Improvement of microwave-assisted hydrolysis of cassava pulp and tapioca flour by addition of activated carbon

Hermiati, Euis; Azuma, Jun-ichi; Tsubaki, Shuntaro; Mangunwidjaja, Djumali; Sunarti, Titi Candra; Suparno, Ono; Prasetya, Bambang

doi:10.1016/j.carbpol.2011.08.033

Cited by 34 publications

(19 citation statements)

References 12 publications

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“…Although more brown compounds formed at the 1% acid concentration than at the other concentrations, the Increasing the acid concentration also reduced the pH value ( Figure 6). The formation of organic acids, such as formic acid and acetic acid produced by the secondary degradation of carbohydrates, might be responsible for the decrease in the pH [19,[29][30]. Acetic acid is also derived from acetyl groups in hemicellulose [30].…”

Section: Figure 3 Reducing Sugar Yield Following the Hydrolysis Of Tmentioning

confidence: 99%

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Digestibility of Betung Bamboo Fiber Following Fungal Pretreatment

Fatriasari¹,

Syafii²,

Wistara³

et al. 2014

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This research evaluated the effect of fungal pretreatment of betung bamboo fibers and enzymatic-and microwaveassisted hydrolysis on the reducing sugar yield. The enzymatic hydrolysis of the pretreated biomass was carried out with cellulase and 10 and 20 FPU/g of substrate in a shaking incubator at 50 °C and 150 rpm for 48 h. The sulfuric acid concentration used in the microwave-assisted acid hydrolysis was 1.0, 2.5, and 5%, either with or without the addition of activated carbon. Microwave irradiation (330 Watt) was applied for 5-12.5 min. The yield of reducing sugar was better with the microwave-assisted acid hydrolysis, and the yield tended to increase with an increase in the irradiation time. Based on the dry weight of the initial biomass (bamboo), pretreatment with 5% inoculum loading resulted in a higher reducing sugar yield (17.06%) than with 10% inoculum loading (14.54%). At a 1% acid concentration, the formation of brown compounds decreased, followed by a reduction in the reducing sugar yield. The addition of activated carbon at a 1% acid concentration seemed to be of no benefit with respect to the yield in the microwaveassisted acid hydrolysis. The pretreatment with the 5% inoculum loading for 12.5 min at 1% acid concentration resulted in the highest reducing sugar yield. Under these conditions, the yield was 6.3-fold that of the reducing sugar yield using 20 FPU/g of cellulase. The rate of bamboo hollocellulose hydrolysis reached 22.75% of the maximum theoretical reducing sugar reducing sugar of dry biomass. AbstrakDigestibilitas Serat Bambu Betung Setelah Pretreatment Jamur. Penelitian ini bertujuan untuk mempelajari pengaruh pretreatment jamur pada serat bambu betung terhadap rendemen gula dari hidrolisis enzimatis dan microwave dengan asam. Hidrolisis enzimatis pada bambu setelah pretreatment menggunakan selulase 10 dan 20 FPU/g substrat dalam inkubator shaker pada suhu 50 °C selama 48 jam pada kecepatan 150 rpm. Konsentrasi asam sulfat yang digunakan dalam hidrolisis asam dengan microwave yaitu 1,0, 2,5 dan 5% baik dengan atau tanpa penambahan karbon aktif pada daya microwave 330 watt selama 5-12,5 menit. Hasil penelitian menunjukkan bahwa hidrolisis asam dengan microwave menghasilkan rendemen gula yang lebih baik yang cenderung meningkat dengan bertambahnya waktu iradiasi. Berdasarkan berat kering dari biomassa awal bambu, pretreatment dengan konsentrasi inokulum 5% menunjukkan rendemen gula pereduksi yang lebih tinggi (17,06%) daripada konsentrasi inokulum 10% (14,54%). Penambahan karbon aktif cenderung menurunkan pembentukan senyawa coklat. Namun, pada konsentrasi asam 1% penurunan pembentukan senyawa coklat juga diikuti dengan penurunan rendemen gula pereduksi. Tampaknya tidak terdapat pengaruh menguntungkan pada rendemen gula dengan adanya penambahan karbon aktif dari hidrolisis microwave dengan asam. Pretreatment dengan konsentrasi inokulum 5% selama 12,5 menit pada konsentrasi asam 1% menghasilkan rendemen gula pereduksi yang tertinggi. Rendemen ini meningkat 6,3 kali daripada rendem...

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Section: Figure 3 Reducing Sugar Yield Following the Hydrolysis Of Tmentioning

confidence: 99%

“…Molecular nonuniformity due to microwave irradiation creates "hot spots" on the surface of activated carbon particles [18]. In a previous study, the addition of activated carbon in microwave hydrolysis of starch pulp increased the glucose yield at a lower heating temperature [19].…”

Section: Introductionmentioning

confidence: 99%

Digestibility of Betung Bamboo Fiber Following Fungal Pretreatment

Fatriasari¹,

Syafii²,

Wistara³

et al. 2014

MST

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“…Activated carbon has been proved to improve saccharification of starch in water medium [5,23]. It can also adsorb the brown compounds produced by the thermohydrolysis [5].…”

Section: Introductionmentioning

confidence: 99%

“…When water medium was used for the hydrolysis, it was found that the maximum glucose yield was obtained after hydrolysis at 230°C for 5 minutes (28.59% of dry matter or 32.41% of theoretical yield) [4]. When some activated carbon was added, glucose yield markedly increased up to 44.49% (of theoretical yield) at a temperature of 220°C for 5 minutes and up to 52.3% (of theoretical yield) at a temperature of 210°C for 15 minutes [5]. However, these results were still lower than those of enzymatic hydrolysis (70-74%) [13,14], or the combination of hydrothermal and enzymatic hydrolysis (± 75%) [18,19].…”

Section: Introductionmentioning

confidence: 99%

“…The starch contained in cassava pulp varies, notably in relation to the efficiency of the starch extraction from the cassava. The starch content in cassava pulp can be as low as 40% [1] and can be as high as 68% [2,3], or even 79% when the cassava pulp is obtained from the tapioca home industry in the area of Bogor, West Java [4,5]. Since starch is the major component of cassava pulp, hydrolysis of starch to glucose can be an important process to better utilize this tapioca industry by-product.…”

Section: Introductionmentioning

confidence: 99%

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Cassava Pulp Hydrolysis under Microwave Irradiation with Oxalic Acid Catalyst for Ethanol Production

2014

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Abstract.Microwave irradiation is an alternative method of starch hydrolysis that offers a rapid process. The aim of this research was to improve microwaveassisted hydrolysis of cassava pulp by using oxalic acid as a catalyst. Suspension of cassava pulp in 0.5% oxalic acid (1 g/20 mL) was subjected to microwave irradiation at 140-230°C for 5 minutes, with 4 minutes of pre-heating. One gram of fractured activated carbon made of coconut shell was added into a number of suspensions that were subjected to the same conditions of microwave irradiation. The soluble fraction of the hydrolysates was analyzed for its total soluble solids, malto-oligomer distribution, glucose content, pH value, and formation of brown compounds. The effects of the combined severity parameter at a substrate concentration of 5-12.5% on the glucose yield were also evaluated. The highest glucose yield (78% of dry matter) was obtained after hydrolysis at 180°C without activated carbon addition. Heating above 180°C reduced the glucose yield and increased the pH and the formation of brown compounds. The use of activated carbon in microwave-assisted acid hydrolysis of cassava pulp reduced the glucose yield, but suppressed the formation of brown compounds. The highest glucose yield (70-80% of dry matter) was attained at a severity parameter of 1.3-1.5.

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