• Title/Summary/Keyword: ${\alpha}$-amylase activity

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Effect of Anaerobic Treatment on Carbohydrate-Hydrolytic Enzyme Activities and Free Amino Acid Contents in Barley Malt

  • Yun, Song-Joong;Choi, Kyeong-Gu;Kim, Jin-Key
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.43 no.1
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    • pp.19-22
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    • 1998
  • Effects of acute anoxia on carbohydrate hydrolytic enzyme activities and free amino acid contents in malt were examined. Malts were prepared with barley grains germinated for 7 days which contained the highest levels of amylolytic and(1-3,1-4)-$\beta$-glucanase activities. $\alpha$-Amylase and $\beta$-amylase activities in malts were not significantly affected by anoxia for 5 or 10 h.(1-3,1-4)-$\beta$-Glucanase activity, however, decreased about 7 to 10% by anoxia for 5 or 10 h. Alanine and $\gamma$-aminobutyric acid content changed drastically. Alanine contents in malts increased by 2.2- and 2-fold, and $\gamma$-aminobutyric acid contents by 1.4- and 1.9-fold under anoxia for 5 and 10 h, respectively.

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A study on the standardisation for the preparation of traditional 'Nochi' (전통적 노치 제조의 표준화를 위한 연구)

  • Lee, Jong-Mee;Kim, Jin-Ah
    • Journal of the Korean Society of Food Culture
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    • v.9 no.2
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    • pp.143-148
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    • 1994
  • 'Nochi' is one of Korean traditional panfried rice cakes made from glutinous rice or millet and malt. The optimum conditions for the preparation of 'Nochi' were investigated. The ${\alpha}-amylase$ activity of malt was 62.5 units/g dry malt and ${\beta}-amylase$ 1.43 units/g dry malt. Reducing sugar content of 'Nochi' increased with the content of malt and saccharifying time. Both the hardness and cohesiveness of 'Nochi', measured by rheometer, were decreased with increasing the content of malt, while adhesiveness and hardness increased with saccharifying time, but cohesiveness decreased. The optimum conditions for the preparation of 'Nochi' were 8.0%(w/w) of malt and 1 hour 45 minutes of saccharifying time.

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Brewing and Properties of Low-Malt Beer with a Sweet Potato Paste (고구마를 첨가한 저맥아 맥주의 양조와 품질 특성)

  • Yang, Ha-na;Oh, Eun-Bi;Park, Jeong-Seob;Jung, Mun-Yhung;Choi, Dong-Seong
    • The Korean Journal of Food And Nutrition
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    • v.30 no.3
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    • pp.491-500
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    • 2017
  • Sweet potato-malt worts were prepared by using sweet potato paste of Shinyulmi and Shinjami as the main adjunct, enzymes, malt, hop, and water. We brewed low-malt beers of the lager- or ale-type by using these worts and inoculating bottom and top fermenting yeast, respectively. Moreover, the componential and functional characteristics of the resulting beers were evaluated. During saccharification of sweet potato, the addition of an enzyme agent containing ${\alpha}-amylase$ caused an improvement in filterability and an increase of total sugar. The sugar content of sweet potato-malt wort which was prepared by the addition of 0.1% enzyme agent containing ${\alpha}-amylase$ and a three-step infusion procedure was $13.5^{\circ}Brix$ adequate for beer brewing. The polyphenol and anthocyanin contents of Shinjami beer were increased with increasing content of the paste, and also increased DPPH and ABTS radical scavenging activities. But in Shinyulmi beer it were decreased. A strong correlation was obserbed between antioxidave activities and polyphenol and anthocyanin contents of sweet potato beers. In all lager- and ale-type low-malt beers using 41.6% of Shinjami pastes, sensory attributes very similar to those of 100% malt beer were obtained and they were very good as they had unique red color.

Character and Function of Restriction Enzyme, EcoRI Inhibiting Substance Extracted from Spinach Chloroplast and Chlamydomonas (시금치 엽록체와 Chlamydomonas로부터 추출한 제한효소 EcoRI 억제물질의 특성과 작용)

  • 황성빈
    • Journal of Plant Biology
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    • v.33 no.4
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    • pp.217-223
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    • 1990
  • Restriction enzyme inhibiting substance (REIS) extracted from spinach chloroplast and Chlamydomonas seems not to be proteinaceous, because its inhibiting activity was not lost by heat or trypsin treatment. And it seems not to be lipid or polysacchride, because its inhibiting activity was not lost by lipase or $\alpha$-amylase treatment, respectively. In Chlamydomonas, putrescine, spermidine and spermine were present. The amount of putrescine was the smallest and that of spermie was the greatest. But only spermine was contained in REIS and the activity of REIS. It was proportional to the amount of spermine in REIS and it was hindered by Na+ ion. So, the inhibiting activity of REIS seems to be deeply related to spermine contained in REIS. But restriction enzyme inhibiting activity remained to the some extent although salts and spermine were eliminated by dialysis.

