Addition Of Various Sugars Research Articles

Pink grapefruit lycopene encapsulated in alginate‐based beads: stability towards freezing and drying

SummaryAlginate‐based beads containing lycopene extract were produced with the addition of various sugars and biopolymers. In present work, lycopene stability was studied on beads subjected to thermal treatments: continuous freezing (−18 °C, 30 days), four freezing/thawing (f/t) cycles, dehydration by vacuum‐ and freeze‐drying. The progress of crystallisation was assessed using transversal relaxation times (T2) obtaining isothermal curves at different temperatures. Alginate beads containing trehalose with β‐cyclodextrin and arabic gum retained a high lycopene content (>80%) after freezing and drying, regardless of the freezing or drying method. Instead, beads containing only alginate showed sever lycopene decrease in all cases. Continuous freezing affected both lycopene content and stability to a higher extent than f/t cycles. Isothermal studies revealed the lower amount of crystallised water in beads containing trehalose (with or w/o other excipients), reducing also the time to arrive at the 50% of crystallisation during freezing.

PENGARUH PEMBERIAN BEBERAPA JENIS GULA DAN SUMBER NITROGEN TERHADAP PRODUKSI NATA DE PINA

The effect of addition of various sugars and nitrogen sou rces on the production of nata de pina was evaluated.Data obtained were treated by the analysis of variance followed by Duncan's New Multiple Range Ttest Resultsof study indicate that various sugars and nitrogen sources significiintly affected the thickness, weight andrcndcmcnt of nata, however no effect of these compounds on the water content. Combination of sucrose assource of sugar and urea as source of nitrogen exhibited the highest production of nuta compared to othertreatments.

Comparison of three Yarrowia lipolytica strains for lipase production: NBRC 1658, IFO 1195, and a local strain

Lipase production was examined with 3 strains of Yarrowia lipolytica: NBRC 1658, IFO 1195, and a local strain. All strains were obtained from Hacettepe University's Department of Food Engineering. The addition of nitrogen and carbon sources and the effects of initial pH and temperature parameters were studied. For all 3 strains, the growth temperature range was 20-40 °C, and maximum growth was determined at 30 °C. The initial pH range was 6-9 for growth and 3-6 for lipase production. Maximum growth results were detected as follows: Y. lipolytica NBRC 1658 at 30 °C and pH 8, Y. lipolytica IFO 1195 at 30 °C and pH 8-9, and Y. lipolytica local strain at 30 °C and pH 7. However, maximum lipase production was detected at 30 °C and pH 4.4 for Y. lipolytica NBRC 1658, at 30 °C and pH 4.8 for Y. lipolytica IFO 1195, and at 30 °C and pH 4.6 for Y. lipolytica local strain. The effects of various nitrogen sources on lipase production showed that ammonium sulfate increased the lipase production, whereas urea, peptone, and casein did not show a distinct effect on lipase production. The addition of various sugars also did not increase lipase production efficiently. However, some oils showed a distinct effect on lipase production. The highest lipase activity determined was 16 U/mL, with the addition of 1% ammonium sulfate and 1% olive oil into the production medium of Y. lipolytica NBRC 1658.

Flavour profiles of low‐fat comminuted sausages as affected by the addition of various sugars in combined with 0.1 m lysine

SummaryThe study was performed to evaluate the flavour profiles of low‐fat comminuted sausage (LFS) as affected by the addition of various concentrations of glucose, fructose and sucrose combined with 0.1 m lysine. Among thirty‐five volatile compounds, the concentrations of furfural, 2‐furan methanol, 2‐methoxy phenol, 2‐methoxy‐4‐methyl phenol, myristicine and pentadecanal occupied approximately 60% of the total concentration of volatile compounds identified in full‐ and low‐fat smoked sausages. Phenols and hetero‐compounds derived mainly from the smoking process were the predominant chemical groups. Nine volatile compounds were affected by fat content and the reduction of fat predominantly increased the headspace concentration of myristicin and pentadecanal. The headspace concentration of total volatile compounds detected in LFS control was significantly higher than those of LFS treatments with the various sugars and lysine. The headspace concentration of most volatile compounds decreased with the addition of various sugars. The results indicate that the addition of glucose, fructose and sucrose at the concentrations higher than 0.05 m in combination with 0.1 m lysine delays the release of some flavour compounds in LFS.

