Steady-state and time-resolved fluorescence studies of stripped Borage oil

In this study we explored the spectroscopic properties of Borage oil, particularly the use of fluorescence techniques to investigate the presence of conjugated fatty acids (CFAs). This research has important health and dietary applications. The absorption and fluorescence spectra of different CFAs and Borage oil in ethanol were measured. Time-domain fluorescence was employed to establish the life times of the samples. We found that Borage oil contains 1.2 × 10−3 mol L−1 of α-eleostearic acid or its isomer (i.e., a conjugated triene), 1.6 × 10−4 mol L−1 of cis-parinaric acid (i.e., a conjugated tetraene) and 1.1 × 10−5 mol L−1 of c-COPA (i.e., a conjugated pentaene). Because of the three-exponential fluorescence intensity decay for Borage oil, other fatty acids with a four conjugated double bond system could not be excluded.