Steeping of Biofortified Orange Maize Genotypes for Ogi Production Modifies Pasting Properties and Carotenoid Stability

Abstract

Biofortified orange maize open-pollinated varieties and hybrids with higher provitamin A carotenoids (pVACs) have been released in sub-Saharan Africa and will be introduced throughout the local food systems. This study assessed the impact of steeping, a traditional processing method, on retention of carotenoids and starch pasting properties of porridges made from select biofortified maize genotypes. Steeping had a modest effect (<9% loss) on total carotenoid stability during relatively shorter steeping periods (<72 h). However, more extended steeping periods (up to 120 h) had a detrimental effect on total carotenoid recovery (61% loss). Xanthophylls showed greater stability (82% retention) compared to carotenes (30% retention) during subsequent wet cooking of fermented flours. Interestingly, steeping of maize did modify pasting properties, with peak viscosities increasing from 24−72 h of steeping potentially impacting cooking stability. These results suggest that steeping can impact carotenoid retention and potentially optimal steeping times would be 24−72 h for acceptable carotenoid retention.

Keywords

• biofortified maize
• pro-vitamin a
• lutein
• zeaxanthin
• carotenoids
• degradation
• retention
• steeping
• fermentation
• food processing
• nutritional impact