Screening of major phenolics and antioxidant activities in teosinte populations and modern maize types

Teosinte is the wild ancestor of modern maize. It has served as a study model of evolutionary processes and even more as a potential source of genomic variation to introgress maize varieties suitable for both food and feed. Although some metabolites have been studied in teosinte, little is known about its secondary metabolites like phenolic compounds. To evaluate the diversity present in teosinte, 22 different teosinte varieties were used to extract and quantify soluble and bound total and specific phenolic compounds by HPLC-PDA, respectively. Also, their antioxidant bioactivities were evaluated. Kernel biophysical parameters showed significant differences among the different teosinte varieties. Teosinte's phenolic profile showed that p-coumaric acid was the predominant phenolic acid form with soluble concentrations around 17 μg/gdw to 31 μg/gdw whereas concentrations of bound ranged from 215 to 238 μg/gdw in all varieties. Teosinte's antioxidant capacities were higher for bound phenolics with values ranging from 50 to 82 mmolTE/100gdw compared to only 7 to 17 mmolTE/100gdw observed in commercial maize. The diversity found in phenolic content and potential bioactivity of teosinte could serve as a platform for the development of new breeding programs into high performance modern maize with distinct nutraceutical potential.