• Food Science and Preservation
• /
• v.11 no.1
• /
• pp.38-41
• /
• 2004

To obtain basic data for utilizing Yuzu(Citrus junos) as row materials to industrial products, enzyme treatments conditions for removing bitter substances was investigated. The amount of nuringin and hesperidin weve 61.94 and 9.98 mg％ in Yuzu juice. When 3％ Amorepacific enzyme and Japanese naringinase were treated with the juice for 120 minutes, naringin and hesperidin were decreased to 6.85 and 1.11 mg％ ; 8.43 and 0.06 mg％, respectively. The changes in Hunter color value of the juice were negligible by enzyme treatments. However, the redness was increased and lightness was decreased by the enzymes. When Yuzu-juice was treated with the enzymes, sensory scores were increased. The optimum amount of Amorepacific for reducing bitter taste was determined to 3％.

• Korean Chemical Engineering Research
• /
• v.54 no.4
• /
• pp.443-447
• /
• 2016

The microalgae have cellulose as a main structural component of their cell wall and the lignin content in microalgae is much lower than other lignocellulosic biomass. Therefore, fermentable sugar production from microalgae (Tetraselmis KCTC 12236BP) can be carried out under pretreatment without high temperature and high pressure. It was investigated that the effect of hot-water pretreatment using sulfuric acid for lipid extracted algae which is expected to be a next generation biomass. The effects of three major variables including extraction temperature, acid concentration and time on the enzymatic hydrolysis were investigated. Among the tested variables, temperature and acid concentration showed significant effects and optimum pretreatment conditions for the economic operation criteria were obtained as follows: reaction temperature of $120^{\circ}C$, sulfuric acid concentration of 2 mol and pretreatment time of 40 min. Under the optimum conditions of acidic hot water pretreatment, experimentally obtained hydrolysis yield were 95.9% which showed about 2.1 fold higher compared with enzymatic hydrolysis process. Therefore, acid pretreatment under mild condition was proven to be an effective method for fermentable sugar production from lipid extracted microalgae.

• Korean Chemical Engineering Research
• /
• v.51 no.3
• /
• pp.335-341
• /
• 2013

Ammonia circulation reactor (ACR) was devised for the effective pretreatment of corn stover. This method is designed to circulate aqueous ammonia continuously so that it can reduce the chemical and water consumption during pretreatment. In this study, ammonia pretreatment with various reaction conditions such as reaction time (4~12 hour), temperature ($60{\sim}80^{\circ}C$), and solid:liquid ratio (1:3~1:8) was tested. Chemical compositions including solid remaining after reaction, lignin and carbohydrates were analyzed and enzymatic digestibility was also measured. It was observed that as reaction conditions become more severe, lignin removal was significantly affected, which was in the range of 47.6~70.6%. On the other hands, glucan and xylan losses were not substantial as compared to that of lignin. At all tested conditions, the glucan loss was not changed substantially, which was between 4.7% and 15.2%, while the xylan loss varied, which was between 7.4% and 25.8%. With (15 FPU-GC220+30 CBU)/g-glucan of enzyme loading, corn stover treated using ammonia circulation reactor for 8~12 hours resulted in 90.1~94.5% of 72-h glucan digestibility, which was higher than 92.7% of $Avicel^{(R)}$-101. In addition, initial hydrolysis rate (at 24 hour) of this treated corn stover was 73.0~79.4%, which was shown to be much faster than 69.5% of $Avicel^{(R)}$-101. As reaction time increased, more lignin removal and it was assumed that the enhanced enzymatic digestibility of treated biomass was attributed to the lignin removal.

• Microbiology and Biotechnology Letters
• /
• v.20 no.4
• /
• pp.437-444
• /
• 1992

An innovative process for high fructose corn syrup (HFCS) production coupled with direct saccharification of raw corn starch in the agitated bead enzyme reactor (bioattitor) was investigated. The required high concentration/purity of glucose solution suitable for isomerization was produced directly in a bioattritor. without condensation of hydrolyzate, 398 g glucose/$\ell$ and 98% glucose content from 400 g/$\ell$ (w/v) of raw corn starch after 24 hours. The unsaccharified residual starch could be separated easily upon centrifugation, and resaccharified. The obtained solution also possessed other desirable requirements as substrate for isomerization, such as. low concentrations of denatured protein and calcium ions, thereby, simplified the purification step. The obtained glucose solution was isomerized in an enzyme reactor paked with immobilized glucose isomerase to evaluate the suitability as a substrate. The proposed new HFCS process seems to have many advantages over the conventional process via liquefaction-saccharification steps. The follow-up investigations of the proposed process need to be conducted to evaluate the feasibility of industrial application.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.418-421
• /
• 2009

Effects of aqueous ammonia soaking to three annual plants (hemp woody core, tobacco stalk and corn stover) awere investigated to focus on the enzymatic saccharification characteristics change by this treatment. At two different levels of treatment ($90^{\circ}C$-16 h and $45^{\circ}C$-6 days), higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme Korea). Difference among annual plants were significant. corn stover was the best response to enzymatic saccharification of cellulose and xylan by comercial enzymes all treatment conditions but tobacco stalk was the worst response to all of them. chemical composition or physical structure difference may brought this difference.