Efficient lipid production with Trichosporonfermentans and its use for biodiesel preparation

Effects of medium components and culture conditions on biomass and lipid production of Trichosporon fermentans were studied. The optimal nitrogen source, carbon source and C/N molar ratio were peptone, glucose and 163, respectively. The favorable initial pH of the medium and temperature were 6.5 and 25°C. Under the optimized conditions, a biomass of 28.1g/l and a lipid content of 62.4% could be achieved after culture for 7 days, which were much higher than the original values (19.4g/l and 50.8%) and the results reported by other groups. T. fermentans could grow well in pretreated waste molasses and a lipid yield of 12.8g/l could be achieved with waste molasses of 15% total sugar concentration (w/v) at pH 6.0, representing the best result with oleaginous microorganisms on agro-industrial residues. Addition of various sugars to the pretreated molasses could efficiently enhance the accumulation of lipid and the lipid content reached as high as above 50%. Similar to vegetable oils, the lipid mainly contains palmitic acid, stearic acid, oleic acid and linoleic acid and the unsaturated fatty acids amount to about 64% of the total fatty acids. The microbial oil with an acid value of 5.6mg KOH/g was transesterified to biodiesel by base catalysis after removal of free fatty acids and a high methyl ester yield of 92% was obtained.

Role of various sugars in improving frozen semen quality of Garut ram

Ram spermatozoa are sensitive to extreme changes in temperature during the freeze-thawed process. The present study was conducted to examine the effects of addition of various sugars in Tris extender on sperm cryosurvival of Garut ram. Semen was collected using an artificial vagina from three mature rams once a week. Immediately after initial evaluation, semen was divided into five parts and diluted with Tris extender (control), Tris extender + 0.4% dextrose, Tris extender + 0.4% raffinose, Tris extender + 0.4% trehalose, and Tris extender + 0.4% sucrose, respectively. Semen was loaded in to 0.25 ml mini straw with the concentration of 200 million or 800 million motile spermatozoa per ml. Semen was equilibrated at 5 o C for three hours, then frozen and stored in liquid nitrogen for seven days. Quality of processed-semen including percentages of motile spermatozoa (MS), live spermatozoa (LS), intact acrosome cap (IAC), and intact plasma membrane (IPM) were evaluated after dilution, equilibration, and thawing, respectively. Data were analyzed using completely randomized design with five treatments and six replicates. Means were compared significant difference test at 0.05 significant level. Results of this research showed that there was no significantly difference (P>0.05) between treatments for all sperm quality parameters after dilution and equilibration. Mean percentages of post thawing MS, LS, IAC, and IPM for dextrose (54.00; 68.00; 66.60, and 57.83%), raffinose (50.00; 64.33; 61.80, and 61.75%), trehalose (50.83; 65.67; 61.40 and 57.75%), and sucrose (49.00; 66.80; 58.50 and 58.50%) were significantly (P<0.05) higher than control (40.83; 52.67; 54.60, and 49.40%) respectively. In conclusion, addition of 0.4% dextrose, raffinose, trehalose or sucrose in Tris extender are effective in improving frozen semen quality of Garut ram. Key Words: Sugars, Tris extender, Frozen Semen Quality, Garut Ram

Effect of sugars on rabbit serum albumin stability and induction of secondary structure.

