Physical and functional properties of carrots differently cooked within the same hardness-range

The physical and functional properties of carrots cooked by different cooking methods within the same hardness-range were compared. Firstly, the hardness was classified into three levels based on the chewing ability of elderly, and then, carrots were cooked by three different cooking methods (boiling, steaming, and microwaving). Each cooking method, especially by microwave heating, led to a significant loss of vivid color compared to the raw carrots. About the antioxidant properties, which were measured by l,l-diphenyl-2-picrylhydrazyl (DPPH) and total polyphenol contents (TPC), both the values increased with longer cooking time, particularly with steaming and microwave heating. The highest amount of beta-carotene was measured by microwave cooking, and proportionally to the cooking time, more calcium was eluted from the cell tissues. For all the three cooking methods, the cooking time resulted negatively correlated with hardness, and more other correlations among variables were observed for microwave heating than the other two cooking methods. As a result, microwave heating seemed to be the most effective cooking method to soften carrot with the shortest time and the highest functional values.