1. 2nd. ISFAS 2012,4-6 September 2012, Puri Pujangga, UKM, Malaysia OR21 Optimization of Liquid Sugar Production for Bioethanol Processing from ArrowrotUsing Aspergillus niger and Amiloglucosidase SAWARNI HASIBUAN, ENDRIANUR RAHMAN ZAIN & ITA NOVITA Department of Agroindustrial Technology, Faculty of Agribusiness and Food Technology,Djuanda University, Jl. Tol Ciawi No. 01, PO Box Ciawi 35, Bogor 16720, West Java, Indonesia Email address: sawarni02@yahoo.com ABSTRACTThe aim of this research is to analyze the optimum condition of liquid sugar production in bioethanol processing fromarrowrot tuber (Maranta arundinaceae Linn) using Aspergillus niger and amiloglucosidase. The bioethanol processingfrom arrowrot tuber consist of saccharification of the sugars in arrowrot tuber essence, and continuous ethanolfermentation of the saccharified liquid. The aim of this study was to compare saccarification process eficiency usingAspergilus niger and commercial amiloglucosidase (AMG). The starter adding treatments were 10% (A1), 15% (A2),and 20% (A3). The hydrolysis was conducted for 11 days in the temperature of 38 oC. The highest glucose result wasachieved after saccharification in A1B3 and A2B3 (12%), and 28,5% in commercial AMG. The highest fermentationresult was contained 6% of alcohol with 65% production efficiency was achieved.Keywords: bioethanol; liquid sugar; arrowrot tuber; liquification; saccharificationINTRODUCTION various sources of raw material for bioethanol. The advantage of arrowroot compared to other sources ofIndonesias high dependence on crude oil for fuel hasstarch is because its usage as a source of food is not asquite a significant impact on the Indonesian economy high as cassava, corn, sweet potatoes, sago, etc.; so itsand people, especially after crude oil prices exceeded competition as a source of food is relatively low.US$ 100/barrel. With a consumption rate exceedingThe general objective of the study is to supportproduction rate, Indonesia has become a net importer ofdiversification of raw materials and alternative fuels,150 million barrels/year (ESDM 2012). In respond toparticularly bioethanol in Indonesia. Whereas thethe condition, the government of the Republic of specific objectives to be achieved are (1) to determineIndonesia issued Presidential Istruction No. 10, 2005the optimum time of conversion of starch sugar intoregarding the saving of energy use; and Presidential syrup from arrowroot tuber starch, (2) to gain anInstruction No 1, 2006 as well as Presidential optimum condition for the addition of A. niger starterInstruction No. 5, 2006 on renewable energy. concentration and Amyloglucosidase in the productionActually, biofeuls are nothing new to our lives; of glucose syrup from arrowroot tuber, and (3) toonly its technology has developed. One example of thedetermine the efficiency of bioethanol production fromuse of biofuel in acient times was the burning ofarrowroot tuber with the addition of S. cerevisae.jatropha seeds for lighting. Nowadays, the applicationof biofuels have changed into more modern and more MATERIALS AND METHODSpopular forms named bioethanol dan biodiesel; bothcalled biofuels. Biofuel business opportuities in theThe materials used in this study were arrowroot flour, A.world are also highly prospective. Based on Clean Edge nger culture, commercial Amyloglucosidase (AMG), S.report as quoted by Ron Pernick and Clint Wilder cereviseae yeast, Potato Dextrose Agar (PDA), distilled(2007), the world biofuel market in 2006 reached US$ water, 70% alcohol, and other chemical materials for20,5 billion (for ethanol dan biodiesel).analysis.The arrowroot tuber plant is one alternative source The study was conducted in two stages, i.e. theof carbohydrate. As a raw material for biofuels, the preliminary research and primary research. The purposearrowroot can be processed into bioethanol as aof the preliminary research was to determine thesubstitute for premium gas. The arrowroot is one sourcehydrolysis time of arrowroot flour with the addition ofof starch that can be decomposed into sugar and then A. niger starter and commercial AMG. While thefermented into bioethanol. In its decomposition, starchobjective of the primary research was to obtain the bestneeds the help of -amylase and glycoamylase enzymes.treatment of saccharification with the addition ofAfter it becomes sugar, then it is fermented into ethanolAspergillus niger starter and commercial AMG for theusing Saccharomyces cerevisiae yeast.production of bioethanol from arrowroot flour.This study contributes to overcome nationalenergy issues, particularly in conducting exploration of 86

