• 한국식품과학회지
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• 제16권1호
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• pp.23-28
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• 1984

멸치를 마쇄하여 자가소화시킬 경우 무염상태에서 20시간까지는 $50^{\circ}C$, pH 4라 최적조건이었고, 식염을 20% 첨가하였을 때는 $50^{\circ}C$, pH 6에서 가수분해가 가장 잘행해졌다. 한편 식염을 첨가하여 8 일동안 가수분해시킬 경우 최적조건이 $40^{\circ}C$, pH 6으로 변화하는 것으로 밝혀졌다. 상기한 최적조건에서 20시간동안 자가소화 시켰을 때 무염상태에서는 총질소중 60.5%가 TCA-가용성 질소를 가수분해되었으나 식염을 20% 첨가하였을 때는 49.8%로 낮아졌다. 그리고 가염상태에서 8 일간 가수분해 시킨 결과 총질소중 83.1%가 TCA-가용성질소로 분해되었고 계속하여 실온에서 52일간 숙성시킨 결과 총질소중 89.6%가 분해되었다.

• 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.

• 한국잠사곤충학회지
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• 제39권2호
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• pp.186-196
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• 1997

The IR crystallinity index of Calcium nitrate treated silk fiber decreased proportionally to the concentration of calcium nitrate. A partial change of conformation was observed in the concentration of over 46.4-47.6% changing from $\beta$-sheet or to random coil in the crystalline region. This is in coincidence with the result of crystallinity index, which was started to be reduced in the concentration range of 46.4-47.6%. A same trend was observed for the X-ray order factor, birefringence, degree of orientation and surface structure. These structural parameters were remarkably changed on the treatment of silk fibers with concentration of 46.4-17, 6% calcium nitrate. Therefore, it seems that there exists a critical concentration of calcium nitrate in affection the structure and morphology of silk fibers. According to the examination of surface morphology, the fine stripe was observed in the direction of fiber axis at 46.4% concentration. However, the treated concentration was exceeded by 47.6%, the cracks were appeared severely on the fiber surface in the transverse direction as well as fiber axis direction. This result might be related to the tensile properties, specially a tenacity of silk fibers. As a result of quantitative analysis of a dilute acid hydrolysis, three different regions, which are known as a amorphous, semi-crystalline and crystalline region, could be obtained. The hydrolysis rate curves were different with various concentrations of treatment and the relative contents of each region could be calculated.

• Asian-Australasian Journal of Animal Sciences
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• 제22권11호
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• pp.1587-1593
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• 2009

Duck egg white (DEW) hydrolysates were prepared by five enzymes (papain, trypsin, chymotrypsin, alcalase, and flavourzyme) and their antioxidant activities investigated in this study. DEW hydrolyzed with papain (DEWHP) had the highest peptide content among the five enzymatic treatments. Besides, the peptide content of DEWHP increased when the enzyme to substrate ratio (E/S ratio) increased. It was suggested that higher E/S ratio contributed to elevate the degree of hydrolysis of DEW effectively. Similar results were also obtained by Tricine-SDS-PAGE. In addition, SDS-PAGE patterns indicated papain was the only one amongst all enzymes with the ability to hydrolyze DEW. In antioxidant properties, DEWHP showed more than 70% of inhibitory activity on linoleic acid peroxidation and superoxide anion scavenging. Moreover, the $Fe^{2+}$ chelating effect of DEWHP was greater than 90%, while no significant difference was observed in DPPH radical scavenging and reducing ability. The results of peptide contents, antioxidant activities and electrophoresis suggested that the higher the peptide content, the stronger the antioxidant activities in DEWHP.

• 한국식품저장유통학회지
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• 제30권3호
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• pp.434-445
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• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.

• Journal of the Korean Wood Science and Technology
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• 제38권3호
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• pp.230-241
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• 2010

