scholarly journals Retensi Ekstrak Karoten pada Olahan Mie Wortel (Daucus carrota L.)

KOVALEN ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 99-105
Author(s):  
Putri Wahyuni ◽  
Ni Ketut Sumarni ◽  
Prismawiryanti ◽  
Jaya Hardi
Keyword(s):  
Shelf Life ◽  
Reaction Kinetics ◽  
Room Temperature ◽  
Storage Period ◽  
Order Reaction ◽  
Zero Order ◽  
Carotene Content ◽  
Zero Order Reaction ◽  
Kinetics Of

Carotene extract from carrots (Daucus carrota L.) can improve the quality of processed noodles. Determining of carotene retention in processed carrot noodles during the storage period that has been done aims to know the reaction kinetics and shelf life of the noodles. Carrot noodles were stored for 8 weeks at room temperature and analyzed its carotene content by using a UV-Vis spectrophotometer every 7 days. The result showed that the retention of carrot noodles during storage of 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks was 53.64%, 53.19%, 52.49%, 51.68%, 51.07%, 46.30%, 45.96, 45.88, and 44.93%, respectively. The retention kinetics of carrot noodles during storage followed a zero-order reaction and had a shelf life of up to 30 weeks, 4 days, 4 hours. Keywords: carrot noodles, retention, self life

The Reaction Kinetics of Aluminum and Isopropanol

2012 ◽  
Vol 164 ◽  
pp. 21-25
Author(s):  
Xiu Hui Wang ◽  
Huan Huan Ni ◽  
Ye Cao ◽  
Gang Li ◽  
Hong Gao ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Catalytic Mechanism ◽  
Reaction Order ◽  
Order Reaction ◽  
Zero Order ◽  
Zero Order Reaction ◽  
Kinetics Of

AlCl3was used as catalyst in the reaction. The reaction kinetics of aluminum and isopropanol was investigated in this paper. Metallograph showed that the surface of the aluminum bar had corrosive pitting. The reaction was zero order reaction when aluminum was overdosed. Reaction order was 0.75 when isopropanol was overdosed. Finally, catalytic mechanism of AlCl3was investigated and the reaction of corrosive pitting was the same as that in microbattery.

The Characteristics and Kinetics of 4-CP with Pb2+ Biodegradation by Fusarium sp.

2013 ◽  
Vol 726-731 ◽  
pp. 2506-2509
Author(s):  
Xiao Xiao Wang ◽  
Xiao Qin Yu ◽  
Jun Ya Pan ◽  
Ji Wu Li
Keyword(s):  
Carbon Source ◽  
Kinetic Equations ◽  
Order Reaction ◽  
Zero Order ◽  
Biodegradation Rate ◽  
Reaction Equation ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Additional Carbon Source

The effects of Pb2+concentration, pH and additional carbon source on biodegradation of 4-chlorophenol (4-CP) byFusariumsp. were investigated, and the characteristic and kinetic of 4-CP biodegradation were analyzed. It was concluded that 4-CP biodegradation rate byFusariumsp. decreased a little at concentration of Pb2+0.20 mg/L and 4-CP 50 mg/L. The suitable biodegradation pH was range from 6 to 7. Additional carbon source (phenol) might increase the rate of 4-CP biodegradation. The kinetic equations of 4-CP biodegradation were well accord with the zero order reaction equation at different concentration of Pb2+.

Pseudo-Homogenous Kinetics Model for the Synthesis of Dimethyl Carbonate from Urea and Methanol with Heterogeneous Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Dimethyl Carbonate ◽  
Side Reaction ◽  
Order Reaction ◽  
Zero Order ◽  
Kinetics Model ◽  
First Order ◽  
Zero Order Reaction ◽  
Kinetics Of

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.

scholarly journals Shelf-life of Dahi (Yogurt) with or without potato mash

2012 ◽  
Vol 29 (1) ◽  
pp. 22-30
Author(s):  
M R Amin ◽  
M N Islam ◽  
M A Habib ◽  
F Islam
Keyword(s):  
Shelf Life ◽  
Room Temperature ◽  
Storage Period ◽  
Keeping Quality ◽  
Different Types

