Pengaruh Pretreatment Alkali Hidroksida Terhadap Produksi Gula Reduksi dari Limbah Kulit Kopi

Abstract

Coffee husks are abundant agroindustrial lignocellulosic materials that can be used to produce reducing sugar. Coffee husks waste composition consist of cellulose, hemicellulose and lignin. However, its highly lignin content make the pretreatment step necessary. This study produced reducing sugars from coffee husks through chemical pretreatments using combined alkaline hydroxide (NaOH-H2O2). Hydrogen peroxide (H2O2) at various concentrations (2.5, 5, and 7.5% (v/v) was mixed into 1% (w/v) of NaOH solution with pH 11.5. The concentration of lignocellulosic content, crystallinity index and reducing sugar content were investigated. The results showed that the highest lignin removal was achieved at the addition of 2.5% H2O2 .The highest crystallinity index of coffee husks waste-treated was achieved 49,87% at variable of 7.5% (v/v) H2O2.  It can be concluded that alkaline hydroxide pretreatment useful for lignin removal and can be applied in reducing sugar.