scholarly journals STABILITY OF CHITOSAN-TRIPOLYPHOSPHATE COMPLEX-ENCAPSULATED ANTHOCYANIN AT HIGH WATER ACTIVITY

2020 ◽  
Vol 31 (2) ◽  
pp. 171-179
Author(s):  
Umi Laila ◽  
◽  
Rochmadi Rochmadi ◽  
Sri Pudjiraharti ◽  
Rifa Nurhayati ◽  
...  
Keyword(s):  
Water Activity ◽  
Half Life ◽  
Incubation Temperature ◽  
Kinetic Constant ◽  
Food Product ◽  
High Water ◽  
Order Kinetic ◽  
Degradation Kinetic ◽  
First Order ◽  
The Stability

Previous study successfully conducted encapsulation of the purple-fleshed sweet potato’s anthocyanin but the study has yet to reveal the stability of encapsulated anthocyanin. Therefore, this research aims to observe the stability of encapsulated anthocyanin regarding the characteristic of low anthocyanin stability, which depends on environmental factors, such as temperature, pH, humidity, and water activity. The kinetic parameters of stability, including kinetic constant (k), reaction order, and half-life (t1/2), were also studied. Stability testing was conducted in high water activity of 0.75 and various in-cubation temperatures at 16, 25, 35, and 45°C. Un-encapsulated anthocyanin extract was also tested for its stability in the same condition in order to be compared with encapsulated anthocyanin. This study re-vealed that the encapsulated anthocyanin had lower stability than un-encapsulated anthocyanin extract. It was proven by higher kinetic constant and lower half-life of encapsulated anthocyanin for every incubation temperature which was induced by higher pH of encapsulated anthocyanin compared with anthocyanin extract. Besides, high water activity reduced glass transition temperature (Tg), in which encapsulated anthocyanin was in rubbery state. Both encapsulated anthocyanin and anthocyanin extract were degraded following the first order kinetic. Using the Arrhenius equation, it was obtained that the degradation kinetic constant of encapsulated anthocyanin was stated as k= 420.44 exp (-23.33/RT). Meanwhile, k= 1.12x106 exp (-46.70/RT) described degradation of kinetic constant of anthocyanin extract. The stability test re-vealed that the application of encapsulated anthocyanin was not suitable for wet-type food product.

scholarly journals Effects of heat treatment and storage temperature on the use of açaí drink by nutraceutical and beverage industries

2012 ◽  
Vol 32 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Tatiane Regina Albarici ◽  
José Dalton Cruz Pessoa
Keyword(s):  
Temperature Effect ◽  
Storage Temperature ◽  
Life Time ◽  
Reaction Rate Constant ◽  
Anthocyanin Content ◽  
Order Kinetic ◽  
First Order ◽  
The Stability ◽  
And Storage ◽  
Anthocyanin Degradation

This study assesses the storage temperature effect on the anthocyanins of pasteurized and unpasteurized açaí pulp. The data was obtained using a pasteurized and lyophilized pulp (PLP) to evaluate the temperature effect (0, 25, and 40 °C). Part of non-pasteurized frozen pulp (NPP) was pasteurized (NPP-P) at 90 °C for 30 seconds; both pulps were stored at 40 °C. The anthocyanin content reduction in the drink was evaluated from the half-life time (t1/2), activation energy (Ea), temperature quotient (Q10), and the reaction rate constant (k). The t1/2 of the PLP anthocyanins stored at 40 °C was 1.8 times less than that stored at 25 °C and 15 times less than that stored at 0 °C; therefore, the higher temperatures decreased the stability of anthocyanins. The pasteurization increased the t1/2 by 6.6 times (10.14 hours for NPP and 67.28 hours for NPP-P). The anthocyanin degradation on NPP-P followed a first order kinetic, while NPP followed a second order kinetic; thus it can be said that the pasteurization process can improve the preservation of anthocyanins in the pulp.

Use of purified lyophilized human lactate dehydrogenase isoenzyme 5 in a study of measuring lactate dehydrogenase activity.

