Characterization of Pectins Extracted from Different Varieties of Pink/Red and White Grapefruits [ Citrus Paradisi (Macf.)] by Thermal Treatment and Thermosonication

LA CAVA, ENZO L.; GERBINO, ESTEBAN; SGROPPO, SONIA C.; GÓMEZ-ZAVAGLIA, ANDREA

JOURNAL OF FOOD SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 83 p. 1613 - 1621

0022-1147

The physical and chemical properties of pectin extracts obtained from different white and pink/red varieties of grapefruit [Citrus paradisi (Macf.)], using both conventional heating (CHE) and thermosonication (TS), were investigated.The content of galacturonic acid (GalA), degree of esterification (%DM), color and antioxidant capacity were analyzed. Fourier-Transform Infrared Spectroscopy (FTIR) associated with multivariate analysis enabled a structural comparisonamong the pectin extracts, and differential scanning calorimetry (DSC) completed a full landscape of the investigated extracts. Pectin extracts obtained by CHE showed mostly higherGalA than those obtained by TS. All the extracts had a highantioxidant capacity, as determined by 2,2 diphenyl 1-picrylhydrazyl (DPPH∗) and 2,2-Azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid) diammonium salt (ABTS∗+) assays, and a high correlation with the GalA content. The main differencesobserved in the FTIR spectra occurred in the 1200 to 900 cm−1 region (differences in GalA). The glass transition temperatures (Tgs) of all extracts were above 85 °C, making them interesting as stabilizing agents for the food industry.