Thursday, May 29, 2008

Dextran Production from Molasses


Teresita O. Macuro, Ma. Lucia C. Sanchez, Ma. Florencia T. Logrono, Dida V. Gatanela, Marilou A. Agravante, Ma. Lourdes T. Escarrilla

The production of dextran is dependent on the amount of glucose in the fermentation broth. Leuconostoc mesenteroides acted on glucose, converting them into glucose-saccharides or glucans. The inversion of sucrose was enhanced by L. mesenteroides microorganisms and the use of hydrochloric acid. During the pH adjustment, considerable amount of sucrose was inverted to glucose and the inversion continued during the fermentation but not all of the sucrose were reduced and used up for dextran production. Inoculated media in the 15o Brix at pH 5 gave the highest yield of dextran and inoculated media in the 20o Brix at pH 5 gave the lowest. The yields of dextran in the inoculated treatments were several times higher than the uninoculated treatments or control.
Dextran content, reducing sugar and sucrose content were monitored up to 48 hours. There was significant correlation between reducing sugar content and dextran production in the inoculated molasses substrate at 15oBrix media both at pH 5. Dextran production also was highest at 24 hrs. In 25oBx at pH 4 inoculated media. Dextran production in all inoculated treatments were very significantly higher than uninoculated treatments.
The microbial activity of L. mesenteroides in the inoculated media was significantly higher that the uninoculated media on all levels of concentrations and pH. Generally, the microbial activity of the inoculated media within the 24-hour fermentation period was high and deteriorated after the 24-hour period. The microbial activity of the control throughout the fermentation period was comparable with the inoculated, however, microbial activity of the uninoculated media was low on all levels of concentrations and pH throughout the fermentation process. The microbial activity of L mesenteroides could be expressed in terms of dextran production, sucrose content and reducing content (glucose) of the fermentation media.
The study also refined the methodology for laboratory-scale extraction of dextran. Refined and absolute alcohol were used to extract dextran. Although the use of refined alcohol is cheaper as an extractant for dextran, absolute alcohol gave higher yield of dextran than refined alcohol.

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Wednesday, May 21, 2008

Effect of different temperatures storage of soil samples on residue of atrazine and diuron herbicides on three soils types in Indonesia

D. Sasongko dan Hendro Santoso M.
Indonesian Sugar Research Institute
Jl.Pahlawan 25 Pasuruan 67126 Indonesia
E-mail :


Usually soil samples for herbicide residue analysis have to be stored in freeze storage (-7 C) before they were analyzed. However the analysis was facing with a problem i.e : capacity of the freeze storage is to small for a great number of soil samples. Herbicide residue was measured using High Performance Liquid Chromatography (HPLC). The purpose of this study is to investigate the influence of storage temperatures of soil sample on residues of atrazine and diuron on the rate of loss. There were two different temperatures of soil samples storage in this study i.e. –7 C (freeze storage) and 27.5 C (average room temperature).
The results showed that herbicide residue of three soil type in Indonesia (Vertisol, Entisol, Ultisol) in the freeze storage were not decreased for up 15 days after incubation. Contrastly, in the average room temperature, rapid disappearance of the atrazine residues were observed during 9 days (61 – 69 % of the initial dose), while the diuron residue decreased about 21 – 38 % when herbicide residue analysis was conducted 7 days after incubation. Moreover residue of atrazine and diuron in the soil samples stored in the average room temperature were still high (more than 90 % and more than 88 %, respectively) when samples were analysed 5 days after incubation. Based on this fact, soil samples for herbicide residue analysis can be stored in the average room temperature (27.5 C) for 5 days especially for analysing herbicide residue on a great number of soil samples, and the sample must be extracted and analysed within 5 days.

Sunday, May 18, 2008

Combination of Strong Base Anion Exchange Resins and Active carbon
for Decolorization of Liquid Sugar

Hendro Santoso M dan Triantarti
(Indoensian Sugar Research Institute-Jl.Pahlawan 25 Pasuruan 67126)


Molasses which contains 60 - 70 % sugars, is a good raw material for liquid sugar but the barrier is its brown colour. One of the technology for making liquid sugar from molasses is a combination of purification process using ion exclusion chromatography and decolorization process using ion exchange resins and active carbon. This paper describes the use of strong base anion exchange resins followed by active carbon treatments for decolorizing liquid sugar resulted from ion exclusion chromatography. Experiments were conducted in complete randomized design with two replications. Two different type of strong base anion resins (IRA 900 and IRA 400) were used and it was followed by active carbon treatments were variation on the amount of active carbon added to liquid sugar was 20; 40; 60; 80 and 100 g per litres of liquid sugar. The observed parameters were ICUMSA colour, turbidity, ash and Total Sugar As Invert (TSAI). The results show that decolorization treatments using a combination of strong base anion resins and active carbon were significantly improved the quality of liquid sugar by reducing of colour, turbidity, ash content and finally increasing the purity of liquid sugar produced. The ICUMSA colour was reduced by 97,46 % using IRA 400 and it was better than using of IRA 900 with colour removal was 90,96 %. Further more by using active carbon between 40 - 100 grams per litre liquid sugar could reduce ICUMSA colour average between 94,42 - 95,73 %. Turbidity removal were between 78,82 to 100 %. The treatment using IRA 900 could remove 2,22 point of ash % brix and it was better than using IRA 400. The ash removal and the increase of sugar purity by treatments using addition of active carbon between 80-100 grams per litre liquid sugar were not significantly different. The ash removal was average 2,18 point of ash %brix and the increase of sugar purity was average 8,28 point of TSAI %brix. Active carbon treatments has only an effect on increasing of TSAI %brix. The choice for the best treatment for decolorization of liquid sugar resulted from purification of molasses using ion exclusion chromatography depends on the requirement of quality from liquid sugar that will be produced.

