The effect of different pH during steeping on avenanthramide content in germinated oats

Abstract: Oat (Avena sativa L.) grains from the cultivar Ivory were steeped at pH 2, 4, 6, 8, 10 and 12 in 0.01M phosphate buffer solution and in tap water: The pH effect during steeping on avenanthramides 2c, 2p, 2f, 2pd, 2fd and 3f was analysed and compared between germinated samples and with a control. Additional unidentified compounds X, Y and Z in oat grains were included in the analysis. Statistically significant differences were obtained between control and pH2, pH4, pH6 and pH8 treatments for 3f (p<0.001) while 2c, 2p and 2f did not show any significant difference from the control. Avenanthramides 2pd and 2fd together with compounds X, Y and Z seemed to peak at higher pH ranges with statistically significant differences found between control and pH8 and pH10 (p<0.001). Analysis of compounds found in roots (A, B, C) and shoots (D, E, F) was also performed using the same experimental method as for avenanthramides. No pattern regarding concentration of unidentified compounds between different pH values was observed for shoot samples; root samples showed increase of compound D in pH2. However, there was no clear trend of increase or decrease.