2. THE HYDROLYSIS OF ARROWROOT FLOUR TABLE 1 Results of the chemical composition ofArrowroot flour was dissolved, then heated and stirredarrowroot flour used in the studyuntil gelatinization occurred. Then it was put into anComposition Average (%)autoclave and sterilized at a temperature of 121oC for 15minutes. After sterilization, the erlenmeyer was cooled Water content 13.95at room temperature. The next process was Ash content1.00saccharification, i.e. the decomposition of starch into Protein content0.93glucose. The starter A. niger was put into a substrateFat content1.79with concentrations of 10%, 15%, and 20%. At the same Fiber content4.56time, a similar process was also carried out usingCarbohydrate content73.53commercial AMG cultures with concentrations of 5%,7.5%, and 10%.The average carbohydrate content of arrowrootflour used in the study was 73.53 g/100 g arrowroot THE FERMENTATION OF ARROWROOT LIQUID SUGAR flour. The amount of carbohydrate in arrowroot starchFermentation was done by putting Saccharomycesdepends on the production process and the cultivar used.cerevisiae yeast - which is able to decompose sugar intoThe total carbohydrate of every 100 g can reach 85,2ethanol - into the substrate, in which an anaerobic g/100 g arrowroot flour. The carbohydrate content offermentation took place. In order to obtain an optimalarrowroot is lower than cassava flour which reachesfermentation, the temperature was maintained between88,2 gram, but higher than rice which is only 78,925oC-30oC while the pH was between 4,5-5,5. The grams and wheat which is 77,3 grams. Although it isseparation of ethanol and water was done throughvery widely used, many people are not familiar with thedistillation at a temperature of 78oC, which is the arrowroot plant; unlike cassava, sweet potatoes or taro,boiling point of ethanol. The ethanol vapor was passedwhich are very popular.through a pipe/hose flown with water, so that it was PRELIMINARY RESEARCHcondensed into liquid ethanol. The analysis conductedon the bioethanol products included total sugar level The enzyme used in this study comes from the A. nigeranalysis, alcohol level analysis, and fermentationfungus, in addition to the commercial AMG. Accordingefficiency. to Tatang (2007), the Aspergilus sp fungus wouldproduce the -amylase and glucoamylase enzymes THE EXPERIMENTAL DESIGNwhich would play roles to decompose starch intoThe experimental design used in this study was theglucose or simple sugar.nested design with two treatments (the kind of starterThe total sugar content analysis was conductedand length of fermentation) and two replications. using a hand refractometer. From the results of theThe mathematical model of the nested design usedanalysis, with amounts of substrates of 10% (A1), 15%was:(A2), and 20% (A3) and hydrolysis time of 6 days (B1),9 days (B2), and 11 days (B3), the average sugarYijk = + Ai + Bj(i) + ijkcontent obtained was between 3% to 12%, as presentedWhere :Yijk : Observation variable as a result of treatments ofin Figure 1. the i-th stage of factor A with the j-th stage of factor B at the k-th repetition : General meanAi : Effects of treatment of the i-th stage of factor A (addition of starter i = 1, 2, 3)Bj(i) :Effects of treatment of the j-th stage (length of fermentation = 1, 2, 3) of factor B nested at the i- th stage of factor A.ijk :Experimental error.RESULTS AND DISCUSSION PRELIMINARY RESEARCHThe arrowroot tuber as raw material used in the studywas obtained from Pekalongan, Central Java. Results ofanalysis on the arrowroot starch (AOAC 1984) used ispresented in Table 1. FIGURE 1. Average total sugar content of arrowroot glucose syrup with A. niger starters. 87 3. The results of analysis of variance showed that thethe production of bioethanol from sweet potato glucoseamount of starter used gave a significant effect on thesyrup conducted by Haryani (2008),with atotal sugar content produced (P