The effect of sugars (sucrose, maltose, and glucose) on the thermal and chemical denaturation of rabbit serum albumin (RSA) has been examined by viscosity and far UV circular dichroism measurements. The viscosity measurements indicate a change in the reduced viscosity from 4.18 to 16.23 ml/g in the temperature range from 20 to 90 degrees C. The T(m) value for RSA obtained by viscosity measurements in the absence of sugar was found to be 63.2 degrees C, but this value increased to 68.4, 70.3, and 73.2 degrees C in the presence of 0.5 M sucrose, 0.5 M glucose, and 0.5 M maltose, respectively. Further, the stability of RSA in the presence of 0.5 M sugars was also investigated by measuring the mean residue ellipticity at 222 nm (MRE(222)) using chemical (0-6 M guanidine hydrochloride) and thermal (20-90 degrees C) transition processes. At the midpoint of the chemical denaturation, the increase in the MRE values at 222 nm in the presence of 0.5 M sugars were of the same order as the increase in the T(m) values, i.e., maltose > glucose > sucrose. Interestingly, a mixture of 0.25 M glucose and 0.25 M fructose showed a cumulative effect on the thermal as well as chemical stability as compared to 0.5 M sucrose alone. In the case of both thermal and chemical denaturation, there was an increase in the MRE(222) values upon addition of various sugars, this indicating induction of secondary structure in the protein.

6-phospho-alpha-D-glucosidase from Fusobacterium mortiferum: cloning, expression, and assignment to family 4 of the glycosylhydrolases.

The Fusobacterium mortiferum malH gene, encoding 6-phospho-alpha-glucosidase (maltose 6-phosphate hydrolase; EC 3.2.1.122), has been isolated, characterized, and expressed in Escherichia coli. The relative molecular weight of the polypeptide encoded by malH (441 residues; Mr of 49,718) was in agreement with the estimated value (approximately 49,000) obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the enzyme purified from F. mortiferum. The N-terminal sequence of the MalH protein obtained by Edman degradation corresponded to the first 32 amino acids deduced from the malH sequence. The enzyme produced by the strain carrying the cloned malH gene cleaved [U-14C]maltose 6-phosphate to glucose 6-phosphate (Glc6P) and glucose. The substrate analogs p-nitrophenyl-alpha-D-glucopyranoside 6-phosphate (pNP alphaGlc6P) and 4-methylumbelliferyl-alpha-D-glucopyranoside 6-phosphate (4MU alphaGlc6P) were hydrolyzed to yield Glc6P and the yellow p-nitrophenolate and fluorescent 4-methylumbelliferyl aglycons, respectively. The 6-phospho-alpha-glucosidase expressed in E. coli (like the enzyme purified from F. mortiferum) required Fe2+, Mn2+, Co2+, or Ni2+ for activity and was inhibited in air. Synthesis of maltose 6-phosphate hydrolase from the cloned malH gene in E. coli was modulated by addition of various sugars to the growth medium. Computer-based analyses of MalH and its homologs revealed that the phospho-alpha-glucosidase from F. mortiferum belongs to the seven-member family 4 of the glycosylhydrolase superfamily. The cloned 2.2-kb Sau3AI DNA fragment from F. mortiferum contained a second partial open reading frame of 83 residues (designated malB) that was located immediately upstream of malH. The high degree of sequence identity of MalB with IIB(Glc)-like proteins of the phosphoenol pyruvate dependent:sugar phosphotransferase system suggests participation of MalB in translocation of maltose and related alpha-glucosides in F. mortiferum.

Buoyancy regulation and aggregate formation in Amoebobacter purpureus from Mahoney Lake