본 연구는 산염이 첨가된 아세톤 용액으로 목질바이오매스를 가수분해하여 효과적으로 화학적 조성분을 분리할 수 있는 최적조건을 확립하는데 있다. 아세톤에 의한 목질바이오매스의 가수분해에서 $Al_2(SO_4)_3$은 우수한 촉매로 작용하였으며, 최적 농도는 0.01 M (6.3 wt%)였다. 본 실험에서는 아세톤과 물의 비율을 9 : 1로 맞추고 $Al_2(SO_4)_3$의 최적 농도조건에서 신갈나무재와 소나무재를 $200^{\circ}C$에서 45분 동안 가수분해하여 각각 92.7%와 92.4% 분해율을 나타냈다. 아세톤과 물의 비율이 8 : 2에서는 반응시간을 60분으로 연장하였을 경우 신갈나무재의 가수분해율은 92.7%였으나, 소나무재는 반응온도를 $210^{\circ}C$로 상승시켜야 신갈나무재에 버금가는 가수분해율을 얻을 수 있었다. 가수분해 온도와 시간을 증가시키면 가수분해산물로부터 분리, 회수되는 리그닌은 증가하였으나, 탄수화물 함량은 급격히 감소하는 경향을 보였다. 리그닌과 당의 회수량을 고려해 보면, 목질바이오매스의 최적 가수분해 조건은 아세톤과 물의 비율 8 : 2, 아세톤 용액에 대한 $Al_2(SO_4)_3$ 농도는 6.3 wt%, 가수분해 온도와 시간은 각각 $190^{\circ}C$와 60분으로 나타났고, 이 조건에서 당의 회수율은 목질바이오매스 전건중량 기준으로 신갈 나무재와 소나무재에서 각각 47.6%와 51.4%로 나타났고, 리그닌 회수율은 각각 18.2%와 13.7%로 측정되었다.

• 한국의류학회지
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• 제11권1호
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• pp.63-69
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• 1987

Silk fibroin is likely to be hydrolyzed by acids or alkalies at high temperature, and the degree of the hydrolysis has been inferred from the changes in tensile strength and elongation. But, in this experiment, it was intended to infer that from the quantitative changes in terminal aminp group content as well as in tensile strength and elongation. Silk yarn was treated with boiling water, hydrochloric acid, and sodium hydroxide under various conditions. The boiling water somewhat degraded silk fibroin. Silk yarn treated with sodium hydroxide contained more terminal amino group than that treated with hydrochloric acid. This result agreed fairly well with the loss in weight, tensile strength, and elongation: the terminal amino group content increased with the decrease of tensile strength, elongation, and weight. The damage by sodium hydroxide to the silk fibroin was greater than that by hydrochloric acid.

• Journal of Microbiology and Biotechnology
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• 제7권4호
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• pp.258-261
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• 1997

For the efficient production of lysophospholipid the hydrolysis of phospholipid using phospholipase $A_1$ from Serratia sp. MK1 was studied in an aqueous-solvent, a two-phase and an emulsion system. Judged on the basis of productivity and the degree of hydrolysis, the yield of lysophospholipid in a two-phase system was found to be better than that obtained in an emulsion system. Among the 13 organic solvents tested phospholipase $A_1$ showed the most efficient catalytic activity and stability in butyl acetate. When 20% phospholipid was used it was completely hydrolyzed in this two-phase system.

• Food Science and Biotechnology
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• 제14권6호
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• pp.818-822
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• 2005

Beta-1,4-mannotriose was prepared by the enzymatic hydrolysis of poonac and the subsequent elimination with yeast of monosaccharides and disaccharide from the resultant hydrolysate. The enzyme system hydrolyzed poonac and produced monosaccharides, disaccharide and ${\beta}$-1,4-mannotriose without other oligomers at the final reaction stage. Poonac (50 g) was hydrolyzed at $50^{\circ}C$ and pH 6 for 48 hr with the crude enzyme solution (500 mL) from Trichoderma harzianum. The elimination of monosaccharides and disaccharide from the hydrolysis products with a yeast (Candida guilliermondii) produced 10.5 g of crystalline [${\beta}$-1,4-mannotriose without the use of chromatographic techniques. After 48 hr of yeast cultivation, the total sugar content fell from 4.8% to 3.4%, and the average degree of polymerization (D.P) rose from 2.5 to 3.2. The preparation method presented was confirmed to be suitable for the preparation of mannotriose from poonac.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.194-198
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• 1993

${\beta}-1$, 4-Mannobiose was prepared by the enzymatic hydrolysis of brown copra meal and the subsequent elimination of mono-saccharides from the resultant hydrolysate with a yeast. The enzyme system hydrolyzed brown copra meal and produced monosaccharides and $\beta$-1, 4-mannobiose without other oligomers at the final stage of the reaction. Brown copra meal (30 g) was hydrolyzed at $50^{\circ}^C$ and pH 5 for 48 hr with the crude enzyme solution (300 ml) from Penicillium purpurogenum. By the elimination of monosaccharides from the hydrolysis products with a yeast (Candida parapsilosis var. komabaensis k-75), 5.2 g of crystalline mannobiose was obtained without the use of chromatographic techniques. After 50 hours of yeast cultivation, the total sugar content fell from 3.5% to 2.4%, and the average degree of polymerization rose from 1.8 to 2.2.