Abstract:

A HPLC method was developed for the analysis of polyphenol composition of different parts of an ear of sweet corn including kernels, cob, silk and leafy husk. The chromatographic separation was performed on an Agilent ZORBAX SB-C18 column (4.6 × 250 mm, 5μm) with a binary mobile phase composed of a mixture of 0.4% aqueous solution (phase A) of acetic acid and acetonitrile (phase B) leading to the following gradients: 0－40 min, phase A 5% + phase B 95%; 40－45 min, phase A 25% + phase B 75%; and 45－50 min followed by 5 min running, phase A 35% + phase B 65% at a flow rate of 1.0 mL/min. Column temperature was set at 30 ℃. The VWD detection was performed at a wavelength of 280 nm. Added together, 13 phenolic compounds were identified in sweet corn kernels, cob, silk and leafy husk, including gentisic acid, rutin, quercetin, picatechin, vanillic acid, benzoic acid, syringic acid, catechin, hyperoside, gallic acid, caffeic acid and ferulic acid, of which, 12 were identified in sweet cob or leafy husk and 8 in sweet silk.

Key words: sweet corn, polyphenols, HPLC