Abstract

Agricultural waste is mainly composed of cellulose and hemicelluloses which can be converted to sugars. The inexpensive sugar from durian peel was hydrolyzed with H₂SO₄, HCl and H₃PO₄ at a concentration of 0.5 to 2.0% (v/v). The hydrolysis times ranging from 15 to 60 min were investigated when the mixture was autoclaved at 121°C. The result shows that acid hydrolysis efficiency (AHE) with H₂SO₄, HCl and H₃PO₄ had values of 72.15 to 77.55, 70.78 to 80.99 and 73.33 to 77.34%, respectively. Hydrolysis with H₂SO₄ and HCl led to increased concentration of AHE, reducing sugar and total sugar, while hydrolysis with H₃PO₄ had no effect on all values. Hydrolysis time had no effect on AHE, reducing sugar and total sugar in hydrolysis with H₂SO₄ and HCl; while in hydrolysis with H₃PO₄, the increasing time increased AHE and reducing sugar but had no effect on total sugar. Sugar in the hydrolysates was determined by high performance liquid chromatography (HPLC). In hydrolysis with H₂SO₄ and HCl, glucose, fructose and xylose were found while in hydrolysis with H₃PO_4, glucose and fructose were found.

Key words: Acid hydrolysis efficiency (AHE), hydrolysis, durian peel, reducing sugar, total sugar.