scholarly journals Synthesis and Storage Stability of Diisopropylfluorophosphate

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Derik R. Heiss ◽  
Donald W. Zehnder ◽  
David A. Jett ◽  
Gennady E. Platoff ◽  
David T. Yeung ◽  
...  
Keyword(s):  
Storage Stability ◽  
Storage Temperature ◽  
Acetylcholinesterase Inhibitor ◽  
Degradation Process ◽  
Synthesis Route ◽  
Toxicological Studies ◽  
Commercial Source ◽  
And Storage ◽  
Hydrolysis Of

Diisopropylfluorophosphate (DFP) is a potent acetylcholinesterase inhibitor commonly used in toxicological studies as an organophosphorus nerve agent surrogate. However, LD50values for DFP in the same species can differ widely even within the same laboratory, possibly due to the use of degraded DFP. The objectives here were to identify an efficient synthesis route for high purity DFP and assess the storage stability of both the in-house synthesized and commercial source of DFP at the manufacturer-recommended storage temperature of 4°C, as well as −10°C and −80°C. After 393 days, the commercial DFP stored at 4°C experienced significant degradation, while only minor degradation was observed at −10°C and none was observed at −80°C. DFP prepared using the newly identified synthesis route was significantly more stable, exhibiting only minor degradation at 4°C and none at −10°C or −80°C. The major degradation product was the monoacid derivative diisopropylphosphate, formed via hydrolysis of DFP. It was also found that storing DFP in glass containers may accelerate the degradation process by generating waterin situas hydrolytically generated hydrofluoric acid attacks the silica in the glass. Based on the results here, it is recommended that DFP be stored at or below −10°C, preferably in air-tight, nonglass containers.

scholarly journals Encapsulated NOLA™ Fit 5500 Lactase—An Economically Beneficial Way to Obtain Lactose-Free Milk at Low Temperature

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 527
Author(s):  
Katarzyna Czyzewska ◽  
Anna Trusek
Keyword(s):  
Low Temperature ◽  
Storage Temperature ◽  
Competitive Inhibition ◽  
Caloric Content ◽  
Substrate Diffusion ◽  
Galactose Inhibition ◽  
The Subject ◽  
And Storage ◽  
Food Processes ◽  
Hydrolysis Of

The current requirements of industrial biocatalysis are related to economically beneficial and environmentally friendly processes. Such a strategy engages low-temperature reactions. The presented approach is essential, especially in food processes, where temperature affects the quality and nutritional value foodstuffs. The subject of the study is the hydrolysis of lactose with the commercial lactase NOLA™ Fit 5500 (NOLA). The complete decomposition of lactose into two monosaccharides gives a sweeter product, recommended for lactose intolerant people and those controlling a product’s caloric content. The hydrolysis reaction was performed at 15 °C, which is related to milk transportation and storage temperature. The enzyme showed activity over the entire range of substrate concentrations (up to 55 g/L lactose). For reusability and easy isolation, the enzyme was encapsulated in a sodium alginate network. Its stability allows carrying out six cycles of the complete hydrolysis of lactose to monosaccharides, lasting from two to four hours. During the study, the kinetic description of native and encapsulated NOLA was conducted. As a result, the model of competitive galactose inhibition and glucose mixed influence (competitive inhibition and activation) was proposed. The capsule size does not influence the reaction rate; thus, the substrate diffusion into capsules can be omitted from the process description. The prepared 4 mm capsules are easy to separate between cycles, e.g., using sieves.

Viability, Efficacy, and Storage Stability of Freeze-Dried Biocontrol Agent Candida sake Using Different Protective and Rehydration Media

2001 ◽  
Vol 64 (6) ◽  
pp. 856-861 ◽  
Author(s):  
M. ABADIAS ◽  
N. TEIXIDÓ ◽  
J. USALL ◽  
A. BENABARRE ◽  
I. VIÑAS
Keyword(s):  
Freeze Drying ◽  
Storage Stability ◽  
Storage Temperature ◽  
Penicillium Expansum ◽  
Freeze Dried ◽  
Skimmed Milk ◽  
The Stability ◽  
Candida Sake ◽  
Initial Starting ◽  
And Storage

