Influence of cooking conditions on organoleptic and health-related properties of artichokes, green beans, broccoli and carrots

• Sous-vide cooking preserved the nutrient content of vegetables better than boiling.
• The antioxidant activity of vegetables greatly depends on the cooking method.
• Induction hobs with temperature control improve vegetable quality.

Colour, pigments, total phenolic content and antioxidant activity were investigated in artichokes, green beans, broccoli and carrots cooked under different conditions. Domestic induction hobs with temperature control were used to evaluate the effect of boiling, sous-vide cooking and water immersion cooking at temperatures below 100 °C on the properties of each vegetable. Sous-vide cooking preserved chlorophyll, carotenoids, phenolic content and antioxidant activity to a greater extent than boiling for all of the vegetables tested and retained colour better, as determined by a∗. A reduction of only 10–15 °C in the cooking temperature was enough to improve the properties of the samples cooked by water immersion, except for green beans. Artichokes and carrots suffered pronounced losses of antioxidant activity during boiling (17.0 and 9.2% retention, respectively), but the stability of this parameter significantly increased with sous-vide cooking (84.9 and 55.3% retention, respectively).