1989 ◽  
Vol 35 (8) ◽  
pp. 1774-1776 ◽  
Author(s):  
D A Smith ◽  
G C Moses ◽  
A R Henderson
Keyword(s):  
Lactate Dehydrogenase ◽  
Half Life ◽  
Specific Activity ◽  
Lactate Dehydrogenase Activity ◽  
Bovine Albumin ◽  
First Order ◽  
First Order Kinetics ◽  
The Stability ◽  
Lactate Dehydrogenase Isoenzymes ◽  
Excellent Stability

Abstract We examined the stability of human lactate dehydrogenase (EC 1.1.1.27) isoenzyme 5--purified to a specific activity of about 400 kU/g--when lyophilized in a buffered, stabilized matrix of bovine albumin. This isoenzyme was prepared with a final activity of about 500 U/L and stored at -20, 4, 20, 37, and 56 degrees C for as long as six months. This isoenzyme decayed with approximate first-order kinetics, with an estimated half-life at -20 degrees C of about 475 years. Stability of reconstituted samples stored at 20 or 4 degrees C was poor, suggesting that the reconstituted material should be used without delay; material stored at -20 degrees C showed excellent stability for 15 days. We propose that such preparations might be further investigated as standards for use in electrophoresis of lactate dehydrogenase isoenzymes.

Sustainable wastewater management technology for tourism in Thailand: case and experimental studies

2019 ◽  
Vol 79 (10) ◽  
pp. 1977-1984
Author(s):  
W. Liamlaem ◽  
L. Benjawan ◽  
C. Polprasert
Keyword(s):  
Kinetic Constant ◽  
Experimental Studies ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Wastewater Management ◽  
Order Kinetic ◽  
First Order ◽  
Treated Effluent ◽  
Management Technology ◽  
Pre Treatment

Abstract Thailand has adopted the concept of eco-tourism as a protocol to protect environmental resources. One of the key factors in enabling the achievement of this goal is the improvement of the quality of effluent from those homestays and resorts which still lack efficient on-site wastewater treatment. This research utilized case studies of subsurface flow constructed wetlands (SFCWs), planted mainly with the Indian shot (Canna indica L.), which were designed to treat wastewaters at three resorts located in Amphawa District, Samut Songkram Province in central Thailand. The results showed that the treated effluent was of sufficient quality to meet the building effluent standards Type C, which require the concentrations of biological oxygen demand (BOD), total Kjeldahl nitrogen (TKN) and suspended solids (SS) to be less than 40, 40 and 50 mg/L, respectively. In addition, the first-order kinetic constants for the design and operation of SFCWs were determined. For treating wastewater containing organic substances, with no prior pre-treatment, the first-order kinetic constant of 0.24 1/d can be applied to predict effluent quality. For treating other types of domestic wastewater, a first-order kinetic constant in the range 0.40–0.45 1/d can be used when sizing and operating SFCWs. This research highlights the great potential of SFCWs as a sustainable wastewater management technology.

Comparison of the biodegradability of the grey fraction of municipal solid waste of Barcelona in mesophilic and thermophilic conditions

2003 ◽  
Vol 48 (4) ◽  
pp. 21-28 ◽  
Author(s):  
S. Mace ◽  
D. Bolzonella ◽  
F. Cecchi ◽  
J. Mata-Alvarez
Keyword(s):  
Kinetic Study ◽  
Methane Production ◽  
Kinetic Constant ◽  
Order Kinetic ◽  
Organic Loading ◽  
First Order ◽  
Loading Rates ◽  
Start Up ◽  
Constant Operation ◽  
Thermophilic Conditions

The results of the start-up of two digesters in mesophilic and thermophilic conditions, together with its steady results at several organic loading rates are described. A kinetic study is also carried out which allows one to estimate the ultimate methane production, together with the first-order kinetic constant. Operation at thermophilic temperature yields better results as it allows a more loaded reactor and the methane production is slightly higher.

