Otimização dos processos de extração da pectina e do óleo de subprodutos da indústria de processamento do maracujá (Passiflora edulis Sims f. flavicarpa Deg.)

Abstract

Brazil is the world's largest producer and consumer of passion fruit (Passiflora edulis Sims f. flavicarpa Deg). This demand is destined mostly for the domestic consumer, mainly the food industry. The seeds and peel of the passion fruit represent about 70% of the fruit and have a great potential for commercial use. However, they are considered by-products in most industrial processes. This work aims to improve the extraction processes of oil and pectin from passion fruit using solvents (ethanol and citric acid). The central composite design and the response surface methodology were used to evaluate the yields and the esterification degree. In the passion fruit oil extraction process, the following variables were considered: extraction temperature, sample mass and extraction time. In the pectin extraction process, the following variables were considered: extraction temperature, citric acid concentration and extraction time. The highest yield of oil extraction, in mass, was approximately 27%, considering: extraction temperature of 60 °C; sample mass of 7.5 g; and extraction time of 30 minutes. The highest values of the yield and degree of esterification of pectin, by mass, were approximately 15% and 56%, respectively, under the following conditions: temperature of 85 °C; concentration of 2.5 g/100mL; and, time of 30 minutes. The solid residue resulting from the extraction of pectin showed a change in the composition of the centesimal composition, in relation to the initial characterization of the peel, with a reduction of mineral matter, total nitrogen and crude protein. The study of drying kinetics was performed to verify the mathematical model with the best fit to the experimental data of convective drying: Page presented the best fit at 55 and 65 °C, and the logarithmic model, at 75 °C. In the drying of the peels the Page model showed the best fit in the three temperatures applied, 55, 65 and 75 °C.