A simple procedure to obtain a medium-size oligogalacturonic acids fraction from orange peel and apple pomace wastes. (1st June 2021) - Cano, María Emilia
Highlights: Acid treatments of juice wastes led to three families of oligogalacturonic acids. A medium size oligosaccharide family was easily obtained by ethanol precipitation. HPAEC, MALDI-MS and SEC -MS were used for complete characterization of OGAs families. These defined fractions are useful to identify the active species for elicitation. Abstract: Pectin oligosaccharides, which can be obtained from fruit wastes, have proven their potential as plant immune-system elicitors. Although the precise size of active species is still under investigation, medium size oligosaccharides have been reported as the most active. Three defined oligogalacturonic acid (OGAs) mixtures were produced from commercial pectin, orange peel and apple pomace residues. The methodology developed involves two sequential acid treatments followed by stepwise ethanol precipitation. Without the need of chromatographic separations, three different fractions were obtained. The fractions were analyzed by high performance anion exchange chromatography (HPAEC) and were completely characterized by mass spectrometry, showing that the small size, medium size and large size fractions contained OGAs of degree of polymerization 3 to 9, 6 to 18, and 16 to 55, respectively.