washed in cold water, superficially dried (paper towels) and fried in a fryer (Beckers, Italy) until the moisture content was below 2 g 100 g−1. The chips were fried (about 3 min) in refined rapeseed oil heated to 180 °C. After discharging of the oil and cooling, 100 g samples of chips were packed in aluminium foil packages and taken for laboratory analysis. All experiments were performed in triplicate and the results shown are the mean values obtained in the investigation.