Table 1 showed that, for chopped peel, the pretreated wastes had higher methane production than the untreated
ones.The pretreatment of the wastes increased methane production to the value of 0.076–0.217m3/kgVS corresponding
to25–350%of improvement.The best pretreatment condition based on the methane yield obtained was for chopped peel
treated at 20∘C for 10min with orange peel waste and hexane ratio of 1 : 12.This pretreatment increased the methane yield
by more than three times. On the other hand, in the case of homogenized peel, the pretreatment resulted in lower
methane production.