Seed oil and seed oil byproducts of common purslane (Portulaca oleracea L.): a new insight to plant-based sources rich in omega-3 fatty acids

Abstract

In the present study, nutritional value, chemical composition and bioactive properties of purslane seeds, seed oils and seedcakes were examined. Data were analyzed by a one-way ANOVA, while means were compared with Tukey's HSD test. For seed oil extraction mechanical and ultrasound assisted methods were tested. Cold extraction methods (CE1 and CE2) resulted in higher oil yield (increased by 33.7% and 38.1%, respectively) comparing to hot extraction (HE) method. Seeds contained the highest amount of fats and energy (15.03 ± 0.06 g/100 g dry basis (db) and 459 ± 1 kcal/100 g db, respectively), while seedcakes from CE2 had the highest content in proteins and ash (31.20 ± 0.03 and 4.27 ± 0.06 g/100 g db, respectively). Seeds and seedcakes contained a balanced content of linoleic and α-linolenic acids (33.80–34.74% and 32.83–34.64%, respectively). HE and CE1 oils had slightly higher amounts of α-linolenic (39.67% and 39.57%, respectively) than linoleic acid (35.44% and 35.13%, respectively), whereas CE2 oils contained twice as much linoleic as α- linolenic acid (49.77% and 24.18%, respectively). In conclusion, the tested materials are good sources of omega- 6 and omega-3 fatty acids and proteins, while extraction method affected oil yield and fatty acids composition of seed oils.Agricultural Machinery, University of Thessaly, Greece, for providing the equipment and technical assistance for hot extraction of seed oils. We are also thankful to Mr. Tsolakidis C. (Giachanas - Cold Pressed Seed Oils S.A.; Evros, Greece) for providing the equipment and technical assistance for cold extraction of seed oils. The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019). L. Barros and A. Fernandes would like to thank the national funding by FCT, P.I., through the institutional scientific employment program-contract for their contracts.info:eu-repo/semantics/publishedVersio