Common purslane is, despite its public image as a weed in many regions, a very nutritious food item — with the plants being high in a number of different important vitamins and minerals. Notably, common purslane (Portulaca oleracea) possesses higher levels of omega 3 fatty acids than any other leafy green vegetable does.
While purslane isn’t very commonly eaten as a food in the US, it is commonly eaten throughout Southern Europe, Mexico, the Near and Middle East, and in parts of Asia. It was (and still is) eaten traditionally throughout many other regions as well, including Australia and parts of Africa. (More information on purslane can be found here: Purslane — Portulaca Oleracea, Verdolaga, Edible Nutritious Weed High In Omega 3 Levels.)
New research published in the journal HortScience has examined purslane’s nutritional value and the affect that various fertility management practices have on the production of various carotenoid and chlorophyll pigments, providing some interesting new findings.
Such pigments are now (and often in many old medicinal traditions as well) thought to dietarily have protective effects, particularly against carcinogens and mutagens.
“Nitrogen (N) can influence phytochemical quality factors, and recent studies demonstrate that N can alter carotenoid and chlorophyll composition and accumulation in leafy specialty crops,” commented authors Dean Kopsell, Kimberly Whitlock, Carl Sams, and David Kopsell.
The press release provides more: “To measure impacts of N fertility levels on pigment concentrations in purslane, they performed experiments with commercially available ‘Golden Leaf’ and ‘Green Leaf’ cultivars. The researchers grew both cultivars in nutrient solution culture under increasing N concentrations of 13, 26, 52, or 105 mg·L-1. They then harvested the plants (45 days after planting), and measured for concentrations of shoot pigments using high-performance liquid chromatography methodology.”
Continuing: “Results showed that increasing N treatment concentrations acted to increase the concentrations of valuable chlorophyll in both purslane cultivars; the increases were most dramatic for ‘Green Leaf’. The biomass parameters measured in the study were not impacted by the interaction of N treatment concentration and purslane cultivar.”
“Purslane in the study accumulated high concentrations of carotenoid phytochemicals,” the authors stated. “Nitrogen treatment significantly influenced shoot tissue beta-carotene, lutein, neoxanthin, total carotenoids, chlorophyll a, chlorophyll b, total chlorophyll, and the chlorophyll a to b ratio in purslane shoot tissues.”
As a result of these findings, the researchers are recommending that N fertility management, and also specific cultivar selection, be used as considerations when growing purslane as a food stuff.