Effects of harvesting times and cooking methods on anthocyanin content and antioxidant activity in purple waxy corn hybrids

Abstract

There is an increasing interest in purple waxy corn due to its health promoting properties. However, data on bioactive compounds in literature about this corn are limited. Therefore, this research aimed to study the effects of harvesting times and cooking methods on anthocyanins and antioxidant activity in purple waxy corn hybrids. The results showed that the concentration of anthocyanins in purple waxy corncobs was higher than that of anthocyanins in kernels. Anthocyanin content increased throughout the development of each part of the corn. The individual anthocyanins were identified and quantified by using HPLC-ESI/MS. Cyanidin-3-glucoside was found to be the most abundant form of anthocyanin found in corn kernels and cobs, followed by cyanidin-3(6’’-malonylglucoside) and cyanidin-3(3’’,6’’-dimalonylglucoside), respectively. Compared to boiling, steaming retained greater bioactive compound content and antioxidant activity. Moreover, the steaming of whole ears resulted in the greatest preservation of anthocyanins and their antioxidant properties. These results would be useful as a source of database for selecting harvesting times and cooking methods, allowing for better preservation of the nutritional values of purple waxy corn.