Characteristics of white, yellow, purple corn accessions: phenolic profile, textural, rheological properties and muffin making potential.

Physicochemical, antioxidant, phenolic profile and muffin-making properties of white, yellow and purple corn accessions were evaluated. HPLC analysis revealed the presence of ferulic acid, quercetin, sinapic acid, gallic acid and protocatechuic acid in different corn accessions. Ferulic acid was the major phenolic acid present in all accessions. Total phenolic content (TPC), DPPH and ABTS inhibition ranged from 903 to 1843 µg GAE/g, 0.73-0.89 and 3.81-4.92 µM trolox/mg, respectively. Purple accessions had higher TPC than yellow and white accessions. Pasting profiles of different accessions revealed high thermal stability indicated by low breakdown viscosity. Muffin-making properties were determined as batter rheology and muffin specific volume, texture and sensory analysis. Storage modulus (G') and loss modulus (G″) of batters for white colored exhibited the highest while yellow colored had the lowest value. Firmness and TPC of muffins ranged from 3.1 to 5.9 N and 811-1406 µg GAE/g, respectively. Muffin cohesiveness and chewiness were correlated positively, whereas firmness was negatively related to paste viscosities. Antioxidant activity was correlated to phenolic content of the muffins. Sensory analysis revealed that muffins prepared from yellow corn accession (IC447648) were highly acceptable, while those made from purple corn (IC447644) were not liked much.