Chemistry of non-enzymic browning. III. Effect of Bisulphite, Phosphate, and Malate on the reaction of Glycine and glucose

1959 ◽  
Vol 12 (2) ◽  
pp. 265 ◽  
Author(s):  
TM Reynolds
Keyword(s):  
Cation Exchange Resin ◽  
Dihydrogen Phosphate ◽  
Sodium Bisulphite ◽  
Quantitative Studies ◽  
Rate Of Reaction ◽  
Dried Fruit ◽  
Enzymic Browning ◽  
Ph Range ◽  
Alkaline Ferricyanide ◽  
By Products

1-Deoxy-1-glycino-D-fructose was obtained in good yield from the reaction of glycine and glucose in the presence of sodium bisulphite and 10 per cent. of water. Small quantities of by-products with similar properties were formed. The results were not affected qualitatively by the reaction temperature or the presence of salts of phosphoric or malic acids. For quantitative studies deoxyglycinofructose was separated from neutral reducing compounds on a cation-exchange resin and determined with alkaline ferricyanide.�The yield of deoxyglycinofructose was dependent on the proportion of glucose and bisulphite to glycine and decreased as the water content of the mixture was increased above 10 per cent. The rate of reaction of glycine and glucose in the presence of bisulphite was studied over the pH range 3.5-5.6 and the temperature range 25 to 100 �C. Pseudo first-order rate constants obtained for pH 3.6 and 4.7 fitted the Arrhenius equation.�The addition of phosphate at pH 3.6 and malate at pH 3.5 increased the rate of reaction of glycine and glucose ; the increase was proportional to the square root of the concentration of dihydrogen phosphate or hydrogen malate ion. The implications of these results in the non-enzymic browning of dried fruit are discussed.

scholarly journals Optimal pH in chlorinated swimming pools – balancing formation of by-products

2013 ◽  
Vol 11 (3) ◽  
pp. 465-472 ◽  
Author(s):  
Kamilla M. S. Hansen ◽  
Hans-Jørgen Albrechtsen ◽  
Henrik R. Andersen
Keyword(s):  
Body Fluid ◽  
Product Formation ◽  
Swimming Pools ◽  
Batch Experiments ◽  
Ph Values ◽  
Precursor Ratio ◽  
Decreasing Ph ◽  
Ph Range ◽  
By Products ◽  
Optimal Ph

In order to identify the optimal pH range for chlorinated swimming pools, the formation of trihalomethanes, haloacetonitriles and trichloramine was investigated in the pH-range 6.5–7.5 in batch experiments. An artificial body fluid analogue was used to simulate bather load as the precursor for by-products. The chlorine-to-precursor ratio used in the batch experiments influenced the amounts of by-products formed, but regardless of the ratio the same trends in the effect of pH were observed. Trihalomethane formation was reduced by decreasing pH, but haloacetonitrile and trichloramine formation increased. To evaluate the significance of the increase and decrease of the investigated organic by-products at the different pH values, the genotoxicity was calculated based on literature values. The calculated genotoxicity was approximately at the same level in the pH range 6.8–7.5 and increased when pH was 6.7 or lower. An optimal pH range for by-products formation in swimming pools was identified at pH 7.0–7.2. In the wider pH range (pH 6.8–7.5), the effect on by-product formation was negligible. Swimming pools should never be maintained at lower pH than 6.8 since formation of both haloacetonitriles and trichloramine increase significantly below this value.

The hydrolysis of maleimide in alkaline solution

1976 ◽  
Vol 54 (9) ◽  
pp. 1400-1404 ◽  
Author(s):  
Remigio Germano Barradas ◽  
Stephen Fletcher ◽  
John Douglas Porter
Keyword(s):  
Alkaline Solution ◽  
Reaction Scheme ◽  
Rate Equations ◽  
Bulk Concentration ◽  
Rate Of Reaction ◽  
Ph Range ◽  
Derived Data ◽  
Hydrolysis Of

The hydrolysis of maleimide has been investigated in the pH range 8.5–14. Polarographic limiting currents were well-defined, so that the bulk concentration of reactant during reduction could be clearly followed as a function of time. Logarithmic analysis of derived data indicated an arrest in the rate of reaction at circa pH 12, and a reaction scheme is proposed to explain this. In this scheme, the neutral maleimide molecule exists in equilibrium with its anion, and both of these species may undergo hydrolysis at the appropriate pH. From derived rate equations, the pKa of maleimide was found to be 10.0, whilst estimates of the rates of hydrolysis were also calculated.

