) to 30%, value next to that found during the manipulation of these cells. We can conclude that the developed methodology revealed efficient for the inactivation of alergens, although it needs to be optimized for the castor cake "in natura" so that it can be used with safety in the agroindustry.


Supported by FAPERJ, CNPq, TECNORTE