Pomegranate peel as a promising source of pectic polysaccharides: A multi-methodological analytical investigation

Diletta Balli; Mohamad Khatib; Lorenzo Cecchi; Alessandra Adessi; Pablo Melgarejo; Cláudia Nunes; Manuel A Coimbra; Nadia Mulinacci

doi:10.1016/j.foodchem.2022.133550

Pomegranate peel as a promising source of pectic polysaccharides: A multi-methodological analytical investigation

Food Chem. 2022 Dec 15:397:133550. doi: 10.1016/j.foodchem.2022.133550. Epub 2022 Jul 29.

Authors

Diletta Balli¹, Mohamad Khatib², Lorenzo Cecchi³, Alessandra Adessi⁴, Pablo Melgarejo⁵, Cláudia Nunes⁶, Manuel A Coimbra⁷, Nadia Mulinacci⁸

Affiliations

¹ Department of Neuroscience, Psychology, Drug and Child Health, Pharmaceutical and Nutraceutical Section, University of Florence, 50019, Italy. Electronic address: diletta.balli@unifi.it.
² Department of Neuroscience, Psychology, Drug and Child Health, Pharmaceutical and Nutraceutical Section, University of Florence, 50019, Italy.
³ Department of Neuroscience, Psychology, Drug and Child Health, Pharmaceutical and Nutraceutical Section, University of Florence, 50019, Italy. Electronic address: lo.cecchi@unifi.it.
⁴ Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, 50144, Italy. Electronic address: alessandra.adessi@unifi.it.
⁵ Department of Plant Science and Microbiology, Universidad Miguel Hernández de Elche, Orihuela, Alicante, Spain. Electronic address: pablo.melgarejo@umh.es.
⁶ CICECO - Aveiro Institute of Materials, Departament of Materials & Ceramic Engineering, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal; LAQV-REQUIMTE, Departament of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal. Electronic address: claudianunes@ua.pt.
⁷ LAQV-REQUIMTE, Departament of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal. Electronic address: mac@ua.pt.
⁸ Department of Neuroscience, Psychology, Drug and Child Health, Pharmaceutical and Nutraceutical Section, University of Florence, 50019, Italy. Electronic address: nadia.mulinacci@unifi.it.

PMID: 35932684
DOI: 10.1016/j.foodchem.2022.133550

Abstract

Polysaccharides from pomegranate peel (Wonderful and Purple Queen® varieties) were extracted by hot water and fractionated using ethanol. Three fractions (F1-F2-F3) were obtained for each sample. Polysaccharides' yield was higher for Purple Queen®: 13% dw. Polysaccharides of the three fractions were characterized by size exclusion chromatography (SEC), dynamic light scattering (DLS), ¹H NMR, methylation, and acylation degree. Differently from SEC, DLS highlighted some differences between the polysaccharides's molecular sizes of the fractions. The highest methylation and acylation degree was observed for F3 of Purple Queen®: 74.0% and 18.6%, respectively. The percentage of galacturonic acid confirmed the presence of pectin in almost all the fractions recognized as homogalacturonan. Arabinan and arabinogalactan were also found in all the collected F3 samples, although in different proportions. The stepwise fractionation process followed by a multi-methodological analytical investigation was helpful to improve the knowledge of the pectic polysaccharides of pomegranate.

Keywords: (1)H NMR; Food by-product; Galacturonic acid; Methylation degree; Pectin; Punica granatum L..

MeSH terms

Chemical Fractionation
Fruit / chemistry
Pectins / chemistry
Polysaccharides / chemistry
Pomegranate*

Substances

Polysaccharides
Pectins