Valorization of orange peels as a source of pectins

V. GUNTERO; C. FERRETTI

Chemistry Proceedings

MDPI

Lugar: Basel; Año: 2022 vol. 8

2673-4583

Pectin is a natural structural polymer that is extensively used in the food industry and in medicinal and pharmaceutical fields. Considering potential applications, in this study, microwave-assisted and conventional extraction were evaluated for the extraction of pectin from orange peel by acid hydrolysis using citric acid as an extractant. For conventional extraction, temperatures higher than 60 °C and long extraction times were necessary to obtained pectin yields of 9.0%. Under conventional conditions of extraction, the degree of esterification of pectin was 55.0%. The extraction procedure assisted by microwave was optimized using an experimental design of 3 factors and 2 levels, and the effect of the operational variables? influence on the pectin yield was analyzed. The optimization of the pectin extraction conditions showed that a temperature of 55 °C, an extraction time of 6 min, and a solid/liquid ratio of 0.02 mg/mL, were necessary to obtain pectin yields of 25.0%. Under the optimal extraction conditions, the degree of esterification of pectin was about 75%. According to the ANOVA analysis, time was the factor that had the greatest influence on the yields of pectin. These results showed that the microwave-assisted procedure to be obtained enabled pectin from the orange peel over mild operation conditions.