Abstract The meromictic Mahoney Lake (British Columbia, Canada) contains an extremely dense layer of purple sulfur bacteria (Amoebobacter purpureus). The buoyant density of Amoebobacter cells grown in pure culture at saturating light intensity was significantly higher (1027–1034 kg m−3) than the density of lake water (1015 kg m−3). When stationary cultures were shifted to the dark, the gas-vesicle content increased by a factor of 9 and buoyant density decreased to 1002 kg m−3 within three days. A novel mechanism of cell aggregation was detected for the Mahoney Lake strain. Dense cell aggregates were formed after depletion of sulfide. Formation of aggregates was correlated with an increase in cell surface hydrophobicity. Cell aggregates could be disintegrated within less than 1 s by addition of sulfide or various thiol compounds. Mercaptanes with a branched structure in the vicinity of the terminal thiol group, compounds with esterified thiol groups (methylmercaptanes), reducing compounds lacking thiol groups and detergents did not influence aggregate stability. Cell aggregates disintegrated upon addition of urea or of proteinase K. Addition of various sugars had no effect on aggregation; this points to the absence of lectins. The results indicate that cell-to-cell adhesion in A, purpureus ML1 is mainly caused by a hydrophobic effect and includes a specific mechanism possibly mediated by a surface protein. Extrapolation of laboratory results to field conditions demonstrated that both regulation of buoyant density and formation of cell aggregates result in passive accumulation of cells at the chemocline and contribute to the narrow stratification of A. purpureus in Mahoney Lake.

Buoyancy regulation and aggregate formation in Amoebobacter purpureus from Mahoney Lake

The meromictic Mahoney Lake (British Columbia, Canada) contains an extremely dense layer of purple sulfur bacteria (Amoebobacter purpureus). The buoyant density of Amoebobacter cells grown in pure culture at saturating light intensity was significantly higher (1027–1034 kg m−3) than the density of lake water (1015 kg m−3). When stationary cultures were shifted to the dark, the gas-vesicle content increased by a factor of 9 and buoyant density decreased to 1002 kg m−3 within three days. A novel mechanism of cell aggregation was detected for the Mahoney Lake strain. Dense cell aggregates were formed after depletion of sulfide. Formation of aggregates was correlated with an increase in cell surface hydrophobicity. Cell aggregates could be disintegrated within less than 1 s by addition of sulfide or various thiol compounds. Mercaptanes with a branched structure in the vicinity of the terminal thiol group, compounds with esterified thiol groups (methylmercaptanes), reducing compounds lacking thiol groups and detergents did not influence aggregate stability. Cell aggregates disintegrated upon addition of urea or of proteinase K. Addition of various sugars had no effect on aggregation; this points to the absence of lectins. The results indicate that cell-to-cell adhesion in A, purpureus ML1 is mainly caused by a hydrophobic effect and includes a specific mechanism possibly mediated by a surface protein. Extrapolation of laboratory results to field conditions demonstrated that both regulation of buoyant density and formation of cell aggregates result in passive accumulation of cells at the chemocline and contribute to the narrow stratification of A. purpureus in Mahoney Lake.

Bouyancy regulation and aggregate formation inAmoebobacter purpureusfrom Mahoney Lake

Abstract The meromictic Mahoney Lake (British Columbia, Canada) contains an extremely dense layer of purple sulfur bacteria (Amoebobacter purpureus). The buoyant density of Amoebobacter cells grown in pure culture at saturating light intensity was significantly higher (1027–1034 kg m−3) than the density of lake water (1015 kg m−3). When stationary cultures were shifted to the dark, the gas-vesicle content increased by a factor of 9 and buoyant density decreased to 1002 kg m−3 within three days. A novel mechanism of cell aggregation was detected for the Mahoney Lake strain. Dense cell aggregates were formed after depletion of sulfide. Formation of aggregates was correlated with an increase in cell surface hydrophobicity. Cell aggregates could be disintegrated within less than 1 s by addition of sulfied or various thiol compounds. Mercaptanes with a branched structure in the vicinity of the terminal thiol group, compounds with esterified thiol groups (methyl-mercaptanes), reducing compounds lacking thiol groups and detergents did not influence aggregate stability. Cell aggregates disintegrated upon addition of urea or of proteinase K. Addition of various sugars had no effect on aggregation; this points to the absence of lectins. The results indicate that cell-to-cell adhesion in A. purpureus ML1 is mainly caused by a hydrophobic effect and includes a specific mechanism possibly mediated by a surface protein. Extrapolation of laboratory results to field conditions demonstrated that both regulation of buoyant density and formation of cell aggregates result in passive accumulation of cells at the chemocline and contribute to the narrow stratification of A. purpureus in Mahoney Lake.

