Volatile Compounds, Fatty Acid Composition and Antioxidant Activity of Centaurea albonitens and Centaurea balsamita Seeds Growing in Van, Turkey

Abstract

Aims: The aim of this study was to determine and compare the potential of Centaurea albonitens and Centaurea balsamita seeds as alternative raw materials for edible oil production and natural antioxidant sources.
 Study Design: C. balsamita and C. albonitens were harvested from the district of Van province during harvest-maturity period in August-September 2017. The plants were identified by a biologist, Prof. Dr. Murat ÜNAL. The Voucher specimens (B5495, MÜ68611) were deposited at the Virtual Herbarium of Lake Van Basin, Van Yüzüncü Yil University, Faculty of Education.
 Place and Duration of Study: The study was carried out between June 2017 - January 2019 in Yüzüncü Yıl University, Faculty of Engineering, Food Engineering Department laboratory.
 Methodology: This study consists of two parts. In the first part, crude oil, moisture, ash, protein content, total phenolic content (TPC), volatile components and antioxidant activities of Centaurea albonitens and Centaurea balsamita seeds were determined. In the second part, fatty acid compositions, tocopherol contents, peroxide values (PV), free fatty acidity (FFA) and color values of seed oils obtained by cold extraction were determined.
 Results: The antioxidant capacities were determined by the 2,2-diphenylpicrylhydrazyl (DPPH) and the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Results were 26.60 and 27.12%, and 80.61 and 95.99 mmol Trolox eq/g for C. balsamita and C. albonitens seeds, respectively. The total phenolic content of the seeds were determined to be 9019 and 11501 mg GAE/kg, respectively. The average α-tocopherol content were found to be 1186 and 1689 mg/kg oil. Oil yields of the seeds were found to be 19.36 and 17.65 %, for C. balsamita and C. albonitens seeds, respectively. In fatty acid profiles; linoleic, oleic, palmitic and stearic acids were determined as the most dominant fatty acids. 22 volatile compounds were detected in C. balsamita seed while this was 26 volatile compounds in C. albonitens seed.
 Conclusion: In this study, it was concluded that C. albonitens and C. balsamita seeds may be considered as alternative raw materials for edible oil production, and these seeds can be used in the formulation of functional foods due to their high level of α-tocopherol, natural antioxidants and polyunsaturated fatty acids.