Advisor(s)
Abstract(s)
Purslane (Portulaca oleraceae L.) is a widespread weed, which is highly appreciated for its
high nutritional value with particular reference to the content in omega-3 fatty acids. In the present
study, the nutritional value and chemical composition of purslane plants in relation to plant part
and harvesting stage were evaluated. Plants were harvested at three growth stages (29, 43 and 52
days after sowing (DAS)), while the edible aerial parts were separated into stems and leaves. Leaves
contained higher amounts of macronutrients than stems, especially at 52 DAS. -tocopherol was the
main isoform, which increased at 52 DAS, as well total tocopherols (values were in the ranges of
197–327 g/100 g fresh weight (fw) and 302–481 g/100 g fw, for -tocopherol and total tocopherols,
respectively). Glucose and fructose were the main free sugars in stems and leaves, respectively,
whereas stems contained higher amounts of total sugars (values were ranged between 0.83 g and
1.28 g/100 g fw). Oxalic and total organic acid content was higher in leaves, especially at the last
harvesting stage (52 DAS; 8.6 g and 30.3 g/100 g fw for oxalic acid and total organic acids, respectively).
Regarding the fatty acid content, stems contained mainly palmitic (20.2–21.8%) and linoleic acid
(23.02–27.11%), while leaves were abundant in -linolenic acid (35.4–54.92%). Oleracein A and C
were the major oleracein derivatives in leaves, regardless of the harvesting stage (values were in the
ranges of 8.2–103.0 mg and 21.2–143 mg/100 g dried weight (dw) for oleraceins A and C, respectively).
Cytotoxicity assays showed no hepatotoxicity, with GI50 values being higher than 400 g/mL for all
the harvesting stages and plant parts. In conclusion, early harvesting and the separation of plant parts
could increase the nutritional value of the final product through increasing the content of valuable
compounds, such as omega-3 fatty acids, phenolic compounds and oleracein derivatives, while at the
same time, the contents of anti-nutritional compounds such as oxalic acid are reduced.
Description
Keywords
Fatty acids Hepatotoxicity Oleracein derivatives Omega-3 fatty acids Phenolic compounds Portulaca oleraceae Purslane Tocopherols α-linolenic acid
Pedagogical Context
Citation
Petropoulos, Spyridon A.; Fernandes, Ângela; Dias, Maria Inês; Vasilakoglou, Ioannis B.; Petrotos, Konstantinos; Barros, Lillian; Ferreira, Isabel C.F.R. (2019). Nutritional value, chemical composition and cytotoxic properties of common purslane (Portulaca oleracea L.) in relation to harvesting stage and plant part. Antioxidants. ISSN 2076-3921. 8, p. 1-15