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The studies on microbe isolated from the cocoon in Korea (한국산 잠견에서 분리된 미생물에 관한 연구(제 II보)(잠견에서 분리된 Bacteria의 Enzyme activity).)

  • 이상원;이철준
    • Journal of Sericultural and Entomological Science
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    • v.10
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    • pp.73-75
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    • 1969
  • There are two fold aims in this experimental study. The aim is to investigate the bacteria which produce the high activity enzyme or the cocoon for utilization to the textile and the industry. The ether is to protect against the bacteria that damage silk protein during storage. The results are summarized as followes: 1. Among the isolated bacteria from the cocoon, No 4 strain had the high activity of the $\alpha$-amylase. But this strain had not been identified. The results of experiment is shown in the table II. 2. Among the isolated bacteria from the cocoon, No II strain had the high activity of the protease on substance of the casein. The results of the experiment is shown in the table II. 3. The bacteria which had the high activity of the degumming effect of the sericin, the part of the operation for 7 days was higher part of the operation for 3 days. The results of the experiment are indicated in Fig I and Fig II.

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Characterization of Heat-Stable Enterotoxin of Enterotoxigenic Escherichia coli eKT-53 (장독성 대장균 eKT-53균주의 내열성 장독소의 성질)

  • 도대홍;김교창;김도영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.6
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    • pp.621-628
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    • 1991
  • Heat-stable enterotoxin(ST) from enterotoxigenic E. coli eKT-53($ST^{+}\;LT^{-}$, transformant from isolate KM-7) that was produced in succinate salts medium. The culture supernatant(crude ST) was purifed by mulitpled steps and investigated some characterization of the ST. The heatstability of purified ST activity was completely lost by treating at $100^{\circ}C$ for 30minutes. ST activity was lost by treatment at pH 1 and 12 conditions, while the activity was not reduced by treatment at pH 2~10, and then the ${\alpha}-amylase$ and pepsin was not decreased activity but disulfide reducing agnets was lost the activity. The molecular weight of the purified ST was approximately 4,200, the isoelectric point was about 4.0.

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Assessment of Nutritional Components, Antioxidant Contents and Physiological Activity of Purple Corn Husk and Cob Extracts (자색옥수수 포엽과 속대 혼합 추출물의 영양성분, 항산화 활성 물질 함량분석 및 생리활성 평가)

  • Lee, Ki Yeon;Kim, Tae hee;Kim, Jai Eun;Park, A-Reum;Noh, Hee Sun;Kim, Si Chang;Ahn, Mun Seob;Kim, Hee Yeon
    • Journal of Food Hygiene and Safety
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    • v.33 no.6
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    • pp.500-509
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    • 2018
  • The objective of this study was to investigate the worth of extract husk and cobs of the Seakso 1 (EHCS) for the functional foods. We aimed to investigate the proximate composition, fatty acids, amino acids, antioxidant active substance contents, antioxidant activity, inhibitory activity of the ${\alpha}-amylase$ and ${\alpha}-glucosidase$. The proximate composition of the EHCS have represented 6.90% moisture, 7.31% crude ash, 0.52% crude fat and 7.07% crude protein. Among the 17 kinds of amino acids that were analyzed in thd EHCS, the glutamic acid was the highest, with 736.08 mg / 100 g. The fatty acids detected in the EHCS were palmitic acid oleic acid and linoleic acid. The proportion of the unsaturated fatty acids was 83.33%. We determined the contents of the antioxidant active substance by the total polyphenol and flavonoid. The total polyphenol and flavonoid contents were 99.87 mg/g and 25.02 mg/g, respectively. The antioxidative activity of the EHCS were determined using a DPPH and ABTS assay. In the antioxidative activity determination, the DPPH and ABTS radical scavenging activities were 95.62% ($1,000{\mu}g/mL$) and 92.00% ($10,000{\mu}g/mL$), respectively. The inhibitory activity of ${\alpha}-amylase$ and ${\alpha}-glucosidase$ (10 mg/mL) were 95.86% and 76.92%, respectively. These results suggest that the EHCS could be potentially used as a resource for the bioactive materials for health functional foods.

