• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.197-203
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• 1992

Studies of the pretreatment of chitin and its subsequent hydrolysis by Aspergillus carneus chitinase are reported. Ball milling was found to be the most effective way among the pretreatment methods tested. Data are presented describing the effect of enzyme and substrate concentrations on the rate and extent of the hydrolysis process. It was found that the successive addition of enzyme improved the saccharification yield. Significant product inhibition of the chitinase was observed when N-acetylglucosamine concentration was 3.6％ or higher. Adsorption of enzymes to the substrate occurred during a 24 hr hydrolysis period. An initial rapid and extensive adsorption occurred, followed by gradual desorption which increased during the time of reaction. Intermediate removal of the hydrolyzate and continuation of the hydrolysis by adsorbed enzyme on the residual chitin was also investigated. A total of 75.4 g/l reducing sugars, corresponding to 69.2％ saccharificaton yield (as N-acetylglucosamine) was obtained. In addition an increase in the amount of recoverable enzymes was observed under these conditions. Evidence presented here suggests that the technique, whereby the free enzymes in the recovered hydrolyzate are re-adsorbed onto the new substrate, may provide a means of recirculating the dissolved enzymes.

• Food Science and Biotechnology
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• 제14권5호
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• pp.651-655
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• 2005

Enzymatic hydrolysis of shark (Squatina oculata) cartilage (SC) was optimized by response surface methodology (RSM) for chondroitin sulfate (CS) preparation. Among 11 commercial proteases, Maxazyme NNP showed highest productivity (CS yield per enzyme cost) of CS. Optimal hydrolysis conditions determined by RSM were 1.63% and 2.87 hr for enzyme concentration and hydrolysis time ($r^2\;=\;0.9527$, p<0.0l), respectively and highest yield of hydrolysate under the conditions was 42.3%. The yield ($43.1{\pm}2.1%$) and CS content ($24.8{\pm}0.1%$) of hydrolysate at optimal condition verified statistical optimization of SC enzymatic hydrolysis was valid.

• 한국식품영양학회지
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• 제10권1호
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• pp.87-91
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• 1997

식혜에 함유된 이소말토올리고당과 밥알에 30unit/ml의 $\alpha$-아밀라아제, 글루코아밀라아제, $\alpha$-글루코시다아제, $\beta$-아밀라아제를 가하여 작용시킨 결과 글루코아밀라아제 외에는 일부밖에 가수분해하지 못하였다. 그리고, 인체의 효소인 $\alpha$-아밀라아제와 $\alpha$-글루코시다아제를 함께 작용시켜도 25% 이상 가수분해하지 못하므로 비피두스균의 활성인자로 작용할 것으로 보인다. 밥알은 물에 녹지 않기 때문에 식이섬유로도 작용할 것으로 보인다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권11호
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• pp.1612-1619
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• 2017

Objective: The objective of this study was to optimize ultrasonic-assisted enzymatic hydrolysis conditions, including enzyme-to-substrate (E/S) ratio, pH, and temperature, for producing porcine liver hydrolysates (PLHs) with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity by using response surface methodology (RSM). Methods: The study used RSM to determine the combination of hydrolysis parameters that maximized the antioxidant activity of our PLHs. Temperature ($40^{\circ}C$, $54^{\circ}C$, and $68^{\circ}C$), pH (8.5, 9.5, and 10.5), and E/S ratio (0.1%, 2.1%, and 4.1%) were selected as the independent variables and analyzed according to the preliminary experiment results, whereas DPPH free radical scavenging activity was selected as the dependent variable. Results: Analysis of variance showed that E/S ratio, pH, and temperature significantly affected the hydrolysis process (p<0.01). The optimal conditions for producing PLHs with the highest scavenging activity were as follows: E/S ratio, 1.4% (v/w); temperature, $55.5^{\circ}C$; and initial pH, 10.15. Under these conditions, the degree of hydrolysis, DPPH free radical scavenging activity, ferrous ion chelating ability, and reducing power of PLHs were 24.12%, 79%, 98.18%, and 0.601 absorbance unit, respectively. The molecular weight of most PLHs produced under these optimal conditions was less than 5,400 Da and contained 45.7% hydrophobic amino acids. Conclusion: Ultrasonic-assisted enzymatic hydrolysis can be applied to obtain favorable antioxidant hydrolysates from porcine liver with potential applications in food products for preventing lipid oxidation.

• 한국약용작물학회지
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• 제26권2호
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• pp.127-133
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• 2018

Background: The demand of recycling renewable agricultural by-products is increasing. Radiation breeding is a method used to improve saccharification efficiency. Thus, we investigated the effect of gamma ray irradiation on the pretreatment and enzymatic hydrolysis of the stalks of Senna tora, an important medicinal plants. Methods and Results: S. tora seeds were irradiated with gamma ray at doses of 100, 200, 300, and 400 Gy. In the pretreated biomass, glucan and lignin content were higher in the M1 ($1^{st}$ generations of irradiation) S. tora stalks than in the M2 ($2^{nd}$ generations of irradiation) stalks, this can be explained by the higher degradation rate in M1. After oxalic acid pretreatment, the concentration of total phenolic compounds (TPCs) in the hydrolysate increased in the gamma ray treated seeds. The highest relative increase rate in crystallinity in the pretreated biomass was observed in M1-400 Gy and M2-100 Gy. The cellulose conversion rate was higher in M1 than in M2, except for 200 Gy. Conclusions: Gamma ray irradiation at an appropriate dose can be used to improve the efficiency of pretreatment and enzymatic hydrolysis, thereby increasing biomass availability.

