• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.306-311
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• 2012

This study was performed to evaluate the effects on saccharification and alcohol fermentation, according to the size of the ground rice (12, 20, 35 mesh) and ultra sonication process (15, 30, 60, 120 min). After saccharification of the ground rice samples for 3 h at $60^{\circ}C$, sugar content was observed to be high in the order of cooked ground rice (CGR) > ultrasonicated ground rice (UGR) > ground rice (GR), in all sizes of ground rice. Further, higher sugar content was obtained by increasing the time of ultrasonication process. Almost 90% saccharification of CGR ($11.5^{\circ}Bx$) could be reached up to $10.2^{\circ}Bx$ by ultrasonicating 35 mesh ground rice for 120 min. After alcohol fermentation on the 35 mesh saccharified-UGR for 4 days at $25^{\circ}C$, 16.7% alcohol concentration could be obtained, as high as of CGR (17.2%). After 4 days of alcohol fermentation, UGR showed a lower pH and a higher acidity (pH 4.06-4.17, 0.99-1.1%) than CGR (pH 4.27, 0.75%).

• Journal of the Korean Home Economics Association
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• v.23 no.3
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• pp.55-61
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• 1985

This study was designed to find out the optimum processing condition and the characteristics of yeots : In this study, Yeoteses were made from glutinous rice, Rice, Millet, Sorghum and Corn by microwave oven. The textural parameters of various Yeotses were determined by sensory evaluation and Rheometermeasurement. RESULTS : 1. The sweetness of all the raw materials before saccharification is 11%. In case of the sweetness of the raw materials after saccharification, Glutinous rice was the highest(28.8%) and Corn was the lowest(17.7%). Also, the sweetness of Glutionous rice Yeots was the highest(86%) and Corn Yeots was the lowest(82.7%).It showed similar tendancy to the sensory evaluation for sweetness. 2. The pH of the raw materials before saccharification was 4.4.The pH of sorgphum after-saccharification was the highest (4.7) and that of Corn was the lowest (4.3). 3. In the sensory evaluation of the various Yeotses, Glutinous rice Yeots showed the best quality and it did not showed any significant difference between glutinous Yeots and Rice Yeots.The overalll quality of Milet, Sorghum and Corn Yeotses were inferior to Glutnous and Rice Yeotses. Textural characteristics by Rheometermeasurement revealed differences among the various Yeotses. Hardness, Cohesiveness, Adhesiveness were the highest in Glutinous rice and Rice Yeotses. Adhesiveness showed similar tendancy to that of the sensory evaluation. 4. However, Becuase glutinous rice is more expensive than rice, it is desirable that we use Rice Yeots.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.305-310
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• 2009

Yellow poplar was selected a promising biomass resources for bio-ethanol production through alkali prehydrolysis, enzymatic saccharification and fermentation using commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 mixtures) and fermenting yeast. In alkali prehydrolysis, 51.1% of Yellow poplar biomass remained as residues, which chemical compositions were 82.2% of cellulose, 17.6% of xylan and 2.0% of lignin. In alkali prehydrolysis process, 96.9% of cellulose, 38.0% of xylan and 5.7% of lignin were remained. Enzymatic saccharification by commercial cellulases led to 87.0% of cellulose to glucose and 87.2% of xylan to xylose conversion. Produced glucose and xylose were fermented with fermenting yeast (Saccharomycess cerevisiae), which resulted in selective fermentation of glucose only to bio-ethanol. Residual monosaccharides after fermentation were consisted to 0.4-1.4% of glucose and 92.1-99.5% of xylose. Ethanol concentration was highest for 24 h fermentation as 57.2 g/L, but gradually decreased to 56.2 g/L for 48 h fermentation and 54.3 g/L for 72 h fermentation, due to the ethanol consumption by fermenting yeast.

• Food Science and Preservation
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• v.17 no.5
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• pp.644-651
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• 2010

We prepared sikhe (CSE/BR-SH) using corn silk extract and black rice. The pH decreased during saccharification, from pH $5.88{\pm}0.03$ to pH $5.67{\pm}0.02$ after 6 h. However, the brix and reducing sugar contents increased during saccharification of CSE/BR-SH, with the highest levels ($7.6{\pm}0.05$ brix and $4.012{\pm}0.05$ g/l, respectively) being attained at 6 h. Amylase activity increased to 116.12% of control values 1 h after saccharification of CSE/BR-SH, and decreased thereafter. CSE/BR-SH was light purple in color. Soluble phenolic concentration increased markedly from an initial 8.43 g/l to 23.09 g/l at the end of saccharification (6 h), as did DPPH radical-scavenging activity (from an initial 17.3% to 70.98%), Increases were noted in all of ABTS radical-scavenging activity (from 40.25% to 75.32%), reducing power (from 0.241 to 0.682), and ferric reducing antioxidant power (FRAP) (from 0.288 to 1.071).

