• Title/Summary/Keyword: saccharides

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Enzymatic transesterification for the synthesis of amino acid-sugar conjugates

  • Jeon, Gyu-Jong;Park, O-Jin;Yang, Ji-Won
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.107-110
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    • 2001
  • Among the tested ten enzymes, Optimase M-440 showed the highest activity in transesterification of N-t-Boc-L-Phe-OTFE with D-glucose. Monosaccharides and their derivatives acted as good acyl acceptors in the Optimase M -440 catalyzed transesterification of N-t-Boc-L-Phe-OTFE. Optimase M-440 showed a preferable catalytic activity on the primary hydroxyl group of saccharides and a good regioselectivity. Optimase M-440 showed the highest activity in pyricline among the tested solvents. As acyl donors, trifluoroethyl esters of amino acids showed a high reactivity in transesterification. Optimase M-440 showed a broad substrate specificity towards amin 。 acid esters and saccharides.

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Functional bioactivity of Polygonatum species

  • Motohashi, Noboru;Zhang, Guo-Wen;Shirataki, Yoshiaki
    • Advances in Traditional Medicine
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    • v.3 no.4
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    • pp.163-179
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    • 2003
  • The genus Polygonatum species belongs to the family Liliaceae which is widely distributed over areas of the north temperature zone. There are about forty more plants of Polygonatum species in the world widely distributed in eastern Europe and south east Asia. The plants of Polygonatum species have been used not only as ornamental plants but also for their medicinal values. This article is concerned with the specific properties and flavour of the drug and its history as a medicine, showing the main functional components of Polygonatum species of flavonoids, steroidal glycosides, and saccharides.

Methods for Preparing Indigestible Dextrin with High Indigestible Fraction (난소화성 획분이 높은 난소화성 덱스트린의 제조 방법)

  • Woo, Dong-Ho;Moon, Tae-Wha
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.610-617
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    • 2000
  • The indigestible dextrin with high indigestible fraction was prepared by treating the enzyme hydrolysate of pyrodextrin with ethanol or strongly acidic cation exchange resin(UBK 530). Optimum conditions of ethanol treatment for preparing the indigestible dextrin from $\alpha-amylase$ and amyloglucosidase treated hydrolysate were determined based on the indigestible fraction, dietary fiber content, and yield. Ethanol was added 5-fold by weight to 30%(w/w) enzyme hydrolysate, and the mixture was kept at room temperature for 3 hr. Low molecular weight saccharides containing glucose and high molecular weight saccharides were separated by strongly acidic cation exchange resin. While initial enzyme hydrolysate by $\alpha-amylase$ and amyloglucosidase showed 43.6% of DPI(glucose) and 51.1% of DP4+(maltotetraose and over), the indigestible dextrin collected to 50% of initial enzyme hydrolysate by treatment of cation exchange resin showed 7.1% of DPI(glucose) and 91.2% of DP4+(maltotetraose and over). In conclusion, 44.5% of indigestible fraction of initial enzyme hydrolysate increased to 78.9% after separation of low molecular weight saccharides.

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Effect of Saccharides on the Gelation and Retrogradation of Starch (전분의 겔화와 노화에 미치는 당류의 영향)

  • 김경이
    • Food Science and Preservation
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    • v.10 no.4
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    • pp.506-511
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    • 2003
  • DSC was used to investigate the thermal mechanism of acorn and corn starch with or without saccharides on gelation and retrogradation. When the samples were starch-saccharide-water system (s-s-w), from measuring of gelation enthalpy and temperatures of initial gelation, peak and conclusion(T$\_$0/, T$\_$p/, T$\_$c/), those of s-s-w system were higher than those of stank-water system (s-w). The retrogradation enthalpy of acorn starch and corn starch was straightly increasing by DSC measurement as storage times. This increase meant slowly becoming recrygtallization of amylopectin. In retrogyadation process, the starch-saccharide-water system's enthalpy was also increased. After 7 days went, the value of the enthalpy was steady. Saccharides were retarding retrogrodation because of stopping the recrystallization of amylopectin. Especially in using fructose and maltose, the retrogradation effect of maltose was well. These elements took effect the number of juntion zone, one of equatorial OH and dynamic hydration number. As these three elements were increasing, a starch-Rel-system was stabilizing.