Viability, efficacy against Penicillium expansum on Golden Delicious apples, and storage stability of freeze-dried Candida sake strain CPA-1 were studied. The effect of several protective agents and rehydration media was investigated in the freeze drying of C. sake. Skimmed milk at 10% concentration was a good rehydration medium for all protectants tested. In general, good viability results were obtained when the same solution was used as a protectant and as a rehydration medium. The best survival was obtained when C. sake cells were protected with 10% lactose + 10% skimmed milk and rehydrated with skimmed milk (85% viability). The potential for biocontrol of the best freeze-dried treatments against P. expansum on apples was compared with that of fresh cells. Freeze-dried treatments at 1 × 107 CFU/ml reduced the incidence of decay by 45 to 66%. The best biocontrol effect was obtained with cells that had been freeze dried using 10% lactose + 10% skimmed milk as a protectant and 1% peptone as a rehydration medium, with a 66% reduction in rot incidence. However, in all treatments, the efficacy of freeze-dried cells was significantly lower than fresh cells. The stability of freeze-dried samples decreased during storage and was influenced by storage temperature. In the best treatment, storage of C. sake cells for 60 days at 4°C resulted in final concentrations of 2.5 × 108 CFU/ml, which was a 10-fold reduction in relation to the initial starting concentration of cells prior to freeze drying.

scholarly journals Thermo-responsive super porous p(NIPAM) cryogels affords enhanced thermal stability and activity for ɑ-Glucosidase enzyme by entrapping in situ

2021 ◽  
Author(s):  
Sahin Demirci ◽  
Nurettin Sahiner
Keyword(s):  
Enzyme Immobilization ◽  
Storage Stability ◽  
Storage Conditions ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Enzyme Functionality ◽  
And Storage ◽  
Enzyme Entrapment ◽  
Temperature Storage

The concept of using a thermo-responsive p(NIPAM) polymer matrix for enzyme immobilization with lower critical solution temperature (LCST) value is rationalized by availability of the compartmental milieu to enzymes to operate within super porous 3-D matrix with special environmental conditions. Therefore, the enzyme immobilization within a support material will be carried out under the storage conditions of enzymes, generally ~-20 oC to afford unnecessarily loss of enzyme functionality in comparison to the other enzyme entrapment methods. Thus, here ɑ-Glucosidase as a model enzyme was entrapped within thermo-responsive super porous p(NIPAM) cryogels (ɑ-Glu@p(NIPAM) during the synthesis that uses cryogenic condition, ~-20 oC. The LSCT value for the prepared p(NIPAM) based cryogels were determined as 34.6±1.2 oC. The immobilization yield, immobilization efficiency, and activity recovery% values were calculated as 89.4±3.1, 66.2±3.3, and 74.0±3.3%, respectively at pH 6.8 and 37 oC for ɑ-Glu@p(NIPAM) cryogel system. Interestingly, the optimum working conditions were achieved as 25 oC and pH 6.8 with higher activity, 98.4±0.2% for the prepared ɑ-Glu@p(NIPAM) cryogel system. The operational and storage stability studies revealed that the prepared ɑ-Glu@p(NIPAM) cryogel system possessed much better operational and storage stability than free ɑ-Glu enzyme e.g., more than 50% activity after 10th usage and 10-day room temperature storage time. Moreover, the kinetic parameters such as Km and Vmax of free-Glu enzyme and ɑ-Glu@p(NIPAM) cryogel system were calculated by non-linear Michaelis-Menten equation.

scholarly journals Influence of temperature and beta-carotene on the processes of hydrolysis and oxidation of triacylglycerins in extra virgin olive oil during storage

2021 ◽  
Vol 83 (2) ◽  
pp. 126-132
Author(s):  
V. S. Kolodiaznaia ◽  
M. Alnakoud ◽  
Т. В. Аlekseeva
Keyword(s):  
Fatty Acids ◽  
Olive Oil ◽  
Storage Temperature ◽  
Virgin Olive Oil ◽  
Beta Carotene ◽  
Extra Virgin Olive Oil ◽  
Climatic Conditions ◽  
Oxidative Processes ◽  
And Storage ◽  
Hydrolysis Of

The article presents the results of studies on the effect of antioxidant beta-carotene and storage temperature on hydrolytic and oxidative processes occurring during storage of extra virgin olive oil obtained from olives grown in the soil and climatic conditions of Syria. The aim is to study the effect of temperature and beta-carotene on the kinetics of reactions of hydrolysis of triacylglycerides (TAG) and oxidation of free fatty acids (FFA) of olive oil during storage. The object of the study was extra virgin olive oil obtained from olives grown in the soil and climatic conditions of Syria according to the generally accepted technology (harvest 2019). Control sample № 1 (without the addition of antioxidant) and experimental samples with the addition of beta-carotene in the amount of 400 (№ 2) and 600 mg/100 g (№ 3) were stored at a temperature of 18 °C for 7 months. Oil sample № 4 without the addition of antioxidants was stored at 4 °C. In the samples under study, the acid value was periodically determined by the titration method, according to the change in which the formation of free fatty acids during the hydrolysis of TAG, as well as the peroxide value characterizing the formation of FFA oxidation products, was estimated. The organoleptic assessment of the oil quality indicators according to the studied descriptors was 5 points. The rate constants of TAG hydrolysis and oxidation of FFA in olive oil have been calculated. It has been shown that during the storage of experimental oil samples the hydrolytic and oxidative processes of TAG significantly slow down with the addition of the antioxidant beta-carotene. It was found that minimal changes in the content of TAG hydrolysis products and FFA oxidation during storage of olive oil at a temperature of + 18 °C are characteristic for samples containing 400 mg/L of beta-carotene and for oil samples stored at a temperature of + 4 °C without the addition of an antioxidant. Expiration dates of olive oil are substantiated depending on the dose of beta-carotene and storage temperature

