Optimized jicama root liquefaction allows to obtain the highest weight loss and sugars content to recover by-products such as food ingredients, biofuels, organic acids, etc. Jicama (Pachyrhizus erosus L.) tissue was treated with Pectinex Ultra SP-L. Optimization of jicama liquefaction and saccharification was done using Response Surface Methodology and Response Surface Methodology-Spline. A mixture of sodium acetate buffer (AAANa) at pH 4.5 and enzyme ratio (mL/g of jicama cubes) of 0.000, 0.008, 0.012, 0.020 and 0.024 were used. Samples were incubated under shaking (150 rpm) for 0.00, 4.24, 10.00, 14.24 and 16.00 h at 40 C. At the optimum conditions (10 h and 0.024 mL/g) the pH was 4.24, total soluble solids (Brix) amount was 9.00, weight loss percentage was 95.82%, the total and reducing sugars liberated were 119.0 and 63.8 g/kg, respectively. Uronic acids obtained were 5.7 g/kg and polyphenols amount was 26.8 mg/kg.