Search results for "Hydrolysate"
showing 10 items of 46 documents
Production of ethyl lactate by activated carbon-supported Sn and Zn oxide catalysts utilizing lignocellulosic side streams
2021
Abstract In this study, activated carbon-supported Sn and Zn oxide catalysts were prepared from hydrolysis lignin and used for the conversion of model solutions of trioses, hexoses, and lignocellulosic biomass hydrolysates to ethyl lactate. Both catalysts, SnO2@AC and ZnO@AC, were able to produce ethyl lactate in high yields. SnO2@AC was a more active and selective catalyst in triose (dihydroxyacetone) conversion, providing 99% yield to ethyl lactate. ZnO@AC, by contrast, was more selective in glucose and hydrolysate conversion, with a yield of 60% and 85%, respectively. The ethyl lactate yields were significantly higher than those from the optimized model solution experiments when using Zn…
Efficiency of acetic acid and formic acid as a catalyst in catalytical and mechanocatalytical pretreatment of barley straw
2016
Abstract In this study, the potential of organic acids (formic acid, acetic acid) in a catalytical and mechanocatalytic conversion of lignocellulosic barley straw to valuable sugars is explored using sulfuric acid as a reference. Acid-catalyzed hydrolysis has been carried out with acid-impregnated samples as well as unmodified barley straw. In the mechanocatalytical approach, pretreatment consists of impregnation with the acid catalyst and mechanical treatment by ball milling following chemical hydrolysis. Straw samples and residues were analyzed by Fourier transform infrared spectrometry (FT-IR) whereas hydrolysate analysis was based on total reducing sugar (TRS) determination following th…
An Influence of Fructan Containing Concentrate from Jerusalem Artichoke Tubers on the Development of Probiotic Dairy Starters on Milk and Oat-based S…
2007
Supplementation of milk and oat hydrolysate containing medium with Jerusalem artichoke concentrate (JAC) and subsequent fermentation with probiotic dairy starters resulted in substantial stimulation of probiotics Bifidobacterium lactis and Lactobacillus acidophilus as well as yogurt starter culture Lactobacillus bulgaricus development and acidification rate. The strain-specific responses of the general yogurt cultures, as well as probiotics to the addition of JAC, should be considered to achieve optimal composition of probiotic strains and conformable fermentation conditions. JAC is suggested to be perspective prebiotic additive for fermented synbiotic milks or oat-hydrolysate-based product…
Alkaline Pre-treatment of Hardwood Chips Prior to Delignification
2013
Scots pine (Pinus sylvestris) chips were pre-treated with alkaline solutions (alkali charges of 1, 2, 3, 4, 6, and 8% of NaOH on the oven-dried wood material) at 130°C and 150°C for various treatment times (30, 60, 90, and 120 minutes). Under these conditions, 2.0–13.6% of the wood d.s. was dissolved into the aqueous hydrolysates. The soluble organic fraction was primarily characterized in terms of carbohydrates (monosaccharides and oligo-/polysaccharides) and their alkali-catalyzed degradation products: aliphatic carboxylic acids containing, besides non-volatile hydroxy carboxylic acids, volatile formic and acetic acids. With increasing alkali charge, temperature, and time, the enhanced fo…
Rapid classification of enzymes in cleaning products by hydrolysis, mass spectrometry and linear discriminant analysis
2008
A method for the rapid classification of proteases, lipases, amylases and cellulases used as enhancers in cleaning products, based on precipitation with acetone, hydrolysis with HCl, dilution of the hydrolysates with ethanol, and direct infusion into the electrospray ion source of an ion-trap mass spectrometer, has been developed. The abundances of the ([M+H]+ ions of the amino acids, from the hydrolysates of both the enzyme industrial concentrates and the detergent bases spiked with them, were used to construct linear discriminant analysis models, capable of distinguishing between the enzyme classes. For this purpose, the variables were normalized as follows: (A) the ion abundance of each …
Peptide-metal complexes: obtention and role in increasing bioavailability and decreasing the pro-oxidant effect of minerals.
2020
Bioactive peptides derived from food protein sources have been widely studied in the last years, and scientific researchers have been proving their role in human health, beyond their nutritional value. Several bioactivities have been attributed to these peptides, such as immunomodulatory, antimicrobial, antioxidant, antihypertensive, and opioid. Among them, metal-binding capacity has gained prominence. Mineral chelating peptides have shown potential to be applied in food products so as to decrease mineral deficiencies since peptide-metal complexes could enhance their bioavailability. Furthermore, many studies have been investigating their potential to decrease the Fe pro-oxidant effect by f…
Dairy Debaryomyces hansenii strains produce the antihypertensive casein-derived peptides LHLPLP and HLPLP
2015
The ability of dairy Debaryomyces hansenii, Kluyveromyces lactis and Kluyveromyces marxianus strains to release the casein-derived antihypertensive sequences RYLGY, AYFYPEL, LHLPLP, HLPLP, VPP and/or IPP was examined. Yeast strains were grown in medium with casein as sole nitrogen source and the yeast casein hydrolysates (CSHs) were analysed by HPLC-MS/MS to search for the six antihypertensive sequences. Only LHLPLP and HLPLP were identified in CSHs and exclusively in D. hansenii Dh1 and Dh14 hydrolysates in which both antihypertensive sequences represented approximately 6 (CSH Dh1) and 10% (CSH Dh14) of total peptide content. In addition, a complete analysis of selected CSHs by HPLC-MS/MS …
Structural mannoproteins released by β-elimination fromCandida albicanscell walls
1994
Abstract Mild alkaline solutions (β-elimination), after removing the non-covalently bonded wall materials by hot SDS, released 13% and 26% of remaining wall proteins from mycelial and yeast cells of Candida albicans, respectively. When the β-elimination was carried out after digestion of the walls with chitinase, four-fold more proteinaceous materials were released from mycelium and a similar amount in yeast walls. The solubilized materials were shown to be highly polydisperse, and endo-glycosidase H reduced their polydispersity and molecular masses, revealing different electrophoretic patterns in yeast and mycelial cell walls. The solubilized mycelial proteins carried N-glycosidic sugar ch…
Bovine lactoferrin pepsin hydrolysate exerts inhibitory effect on angiotensin I-converting enzyme-dependent vasoconstriction
2007
Abstract The inhibitory effect of a pepsin hydrolysate of bovine lactoferrin (LFH) on angiotensin I-converting enzyme (ACE) has been examined using in vitro and ex vivo functional assays. In vitro assays showed a LFH inhibitory effect on ACE activity with an IC 50 value of 0.95±0.06 mg mL −1 . Ex vivo functional assays using rabbit carotid artery segments showed a LFH inhibitory effect on ACE-dependent angiotensin I-induced contraction, but not on angiotensin II-induced contraction, suggesting that the effect of LFH is not due to antagonism of receptors for angiotensin II. LFH was shown to possess ACE inhibitory effect with potential to modulate hypertension, although the possible inhibitor…
Possibilities and necessities of parenteral nutrition with amino acid mixtures.
1975
In recent years, there have been conclusive findings in the field of maintaining homeostasis following trauma, bleeding, nutritional and metabolic disturbances and infections. These findings can help save the lives of an increasing number of injured and sick by enlarging the therapeutic possibilities which have previously been unimaginable. This development has been made possible by the good cooperation of both basic research and clinical staff whose common aim was to achieve advances in this field of intensive care. The aim of the present study is to make a relevant theoretical and practical contribution to the widening possibilities and necessities in this field.