Abstract

THE EFFECTS OF COOKING METHODS ON ANTIOXIDANT ACTIVITY AND PHENOL CONTENT IN VEGETABLES

Ali Mirzaei, Hamdollah Delaviz*, Hamidreza Mohammadi

ABSTRACT

Introduction: Total phenol and antioxidant activity of vegetables may be changed by different ways of cooking such as, baking, steaming, pressure cooking, microwaving and frying. This study is conducted to determine the antioxidant activity and phenol content of three Iranian vegetables by different cooking methods. Materials and Method: Fresh Broccoli (Brassica oleracea, L. pepper (Capsium annuum, L and spinach (Spinacia oleracea,L.) were obtained from a market in Yasuj, Iran. One portion was kept raw as control and stored at 4 ◦C in the refrigerator, others were subjected for four different cooking methods. After cooking, the cooked vegetables were cooled and then all vegetables were homogenized in a 2 min , and stored at −20 ◦C until analyses. Raw and cooked vegetables were analyzed by differentantioxidant activity methods and total phenol contents based on dry matter. Results: The fresh vegetables total phenol content ranged 882–1306 mg GAE/100 g dm. After cooking procedures, the total phenolics content of spinach and broccoli was insignificantly reduced. Conversely, total phenolic content of pepper was significantly increased in boiling (8%) and frying (4%) methods. Total antioxidant activity of DPPH against of TEAC method in all samples increased during all cooking procedures compared to the fresh procedure. Conclusion: depends on cooking methods and kind of vegetables nutritional and physicochemical qualities changed by domestic cooking.

Keywords: Antioxidant Activity, Brassica oleracea, Capsium annuum, Spinacia oleracea, Cooking Methods.