• Food Science and Preservation
• /
• v.14 no.6
• /
• pp.650-654
• /
• 2007

Ginseng sikhye is a unique beverage containing medicinal ingredients and having the unique flavor of ginseng. In this study, changes in the sugar composition of ginseng sikhye were investigated during the saccharification process. The concentration of ginseng sikhye was varied and the sugar content analyzed during the process. The amount of ginseng powder was varied from 3% to 12% in a mixture of malt (20 g), steamed rice (400 g) and 0.2 mL ${\alpha}$-amylase (Teramyl). With increasing time and temperature during the saccharification process, the sugar content in the ginseng sikhy eincreased, reaching levels similar to commercial sikhye. However, based on analysis of free sugars, the maltose content in ginseng sikhye was over 4.3%, which was higher than for commercial sikhye. Therefore, ginseng sikhye shows excellent marketability quality.

• KSBB Journal
• /
• v.23 no.6
• /
• pp.499-503
• /
• 2008

The bioethanol for use as a liquid fuel by fermentation of renewable biomass as an alternative to petroleum is important from the viewpoint of global environmental protection. Recently, many scientists have attempted to increase the productivity of bioethanol process by developing specific microorganism as well as optimizing the process conditions. In the present study, which is based on our previous investigation on the pretreatment process, theproductivity of bioethanol obtained from simultaneous saccharification and fermentation (SSF) process was compared between various domestic materials including barley, brown rice, corn and sweet potato. Additionally, Solid glucoamylase (SGA; developed in Changhae Co.), from modified strain with UV, was used. The result was compared to commercial glucoamylase (GA). It was observed that the fermentation rate was increased together with the yield which can be derived from the final ethanol concentration. Especially, in the case of brown rice, compared to the experimental results using GA, the final ethanol concentration was 1.25 times higher and 18.4 g/L of the yield was increased. Also, the time required for reaching 95% of the maximum ethanol concentration is significantly reduced, which is approximately 36 hours, compared to 88 hours using GA. It means that SGA has excellent saccharogenic power.

• Microbiology and Biotechnology Letters
• /
• v.44 no.2
• /
• pp.145-149
• /
• 2016

Thermal acid hydrolysis pretreatment of Kappaphycus alvarezii was carried out with 12% (w/v) seaweed slurry and 180 mM H₂SO₄ at 140°C for 5 min. Utility of the thermotolerant yeast Kluyveromyces marxianus KCTC7150 was evaluated with respect to cell growth and ethanol fermentation at 40°C was close to optimal for enzymatic hydrolysis. This could lead to the integration of both the saccharification and fermentation processes. The levels of ethanol production by simultaneous saccharification and fermentation (SSF) with non-adapted and adapted K. marxianus KCTC7150 were 9.1 g/l with an ethanol yield (Y_EtOH) of 0.24 and 10.2 g/l with an ethanol yield (Y_EtOH) of 0.27 at 156 h, respectively. The two-phase SSF process was employed in this study to improve the efficiency of ethanol fermentation. Adapted K. marxianus KCTC7150 using the two-phase SSF process produced 13.5 g/l with an ethanol yield (Y_EtOH) of 0.35 at 96 h. Development of the two-phase SSF process could enhance the overall ethanol fermentation yields of the seaweed K. alvarezii.

• KSBB Journal
• /
• v.5 no.1
• /
• pp.59-67
• /
• 1990

Enzymatic hydrolysis of insoluble cellulose was performed in a bubble column with tangential flow ulrafiltration membrane unit. The reactor was operated in a batch mode as well as semi-continuous and continuous with continuous removal of products through the tangential flow ultrafiltration membrane. The optimum superficial gas velocity was 1-3cm / sec so as to avoid bubble coalescence and enzyme denaturation. In continuous and selni-cotinuous process, the conversion was gradually increased but the total reduced sugar concentration was drcastically dereased with the dilution rate. It was concluded that the bubble column attaching tangential flow ultrafiltration membrane unit was effective on continuous hydrolysis of cellulose and recovery of enzyme.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2018.10a
• /
• pp.245-245
• /
• 2018