Characterization of fatty acids in citrus seed oils by 1H NMR spectroscopy: A qualitative tool

Citrus seed oils (CSOs) are one of the major by-products of fruit processing. They have been utilized as functional foods, cosmetics, and pharmaceuticals because of their essential bioactivity. In this study, proton nuclear magnetic resonance (1H NMR) spectroscopy, as a non-destructive method, was used to analyze fatty acids (FA) in seven CSOs. The seed percentage ranged from 1.11 ± 0.02% to 18.2 ± 2.55% and the oil content of the analyzed CSOs ranged from 25.73 ± 1.31% to 33.57 ± 1.89%. The results showed a significant difference in seed percentage (p 0.05). The percentage of saturated, mono, di, and tri-unsaturated acyl groups was measured by the integration areas of specific 1H NMR signals. The oil content ranges from 25.73 ± 1.31% to 33.57 ± 1.89%. 1H NMR showed that all samples had similar FA profiles. The unsaturated FAs (UFAs) were in higher amounts than saturated FAs (SFAs). The seed oils had ∑UFA content ranging from 61.49 ± 0.30% to 65.99 ± 0.61% and SFA content ranging from 34.01 ± 0.61% to 38.51 ± 0.30%, respectively. This research provides the potential of 1H NMR spectroscopy to give precise details about the composition of CSOs. This will make 1H NMR a valuable tool for future research and development of citrus oils as a new natural functional food.