Enhancement of holocellulose accessibility in Chokanan mango (Mangifera indica) leaves via acid and alkaline pretreatment

Lignocellulosic (LC) biomass especially agricultural waste with wide availability have been recognized as the most sought after feedstock for bioethanol production. However, the natural recalcitrance of LC plant cell wall gives a resistance to enzymatic hydrolysis. This is considered to be the great challenge in the conversion of LC biomass into bioethanol. As a consequence, pretreatment is required to disrupt the complex lignin barrier and increase the accessibility to holocellulose (cellulose and hemicellulose) of LC biomass prior to enzymatic hydrolysis to ensure an effective bioethanol production. Out of various pretreatment available, chemical pretreatment has established itself as an effective delignification process. Thus, through this research, mango leaves are pretreated through acid (H2SO4) and alkaline (NaOH) treatment. In alkaline pretreatment, the biomass is well delignified (71.59±0.61%) with minimal loss of holocellulose at 3.66%. Hence, this is known to be a preferential pretreatment process because the cellulose as well as hemicellulose could be broken down and converted into bioethanol.