Rediscovering Ancestral Maize: Uncovering Lost Nutritional and Health Benefits for Modern Challenges

Nearly 60 million Americans are impacted by chronic metabolic disease, underscoring the urgent need for dietary solutions. Maize, a common staple food, is rich in starch but low in protein and other bioactive compounds, potentially exacerbating malnutrition. Unlike its wild ancestor, teosinte and landraces, modern maize has lost much of its kernel diversity—potentially along with key phytochemicals that impart vibrant colors. This study focuses on identifying the potential health-promoting traits of ancestral maize to uncover lost benefits that could address modern nutritional challenges. It comprised 26 varieties of modern maize, 25 landraces, and 25 teosinte varieties. The metabolites were analyzed in both raw and gastrointestinal (GI) digested kernels by GC-QTOF-MS analysis. Finally, in-vitro experiments using HT-29 cells studied the bioactive properties of the GI-digested kernels.

The metabolite analysis in raw kernels revealed that modern maize and landraces have a higher abundance of carbohydrates than teosinte, but antioxidant precursors like caffeic, quinic, and chlorogenic acids were higher in teosinte varieties. After GI digestion, there was no significant difference in the relative level of most metabolites between the three groups, except for quinic acid and its derivatives levels, which were significantly higher in teosinte. Moreover, peptide profiling uncovered that digested teosinte varieties were rich in dipeptides and tripeptides containing hydrophobic residues, known to possess bioactive properties. Later, in-vitro studies showed that teosinte digesta significantly reduced oxidative stress in HT-29 cells. A negative correlation was also observed between cellular oxidative stress vs quinic acid and its derivatives, both in raw and digested kernels. Further, genomic population studies discovered quantitative trait loci associated with quinic acid between maize inbreds and teosinte lines, suggesting quinic acid as a potential bioactive metabolite lost during domestication. These findings conclude that domestication led to the loss of potential health-beneficial compounds, once abundant in teosinte.