The Influence of Boria and EDTA on the Hydrodesulfurization Activity on CoMoS Supported Catalysts

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Matin Parvari ◽  
Peyman Moradi
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Supported Catalysts ◽  
Batch Reactor ◽  
Kinetic Constant ◽  
Order Kinetic ◽  
First Order ◽  
Pseudo First Order ◽  
Xrd Studies ◽  
Al2o3 Catalyst ◽  
Hydrodesulfurization Activity

The hydrodesulfurization of dibenzothiophene (HDS of DBT) in a high pressure batch reactor at 320°C was carried out over CoMo/Al2O3-B2O3 catalysts with different B2O3 contents (4, 10, and 16 wt%). Ethylenediaminetetraacetic acid (EDTA) with different EDTA/Co mole ratios (0.6, 1.2 and 1.8) was used as a chelating ligand during the preparation of CoMo/Al2O3-B2O3. XRD studies, FTIR, TPD of NH3, and BET experiments were used to investigate the catalyst samples. The results showed that the catalyst using the support with 4 wt% B2O3 and an EDTA/Co mole ratio of 1.2 had a hydrodesulfurization activity (in pseudo first order kinetic constant basis) value of ~2.96 times higher than that of the simple CoMo/Al2O3 catalyst.

Mathematical modeling and simulation of hexane degradation in fungal and bacterial biofilters: effective diffusivity and partition aspectsThis article is one of a selection of papers published in this Special Issue on Biological Air Treatment.

2009 ◽  
Vol 36 (12) ◽  
pp. 1919-1925 ◽  
Author(s):  
Sonia Arriaga ◽  
Sergio Revah
Keyword(s):  
Mathematical Modeling ◽  
Kinetic Constant ◽  
Effective Diffusivity ◽  
Reaction Model ◽  
Small Error ◽  
Bacterial Biofilm ◽  
Order Kinetic ◽  
Biofilm Thickness ◽  
First Order ◽  
Superficial Area

Mathematical modeling in the biofiltration of volatile organic compounds is a valuable tool for performance prediction and in scaling up. Majority of the published models include parameters obtained from fitting experimental data, thus masking their real influence as they are lumped generally. The present work aims to evaluate experimentally some of the most relevant parameters including kinetic constant, partition coefficient in the biofilm, biofilm thickness, superficial area, and effective diffusivity. For the fungal biofilm, all the parameters mentioned above were obtained experimentally; and for the bacterial biofilm, the biofilm thickness and some intrinsic parameters used to obtain the first-order kinetic constant were taken from the literature. These parameters were then incorporated in a mathematical model to describe the steady-state degradation of hexane in bacterial and fungal biofilters operating under continuous mode. Experimentally, the dimensionless partition coefficients (mG) indicated that hexane was 4 and 35 times more soluble in the bacterial (mG = 9.14) and fungal (mG = 0.88) biofilters, respectively, than in water (mG = 30.4). Comparison of model estimates with experimental concentration profiles of the pollutant along the height of the biofilters proves that the first-order limited by reaction model was appropriate to interpret the experimental results with a small error of ∼1%.

scholarly journals Stability of cactus-pear powder during storage

2016 ◽  
Vol 20 (2) ◽  
pp. 169-173
Author(s):  
Plúvia O. Galdino ◽  
Rossana M. F. de Figueirêdo ◽  
Alexandre J. de M. Queiroz ◽  
Pablícia O. Galdino ◽  
Tâmila K. da S. Fernandes
Keyword(s):  
Water Content ◽  
Water Activity ◽  
Reducing Sugars ◽  
Titratable Acidity ◽  
High Water ◽  
Soluble Solids ◽  
High Water Content ◽  
Cactus Pear ◽  
Total Titratable Acidity ◽  
The Stability

ABSTRACT The stability of cactus-pear powder, obtained by the process of spray drying for 40 days, was evaluated under controlled conditions of relative air humidity (83%) and temperature (25 and 40 °C). The whole pulp was characterized with regard to its physico-chemical parameters: pH, total titratable acidity, soluble solids, water content, total solids, ashes, reducing sugars, total sugars, non-reducing sugars, luminosity, redness, yellowness and water activity. The stored samples in powder were evaluated every 10 days for water content, water activity, total titratable acidity and color (luminosity, redness and yellowness). The whole pulp was slightly acidic and perishable, due to the high water content. During storage, the packages did not prevent water absorption, thus increasing water content and, consequently, water activity. Yellowness oscillated along the storage time, but the predominance of the yellow color was not affected.

