Abstract: | The effects of irradiation on microbiological load and chemical components of empty fruit bunch (EFB) and palm press fibre (PPF) were investigated as the preliminary study for upgrading of oil palm wastes to animal feeds by fermentation. The initial contamination of microorganisms in both EFB and PPF was very high and there is no significant difference between the samples collected from various palm oil mills. The dose required to eliminate below the detectable level was more than 15 kGy for total aerobic bacteria, but 5–6 kGy is enough for fungi. The contents of holocellulose and lignin were c 60% and 25%, respectively, in both EFB and PPF, and the change in components by irradiation was small. EFB and PPF have a high water holding capacity suggesting that they are suitable substrates for fermentation. These results show that the irradiation by 5–10 kGy on EFB and PPF is applicable for the pasteurisation of fermentation media without any significant change in components. |