Fructose Syrup Production from Tapioca Solid Waste (Onggok) By Using Enzymatic Hydrolysis in Various pH And Isomerization Process

Abstract

Abstract Tapioca solid waste (onggok) from cassava contains high carbohydrate (about 76%). The carbohydrate contains amylose and amylopectin which are the raw material of glucose syrup. Fructose is isomer of glucose which has higher dextrose equivalent. It is potential to produce fructose syrup from onggok by using enzymatic hydrolysis and through isomerization process. This research aimed to produce fructose syrup from cassava solid waste in various pH of enzymatic hydrolysis (liquefaction and saccharification) and isomerizing the glucose to be fructose syrup. Onggok in particle size 63 μm was dissolved in distilled water to make substrate concentration of 25%, 30%, and 35% (w/v). Each of the substrate concentration was hydrolyzed with α-amylase as the liquefaction process and was continued with addition of glucoamylase in saccharification process. The hydrolysis process was set in various pH, 5.5, 6, and 6.5. In liquefaction, the substrate suspension was added by 0.067% α-amylase (v/v) with heating temperature 90°C for 60 min. Then, it was continued for saccharification by adding glucoamylase in the same ratio with α-amylase for 120 minutes in 55°C. During the hydrolysis process, the sample was taken from each solution in 10 minutes to analyze the reducing sugar concentration by DNS reagent. After the hydrolysis process, the suspension was filtered and evaporated to reduce the water content. Filtrate with the highest reducing sugar concentration was isomerized by adding 1% of glucose isomerase and heated in 60°C, pH 8.2 for 43 hours. The fructose syrup concentration was then analyzed by resorcinol reagent and the result was 229.3 g/l, yield 9.298%, and conversion 24.587%.