Abstract:
Sorghum grain (Sorghum bicolor L. Moench) is a gluten-free cereal with excellent nutritional
value and is a good source of antioxidants, including polyphenols, as well as minerals
with proven health benefits. Herein, the phenolic composition, elemental profile, and antioxidant
activity of sixteen food-grade sorghum grains (S1–S16) grown under agroecological conditions
in Serbia were determined. Nine phenolic compounds characteristic of sorghum grains, such
as luteolinidin, 5-methoxyluteolinidin, luteolidin derivative, luteolidin glucoside, apigeninidin,
7-methoxyapigeninidin, apigeninidin glucoside, and cyanidin derivative, were quantified. The antioxidant
potential of the analyzed sorghum grains was evaluated by UV/Vis (DPPH, ABTS, and
FRAP) and Electron Paramagnetic Resonance spectroscopy (hydroxyl and ascorbyl radical scavenging
assays). The content of macro- and microelements was determined by Inductively Coupled Plasma
Optical Emission spectroscopy. Theoretical daily intakes of selected major and trace elements were
assessed and compared with the Recommended Daily Allowance or Adequate Intake. Sample S8 had
the highest amount of phenolic compounds, while S4, S6, and S8 exhibited the strongest antioxidative
potential. The sorghum studied could completely satisfy the daily needs of macro- (K, Mg, and P) and
microelements (Se, Zn, Fe). Pattern recognition techniques confirmed the discrimination of samples
based on phenolic profile and elemental analysis and recognized the main markers responsible for
differences between the investigated samples. The reaction between hydroxyl radicals and luteolinidin/
apigeninidin was investigated by Density Functional Theory and thermodynamically preferred
mechanism was determined.