THE RADIOLYSIS OF ALKALINE AQUEOUS SOLUTIONS CONTAINING HYDROGEN AND OXYGEN

1966 ◽  
Vol 44 (6) ◽  
pp. 737-741 ◽  
Author(s):  
W. A. Armstrong
Keyword(s):  
Reaction Mechanism ◽  
Radical Reactions ◽  
Alkaline Solutions ◽  
Oh Radicals ◽  
Neutral Solution ◽  
A Value ◽  
Rate Of Reaction ◽  
Γ Rays ◽  
Ph Range ◽  
The Relationship

The initial yields of H2O2 in aerated water, [Formula: see text] and in water containing H2 and O2, [Formula: see text] have been measured for alkaline solutions irradiated with 60Co γ-rays. [Formula: see text] decreases with increasing pH from a value of 1.22 in neutral solution to 0.63 in solutions of pH 13.92 and the relationship[Formula: see text]is valid over the pH range 7 to 14.[Formula: see text] decreases from 3.30 in neutral solution to a minimum of 2.00 at pH 11.35 and then increases to 2.65 at pH 13.92. The equation[Formula: see text]which is applicable for neutral solutions, is not valid for basic solutions.A reaction mechanism in accordance with the observed results and the literature values of the rate constants of likely radical reactions has been developed. It is assumed that in the alkaline solutions investigated OH radicals react with OH− ions to form O− radicals which react preferentially with O2 to form O3− radicals which then react either with H2 or H2O2. The increase in [Formula: see text] at PH > 12 is attributed to a difference in the rate of reaction of O3− with H2O2 and HO2−, k(O3− + H2O2)/k(O3− + HO2−) = 2.45.

scholarly journals Conversion of Shrimp Head Waste for Production of a Thermotolerant, Detergent-Stable, Alkaline Protease by Paenibacillus sp.

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 798 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
I-Hong Wen ◽  
Van Bon Nguyen ◽  
Anh Dzung Nguyen ◽  
...  
Keyword(s):  
Alkaline Protease ◽  
Nitrogen Nutrition ◽  
Crab Shell ◽  
Carbon And Nitrogen ◽  
Optimal Activity ◽  
Shrimp Shell ◽  
Paenibacillus Sp ◽  
Shrimp Head ◽  
Ph Range ◽  
By Products

Fishery processing by-products have been of great interest to researchers due to their beneficial applications in many fields. In this study, five types of marine by-products, including demineralized crab shell, demineralized shrimp shell, shrimp head, shrimp shell, and squid pen, provided sources of carbon and nitrogen nutrition by producing a protease from Paenibacillus sp. TKU047. Strain TKU047 demonstrated the highest protease productivity (2.98 U/mL) when cultured for two days on a medium containing 0.5% of shrimp head powder (SHP). The mass of TKU047 protease was determined to be 32 kDa (approximately). TKU047 protease displayed optimal activity at 70–80 °C and pH 9, with a pH range of stability from 6 to 11. TKU047 protease also showed stability in solutions containing surfactants and detergents. Based on its excellent properties, Paenibacillus sp. TKU047 protease may be a feasible candidate for inclusion in laundry detergents.

scholarly journals Usefulness of Activated Carbon Prepared from Industrial Wastes in the Removal of Nickel from Aqueous Solution

2009 ◽  
Vol 6 (2) ◽  
pp. 361-370 ◽  
Author(s):  
R. Rajalakshmi ◽  
S. Subhashini ◽  
P. Lalitha
Keyword(s):  
Aqueous Solution ◽  
Industrial Wastes ◽  
Polluted Water ◽  
First Order Kinetics ◽  
Successful Removal ◽  
Ph Range ◽  
Direct Proportionality ◽  
By Products ◽  
Maximum Removal ◽  
Nickel Adsorption

Elimination of heavy metals like nickel from waste water is an important subject in view of public health. In the present study, an attempt has been made to study the applicability of industrial by-products as potential metal adsorbents to remove nickel from aqueous solutions and polluted water. A direct proportionality between the percentage of Ni(II) removal and adsorbent dosage was noted. Maximum removal ⁄ recovery of nickel was achieved at pH range of 10-12 for all adsorbents. An optimum temperature of 40 °C for efficient removal of Ni(II) was observed. The effect of nickel adsorption was affected by salinity. The adsorption isotherm data confirmed to Freundlich and Langmuir isotherms. Conformation of data to the Lagergren᾽s rate equation indicated first order kinetics. The suitability of the industrial by-products in the successful removal of nickel from aqueous solution is quite obvious from the study.

