Search results for " hydrolysis"
showing 10 items of 142 documents
Enzyme recovery and fouling mitigation by ultrasound-enhanced ultrafiltration
2013
Abstract The development of second-generation biofuels from cellulosic/lignocellulosic biomass has advantages from energy and environmental aspects, but the overall cost of the process is mainly dependent on the cost of the enzymes. Enzyme recovery and recycling is one of the most important and effective means of increasing the efficiency of enzymatic hydrolysis processes by lowering the enzyme costs. The primary objective of this study was to investigate the possibilities of enzyme recovery by membrane separation. Ultrafiltration (UF) membranes with various cut-off values and materials were used to recycle cellulase and cellobiase in model solutions and cellulosic hydrolysates. The membran…
Bioaccessibility and bioavailability of fumonisin B2 and its reaction products with isothiocyanates through a simulated gastrointestinal digestion sy…
2014
Abstract Fumonisins (FBs) are toxins produced mainly by the molds Fusarium verticillioides (also known as Fusarium moniliforme) and Fusarium proliferatum. These mycotoxins are contaminants of wheat, maize, maize-based foods and other grains worldwide. Isothiocyanates (ITCs) are natural compounds produced by the enzymatic hydrolysis of glucosinolates, which are found in plants of the Brassicaceae family. The use of ITCs as food preservatives has been extensively researched. In this study, allyl (AITC), phenyl (PITC) and benzyl isothiocyanates (BITC) fumigation systems (500 μL/L) were employed to reduce FB2 levels naturally produced in bread by Gibberella moniliformis CECT 2987. Reaction prod…
A new plant wide modelling approach for the reduction of greenhouse Gas emission from wastewater treatment plants
2017
Recent studies about greenhouse gas (GHG) emissions show that sewer collection systems and wastewater treatment plants (WWTPs) are anthropogenic GHG potential sources. Therefore, they contribute to the climate change and air pollution. This increasing interest towards climate change has led to the development of new tools for WWTP design and management. This paper presents the first results of a research project aiming at setting-up an innovative mathematical model platform for the design and management of WWTPs. More specifically, the study presents the project’s strategy aimed at setting-up a plant-wide mathematical model which can be used as a tool for reducing/controlling GHG from WWTP.…
New biodegradable hydrogels based on a photocrosslinkable modified polyaspartamide: synthesis and characterization
1999
Abstract α,β-Poly( N -2-hydroxyethyl)- dl -aspartamide (PHEA), a synthetic water-soluble biocompatible polymer, was derivatized with glycidyl methacrylate (GMA), in order to introduce in its structure chemical residues having double bonds and ester groups. The obtained copolymer (PHG) contained 29 mol% of GMA residues. PHG aqueous solutions at various concentrations ranging from 30 to 70 mg/ml were exposed to a source of UV rays at λ 254 nm in the presence or in the absence of N , N ′-methylenebisacrylamide (BIS); the formation of compact gel phases was observed beginning from 50 mg/ml. The obtained networks were characterized by FT-IR spectrophotometry and swelling measurements which evide…
New biodegradable hydrogels based on an acryloylated polyaspartamide cross-linked by gamma irradiation
1999
Alpha, beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), a synthetic biocompatible macromolecule, was functionalized with glycidyl methacrylate (GMA) in order to introduce in its side chains residues having double bonds and ester groups. The copolymer (PHG), obtained from PHEA and GMA, had a degree of derivatization of 29 mol%. PHG aqueous solutions are cross-linked by gamma radiation at 0 degrees C either in the presence or absence of N,N'-methylenebisacrylamide (BIS) giving rise to new hydrogel systems. In both cases gelation occurs at quite low doses (0.26 and 0.4 kGy, respectively). The obtained networks were characterized by FT-IR spectrophotometry which confirmed that the cross-linki…
Quantitation of Free and Glycosidically Bound Volatiles in and Effect of Glycosidase Addition on Three Tomato Varieties (Solanum lycopersicumL.)
2007
The volatile fractions of three tomato cultivars (p73, Jorge, and Durinta) were studied in both free and glycosidically bound forms. The possibility of increasing the concentration of free volatile compounds by adding selected glycosidases was also tested. The free volatile fraction (FVF) of tomato juice was directly determined by headspace solid-phase microextraction (SPME). To analyze the glycosidically bound fraction (GBF), tomato juice samples were extracted with C18 cartridges and the resulting glycoside extracts were enzymatically hydrolyzed. The released aglycons were determined by headspace SPME. Of these compounds, six were not previously reported to belong to the tomato GBF. The c…
Sourdough Fermentation Degrades Wheat Alpha-Amylase/Trypsin Inhibitor (ATI) and Reduces Pro-Inflammatory Activity
2020
The ingestion of gluten-containing foods can cause wheat-related disorders in up to 15% of wheat consuming populations. Besides the role of gluten, &alpha
Amino acid profile of milk-based infant formulas
2000
The protein content and amino acid profile of three milk-based infant formulas, two of which were powdered (adapted and follow-on) and the third liquid, were determined to check their compliance with the EU directive and to evaluate whether or not they fulfil an infant's nutritional needs. To obtain the amino acid profile proteins were subjected to acid hydrolysis, prior to which the sulfur-containing amino acids were oxidized with performic acid. The amino acids were derivatized with phenylisothiocyanate (PITC) and then determined by ion-pair reverse phase high performance liquid chromatography (HPLC) In the case of tryptophan a basic hydrolysis was applied and there was no need of derivat…
Alkaline hydrolysis/methylation-acetylation: a new technique for ultrastructural DNA cytochemistry.
1991
SUMMARY A new technique for the visualization of DNA-containing structures in electron microscopy is described. Samples of glutaraldehyde-fixed bone marrow from rats were subjected to alkaline hydrolysis to remove RNA and the phosphate of phospho-proteins, followed by a combined blockage of protein carboxyl and amino groups through methylation-acetylation. After uranyl acetate staining of epoxy-embedded ultrathin sections, chromatin from all cell types showed a highly selective and intense electron opacity. Staining methods for DNA were also positive in semithin sections. This simple procedure could be very useful in ultrastructural cytochemistry of DNA and chromatin.
Über die bestimmung des zahlenmittels des molekulargewichts von polyoxymethylenen. 36. Mitt. Über polyoxymethylene
1968
Die Bestimmung des Zahlenmittels des Molekulargewichts (Mn) von Polyoxymethylenen durch Osmose, durch Kryoskopie, durch chemische und infrarotspektroskopische Endgruppenbestimmung und durch andere Methoden wird diskutiert. Osmotische Messungen in Phenol bei 90°C gelangen mit Cellophanmembranen besser als mit Glasmembranen. Kryoskopische Messungen nach RAST in Campher ergaben nur in Gegenwart eines Antioxydans zuverlassige Ergebnisse. Zur Endgruppenanalyse wurde vor allem die infrarotspektroskopische Bestimmung von Acetatgruppen weiterentwickelt; zur Auswertung wurde die Intensitat der Carbonylbande bei 5,70 μ in Beziehung gesetzt zu der CH2-Bande bei 6,8 μ und eine Eichung mit Hilfe des Chr…