Abstract

Peroxidase (POD) activity in wheat seeds using guaiacol-H2O2 as substrate was determined by measuring absorbance changes at 470 nm using a spectrophotometer. The POD activity of wheat was studied under different extraction conditions (three kinds of buffers, three kinds of extraction methods, four kinds of extraction times, six kinds of extraction temperatures and four kinds of extraction eccentricities). Results showed that POD activity using acetate buffer was higher than those of KH2PO4 and sodium phosphate. The assay was repeated three times every 6 h for a single extraction, and the average CVs of the POD values for the buffers were of the order: phosphate buffer (CV=0.031) > sodium acetate (CV=0.0268) > KH2PO4 (CV=0.0168). The repeatability of the extraction method that involved grinding in buffer was lower than those that involved soaking and shaking. The optimum extraction temperature and extraction time were dependent on the cultivars and buffers. No significant differences in the activity of the POD were observed among the different eccentricities of 20000 × g, 15000 × g, 10000 × g and 4000 × g.