Carotenoid content and antioxidant activity of hexane extracts from selected Croatian corn hybrids

Abstract

Carotenoids, which occur naturally in corn grains, have been associated with reduced risk of degenerative diseases. The aim of this research was to measure the carotenoid content of hexane extracts of six commercial high-yield corn hybrids and determine the relationship between carotenoid content and antioxidant activity. Levels of lutein, zeaxanthin, β-cryptoxanthin and β-carotene in hexane extracts were determined using HPLC, and antioxidant activity was assayed using the TEAC system based on the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS+), and the TBARS system based on a linoleic acid emulsion. Corn hybrids varied in carotenoid content and antioxidant activity in both assays. Lutein and zeaxanthin were the predominant carotenoids; their levels were 15-fold higher than those of β-cryptoxanthin and β-carotene. Antioxidant activity in both assays increased linearly with total carotenoid content. Lutein and β-carotene were the primary contributors to TEAC activity, while lutein, β-cryptoxanthin and β-carotene were primary contributors to TBARS activity.