Rheological and high gelling properties of mango (Mangifera indica) and ambarella (Spondias cytherea) peel pectins

Ambarella and mango peels are good sources of pectins (15–20%), with high degree of methylation (60–78%) and high molar masses. Ambarella and mango (Ame´liore´e and Mango varieties) peel pectins wereextracted using HCl or oxalic acid ⁄ ammonium oxalate (OAAO). Purified pectins were analysed for their flowbehaviour and phase diagrams were established at pH 3 as sucrose vs. pectin concentration. The gelationkinetics and mechanical spectra of these pectin gels were studied and compared to those of commercial citrus(lime) pectins. At a concentration of 1% (w ⁄ v), all pectic solutions had a shear thinning behaviour but at0.6% (w ⁄ v), only OAAO-extracted pectins exhibited such behaviour. Phase diagrams showed that at pH 3,gelation of OAAO mango extracted pectins was possible at low polymer concentration (0.2%; w ⁄ w) for asucrose concentration of 60% (w ⁄ w). OAAO-extracted pectins exhibited a higher gelling ability than HCl-extracted ones. Sucrose (45–50%) and pectin (0.2–0.6%) concentration had a deep impact on the gelstrength. Our results enable to conclude that the OAAO extraction from mango and ambarella peels allowedthe recovery of pectins that exhibit high gelling properties