• 한국식품과학회지
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• 제31권2호
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• pp.391-398
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• 1999

국내산 생강의 높은 원료비를 극복하면서 품질이 우수한 중간소재성 가공제품을 개발하기 위하여 효소적 추출기법을 적용하였을 때의 수율 및 품질변화를 조사하였다. 생강을 1차 착즙하고 남은 잔사를 $\alpha$-amylase로 가수분해한 후 2차 착즙하고 다시 남은 잔사에 90% 에탄올로 $30^{\circ}C$에서 1시간 추출하여 각각 착즙액을 혼합할 경우 단순 착즙액보다 동일 $^{\circ}Brix$ 기준으로 약 2.8배 정도, 펄프보다는 건물기준으로 약 5배 이상 착즙수율을 증진시킬 수 있었다. 이와 같이 제조된 최종 추출액에는 착즙액 보다 조섬유가 약 62%, 전분이 48%정도 감소하는 결과를 나타내어 작업공정의 개선이 가능함을 알 수 있었다. 또한 최종 추출액은 착즙액에 비하여 유리아미노산이 약 40% 정도 소실한 반면 유리당은 약 270% 증가하는 결과를 보여주고 있어, 생강의 효소적 추출법은 생강 가공제품 제조시 단맛을 강화하는 효과를 제공할 수 있었다.

• 공업화학
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• 제22권3호
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• pp.336-339
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• 2011

해조류는 잠재력이 있는 풍부한 발효기질이다. 해조류의 효소가수분해를 상업용 셀룰라아제 및 비스코자임과 함께 알칼리 과산화수소 전처리에 의해서 검토하였다. 본 연구에서 사용된 해조류는 구멍갈파래이며, 전처리 평가는 효소가수분해 후 얻어진 글루코오스의 수율로 나타내었다. 알칼리 과산화수소는 과산화수소 1 wt%에 수산화나트륨을 1~1.75 wt% 범위로 혼합하였다. $60^{\circ}C$에서 3 h 동안 전처리한 결과 5 wt% 과산화수소를 사용했을 때에 가장 높은 글루코오스 전환율을 보였다. 알칼리 과산화수소로 전처리한 후 필요한 효소의 양은 전처리하지 않은 구멍갈파래에 비하여 상당히 절감되었으며, 아울러 효소 가수분해동안 얻어진 글루코오스의 양은 증가되었다.

• Journal of the Korean Wood Science and Technology
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• 제52권2호
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• pp.101-117
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• 2024

The conversion characteristics of the major components of Liriodendron tulipifera were investigated during acid-catalyzed organosolv pretreatment. Glucan in L. tulipifera was slowly hydrolyzed, whereas xylan was rapidly hydrolyzed. Simultaneous hydrolysis and degradation of xylan and lignin occurred; however, after complete hydrolysis of xylan at higher temperatures, lignin remained and was not completely degraded or solubilized. These conversion characteristics influence the structural properties of glucan in L. tulipifera. Critical hydrolysis of the crystalline regions in glucan occurred along with rapid hydrolysis of the amorphous regions in xylan and lignin. Breakdown of internal lignin and xylan bonds, along with solubilization of lignin, causes destruction of the lignin-carbohydrate complex. Over a temperature of 160℃, the lignin that remained was coalesced, migrated, and re-deposited on the surface of pretreated solid residue, resulting in a drastic increase in the number and content of lignin droplets. From the results, the characteristic conversions of each constituent and the changes in the structural properties in L. tulipifera effectively improved enzymatic hydrolysis in the range of 140℃-150℃. Therefore, it can be concluded that significant changes in the biomass recalcitrance of L. tulipifera occurred during organosolv pretreatment.

• 한국의류학회지
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• 제36권6호
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• pp.653-662
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• 2012

This study measured the effect of general pre-treatment on PLA fabrics to confirm the benefits of enzymatic processing on PLA fabrics in the textile industry as well as evaluated the hydrolytic activities of three lipases. The effects of lipase hydrolysis were analyzed through moisture regain, dyeing ability, tensile strength, and surface morphology. As a result, PLA fibers were easily damaged by a low concentration of sodium hydroxide and a low treatment temperature. The optimal treatment conditions of Lipase from Candida cylindracea were pH 8.0, $40^{\circ}C$, and 1,000 U. The optimal treatment conditions for Lipase from Candida rugosa were pH 7.2, $37^{\circ}C$, and 1,000 U. The optimal treatment conditions for Lipase from Porcine pancreas were pH 8.0, $37^{\circ}C$, and 2,000 U. The moisture regain and dyeing ability of PLA fabrics increased and the tensile strength of PLA fabrics decreased. The results of surface morphology revealed that there were some cracks due to hydrolysis on the surface of the fiber.

• Food Science and Biotechnology
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• 제16권3호
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• pp.381-385
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• 2007

The objective of this experiment was to study the influence of feed moisture content on the degree of enzymatic hydrolysis of com starch in a twin screw extruder and the saccharification yield of the dried extrudate. The feed moisture content was set at 25, 30, and 35% and ${\alpha}$-amylase solution was directly injected into the feed section at a barrel temperature of $95^{\circ}C$ and screw speed of 250 rpm. Amyloglucosidase was used for the saccharification of the dried extrudate at a concentration of 0.055%(w/w). Expansion ratio and swelling factor of extrudates decreased with increasing the feed moisture content. Addition of ${\alpha}$-amylase during extrusion process raised reducing sugar content of extrudates which also increased with the feed moisture content. The saccharification yield of dried extrudate was higher for the extrudate with lower feed moisture content.