Relationships between the evolution of the percentage in weight of polar compounds and that of the molar percentage of acyl groups of edible oils submitted to frying temperature

► Extra virgin olive, sunflower and virgin linseed oils were submitted to frying temperature. ► The degradation of their acyl groups was monitored over time by 1H NMR. ► The percentage in weight of polar compounds (PC%) was also monitored over time. ► PC% and molar percentage of acyl groups are closely related. ► The equation that represents these relationships has predictive value.