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.460-460
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• 2003

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.598-606
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• 2001

A mathematical model is proposed that can depict the kinetics of simultaneous saccharification and fermentation (SSF) using steam-exploded wood(SEW) with a glucose- and cellobiose-fermenting yeast strain. Brettanomyces custersii. An expression to describe the reduction of the relative digestibility during the hydrolysis of the SEW is introduced in the hydrolysis model. The fermentation model also takes two new factors into account, that is, the effects of the inhibitory compounds present in the SEW hydrolysates on the microorganism and the fermenting ability of Brettanomyces custersii, which can use both glucose and cellobiose as carbon sources. The model equations were used to simulate the hydrolysis of the SEW, the fermentation of the SEW hydrolysates, and a batch SSF, and the results were compared with the experimental data. The model was found to be capable of representing ethanol production over a range of substrate concentrations. Accordingly, the limiting factors in ethanol production by SSF under the high concentration of the SEW were identified as the effect of inhibitory compounds present in the SEW, the enzyme deactivation, and a limitation in the digestibility based on the physical condition of the substrate.

• Korean Journal of Agricultural Science
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• v.36 no.2
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• pp.225-232
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• 2009

The ratio of saccharification and formation of furans during the acid hydrolysis of agar with oxalic acid and sulfuric acid were examined base on the contents of the agar and acids. The ratio of saccharification in oxalic acid appeared to be 51~59% somewhat higher than 49~61% of sulfuric acid. Formation of the furans during the acid hydrolysis increased proportional to the contents of agar and acid. The relative formation ratio was high 10~47% for furfural (FUR) and 15~29% for hydroxy-methyl furfural (HMF) in 0.5~1.25% sulfuric acid rather than those of oxalic acid. When comparing the removal efficiency of the furans using an alkali treatment, steam stripping and hydrophobic resins, FUR was eliminated 60% by the alkali treatment, 62~90% by steam stripping and 71~75% by Amberlite XAD4 and 7HP, while HMF was removed to low levels of 10.5%, 4~17% and 13~25%, respectively. The loss of reducing sugar was also observed in process of the removal of furans, and the loss rate was the level of 2~4% in alkali treatment, 11~16% in steam stripping and 7~9% in Amberlite resins.

• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.69-77
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• 2020

Lignocellulosic biomass has recalcitrant characteristics against chemical and biological conversion due to its structural heterogeneity and complexity. The pretreatment process to overcome these recalcitrant properties is essential, especially for the biochemical conversion of lignocellulosic biomass. In recent years, pretreatment methods using ionic liquids (ILs) and deep eutectic solvents (DESs) as the green solvent has attracted great attention because of their advantages such as easy recovery, chemical stability, temperature stability, nonflammability, low vapor pressure, and wide liquids range. However, there are some limitations such as high viscosity, poor economical feasibility, etc. to be solved for practical use. This paper reviewed the research activities on the pretreatment effect of various ILs including DESs and their co-solvents with organic solvents on the enzymatic saccharification efficiency of lignocellulosic biomass and the nanocellulose preparation from the pretreated products.

• KSBB Journal
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• v.14 no.1
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• pp.24-30
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• 1999

The fed-bach simultaneous saccharification and fermentation (SSF) of newspaper to ethanol with Brettanomyces custersii was studied. The initial substrate concentration for the effective fed-batch SSF was 8% (w/v). The initial optimum enzyme concentration was 30 FPU/g cellulose for cellulase and the optimum volumetric ratio of $\beta$-glucosidase to cellulase was 0.1. When 4% (w/v) of ball-milled newspaper was supplemented intermittently at time intervals, considering the mixing of newspaper slurry, the fed-batch SSF showed higher ethanol concentration (26.80 g/L) and two times higher ethanol production yield based on enzyme than the batch SSF.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.45-51
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• 1989

A major problem in the enzymatic hydrolysis of lignocellulosic substrates is the very strong bonding of cellulase to lignin and even cellulose in the hydrolysis residues. This phenomenon inhibits recycle of the cellulase which is a major expense of the enzymatic hydrolysis process. In this paper, autohydrolyzed wood was delignified by two-stage with a 0.3% Na OH extraction and oxygen-alkali bleaching and was subjected to enzymatic hydrolysis with cellulase. Also, an improved almost quantitative recycle process of cellulase enzyme was discussed. In enzyme recovery by affinity method. the first recycling showed relatively high hydrolysis rate of 97.4%. Even at the third recycle. hydrolysis rate was 86.7 percents. In the case of cellulase recovery by ultrafiltration method, first 2 recycling treatments resulted very high hydrolysis rate(97.0-97.7%). Even the third recycling showed about 94.2%. Authoydrolysis of oak wood followed by 2-stage delignification with alkali and oxygen-alkali produced a substrate for enzymatic hydrolysis that allowed almost quantitative recycle of cellulase.