Comparison of Fermentation Characteristics of Italian Ryegrass (Lolium multiflorum Lam.) and Guineagrass (Panicum maximum Jacq.) during the Early Stage of Ensiling

  • Shao, Tao;Zhang, Z.X.;Shimojo, M.;Wang, T.;Masuda, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.12
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    • pp.1727-1734
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    • 2005
  • The fermentation characteristics and mono- and di-saccharides compositions during the early stage of ensiling were studied with a temperate grass, Italian ryegrass (Lolium multiflorum Lam.) and a tropical grass, guineagrass (Panicum maximum Jacq.). The laboratory silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5 and 7 days (14 days in Italian ryegrass) after ensiling, respectively. The Italian ryegrass silage showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days of ensiling and succeeded to achieve lactic acid type fermentation; high lactic acid/acetic acid and lactic acid content at the end of ensiling (14 days), low values of pH (3.74), acetic acid, ethanol and ammonia-N/total nitrogen, none or only small amounts of Butyric acid, valeric acid and propionic acid. The guineagrass silage showed a slow decrease in pH and a slow increase in lactic acid content during the full ensiling period, causing a high final pH value, low contents of lactic acid, acetic acid, total volatile fatty acids and total organic acids. In Italian ryegrass silage, mono- and di-saccharides compositions decreased largely within the initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within the initial 0.5 day of ensiling, but fructose and glucose contents showed an initial rise by the activity of enzymes in plant tissues, and then decreased gradually. On the other hand, the contents of monoand di-saccharides in guineagrass showed the largest decreases due mainly to plant respiration within the initial 0.5 day of ensiling, and no initial rises in fructose and glucose contents during the early stage of ensiling because of the absence of fructans which are hydrolyzed into fructose and glucose in temperate grasses. In both silages, the rate of reduction in mono- and di-saccharides compositions within the initial 5 days of ensiling was ranked in the order of glucose>fructose>sucrose, suggesting that glucose and fructose might be more favorably utilized than sucrose by microorganisms and glucose is the first fermentation substrate. It was concluded that the silage made from Italian ryegrass with high moisture content had a good fermentation quality owing to the dominance of lactic acid bacteria and active lactic acid fermentation during the initial stage of ensiling. These results can be explained by rapid plant sap liberation and the high activity of plant enzyme hydrolyzed fructans into fructose and glucose within the initial 2 days of ensiling, which stimulate the homofermentative lactic acid bacteria growth. In ensiling a temperate grass, the physical characteristics may ensure the rapid onset of fermentation phase, which results from the smaller losses of water-soluble carbohydrates during the initial stage of ensiling and providing sufficient water-soluble carbohydrates for lactic acid bacteria. The silage made from guineagrass with intermediate dry matter and high initial mono- and di-saccharides content was stable silage. This could be explained by the higher incorporation of air during the very early stage of ensiling and the restriction of cell breakdown and juice release due to the properties of a tropical grass with coarse porosity and stemmy structures. These physical characteristics delayed the onset of lactic acid bacteria fermentation phase by extending the phases of respiration and aerobic microorganisms activity, causing the higher loss of water-soluble carbohydrates and the shortage of lactic acid bacteria fermentation substrates.

