Extraction And Characterization Of Pectin From The Fruit Peel Ofopuntia Robusta

In this study, pectin extraction from fruits peel ofOpuntia robustawas investigated. Pectin was extracted by microwave and conventional heating methods, and the product was analysed to determine theyield, esterification degree, galacturonic acid content, molar mass, antioxidant, emulsifying and rheological properties. The extraction methods resulted in two different types of pectin: pectin I, with high (>50 %) methoxyl degree of esterification, and pectin II, with low, (<50 %) methoxyl degree of esterification. The extractionyieldof these pectins was 14.64 and 15.71 %, with molar masses of 33,110 and 20,339 g mol(-1), respectively. Pectin II showed the highest galacturonic acid content (47.05 %) in comparison with pectin I (31.74 %). The antioxidant properties of pectins showed similar polyphenols content. However, pectin II had the highest scavenging activity. Finally, pectin I displayed the best emulsifying properties, and both pectins produced shear-thinning solutions and predominantly elastic gel behaviour.