Search results for "Turing"
showing 10 items of 2644 documents
Effect of modified starch or maltodextrin incorporation on the barrier and mechanical properties, moisture sensitivity and appearance of soy protein …
2012
Abstract This work aimed to study the effect of starch (acetylated di-starch phosphate and starch acetate) and maltodextrin (DE 10.2 and DE 15.6) on the properties of soy protein isolate (SPI) films. Films were cast from heated (70 °C for 20 min) alkaline (pH 10) aqueous solutions of soy protein isolate (8%) containing glycerol (50% of SPI) as a plasticizer and starch or maltodextrin (20% of SPI). For all types of films, water vapor sorption kinetics during 24 h at 25 °C and 75% relative humidity (RH), diffusion coefficient of water vapor, water vapor permeability at 25 °C for two relative humidity differentials (40–75 and 40–100%), tensile strength and elongation at break, color and micros…
Resin adsorption as a means to enrich rare stilbenes and coumarin from pigeon pea leaves extracts
2011
Abstract In this study, resin adsorption as a means to enrich rare stilbenes cajaninstilbene acid (CSA) and longistyline C (LLC), and coumarin cajanuslactone (CL) from pigeon pea leaves was investigated. Among widely used twenty macroporous adsorption resins, NKA-9 resin presented higher adsorption capacity and desorption ratio in static tests. The adsorption kinetic model fitted better depended on types of compounds and pH values. The experimental adsorption data were better fitted to Langmuir isotherm (R2 0.921–0.991) than Freundlich isotherm (R2 0.753–0.988). In order to optimize the operating parameters for separating CSA, LLC and CL, dynamic adsorption and desorption tests were carried…
Negative pressure cavitation accelerated processing for extraction of main bioactive flavonoids from Radix Scutellariae
2011
Abstract To enhance the extraction efficiency and reduce the energy consumption, an emerging technology named negative pressure cavitation extraction (NPCE) has been shown to be a feasible option for the extraction of bioactive compounds in agricultural crops and medicinal plants. Meanwhile, it can be applied at the pilot scale as a manufacturing process for edible and medicinal plants. Currently, NPCE was proposed for extraction of baicalin, wogonoside, baicalein and wogonin from Radix Scutellariae on the basis of a central composite design (CCD) and response surface methodology (RSM). With proper optimization (80 mesh of particle size, 40 mL/g of liquid/solid ratio, 75% aqueous ethanol as…
Enhanced extraction of isoflavonoids from Radix Astragali by incubation pretreatment combined with negative pressure cavitation and its antioxidant a…
2011
Abstract Incubation pretreatment with the function of endogenous enzyme combined with negative-pressure cavitation extraction (IP-NPCE) was established to extract calycosin and formononetin from Radix Astragali. Significant factors involved in the process were selected using Plackett–Burman factorial design (PBD) and then were optimized by central composite design (CCD). The optimum experimental conditions were incubation at 35 °C, 60 min, pH 4.0 and extraction at negative pressure − 0.080 MPa, ethanol concentration 60%, 60 mesh, 30 min, solid-to-liquid ratio 1:25 and two cycles. Under the optimal conditions, the extraction yields of calycosin and formononetin were 0.650 ± 0.015 and 0.307 ±…
Quantitative Bestimmung von Trichothecenen HT-2 Toxin in verschimmelten pflanzlichen Nahrungsmitteln
1982
Es wird ein Verfahren zur quantitativen Bestimmung von HT-2 Toxin in verschimmeltem Reis, Mais, Weizen, Hafer, Roggen bzw. Erbsen beschrieben. Extrahiert wurde mit einer Mischung von 9 Teilen (Volumen) Acetonitril und einem Teil wasriger 4%iger KCl-Losung. Die Extrakte musten teilweise chromatographisch vorgereinigt werden. Die terminale Bestimmung erfolgte nach zweidimensionaler dunnschichtchromatographischer Trennung durch Fluorescenzintensitatsmessung der mit H2SO4 behandelten DC-Platten. Versuche mit zugesetztem HT-2 Toxin ergaben eine Wiederfindung von 88% (Variationskoeffizient 7).
