Chemical Composition and Yield of Six Genotypes of Common Purslane (Portulaca oleracea L.): An Alternative Source of Omega-3 Fatty Acids.

Spyridon Α Petropoulos,Lillian Barros,Anestis Karkanis,Christos Lykas,Georgia Ntatsi,Ângela Fernandes,Ebrahim Khah,Konstantinos Petrotos,Isabel C F R Ferreira

doi:10.1007/s11130-015-0511-8

Abstract

Common purslane (Portulaca oleracea L.) is an annual weed rich in omega-3 fatty acids which is consumed for its edible leaves and stems. In the present study six different genotypes of common purslane (A-F) were evaluated for their nutritional value and chemical composition. Nutritional value and chemical composition depended on genotype. Oxalic acid content was the lowest for genotype D, whereas genotypes E and F are more promising for commercial cultivation, since they have low oxalic acid content. Genotype E had a very good antioxidant profile and a balanced composition of omega-3 and omega-6 fatty acids. Regarding yield, genotype A had the highest yield comparing to the other genotypes, whereas commercial varieties (E and F) did not differ from genotypes B and C. This study provides new information regarding common purslane bioactive compounds as affected by genotype and could be further implemented in food industry for products of high quality and increased added value.

Highlights

For chemical composition sampling, plant tissue samples were taken from 15 plants from each genotype and all the samples were pulled in one and stored at deep freezing conditions (-80°C) and freeze dried prior to analysis
The antioxidant activity of the methanol:water (80:20, v/v) extracts was evaluated by DPPH radical-scavenging activity, reducing power, inhibition of β-carotene bleaching in the presence of linoleic acid radicals and inhibition of lipid peroxidation using TBARS in brain homogenates [18]
Total phenolics were estimated by Folin-Ciocalteu colorimetric assay according to procedures previously described and the results were expressed as mg of Gallic acid equivalents (GAE) per g of sample [19]

Summary

Introduction

Plant tissue samples (whole aerial parts) were taken from 15 plants from each genotype and all the samples were pulled in one and stored at deep freezing conditions (-80°C) and freeze dried prior to analysis. Organic acids were determined following a procedure previously described by the authors [17]. Free sugars were determined by high performance liquid chromatography coupled to a refraction index detector (HPLC-RI), after an extraction procedure previously described [18]. Total phenolics were estimated by Folin-Ciocalteu colorimetric assay according to procedures previously described and the results were expressed as mg of Gallic acid equivalents (GAE) per g of sample [19]. Total flavonoids were determined by a colorimetric assay using aluminum trichloride, following procedures previously reported [19]; the results were expressed as mg of (+)-catechin equivalents (CE) per g of sample. The chemical composition and antioxidant activity were analysed using one-way analysis of variance followed by Tukey’s HSD test with α= 0.05 using the SAS v. A low value of SYI indicates unsustainable management practice [21]

Objectives

Results

Conclusion