Pretreatment of sugarcane top leaves by ozonation as a promotion of susceptibility to hidrolysis

Studies about Ozone (O 3 ) application in sugarcane residues for ethanol production are ongoing. This study was undertaken to evaluate the use of ozone as a pretreatment to facilitate hydrolysis of sugarcane top leaves. In the first experimentation, sugarcane top leaves were subjected to ozone (62.37 mg O 3 min -1 over a three hour period) and water only (control). Following ozonation, the material was separated into a liquid and solid fraction. The analysis of liquid fraction showed that phenolic concentration and soluble solids did not vary. However, there was a decrease in pH and an increase in reducing sugars. This treatment increased saccharification. During the second treatment, ozone was added by direct infusion in a suspension of sugarcane top leaves and distilled water at a ratio of 1:10 (w.v -1 ).  Additionally, the lignocellulosic analysis showed a positive relationship between the dose of ozone and decomposition of lignin and an increase in the proportion of cellulose and hemicellulose in the material. All aspects are good signs for the use of ozone in pretreatment of lignocelullosic feedstocks.