Comparative elucidation on the phenolic fingerprint, sugars and antioxidant activity of white, orange and purple-fleshed sweet potatoes (Ipomoea batatas L.) as affected by different cooking methods

Gamze Guclu; Mumine Melike Dagli; Ozge Aksay; Muharrem Keskin; Hasim Kelebek; Serkan Selli

doi:10.1016/j.heliyon.2023.e18684

Comparative elucidation on the phenolic fingerprint, sugars and antioxidant activity of white, orange and purple-fleshed sweet potatoes (Ipomoea batatas L.) as affected by different cooking methods

Heliyon. 2023 Jul 26;9(8):e18684. doi: 10.1016/j.heliyon.2023.e18684. eCollection 2023 Aug.

Authors

Gamze Guclu¹, Mumine Melike Dagli¹, Ozge Aksay², Muharrem Keskin³, Hasim Kelebek², Serkan Selli¹

Affiliations

¹ Department of Food Engineering, Faculty of Engineering, Cukurova University, 01330, Adana, Türkiye.
² Department of Food Engineering, Faculty of Engineering, Adana Alparslan Turkes Science and Technology University, 01250, Adana, Türkiye.
³ Department of Biosystems Engineering, Faculty of Agriculture, Hatay Mustafa Kemal University, 31040, Antakya, Hatay, Türkiye.

Abstract

In this study, three cooking methods (baking, boiling, sous vide (SV)) were applied to Turkish sweet potatoes with three flesh colors (white, orange, purple) to examine the effects of the product color and cooking methods on the total phenolics, antioxidant activity, sugars, phenolic acids, and anthocyanins. LC-MS-MS was employed in the characterization of these compounds. It was observed that the product color and cooking method significantly affected the concentrations of bioactive compounds like polyphenols. Both the highest total phenolic content (11.36 mg/g) and antioxidant activity (DPPH (50.3 μM TE/g) and ABTS (63.53 μM TE/g)) were determined in the purple sweet potato cooked with the SV method. 10 phenolic acids were quantified in all samples which were in the highest amounts in the orange colored samples followed by the purple samples. Baking resulted in the highest total phenolic acids in all samples. 13 anthocyanins were detected in the purple-colored samples, while the SV cooking best preserved the anthocyanins. In sum, purple sweet potatoes cooked by SV are recommended for higher phenolic contents, antioxidant capacity and anthocyanins.

Keywords: Anthocyanins; Antioxidant capacity; Ipomoea batatas L.; Phenolics; Sweet potato.