Study of Bixin oxidation by ionizing irradiation

Abstract

Brazil is the world's largest producer of annatto, followed by Kenya and Peru (CORLETT, 2007). The fruit of the annatto tree is constituted by a capsule containing external spines and internal seeds with reddish coloration, providing a natural pigment which is environmentally efficient, being able to replace synthetic pigments and dyes. The active substance of the pigment is Bixin, which is a type of carotenoid which constit utes a greater percentage of pigment in these seeds and has a lipo soluble character ( CUSTODIO , 2002 ). Bixin reacts with NaOH in a saponification reaction giving norbixin, which is water soluble. It is known that the destination of the dye extracted from t he fruit is intended for industry, especially the food industry. The culture of annatto tree brings prospects of development of agricultural programs for medium and small producers, which are able to use decadent areas of other crops. In addition to the fo od sector, new applications for the pigment helps the development of family farming (BERTOLIN, 2016). The pigment extracted from annatto undergoes a natural oxidation; this work aims to evaluate this phenomenon and also the oxidation of the pigment after the irradiation process. This work also evaluates of the how the oxidation process is affected by irradiation and the modifications introduced to irradiated pigments. Irradiated and non irradiated samples were characterized by UV vis s pectrophotometry a nd infrared spectroscopy (FTIR). The results are then discussed.