Production of Xylooligo-Saccharides and Purification of Extracellular Xylanase from Streptomyces chibaensis J-59 (방선균 Streptomyces chibaensis J-59 Xylanase의 정제 및 자일로 올리고당(Xylooligo-Saccharides)의 생산)

  • Joo, Gil-Jae;Rhee, In-Koo
    • Current Research on Agriculture and Life Sciences
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    • v.14
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    • pp.111-122
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    • 1996
  • S. chibaensis J-59 produced an extracellular xylanase in a CSL medium composed of 1.5% com steep liquor, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, and 0.15% glucose containing xylan. but it did not produce in the culture medium containing xylose. The production of enzyme reached to a maximum level (0.83 uints/ml) when bacteria were cultured in 2.5 l jar fermentor for 48hrs at $30^{\circ}C$ and pH 7.0. Furthermore, S. chibaensis J-59 produced an intracellular glucose isomerase in a medium containing xylan and/or xylose. Xylanase was purified 29-fold over the culture supernatants of S. chibaensis J-59 by ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50, and gel filtration on Sephadex G-200. The purified enzyme is a monomeric enzyme with a native molecular mass of 25 kDa and a subunit molecular mass of 25 kDa. The purified enzyme requires $Mg^{2+}$ for activity, $Ca^{2+}$, $Co^{2+}$ is not an inhibitor but inhibit by $Fe^{3+}$, $Hg^{2+}$, and $Cu^{2+}$, sodium dodecyl sulfate, N-bromosuccinide. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down birchwood xylan at random giving xylobiose, xylotriose and xylotetrose as the main end products.

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P(3HB) Accumulation in Alcaligenes eutrophus H16(ATCC 17699) under Nutrient-Rich Condition and Its Induced Production from Saccharides and Their Derivatives

  • Song, Jae-Jun;Shin, Yong-Chul
    • Journal of Microbiology and Biotechnology
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    • v.3 no.2
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    • pp.115-122
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    • 1993
  • Poly(3-hydroxybutyrate)(P(3HB)) accumulation under nutrient-rich condition with various amounts of $(NH_4)_2 SO_4$ was systematically investigated. The results of the electron-microscopy and the solvent extraction showed that the P(3HB) accumulation is unavoidable even under nutrient-rich condition. This indicates that in a two-step culture of Alcaligenes eutrophus H16, the researches should be careful in interpreting the data of polyhydroxyalkanoates(PHAs) accumulation in terms of the carbon-source fed in the second step because the two-step culture product contains the P(3HB) produced under nutrient-rich condition. The polyester production capability in a two-step batch culture of A. eutrophus H16(ATCC 17699) was also investigated using various saccharides and their derivatives such as glucose, fructose, gluconic acid, glucaric acid, sorbitol, lactose, galactose, and mannose. The polyesters synthesized were characterized by 500 MHz$^{1}H-NMR$ spectroscopy, intrinsic viscosity$[\eta]$ measurement in chloroform and differential scanning calorimetry(DSC). 500 MHz $^{1}H-NMR$ analysis showed that all polyesters synthesized generally contained 1~2 mol% of 3HV. Another finding is that the glucose utilization can be increased by changing the autoclaving procedure of the substrate to enhance the P(3HB) production yield up to 46 wt% of P(3HB) in dry cells.

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Effect of Additives on the Fermentation Quality and Residual Mono- and Disaccharides Compositions of Forage Oats (Avena sativa L.) and Italian Ryegrass (Lolium multiflorum Lam.) Silages

