Insights into the bioactive compounds and physico-chemical characteristics of the extracted oils from Urtica dioica and Urtica pilulifera

Abstract

In this work, proximate analysis of nettle seeds varieties of Urtica dioica and Urtica pilulifera grown in Iran and physico-chemical properties and bioactive contents of the related seed oils were assessed. The results indicated that the seeds of U. dioica and U. pilulifera were rich sources of oil (34.1% and 29.5%), protein (21.8% and 22%) and fiber (30.2% and 29.3%). Also, significant differences (p < 0.05) were observed among some of the other measured characteristics of the oils such as iodine value, saponification value, acid value, peroxide value and total phenolic content. The predominant fatty acids were linoleic, oleic and palmitic acids. U. dioica and U. pilulifera oils mainly contained γ-tocopherol followed by δ-tocopherol and α-tocopherol. Total amount of phytosterols reached 93.1 and 99.8 mg/100 g of oil, respectively, with a predominance of Δ5,23-stigmastadienol. The amount of carotenoid and chlorophyll contents in U. dioica seed oil was approximately twice that of U. pilulifera oil. The results of the present study revealed that nettle seed is a potential source of oil which can be used as a nutritional dietary substance and has great usage potential for both edible and/or other industrial applications.