Bouyancy regulation and aggregate formation in Amoebobacter purpureus from Mahoney Lake

The meromictic Mahoney Lake (British Columbia, Canada) contains an extremely dense layer of purple sulfur bacteria ( Amoebobacter purpureus). The buoyant density of Amoebobacter cells grown in pure culture at saturating light intensity was significantly higher (1027–1034 kg m −3) than the density of lake water (1015 kg m −3). When stationary cultures were shifted to the dark, the gas-vesicle content increased by a factor of 9 and buoyant density decreased to 1002 kg m −3 within three days. A novel mechanism of cell aggregation was detected for the Mahoney Lake strain. Dense cell aggregates were formed after depletion of sulfide. Formation of aggregates was correlated with an increase in cell surface hydrophobicity. Cell aggregates could be disintegrated within less than 1 s by addition of sulfied or various thiol compounds. Mercaptanes with a branched structure in the vicinity of the terminal thiol group, compounds with esterified thiol groups (methyl-mercaptanes), reducing compounds lacking thiol groups and detergents did not influence aggregate stability. Cell aggregates disintegrated upon addition of urea or of proteinase K. Addition of various sugars had no effect on aggregation; this points to the absence of lectins. The results indicate that cell-to-cell adhesion in A. purpureus ML1 is mainly caused by a hydrophobic effect and includes a specific mechanism possibly mediated by a surface protein. Extrapolation of laboratory results to field conditions demonstrated that both regulation of buoyant density and formation of cell aggregates result in passive accumulation of cells at the chemocline and contribute to the narrow stratification of A. purpureus in Mahoney Lake.

483—Monitoring cell potential of Escherichia coli with use of an electrode sensitive to tetraphenyl phosphonium : Change by addition of various sugars

An electrode sensitive to tetraphenyl phosphonium cation (TPP +) was applied to the determination of the membrane potential of E. coli (strain B, IAM 1268). This strain did not require EDTA (ethylenediamine tetraacetic acid)-treatment for accumulation of TPP +. As reported previously, some part of the TPP +-uptake was due to the binding to cell envelopes. The time course of TPP +-uptake by cells on addition of sugars was analysed, and the result indicated that the additional binding of TPP + no longer occured. The change in the membrane potential on addition of various sugars was evaluated.

Monitoring cell potential of Escherichia coli with use of an electrode sensitive to tetraphenyl phosphonium : Change by addition of various sugars

An electrode sensitive to tetraphenyl phosphonium cation (TPP +) was applied to the determination of the membrane potential of E. coli (strain B, IAM 1268). This strain did not require EDTA (ethylenediamine tetraacetic acid)-treatment for accumulation of TPP +. As reported previously, some part of the TPP +-uptake was due to the binding to cell envelopes. The time course of TPP +-uptake by cells on addition of sugars was analysed, and the result indicated that the additional binding of TPP + no longer occurred. The change in the membrane potential on addition of various sugars was evaluated.

Sweet-sensitive protein from the rat tongue: Its interaction with various sugars

1.1. The difference spectral absorbancy in the ultraviolet range, induced by addition of various sugars to the extract from the epithelial tissues of the rat tongue was measured.2.2. The relative effectiveness of sugars is in the order of sucrose > fructose > sorbose > mannose > maltose > xylose > raffinose > rhamnose > galactose > glucose.3.3. The interaction between sucrose and the extract is independent of pH change between 5.4 and 8.6.

Influence of Crop Residue Decomposition Products on the Germination of Fusarium solani f. phaseoli Chlamydospores in Soil

Fusarium solani f. phaseoli, the cause of stem and root rot of bean, has been shown to exist in nature primarily in the form of chlamydospores1. Such chlamydospores germinate on the addition of various sugars or amino-acids but not ordinarily when water alone is used1. The chlamydospores have also been shown to germinate in the presence of exudates of the host and various other plants2,3. Evidence is presented here to show that substances produced during the decomposition of crop residues under natural field conditions can also influence the germination of chlamydospores in the absence of exudates from living plants.