Quantitative Bestimmung der Penicillins�ure in pflanzlichen Lebensmitteln
1981
Es wird ein Verfahren zur quantitativen Bestimmung der Penicillinsaure in pflanzlichen Lebensmitteln (Erbsen, Reis, Haferflocken und Kokosraspeln) angegeben. Als Extraktionsmittel wird ein Gemisch von Dichlormethan/Methanol (1 + 1) benutzt. Die terminale Abtrennung der Penicillinsaure erfolgt durch zweidimensionale Dunnschichtchromatographie. Durch Umsetzung mit Diphenylborsaure-2-ethanolamin in einem Tauchverfahren wird die Penicillinsaure auf der Platte in ein stark fluorescierendes Derivat verwandelt (maximale Emission bei 440–445 nm nach Anregung bei 365–370 nm).
Effect of storage conditions on furosine formation in milk-cereal based baby foods
2008
[EN] The effect of storage during 9 months at 25, 30 and 37 degrees C on furosine formation in three milk-cereal based baby foods was studied to evaluate development of the Maillard reaction. Furosine was measured by HPLC-UV. Immediately after the manufacturing process, furosine contents were 310-340 mg/100 g protein and at the 9th storage month were 426-603 mg/100 g protein. Storage time and temperature have a significant increase (p < 0.05) of furosine content during storage. Furosine contents were higher in sample containing honey than in those without honey. Interactions (p < 0.05) between storage time and temperature or type of sample were found. A predictive model equation of the evol…
Lipid hydroperoxides determination in milk‐based infant formulae by gas chromatography
2003
A simple gas chromatograph using a flame ionization detector and a polar capillary column method is proposed for determining hydroperoxides in the lipid fraction of milkbased infant formulas. Tricosanoic acid is used as internal standard. The method includes the following steps: a) the extraction of fat with chloroform/methanol (2:1, v/v), b) the reduction of hydroperoxide acids to hydroxide acids with hydrogen gas and palladium as a catalyst, c) the transmethylation to obtain the methyl esters with acetyl chloride and methanol/ hexane (4:1, v/v), and d) an acetylation with acetic anhydride/ pyridine (4:1, v/v) to obtain an acetoxy derivate of the hydroxide present. Two chromatography runs,…
Role of Phase Behavior and Atomization in the Supercritical Antisolvent Precipitation
2003
An experimental study on supercritical antisolvent (SAS) precipitation has been performed to gain insight into the role of phase behavior and atomization in controlling morphology and dimension of precipitates. The mixture yttrium acetate/dimethyl sulfoxide has been used as the main model system and supercritical CO 2 has been used as the antisolvent. Two SAS apparatuses (laboratory and pilot scale) with two injector arrangements and operating with various injector diameters in the range 60-500 μm have been used. The results showed that operating above the mixture critical point (MCP) of the ternary mixture yttrium acetate/dimethyl sulfoxide/ carbon dioxide, sub-micrometric particles are ge…
Electrochemical Synthesis of d,l-Homocysteine Thiolactone Hydrochloride in a Batch Continuous Recirculation Reactor Equipped with Carbon Felt Cathode…
2007
The electrochemical reduction of D,L-homocystine hydrochloride to the corresponding cysteine was performed in a batch continuous recirculation reaction system that was equipped with a FM01-LC electrochemical reactor. Electrolyses were performed under amperostatic conditions, using carbon felt cathodes and DSA anodes divided by Nafion 324 cationic membranes. A simple reactor mathematical model was used to assess the effect of operative parameters (the initial substrate concentration, the reaction temperature, the current density, and the linear velocity of the catholyte) on the performances of the process, with the objective of determining the optimized conditions to perform the electrosynth…