Characterization of Dioctyl terephthalate biodegradation by food waste composting

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940048 ◽  
Author(s):  
Sung Tse Lee ◽  
Huu Tuan Tran ◽  
Chitsan Lin ◽  
Hong Giang Hoang ◽  
Thi Dieu Hien Vo ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Food Waste ◽  
Half Life ◽  
Order Kinetic ◽  
Aerobic Composting ◽  
First Order ◽  
Competitive Process ◽  
Plastic Products

Dioctyl terephthalate (DOTP), a plasticizer is used as an additive in many plastic products. Disposal of DOTP into environment has been of concern because it is hardly biodegradable in nature. Therefore, the aim of this study is to investigate the biodegradation of DOTP by aerobic composting processes without bioaugmentation. The initial DOTP concentration in the compost mixture was 11,882 mg/kg, after 35-day incubation, the removal efficiency of the compost reactor was 98%. The degradation was found to follow the first-order kinetic with the half-life of 5.2 days. Food waste composting was demonstrated as a technically robust and economically competitive process for the degradation of DOTP, and that of other similar plasticizers are expected.

UV Protectants for the Biopesticide Based on Photostabilization of Ecdysone

2011 ◽  
Vol 183-185 ◽  
pp. 401-405 ◽  
Author(s):  
Hua Nan Guan ◽  
De Fu Chi ◽  
Jia Yu
Keyword(s):  
Ultraviolet Light ◽  
Larvicidal Activity ◽  
Half Life ◽  
Moderate Degree ◽  
Order Kinetic ◽  
Synthetic Compounds ◽  
First Order ◽  
Glass Slides ◽  
Life Values ◽  
Order Kinetic Equation

The ultraviolet protectant (UV protectant) properties of different natural and synthetic compounds were investigated for a biopesticide based on ecdysone. This study examined the photostabilization of ecdysone when exposed to ultraviolet light in the presence of some ultraviolet protectants. Ecdysone solutions with and without UV protectants in methanol were applied onto the surface of glass slides. At particular intervals, the remaining concentration of ecdysone was analyzed by HPLC. Using first-order kinetic equation, the dissipation half-life values (DT50) for the degradation of ecdysone under ultraviolet radiation were obtained. The larvicidal activity was evaluated against the larvae of Martianus dermestoides Chevrolat. It indicated that the addition of congo red, yeast, starch and arabia gum provided moderate degree of photostabilization of ecdysone and that addition of lignin provided the best photostabilization of ecdysone, among these UV protectants studied. Toxicity of the ecdysone with UV protectants was higher to the larvae of M. dermestoides Chevrolat compared to the ecdysone alone as indicated by the lower EC50 value. The dissipation half-life values of ecdysone after irradiation under ultraviolet light and the larvicidal activity suggested that the addition of lignin (in 1:l mol ratio) can provide better photostabilization of ecdysone molecule.

Photocatalytic Degradation of Antibacterial Sulfanilamide from Aqueous Solution Using TiO2 Nanocatalyst

2017 ◽  
Vol 46 ◽  
pp. 111-122 ◽  
Author(s):  
Hosein Ghahremani
Keyword(s):  
Photocatalytic Degradation ◽  
Uv Irradiation ◽  
Reaction Rate ◽  
Inorganic Salt ◽  
Uv Light ◽  
Kinetic Constant ◽  
Nano Particles ◽  
Order Kinetic ◽  
First Order ◽  
Low Concentrations

Photocatalytic degradation of sulfanilamide (SNM) as a kind of pollutant agent through titanium dioxide nano particles (TiO2) under UV irradiation was evaluated. The effect of different parameters, such as TiO2 and SNM concentrations, amount of pH, inorganic salt and type of light source on the reaction rate was investigated. The results show that SNM was completely removed from the solution after 60 min under UV irradiation. Furthermore, kinetic studied were performed at 25°C over different ranges of SNM concentrations from 100 to 300 ppm, TiO2 concentrations from 0.05 to 1 gL-1 and pH of suspensions from 3 to 11. In this range of concentration of materials, a Langmuir–Hinshelwood kinetic model can describe the process. An overall pseudo-first order kinetic constant was calculated for sulfanilamide conversion. The optimum TiO2 loading, which provides enough surface area for reaction without irradiation loss due to scattering of UV light, was found to be 0.1gL-1, and SNM concentration was100 ppm. Higher degradation efficiency of SNM was observed at pH=9. Finally, the results of this work proved that photocatalysis of SNM is a promising technology to reduce persistent substances even if they are present in low concentrations.

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