Four different types of Dahi (Yogurt) were prepared and kept at room and   refrigeration temperatures with different concentrations of potato mash (0, 5, 10 and 15%). These Dahi samples were analyzed for smell and taste, body and consistency, colour, texture and acidity and pH at pre and post storage period. The quality of Dahi deteriorated quickly at room temperature than at refrigeration temperature. With (5%) or without potato mash keeping quality was preserved for up to three days but at refrigeration temperature they were suitable up to 12 days. Addition of 10% and 15% potato mashes were suitable for keeping Dahi up to two days at room temperature while in refrigeration temperature it was acceptable up to ten and eight days, respectively. Preparation of Dahi in incorporating potato mash may be economically feasible without compromising it qualities. DOI: http://dx.doi.org/10.3329/bvet.v29i1.11886 Bangl. vet. 2012. Vol. 29, No. 1, 22-30 

Biodegradation Kinetics of Phenols in an Aerobic Biofilm at Low Concentrations

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1375-1384 ◽  
Author(s):  
Erik Arvin ◽  
Bjørn K. Jensen ◽  
Anders Torp Gundersen
Keyword(s):  
Phenol Degradation ◽  
Carbon Sources ◽  
Order Reaction ◽  
Zero Order ◽  
Biofilm Reactor ◽  
Aerobic Biodegradation ◽  
Maximum Capacity ◽  
Low Concentrations ◽  
Zero Order Reaction ◽  
Kinetics Of

Aerobic biodegradation of the phenols: phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, 3,5-dimethylphenol and 2,4,6-trimethylphenol was studied in a biofilm reactor to establish kinetic constants under conditions where the phenols were the sole carbon sources. Phenol concentrations were very low, in the µg/l concentration range. 2,4,6-trimethylphenol was not degraded. The degradation of the other phenols was 1'st order at concentrations in the bulk phase below 20-50 µg/l. Zero order reaction seemed to govern the reaction above 200 µg/l. The l'st order rate constants are 3-30 times higher than the constants calculated for easily degradable organic compounds degraded at 100-1000 times higher concentrations (mg/l range). However, the maximum phenol utilization rates and the Monod constants were much lower compared with constants obtained for the microorganisms grown in the mg/l concentration range. The Monod constant was about 100 times lower. The removal of “total biodegradable phenol” (TB-phenol) was very similar to the removal of a specific compound. The degradation of TB-phenol was l'st order at concentrations below 200 µg/l. When the total biodegradable phenol degradation is near its maximum capacity (o'order reaction) there was a preferential degradation of the most easily degradable phenols, phenol and 2-methylphenol, leading to an apparent inhibition of the degradation of the more slowly degradable phenols, in particular 2,4-dimethylphenol and 3,5-dimethylphenol.

Solutions of phenyliodoso acetate. Decomposition in acetic acid and the effect of perchloric acid

1971 ◽  
Vol 24 (11) ◽  
pp. 2281 ◽  
Author(s):  
WD Johnson ◽  
JE Sherwood
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Room Temperature ◽  
Spectroscopic Studies ◽  
Small Degree ◽  
Order Reaction ◽  
Zero Order ◽  
Hydrogen Ions ◽  
Ionic Dissociation ◽  
Zero Order Reaction

Phenyliodoso acetate appears capable of sustaining both free-radical and ionic reactions. Conductivity studies on solutions of phenyliodoso acetate in acetic acid indicate a small degree of ionic dissociation at temperatures above room temperature. Photolysis of the iodoso compound is a zero-order reaction and a homolytic mechanism is proposed for the decomposition. Evidence from conductivity and spectroscopic studies indicates that there is interaction between the iodoso compound and hydrogen ions. The decomposition of phenyliodoso acetate in acetic acid is markedly accelerated by the addition of perchloric acid. In the absence of acid no conclusion about mechanism is possible; when acid is present decomposition occurs by an ionic mechanism.

scholarly journals Chemical, Microbiological and Sensory Stability of Steam Extracted Jaboticaba (Myrciaria jaboticaba) Juice

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 732
Author(s):  
Ana Beatriz Neves Martins ◽  
Mariana Canto ◽  
Daniel Perrone ◽  
Mariana Monteiro
Keyword(s):  
Phenolic Compounds ◽  
Reaction Kinetics ◽  
Total Phenolics ◽  
Order Reaction ◽  
Zero Order ◽  
Purchase Intent ◽  
First Order ◽  
Color Changes ◽  
Steam Extraction ◽  
Zero Order Reaction

