Antioxidant activity of phytogenous industrial waste and derived extracts for the production of feed and food additives

Organic wastes as well as their ethanolic, water and heptane extracts and fermented products derived from herbs, fruit and vegetables obtained worldwide from food and pharmaceutical industries were investigated regarding their antioxidant activities using different methods [1.1-diphenyl-2-picrylhydrazyl, Fe-III-reduction method and photochemiluminescence (PCL)]. The highest antioxidative activities were exhibited by different products of grape seed wastes (350-830 mg rosmarinic acid equivalent g(-1) dried material = rae g(-1) dm) followed by ethanolic extracts of blueberry (475 mg rae g(-1) dm), larch (219 mg rae g(-1) dm), willow (193 mg rae g(-1) dm) and sunflower presscake (154 mg rae g(-1) dm). Ethanolic extracts of the residues showed comparatively higher activity than water extracts. The least antioxidative capacities were found in heptane extracts of serenoa products (0.4; 0.6 mg rae g(-1) dm) and fermented waste of carrots (1.6 mg rae g(-1) dm). Correlating different assay methods, the strongest correlation was found between Fe-III-reduction and DPPH-method (correlation coefficient r(2) = 0.99**) and the weakest between Fe-III-reduction and PCL method (r(2) = 0.57**) for raw materials.