Removal of Cr(III) from Acid-Dissolution Water of Chromium Sludge by Cation Exchange Resin

2013 ◽  
Vol 813 ◽  
pp. 506-513
Author(s):  
Huai Li ◽  
Zi Fang Chi ◽  
Jian Zheng Li
Keyword(s):  
Cation Exchange ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Model Solution ◽  
Acid Dissolution ◽  
Waste Solution ◽  
First Order Kinetics ◽  
Loaded Resin ◽  
Ph Range ◽  
Efficient Adsorbent

The purpose of the present study was to demonstrate the feasibility of adsorbent IRN77 resin for removal of Cr (III) from acid-dissolution water of chromium sludge. Extractions of Cr (III) from a model solution and a acid-dissolution water of chromium sludge were studied by IRN77 cation-exchange resin, respectively. The results suggested that extraction of Cr (III) with this resin followed the Lagergren first-order kinetics. The resin was high selective for Cr (III) sorption in the pH range 1-5 from a model solution containing 150 mg/L Cr (III), and a Cr (III) extraction above 99% was obtained. The studies further showed that 80% Cr (III) from a diluted acid-dissolution water containing about 150 mg/L Cr (III) could be removed which validated the process developed with model waste solution. At the same time, from the loaded resin 99% Cr (III) was eluted with 10% H2SO4. Therefore, this cation-exchange resin could be used as an efficient adsorbent material for the removal of chromium from acid-dissolution water of chromium sludge.

Kinetic and thermodynamic study of Os(VIII) catalysed oxidation of glycine by ferrate(VI) in alkaline medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Main Product ◽  
Activation Parameters ◽  
Basic Medium ◽  
First Order ◽  
Catalysed Oxidation ◽  
Rate Of Reaction ◽  
Different Temperatures ◽  
Experimental Findings ◽  
Kinetic And Thermodynamic Study ◽  
By Products

Kinetic and thermodynamic investigation on Os(VIII) catalysed oxidation of glycine by ferrate(VI) has been done in basic medium and in the temperature range 30– 450C. Rate of oxidation increases with increase in [FeO4]2- and [Os(VI)] and shows first order dependence. Rate of oxidation also increases with the increase in [S] but order is fractional. The rate decreases with an increase in pH. Rate of reaction is independent of [KCl], [KNO3] and change in ionic strength. The values of rate constant observed at four different temperatures were used to calculate the activation parameters. The energy of activation (ΔE*) of the reaction at pH 11 and temperature 350C was found to be 49.56 kJmol-1. [OsO4(H2O)2] and [FeO42−] are proposed to be the reactive species of Os(VIII) and Fe(VI) respectively in the present investigation. Formaldehyde is found to be main product of the reaction along with carbon dioxide and ammonia as by products. On the basis of experimental findings, a suitable mechanism consistent with the observed kinetics is proposed and a rate law has been derived on the basis of obtained data.

Kinetics of ozone reactions with 1-naphthalene, 1,5-naphthalene and 3-nitrobenzene sulphonic acids in aqueous solutions

2001 ◽  
Vol 44 (5) ◽  
pp. 7-13 ◽  
Author(s):  
V. Calderara ◽  
M. Jekel ◽  
C. Zaror
Keyword(s):  
Aqueous Solutions ◽  
Hydroxyl Radicals ◽  
Oxidation Kinetics ◽  
Order Kinetic ◽  
Rate Of Reaction ◽  
Direct Reactions ◽  
Kinetics Of ◽  
By Products ◽  
Ozone Reactions ◽  
Primary Oxidation

This paper describes the ozone oxidation kinetics of 1-naphthalene (1NS), 1,5-naphthalene (1,5NDS), and 3-nitrobenzene (3NBS) sulphonic acid. The presence of hydroxyl radicals and their effect on the overall rate of reaction was studied. Second order kinetic constants of direct reactions were estimated at around 252 M-1s-1, 41 M-1s-1 and 22 M-1s-1, for 1NS, 1,5NDS, and 3NBS sulphonic acids, respectively. At pH 3, the indirect reaction accounted for 2%, 15% and 4% of total primary oxidation of 1NS, 1,5NBS, and 3NBS sulphonic acids, respectively. At pH 9, indirect reaction contribution increased to 73%, 84% and 48%, respectively. C4 compounds (maleic and fumaric acids), C2 (oxalic), C1 (formic) and sulphate were identified as oxidation by-products in all cases. TOC slowly decreased throughout ozonation, reaching around 40-60% and 60-70% reduction over 90 minutes at pH 7 and 3, respectively.

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