To determine whether the resulting from coffee roasting waste of silver skin and coverings of
the endosperm as a food additive or dietary products may find use, samples of four different
Austrian roasters (Company Eduscho/Tchibo, Company Segafredo, Company Meinl and
Kaffeerösterei Alt Wien) were examined phytochemically, on their antioxidant activity and
analysed on their nutrient composition. In all four samples the methylxanthine caffeine that
has adaptogenic effect as adenosine antagonist and as phosphodiesterase inhibitor on
different body cells, comparable to the features of beta-agonists, could be determined as an
Swelling index was found from 5.5 to 24.5 ml/g indicating a high fiber content and was
comparable with those of Psyllii semen (10 ml/g) or Plantaginis ovatae semen (9 ml/g).
Using Folin-Ciocalteau reagent the total phenol contents in caffeic acid-equivalents reached
amounts from 10.3 mg/g in the sample of Company Segafredo to 18.8 mg/g in the sample of
Eduscho/Tchibo. Acidification achieved an increase of caffeic acid-equivalents of 1.2 % in
the sample of Eduscho/Tchibo, of 1.4 % in the sample of Segafredo, and of 1.3 % in the
sample of Alt Wien and the sample of Meinl. In contrast, the antioxidant activity determined
by DPPH-method could be increased by acidification of the extracts of the four samples from
8.9 mg/g (Segafredo), 12.2 mg/g (Alt Wien), 16.5 mg/g (Meinl) and 24.1 mg/g
(Eduscho/Tchibo) about to 4.9 % (Segafredo) calculated in Trolox-equivalents. No increase
of antioxidant activity could be recognized by pH-lowering in the Fe3+-reduction-method.
The fiber content value found in the Weender analysis of the sample of Kaffeerösterei Alt
Wien was 1.3 to 1.6 % higher compared to the other three samples.
Although the sample of the Company Meinl showed 1.7 to 2.4 % higher fat values, however,
the sample of the Company Eduscho/Tchibo presented the highest value of 19.058 J/g in
Concerning the volume elements high differences in the potassium values were found from 30
g/kg in original substance (os) in the sample of the Company Eduscho/Tchibo to 14 g/kg in
os in the sample of Kaffeerösterrei Alt Wien. In the testing of the trace-elements the iron
values detected in these two samples with 2.3 and 2.7 g/kg in os used to be between 4.1 to 5
% higher than in the sample of the Company Meinl and even 5.2 to 6.4 % higher than in the
coffee roast material of the Company Segafredo.
As a supplement for animal feed, for example in obese animals, this free coffee roasting
waste could be used well through the interplay of the various substances contained.