Effect of Salt Stress on Purslane and Potential Health Benefits: Oxalic Acid and Fatty Acids Profile

Polyunsaturated fatty acids (PUFAs) are crucial for human health and nutrition since they cannot be synthesized in the body and hence must be provided by the diet. Portulaca oleracea L. (purslane) is the eighth most commonly distributed plant in the world. It is a heat- and drought-tolerant plant and our previous study demonstrates that their leaf provide high amounts of antioxidants, minerals, vitamins and proteins. In the present study, we set out to characterize the oxalic acid and the fatty acid composition (particularly the ratio 3/6) in saline stress studies on two purslane cultivars cultured in a hydroponics system, with the main goal of determine the effects of the exposure of the plant to saline environment on those constituents in leaves (edible part of the plant). Five saline treatments were applied: 20, 40, 60, 90, and 120 mmol NaCl; the control had only the base nutritive solution. In both purslanes, a sharp decrease on total oxalic acid concentration was observed when the salt concentration increase in the hydroponic solution after 30 days of saline stress. Palmitic acid (C16:0) linoleic acid (C18:2) and linolenic acid (C18:3) here the major fatty acids detected and they amounts slightly increases with the increase of salinity until approximately 40 mmol of NaCl. The ratio of ω6 to ω3 was similar in both cultivars and did not change with saline stress. Consumption of purslane will contribute to dietary ω3 PUFA intake, with benefits to human health.