Effects of Different Cooking Methods on Nutritional and Physicochemical Characteristics of Selected Vegetables
CRISTIANA MIGLIO,† EMMA CHIAVARO,‡ ATTILIO VISCONTI,§VINCENZO FOGLIANO,§ AND NICOLETTA PELLEGRINI*,†
Department of Public Health, University of Parma, via Volturno 39, 43100 Parma, Italy, Department of Industrial Engineering, University of Parma, viale GP Usberti 181/A, 43100 Parma, Italy, and Department of Food Science, University of Napoli “Federico II”, Parco Gussone, 80055 Portici, Napoli, Italy

J. Agric. Food Chem. 2008, 56, 139–147    

The objective of the present study was to evaluate the effect of three common cooking practices (i.e., boiling, steaming, and frying) on phytochemical contents (i.e., polyphenols, carotenoids, glucosinolates, and ascorbic acid), total antioxidant capacities (TAC),...

Water-cooking treatments better preserved the antioxidant compounds, particularly carotenoids, in all vegetables analyzed and ascorbic acid in carrots and courgettes. Steamed vegetables maintained a better texture quality than boiled ones, whereas boiled vegetables showed limited discoloration. Fried vegetables showed the lowest degree of softening, even though antioxidant compounds were less retained. ...

 Our findings defy the notion that processed vegetables offer lower nutritional quality and also suggest that for each vegetable a cooking method would be preferred to preserve the nutritional and physicochemical qualities.
 

..........In conclusion, the present study clearly indicates that physicochemical and nutritional qualities of vegetables are deeply modified by domestic cooking and that modifications of the evaluated parameters are also strongly dependent upon the vegetable species. ...

These conditions would have promoted the release of antioxidant compounds from the vegetable matrix and determined the formation of new antioxidant compounds.....

Moreover, our results suggest that for each vegetable a preferential cooking method could be selected to preserve or improve its nutritional and physicochemical qualities.