Citrus pulps were examined during colonisation with Penicillium roqueforti Pr2. Fungal growth increased the crude protein content from 5.62 to 8.55 (% dry matter) in orange pulp and from 5.77 to 11.89 (% dry matter) in lemon pulp. The ether extract increased respectively from 1.62 to 4.38 (% dry matter) and from 0.97 to 6.78 (% dry matter). The neutral detergent fiber content increased from 14.49 to 32.60 (% dry matter) and from 15.54 to 38.70 (% dry matter). The acid detergent fiber content increased from 11.15 to 24.79 (% dry matter) and from 10.96 to 30.73 (% dry matter).