Search results for "hydrolysis"
showing 10 items of 632 documents
Multivariate Correlation between Analysis Data on Dissolved Organic Material from Scots Pine (Pinus sylvestris) Chips and their Autohydrolysis Pre-Tr…
2013
Various chemometric techniques were used to establish the relationship between the autohydrolysis conditions prior to pulping and the chemical compositions of the soluble organic materials removed from Scots pine (Pinus sylvestris) wood chips. The aqueous chip pre-treatments (autohydrolysis) were administered at 130 °C and 150 °C for 30, 60, 90, and 120 min, and the hydrolysates obtained were characterized in terms of total carbohydrates (various mono-, oligo-, and polysaccharides together with uronic acid side groups), volatile acids (acetic and formic acids), lignin, and furans (furfural and 5-(hydroxymethyl)furfural). Based on the analytical data gathered, a relatively accurate model for…
Properties and amino acid composition of pure epoxide hydratase
1975
1. Introduction Rat liver epoxide hydratase [EC 4.2.1.631 which catalyses the conversion of epoxides to trurans-dihydro- diols has been purified to apparent homogeneity as determined by three independent criteria [l] . The preparation obtained was capable of catalysing the hydration of both styrene oxide and the 4,5- (K- region)epoxide of benzo(a)pyrene [ 11. Epoxides of polycyclic hydrocarbons have been implicated as the agents responsible for the cytotoxic and carcinogenic properties of such compounds (for reviews see [2-41). A detailed knowledge of the properties of epoxide hydratase may, therefore, contribute towards an understanding of the mechanisms of cytotoxicity and carcinogenesis.…
Cross-talk between phosphatidic acid and ceramide during ethanol-induced apoptosis in astrocytes
2005
Background Ethanol inhibits proliferation in astrocytes, an effect that was recently linked to the suppression of phosphatidic acid (PA) formation by phospholipase D (PLD). The present study investigates ethanol's effect on the induction of apoptosis in astrocytes and the formation of ceramide, an apoptotic signal. Evidence is presented that the formation of PA and ceramide may be reciprocally linked during ethanol exposure. Results In cultured rat cortical astrocytes, ethanol (0.3–1 %, v/v) induced nuclear fragmentation and DNA laddering indicative of apoptosis. Concomitantly, in cells prelabeled with [3H]-serine, ethanol caused a dose-dependent, biphasic increase of the [3H]-ceramide/ [3H…
Formation of Calcium-Deficient Hydroxyapatite via Hydrolysis of Nano-Sized Pure Α-Tricalcium Phosphate
2015
Nano-sized pure α-tricalcium phosphate (α-TCP) fabricated by a novel synthesis approach shows great potential for a faster transformation into calcium-deficient hydroxyapatite (CDHA) than conventionally prepared α-TCP. In this work, amorphous tricalcium phosphate precursors were precipitated and treated with a solvent (water or ethanol), and dried (freeze-dried and oven-dried) before heating at 775 °C. Nanosized α-TCP powders were investigated for their phase composition and crystallinity, particle shape and size, reactivity and cellular biocompatibility. Reaction with water showed faster CDHA formation for freeze-dried powder, at 6 hours, compared to ethanol treated powders, whereas a high…
Pembuatan dan Analisis Bioetanol dari Pati Sagu (Metroxylon Sago) Asal Papua
2012
Preparation and bio-ethanol analysis of sago (M. sago) starch from Papua have been carried out. The preparation of bioethanol was conducted by hydrolysis, fermentation, distillation and purification. The length of fermentation applied is 3, 4, 5, 6, 7 and 8 days. Bioethanol then was analyzed qualitatively and quantitatively. Qualitative analyses were boiling point and molecular weight determination. Quantitative analyses were determination of the volume of bioethanol content and the composition of bioethanol of every length of fermentation. Based on the qualitative analyses, the samples obtained was ethanol with boiling point of 79 oC and molecular weight of 46 gram/mol. Whereas, based on t…
Anaerobic digestion of grass silage in batch leach bed processes for methane production.
2007
Abstract Anaerobic digestion of grass silage in batch leach bed reactors, with and without a second stage upflow anaerobic sludge blanket (UASB) reactor, was evaluated. Sixty six percent of the methane potential in grass was obtained within the 55 days solids retention time in the leach bed–UASB process without pH adjustment, whereas in the one-stage leach bed process 20% of the methane potential in grass was extracted. In two-stage operation, adjustment of the pH of influent to the leach bed reactor to 6 with HCl led to inhibition of both hydrolysis/acidogenesis and methanogenesis. In the leach bed–UASB process 39% of the carbohydrates and 58% of the acid soluble lignin were solubilised wi…
In Vitro Bioactivity of Astaxanthin and Peptides from Hydrolisates of Shrimp (Parapenaeus longirostris) By-Products: From the Extraction Process to B…
2021
Non-edible parts of crustaceans could be a rich source of valuable bioactive compounds such as the carotenoid astaxanthin and peptides, which have well-recognized beneficial effects. These compounds are widely used in nutraceuticals and pharmaceuticals, and their market is rapidly growing, suggesting the need to find alternative sources. The aim of this work was to set up a pilot-scale protocol for the reutilization of by-products of processed shrimp, in order to address the utilization of this valuable biomass for nutraceutical and pharmaceuticals application, through the extraction of astaxanthin-enriched oil and antioxidant-rich protein hydrolysates. Astaxanthin (AST) was obtained using …
In-vitro antioxidant capacity and cytoprotective/cytotoxic effects upon Caco-2 cells of red tilapia (Oreochromis spp.) viscera hydrolysates.
2019
Abstract The antioxidant capacity of red tilapia viscera hydrolysates (RTVH) with different degrees of hydrolysis (DH) as well as their ultrafiltration membrane fractions, were analyzed using different chemical assays. Their protective effects against oxidative stress were evaluated using H2O2-stressed human intestinal differentiated Caco-2. The highest antioxidant capacity was obtained with a DH of 42.5% (RTVH-A) and its
Evaluation of Two Method to Measure Xylanase Activity in Relation with Rheological Effects of Xylanases on White Flour
2011
Many methods are available to measure the xylanase activity of enzymatic preparation. Most of method uses different substrates from those that will be hydrolyzed in various applications in food industry. This fact will lead to a deformed image about how evaluated xylanases will really act in a specific application. The aim of this study is to evaluate the activity of seven xylanase preparation with two method, a colorimetric method with birch insoluble xylan as substrate and a viscometric method with wheat soluble arabinoxylan as substrate.
The identification of irradiated crustaceans and evaluation of the dose by thermoluminescence: Intercomparison between two methods for extracting min…
2010
Abstract The thermoluminescence (TL) is one of the physical methods recommended by the European Committee for Standardization, for the identification of irradiated food from which silicate minerals can be extracted. The efficacy of the method strongly depends on the quantity and purity of the extracted minerals, and therefore on the extraction procedure. In this work we applied the TL for the identification of crustacean Nephrops norvegicus irradiated at 0.5−1.5−3.0 kGy, comparing two different procedures for extracting minerals: by means of a density gradient or with acid hydrolysis. The identification of the irradiation treatment was always achieved with both procedures, without any false…