Key words : Active carbon, Resin, Color, Liquid sugar

Jurnal Ilmu Dasar Volume 7 No.2 Juli 2006 : 86-93

Thursday, May 15, 2008


Yahya Kurniawan dan Simping Yuliatun

Indonesian Sugar Research Institute
Jalan Pahlawan Nomor 25
Pasuruan 67126

E-mail :


The exhaustion of fossil oil resources in Indonesia and the increasing price of petroleum oil in the world about 60 dollars per barrel make the alternative energy important. There are some alternative energy such as hydrothermal, cool, solar, natural gas, hydro, wind and green energy. Among those alternatives, green energy as a renewable energy the promising energy for transportation. Gasohol as a renewable energy is the most competitive alternative energy for transportation. ethanol is one of the more feasible for transportation. Gasohol is a mixture of 10 to 25 percent ethanol with gasoline can be used in any gasoline engine without modification. Ethanol has good oxygenating properties, improving gasoline combustion and reducing emissions of carbon monoxide (CO), particulate matter and other pollutants. Ethanol is made by fermentation process, distillation and dehydration. The raw materials are from sugar materials such as sugarcane, molasses, sweet sorghum and starch materials such as corn, cassava etc. Sugarcane produces 6000 liters- 9000 liters ethanol per hectare. Corn produces 2400 liters ethanol per hectare and cassava produces 2600 liters ethanol per hectare. In Indonesia, the growth consumption of the gasoline is relatively high, the gasoline consumption is estimated around 23 billion liters in 2010. If ten percents of the gasoline demand are substituted by ethanol, it will open the market about 2.3 billion liters ethanol. The use of gasohol as green energy for transportation has beneficial impact to the growth of national agro industry and increasing the income of farmers, reducing dependency on fossil fuels, lowering pollutant emission and the green house effect.

Key words: gasohol, ethanol, bio energy, bio fuel

Thursday, May 8, 2008


By Electo Eduardo Silva Lora, Marcelo Zampieri, Osvaldo José Venturini, Jose Joaquim Santos

(Excellence Group in Thermal Power and Distributed Generation, Federal University of Itajubá).


This paper shows the advantages of using thermodynamic and economic concepts, the so called “thermo-economics”, to carry out the assessment of repowering alternatives in sugar and alcohol mills’ cogeneration plants, which allows the determination of the cost of each product separately. The present scheme of an existing sugar and alcohol mill (1000 tonnes of crushed cane per hour) and four repowering alternatives are modelled using the Gate-Cycle Enter software. Different steam parameters (63 bars/480oC and 82 bars/520oC) are considered. The cogeneration plant thermal efficiency is calculated according to four different criteria and conclusions are made according to the way each of these criteria considers real processes. Exergetic and monetary cost for steam, mechanical power and electricity are presented for all the evaluated scenarios.

KEYWORDS: cogeneration, sugar and alcohol industry, thermoeconomics.

(ISSCT XXVIth CONGRESS Durban, South Africa 29th July - 2nd August 2007)

Sunday, May 4, 2008

Ethanol production by Kluyveromyces lactis immobilized cells in copolymer carriers produced by radiation polymerization;

El-Batal AI et al.;


The conditions for batch and continuous production of ethanol, using immobilized growing yeast cells of Kluyveromyces lactis, have been optimized . Yeast cells have been immobilized in hydrogel copolymer carriers composed of polyvinyl alcohol (PVA) with various hydrophilic monomers, using radiation copolymerization technique . Yeast cells were immobilized through adhesion and multiplication of yeast cells themselves . The ethanol production of immobilized growing yeast cells with these hydrogel carriers was related to the monomer composition of the copolymers and the optimum monomer composition was hydroxyethyl methacrylate (HEMA) . In this case by using batch fermentation, the superior ethanol production was 32.9 g L(-1) which was about 4 times higher than that of cells in free system . The relation between the activity of immobilized yeast cells and the water content of the copolymer carriers was also discussed . Immobilized growing yeast cells in PVA: HEMA (7%: 10%, w/w) hydrogel copolymer carrier, were used in a packed-bed column reactor for the continuous production of ethanol from lactose at different levels of concentrations (50, 100 and 150) g L(-1) . For all lactose feed concentrations, an increase in dilution rates from 0.1 h(-1) to 0.3 h(-1) lowered ethanol concentration in fermented broth, but the volumetric ethanol productivity and volumetric lactose uptake rate were improved . The fermentation efficiency was lowered with the increase in dilution rate and also at higher lactose concentration in feed medium and a maximum of 70.2% was obtained at the lowest lactose concentration 50 g L(-1).

(Acta Microbiol Pol, 2000, 49(2), 157 – 66)