The antioxidant activity of rutin and selected common buckwheat-originated materials, namely groat, hull, flour and sprouts were measured against stable, non-biological radicals such as 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cation (ABTS•) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) using a spectrophotometric assay, against the key reactive oxygen intermediate – superoxide anion radical (O2-•) with a photochemiluminescence assay (PCL) while reducing capacity was determined with the cyclic voltammetry method (CV). The antioxidant activity was presented independently of the techniques used as TEAC values and then the contribution of rutin to the antioxidant capacity of buckwheat material was calculated. The order of the antioxidant activity of rutin provided by the updated analytical strategy was as follows: CV = DPPH RSA > PCL > ABTS RSA. Buckwheat groat and hull represented low antioxidant capacity samples whilst that of sprouts was ranked as high antioxidant capacity one. The results showed a low contribution of rutin to the antioxidant capacity of buckwheat groat and hull. The highest contribution of rutin to the antioxidant capacity was noted in buckwheat sprouts, especially those produced in light. The specificity of the rank of methods used as CV = DPPH RSA > ABTS RSA > PCL was concluded since the lowest antioxidant gap was provided with CV and DPPH RSA whilst the highest one with ABTS RSA and PCL.