Obtaining a dye from passion fruit cortex with the use of conventional extraction techniques

Abstract

Passion fruit is a tropical fruit that is usually cultivated to obtain pulp, being the cortex its main not exploited by-product, because of the actual absence of industrial interest. However, with the aim of diversifying the derivates from the production of passion fruit products, it has been demonstrated that the cortex contains carotenoids, such as -carotene and lutein; which could be used in food due to its antioxidant capacity, or even like a food colorant. Therefore, the objective of this work was to obtain a carotenoidrich extract from its cortex; for this, three techniques of extraction with ethanol were evaluated, by immersion, thermostatic bath and Soxhlet. Being the last technique that one with which the best yield was obtained. With the highest yield technique, the following factors were evaluated: ethanol concentration on 80% and 90% v/v, solventraw material ratio on 40:1 and 50:1 and time on 90 and 150min. The best yield was obtaining to 90% ethanol, 50mL solvent/g raw material and 150min, for an extraction yield of 2208.53g -caroten/100 g sample. Finally, the color difference between the optimal extract and a tartrazine solution was determined, evidencing a color difference of 3.07cieLAB units; this shows that the passion fruit leaching product has the potential to be used as a food additive, replacing synthetic dyes such as tartrazine.