  • Shao, Tao;Shimojo, M.;Wang, T.;Masuda, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1582-1588
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    • 2005
  • This study aimed to evaluate the effects of silage additives on the fermentation qualities and residual mono- and disaccharides composition of silages. Forage Oats (Avena sativa L.) and Italian Ryegrass (Lolium multiflorum Lam.) were ensiled with glucose, sorbic acid and pre-fermented juice of epiphytic lactic acid bacteria (FJLB) treatments for 30 days. In both species grass silages, although the respective controls had higher contents of butyric acid (20.86, 33.45g $kg^{-1}$ DM) and ammonia-N/total nitrogen (100.07, 114.91 g $kg^{-1}$) as compared with other treated silages in forage oats and Italian ryegrass, the fermentation was clearly dominated by lactic acid bacteria. This was well indicated by the low pH value (4.27, 4.38), and high lactic acid/acetic acid (6.53, 5.58) and lactic acid content (61.67, 46.85 g $kg^{-1}$ DM). Glucose addition increased significantly (p<0.05) lactic acid/acetic acid, and significantly (p<0.05) decreased the values of pH and ammonia-N/total nitrogen, and the contents of butyric acid and volatile fatty acids as compared with control, however, there was a slightly but significantly (p<0.05) higher butyric acid and lower residual mono- and di-saccharides as compared with sorbic acid and FJLB additions. Sorbic acid addition showed the lowest ethanol, acetic acid and ammonia-N/total nitrogen, and highest contents of residual fructose, total mono- and di-saccharides and dry matter as well as high lactic acid/acetic acid and lactic acid content. FJLB addition had the lowest pH value and the highest lactic acid content, the most intensive lactic acid fermentation occurring in FJLB treated silages. This resulted in the faster accumulation of lactic acid and faster pH reduction. Sorbic acid and FJLB additions depressed clostridia or other undesirable bacterial fermentation, thus this decreased the water-soluble carbohydrates loss and saved the fermentable substrate for lactic acid fermentation.

Effect of Saccharides and Incubation Temperature on pH and Total Acidity of Fermented Black Tea with Tea Fungus (배양액 제조에 사용된 당의 종류와 농도 및 배양 온도가 Tea Fungus발효 홍차의 pH 변화와 Total Acids생성에 미치는 영향)

  • Choi, Mi-Ae;Kim, Jeong-Ok;Choi, Kyung-Ho
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.405-410
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    • 1996
  • The fermented black tea with tea fungus (FBTF) known to cure various diseases was prepared by culturing tea fungus biomass in black tae with different kinds (sucrose, glucose, fructose and corn syrup) and concentrations (10-60% m/v) of saccharides. pH changes and total acid production of FBTF were investigated during 14 dats incubation at $5-45^{\circ}C$ The patterns of acid production in sucrose and fructose black tea solution were similar each other, and those in glucose and corn syrup black tea solution were similar each other showing that tea fungus biomass utilizes fructose than glucose more efficiently. The optimum incubation temperature for the formation and growth of tea fungus Biomass, and the acid production was $30^{\circ}C$ Low contents of total aids (0.1%-0.2%) were produced in 20% of higher concentrations of sucrose and fructose black tea solution, while 1.8% and 0.68% were produced in the 10% of sucrose and fructose black tea solutions, respectively, pH of FBTF dropped to 2.74-3.56 after 2 days of incubation of all the culture solution and Kept this level to 14 days incubation.

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Quality Characteristics of Apricot Sulgidduk by the Saccharides Assortment (당 종류별 살구설기떡의 품질특성)

  • Shin, Young-Ja;Park, Geum-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.2
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    • pp.233-240
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    • 2007
  • The purpose of this study was to evaluate the effect of different saccharides on the quality of apricot sulgidduk. Appearance color of honey-added group as compared to other samples in apricot sulgidduk were preferable and scanning electron microscopy exhibited smaller pores. pH and acidity of white-added group immediately after preparation were higher than those of other groups. Higher moisture contents of honey-added groups during storage were found but total bacterial counts immediately before storage were 1 log cycle lower than that of other samples. The highest 'L' values were found for white sugar added group but the highest 'a' and 'b' were for yellow sugar-added sample. In mechanical characteristics of apricot sulgidduk for 48 hrs during storage at $20^{\circ}C$, hardness, gumminess and brittleness were higher in oligosaccharide-added sample as compared to other samples, while cohesiveness and springiness were the highest in honey-added group. In sensory evaluation of the sulgidduk, honey-added group obtained the highest score in color, sweet taste, moisture, after swallowing and overall quality (p<0.05) These results suggest that apricot sulgidduk with honey can be used as commercially successful rice cakes.