Fig. 6: ATR-FTIR spectroscopic analysis.

The spectrum of Mann-S1 (red line) was compared to that of a fresh virgin olive oil (green line). The strong carbonyl absorption of the triacylglycerol esters (1745 cm⁻¹) detected in fresh oil was shifted to the typical carbonyl frequencies of free acids (1707 cm⁻¹) and estolides (1733 cm⁻¹).