Kajian Pemanfaatan Pod Kakao (Theobroma cacao) melalui Hidrolisis Asam Lignoselulosa untuk Menghasilkan Etanol.

Abstract

Cocoa is one of commodities that its role is important enough for the national economy. Cocoa commodity exports ranked third in the agriculture sector contributes foreign exchange, after the rubber and palm oil. Currently Indonesian cocoa production ranks third largest after the Ivory Coast and Ghana. In 2006 cocoa exports reached U.S. $ 975 million, an increase of 24.2% over the previous year (Suryani and Zulfebriansyah, 2005). Increased efforts in the field led to increased cultivation of cocoa pod waste. This is a challenge, given the amount of cocoa pod components for 73.73% of the cacao fruit (Siswoputranto, 1983). If the cocoa pod is not handled properly it will result in losses. In the research is studied on the acid hydrolysis using cocoa pod to produce ethanol. In addition to get the best treatment of acid hydrolysis that is affected by acid concentration and hydrolysis time and to get the highest yield of sugar and ethanol. This research was conducted in three main stages that were preliminary treatment of raw material preparation and characterization of raw materials, acid hydrolysis, and fermentation to produce ethanol. Hydrolysis of cocoa pod is done in two stages using sulfuric acid. In the first hydrolysis used sulfuric acid concentration of 1% with a time of hydrolysis for 1, 2, 3, 4, 5, 6, and 7 hours. In the second hydrolysis using acid with higher concentrations of 5, 10, 15, and 20% with hydrolysis time of 1, 2, 3, 4, and 5 hours. Analysis was conducted on the reducing sugar, total sugar, dextrose equivalent, and fiber components of lignocellulose. Fermentation using two different substrates derived from the hydrolysis of the first stage and second stage. In fermentation measured volume of CO2 formed, ethanol content, total residual sugar, the efficiency of substrate utilization and product yield of ethanol. On the characterization of raw materials obtained value of cocoa pod ash content 1.87% (db), fat 3% (db), protein 2.25% (db), carbohydrate 92.89% (db), and 53.82% crude fiber (db). Crude fiber fraction containing cellulose 28.78% (db), hemicellulose 8.70% (db) and lignin 42.90% (db). In the first hydrolysis, the results of analysis showed that the highest reducing sugar of 27.31 mg/ml was produced from treatment of 1% sulfuric acid and hydrolysis time of 4 hours. The highest total sugar also produced from the same treatment with a value of 32.74 mg/ml. Dextrose equivalent values ranged from 50.63% to 84.32%. On analysis of lignocellulose after the first hydrolysis, there is a decrease of lignin content, hemicellulose, and cellulose so that its value in a row to 30.82%, 6.52% and 25.75%. In the second hydrolysis, the best treatment that produces the highest reducing sugar and total sugar by using 5% acid concentration and time of hydrolysis for 4 hours. This treatment produces reducing sugar 15.91 mg/ml and the total sugar 29.26 mg/ml. In the second hydrolysis dextrose equivalent values ranged from 47.08% to 89.67%. Lignocellulose fiber components of cocoa pod is decreasing because the second hydrolysis, so that the lignin content to 28.88%, 4.45% hemicellulose, and cellulose 21.98%.