Inhibitory Activities of Digestive Enzymes and Antioxidant Activities of Fermented Beverages Using Momordica charantia L. (여주를 첨가한 발효음료의 소화효소 억제와 항산화 활성)

  • Park, Suin;Yeo, Seoungsoon;Lee, Youngseung;Jeong, Yoonhwa;Kim, Misook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.11
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    • pp.1308-1315
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    • 2017
  • This study was conducted to develop Momordica charantia L. juice fermented by four Lactobacillus species such as Lactobacillus paracasei (LPA), Lactobacillus plantarum (LPL), Lactobacillus rhamnosus (LRH), and Lactobacillus reuteri (LRE) as well as to investigate their inhibitory effects against digestive enzymes and antioxidant activities. Fermentation was performed at $37^{\circ}C$ without nutrient supplementation for 72 h. The pH and total lactic acid contents were within the ranges of 3.75~3.96 and 5.21~10.04% in fermented juices, respectively. The type of starter culture and fermentation time induced changes in flavonoid contents more than total phenolic contents. All juices fermented for 48 h strongly inhibited ${\alpha}$-glucosidase activity with the percentage of inhibition ranging of 91.24~95.05%. Antioxidant activities of all juices mostly increased after 48 h of fermentation. Our results suggest that fermented juice possesses inhibitory activity against digestive enzymes and antioxidant activity, and they can be used as health functional beverages.

Studies on the Comparison of Physicochemical Properties and the Presumption of Sensory Quality of Japonica Rice Varieties Cultivated in Korea and Japan (한국과 일본의 자포니카종 쌀에 대한 이화학적 특성의 비교 및 관능품질의 추정에 관한 연구)

  • 홍원표;이성갑;박승남
    • The Korean Journal of Food And Nutrition
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    • v.14 no.6
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    • pp.596-604
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    • 2001
  • Twelve varieties of Korean rice and ten varieties of Japanese rice were selected. After being milled. they were analyzed about various physicochemical properties such as moisture, protein and amylose, a -amylase activity, gelatinization properties. And after being cooked with proper amount of water texture and other physical properties were measured by Texturometer, Tensipresser and Rheolograph-micro. Finally the sensory evaluation test was carried out. The results were as follows. 1. In case of protein contents, amylose contents and $\alpha$-amylase activity, Korean rice had a slightly higher value than Japanese As a consequence. Korean rice showed a little stronger hardness and a little weaker stickiness compared with Japanese rice. 2. Amylose contents showed very high correlation with other physicochemical properties and peak viscosity and gelatinization temperature of RVA, the ratio of stickiness to hardness( -Hl/Hl ) of Texturometer and the tan $\delta$(the ratio of dynamic loss to dynamic viscoelasticity) of Rheolograph-micro showed high correlation with other analyzed properties. 3. The ( -/+)work balance of low compression test(25% ) of Tensipresser analysis(texture analysis on the surface of cooked rice) and tan f of Rheolograph-micro showed very high correlation with sensory evaluation results. By using this parameters as major independent variables, some trials to derive high confidence multiple regression equations were accomplished. By the equations it would be possible to make an approximate pre-estimate of eating quality for unknown japonica rice.

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Expression of Bacillus macerans Cyclodextrin Glucanotransferase in Bacillus subtilis

  • Kim, Chang-Sup;Han, Nam-Soo;Kweon, Dae-Hyuk;Seo, Jin-Ho
    • Journal of Microbiology and Biotechnology
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    • v.9 no.2
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    • pp.230-233
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    • 1999
  • A plasmid vector was constructed for the expression and secretion of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in Bacillus subtilis. The vector, pUBACGT, was composed of the ribosome-binding sequence, signal sequence, and cgt gene from B. macerans under the control of amyR2, the promoter of amyE gene coding for $\alpha$-amylase from B. subtilis var. natto. Bacillus subtilis LKS88, a mutant strain lacking genes for an amylase and two proteases, was used as a host for the transformation of the plasmid vector. The transformants were selected on kanamycin-containing Luria-Bertani plates. The starch hydrolyzing activity was observed on the starch-containing plates by the iodine method and cyclodextrin-forming activity was detected in the culture medium. A SDS-PAGE analysis showed that most of the expressed CGTase in the recombinant B. subtilis was secreted into the medium at a high expression level.

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