Changes in Antioxidant Properties and Phenolics in Sweet Potatoes (Ipomoea batatas L.) Due to Heat Treatments.

Hana Franková,Janette Musilová,Judita Lidiková,Július Árvay,Marek Šnirc,Ivona Jančo,Alena Vollmannová

doi:10.3390/molecules27061884

Hana Franková, Janette Musilová + Show 5 more

Open Access

https://doi.org/10.3390/molecules27061884

Copy DOI

Abstract

Processing is one of the most crucial factors affecting polyphenol content in foods. Therefore, the study is aimed at the evaluation of heat treatment effects (microwaving, steaming, baking, and boiling) on the content of chlorogenic acids, total polyphenols, and antioxidant activity of three varieties of sweet potato with different flesh colors (Beauregard—orange-fleshed, O’Henry—white-fleshed, 414-purple—purple-fleshed). According to high performance liquid chromatography analysis, chlorogenic acid was the predominant chlorogenic acid in sweet potatoes. Obtained results also suggested the purple-fleshed variety (414-purple) had significantly (p < 0.05) higher total polyphenol content and thus the highest antioxidant activity. Heat treatment positively influenced the chlorogenic acid content, total polyphenols, and antioxidant activity of sweet potatoes. Among the used methods, steaming had the greatest effect on the chlorogenic acids and total polyphenols, while microwaved samples showed the highest antioxidant activity (DPPH). The content of chlorogenic acids and total polyphenols decreased in the order of steaming > baking > microwaving > boiling > raw. However, the individual varieties differed not only in the flesh color but also in the reaction to the used heat treatment methods. Spearman’s correlation coefficient showed a strong correlation between chlorogenic acid and antioxidant activity.

Highlights

The sweet potato (Ipomoea batatas L.) is a dicotyledonous viny plant and the only economically important member of the Convolvulaceae
Even varieties with the same flesh color can differ in the total polyphenol content, antioxidant activity, and phenolic acid profile [11]
The present study provides information on antioxidant activity

Summary

Introduction

The sweet potato (Ipomoea batatas L.) is a dicotyledonous viny plant and the only economically important member of the Convolvulaceae. It originates in Central and South America and is grown mainly in tropical and warm temperate climatic areas, mainly due to its tuberous roots [1,2], but is currently an important crop grown in more than 100 countries all over the world [3]. In many countries of Asia and Africa, sweet potato is an important agricultural crop [5,6], which is reflected in their high production compared to other countries worldwide. Especially in Asia and Africa, the young shoots and leaves of sweet potatoes are sometimes eaten as greens [5–7]. The advantage of sweet potato leaves is the possibility of harvesting several times a year, and their yields are much higher than the yields of green leafy vegetables [8]

Methods

Results

Conclusion