scholarly journals The Effects of Temperature on the Quality and Storage Stalibity of Sweet Potato (Ipomoea batatas L. [Lam]) Grown in Central Europe

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1665
Author(s):  
Barbara Krochmal-Marczak ◽  
Barbara Sawicka ◽  
Barbara Krzysztofik ◽  
Honorata Danilčenko ◽  
Elvyra Jariene
Keyword(s):  
Sweet Potato ◽  
Central Europe ◽  
Ipomoea Batatas ◽  
Storage Stability ◽  
Storage Temperature ◽  
Weight Losses ◽  
Genetic Features ◽  
Effects Of Temperature ◽  
And Storage

The research focuses on the effects of temperature on the quality and storage stability of sweet potato (Ipomoea batatas L. [Lam]). It is based on the results of a field experiment conducted between 2015–2017 in Żyznów (49°49′ N, 21°50′ E). The experimental factors were: storage temperatures (5° and 15 °C) and sweet potato cultivars (‘Carmen Rubin’, ‘White Triumph’, ‘Beauregard’, ‘Satsumo Imo’, ‘Purple’). Tubers were harvested at BBCH stage 97. Tubers were stored in a climatic chamber with temperature control and fixed ambient humidity for 6 months during the 2015/16–2017/18 seasons. The storage of tubers at 15 °C helped reduce tuber waste and weight losses resulting from germination, transpiration, respiration and rotting. The quality of the stored tubers depended mostly on storage temperature. It was observed that at 15°, the content of dry matter and total sugars was higher than at 5°, whereas the content of starch was lower. The factor determining storage stability was the genetic features of the cultivars under study. The cultivars ‘Purple’ and ‘Satsumo Imo’ demonstrated good storage stability. The cultivar ‘Carmen Rubin’ turned out least suitable for long storage. The experiment results can contribute to developing storage technology of sweet potato tubers cultivated in Central Europe.

scholarly journals Physiological Activities of Perilla Frutescens Var. Frutescens Leaf Extracts and Storage Stability in Kneaded Noodles

2018 ◽  
Vol 2 (2) ◽  
pp. 12
Author(s):  
Yoshiyuki Watanabe ◽  
Hiroko Kitayama ◽  
Mina Yamamoto ◽  
Yusuke Kono ◽  
Yasue Yamada ◽  
...  
Keyword(s):  
Storage Stability ◽  
Storage Temperature ◽  
Radical Scavenging ◽  
Suppressive Effect ◽  
Perilla Frutescens ◽  
Processed Food ◽  
Inhibitory Effects ◽  
Leaf Extracts ◽  
Acidic Fraction ◽  
And Storage

<p><em>P</em><em>erilla </em><em>(Perilla frutescens var. frutescens) </em><em>lea</em><em>ves</em><em> w</em><em>ere</em><em> fractionated</em><em> based </em><em>on their chemical </em><em>properties</em><em>, and the physiological activities of the fractions were evaluated</em><em>.</em><em> </em><em>T</em><em>he acidic fraction had high </em><em>radical scavenging </em><em>ability</em><em>, whereas the superoxide dismutase-like activities of all fractions were low</em><em>.</em><em> A positive correlation was observed between scavenging activity and polyphenol content. The inhibitory effects of the extracts on </em><em>a</em><em>-amylase and on </em><em>a</em><em>-glucosidase activities were low, indicating a weak suppressive effect of the leaf extracts on diabetes. The acidic and phenolic fractions suppressed pancreatic lipase activity and accelerated lipid hydrolysis in adipocytes differentiated from 3T3-L1 cells. F</em><em>lour noodles kneaded </em><em>with </em><em>lea</em><em>f</em><em> powder</em><em> </em><em>were prepared, and storage stability was </em><em>examine</em><em>d</em><em>. The functional compounds in the leaves were heat-sensitive in the flour noodles. We fractionated perilla leaves to isolate and identify valuable components to provide functionality to processed food and determined that some conditions, such as storage temperature, must be considered to effectively use the compounds.</em><em></em></p>

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