Jaboticaba (Myrciaria jaboticaba) is a Brazilian berry rich in phenolic compounds, much appreciated for its sweet and slightly acid taste, and highly perishable. Thus, we aimed at producing jaboticaba juice by steam extraction and at investigating its microbiological, sensorial and chemical qualities during storage for up to 168 days. Juice was microbiologically safe and even though unsweetened juice was well accepted, sucrose addition further improved flavor (21%), overall impression (11%) and purchase intent (21%) scores. Cyanidin-3-O-glucoside (C3G) was the major phenolic (40%), followed by gallic (28%) and ellagic acids (21%). Total phenolics contents decreased from 27% (50 °C) to 50% (25 °C), mainly driven by C3G degradation. At 60 °C, total phenolics contents did not change after 42 days since C3G degradation was counterbalanced by gallic acid formation (129%), which followed zero-order reaction kinetics. Anthocyanins degradation followed first-order reaction kinetics (C3G half-life at 25 °C = 21.7 days) and was associated with color changes during storage. In conclusion, steam extraction followed by hot-filling technique ensured a juice with at least six months of shelf life.

Urokinase Activation of Plasminogen and Spontaneous Inactivation of the Plasmin Formed

1968 ◽  
Vol 19 (01/02) ◽  
pp. 145-160 ◽  
Author(s):  
W Berg
Keyword(s):  
Order Reaction ◽  
Zero Order ◽  
Inactivation Rate ◽  
First Order Reaction ◽  
Activity Levels ◽  
First Order ◽  
Activation Rate ◽  
Zero Order Reaction ◽  
High Concentrations ◽  
Kinetics Of

SummaryThe kinetics of the activation of plasminogen into plasmin with urokinase and the inactivation rate of the plasmin formed are studied.As a first order reaction is obtained with low plasminogen concentrations and a zero-order reaction is obtained with high concentrations, the activation seems to follow the Michaelis-Menten’s law. The reaction does not go to completion, however. Different activity levels, which are dependent on the urokinase concentration, can be observed.The activation rate increases with temperature. A maximum can be seen at about 42° C.Between 4° C and 15° C, the inactivation of the plasmin formed is minimal, but it increases rapidly at higher temperatures. The inactivation follows approximately a first order reaction with respect to time. If the plasminogen concentration is low, the over-all reaction will be that of two consecutive first order reactions.

Establishment of electrochemical treatment method to dye wastewater and its application to real samples

2021 ◽  
pp. 1-15
Author(s):  
Nian Cheng ◽  
Jingyi Huang ◽  
Yingru Wang
Keyword(s):  
Free Radicals ◽  
Reaction Kinetics ◽  
Removal Rate ◽  
Electrochemical Treatment ◽  
Order Reaction ◽  
Zero Order ◽  
Electrode Spacing ◽  
Dye Wastewater ◽  
Zero Order Reaction ◽  
Hydroxyl Free Radicals

It is of great significance to study the treatment of organic dye pollution. In this work, a method of electrochemical treatment for reactive blue 19 dye (RB19) wastewater system was established, and it was applied to the actual dye wastewater treatment. The effects of applied voltage, electrolyte concentration, electrode spacing, and initial concentration on the removal effect of RB19 have been studied in detail. The results show that the removal rate of RB19 can reach 82.6% and the chemical oxygen demand (CODcr) removal rate is 54.3% under optimal conditions. The removal of RB19 in the system is mainly the oxidation of hydroxyl free radicals. The possible degradation pathway is inferred by ion chromatography: hydroxyl free radicals attack the chromophoric group of RB19 to make it fall off, and then decompose it into ring-opening. The product is finally oxidized to CO2 and water. The kinetic fitting is in accordance with the zero-order reaction kinetics. At the same time, using the established electrochemical system to treat the actual dye wastewater has also achieved good results. After 3 hours of treatment, the CODcr removal rate of the raw water is 44.8%, and the CODcr removal of the effluent can reach 89.5%. The degradation process conforms to the zero-order reaction kinetics. The result is consistent with the electrochemical treatment of RB19.

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