scholarly journals The Effect of Dicarboxymethyl Cellulose on the Prevention of Protein Haze Formation on White Wine

Beverages ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 57
Author(s):  
Diana Gago ◽  
Ricardo Chagas ◽  
Luísa M. Ferreira
Keyword(s):  
High Performance ◽  
Heat Stability ◽  
White Wine ◽  
Protein Quantification ◽  
Chromatography Method ◽  
White Wines ◽  
Heat Stable ◽  
Before And After ◽  
Haze Formation ◽  
Liquid Chromatography Method

Wine clarity is a critical aspect in the commercialization of white wines. The formation of wine haze can be attributed to the aggregation and precipitation of heat-unstable wine proteins. Bentonite fining is the commonly used method in winemaking for protein removal, but it is responsible for loss of wine volume and quality. Dicarboxymethyl cellulose (DCMC) was developed as a potential alternative to bentonite. Water-insoluble DCMC was prepared via catalyzed heterogeneous etherification using sodium chloromalonate and potassium iodide. White wine fining trials were benchmarked with different dosages of DCMC against a bentonite. A high-performance liquid chromatography method was optimized for protein quantification. The samples underwent heat stability tests to evaluate wine turbidity before and after fining. Results show that DCMC successfully reduced the wine protein content and turbidity. DCMC produced heat-stable wines with dosages higher than 0.25 g/L. The innovative application of DCMC in the wine sector shows potential due to its ability to stabilize white wines while overcoming problems associated with bentonite, such as lees production and loss of wine, contributing to a more sustainable process.

Thiamine levels in Indonesian children with congenital heart diseases undergoing surgery using cardiopulmonary bypass machine

2021 ◽  
pp. 021849232110241
Author(s):  
Eva M Marwali ◽  
Putri Caesa ◽  
Yoel Purnama ◽  
Muhammad Rayhan ◽  
Novik Budiwardhana ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
High Performance ◽  
Congenital Heart ◽  
Heart Diseases ◽  
Cross Sectional Study ◽  
Congenital Heart Diseases ◽  
Chromatography Method ◽  
Cross Sectional ◽  
Before And After ◽  
Liquid Chromatography Method

Background This study evaluated thiamine levels in Indonesian children with congenital heart diseases before and after cardiopulmonary bypass and their relationship with clinical and surgical outcomes. Method A prospective, single center cross-sectional study was conducted to evaluate thiamine levels in 25 children undergoing congenital heart diseases surgery with cardiopulmonary bypass procedure. Thiamine levels were quantified using a high-performance liquid chromatography method. Result Preoperative thiamine deficiency was observed in one subject. Thiamine levels did not differ statistically between nutritional status and clinical outcomes categories. There were no significant changes in thiamine levels before and after cardiopulmonary bypass (median pre versus post (P25–75): 50 ng/mL (59.00–116.00) and 83.00 ng/mL (70.00–101.00), p = 0.84), although a significant reduction in thiamine levels were observed with longer cardiopulmonary bypass duration ( p = 0.017, R = −0.472). Conclusion Thiamine levels were not significantly impacted by cardiac surgery except in patients undergoing extremely long cardiopulmonary bypass duration. However, clinical outcome was not affected by thiamine levels.

scholarly journals Impact of white wine macromolecules on fractionation performance of ultrafiltration membranes

OENO One ◽  
2011 ◽  
Vol 45 (3) ◽  
pp. 181
Author(s):  
Johannes De Bruijn ◽  
José Martínez-Oyanedel ◽  
Cristina Loyola ◽  
Francisco Lobos ◽  
Javier Seiter ◽  
...  
Keyword(s):  
Protein Aggregation ◽  
Membrane Filtration ◽  
New Technology ◽  
White Wine ◽  
White Wines ◽  
Sauvignon Blanc ◽  
Heat Stable ◽  
Specific Proteins ◽  
Haze Formation ◽  
Uf Membranes

<p style="text-align: justify;"><strong>Aim</strong>: The aim of this study was to investigate the performance of ultrafiltration (UF) membranes to achieve a selective separation of macromolecules from Sauvignon blanc wine into stable and unstable fractions and to characterize the main compounds separated.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The macromolecules from two Sauvignon blanc wines (Curicó Valley and Casablanca Valley, Chile) were separated by a cascade of UF membranes into three nominal fractions (10-30, 30-100 and 100-300 kDa). These fractions were characterized by native and SDS electrophoresis and membrane performance was evaluated by protein rejection and transmission. Separation by UF allowed the concentration of thermally unstable proteins in the 10-30 kDa retentate fraction, increasing heat induced haze by 8.9 fold, while heat stable glycoproteins were concentrated into the 100-300 kDa retentate fraction, reducing heat induced haze by 5.3 fold compared to unfiltered wine. The retention of high macromolecular species by the UF membrane with a 100 kDa molecular weight cut-off contributed to increased protein aggregation in the filtered wines.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The concentration and purification of anti-hazing compounds by membrane filtration seem to be a new technology to improve the protein stability of white wines.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: Specific wine proteins are responsible for wine instability, resulting in haze formation in white wines. On the other hand, glycoproteins prevent protein aggregation and precipitation, thereby improving wine stability. Fractionation of wine macromolecules by UF membranes may help us to improve our knowledge about the contribution of specific proteins and glycoproteins to the haze stability of white wines.</p>

scholarly journals Characterization of Ciprofloxacin-Bismuth-Loaded Antibacterial Wound Dressing

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5096
Author(s):  
Dorota Kowalczuk ◽  
Małgorzata Miazga-Karska ◽  
Agata Gładysz ◽  
Paweł Warda ◽  
Agnieszka Barańska ◽  
...  
Keyword(s):  
Wound Dressing ◽  
High Performance ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Chromatography Method ◽  
Modification Process ◽  
Bromine Solution ◽  
Before And After ◽  
Liquid Chromatography Method

The research was focused on developing a potentially antibacterial wound dressing made of polyurethane foam and loaded with bismuth-ciprofloxacin (Cip-Bi). The Cip-Bi chemical structure was confirmed by Fourier transform infrared spectroscopic (FTIR) analysis. The sought after antibacterial wound dressing was obtained by modification of the raw dressing with an iodine or bromine solution and subsequently with a Cip-Bi hydrogel. The amount of Cip-Bi loaded into the dressing matrix was determined indirectly on the basis of the differences in Cip-Bi concentrations, before and after the modification process, and the determination was performed with the HPLC (high-performance liquid chromatography) method. The modified dressing was found to have a two-step release of Cip-Bi, a feature helpful in the treatment of locally infected wounds and prevention of secondary bacterial infection. The zone of inhibition test against the selected Gram-positive and Gram-negative bacteria confirmed the antibacterial activity of the Cip-Bi-modified dressing. Preliminary tests conducted so far have been indicative of the Cip-Bi dressing’s relatively high activity against the tested organisms.

scholarly journals HPLC Quantification of Cytotoxic Compounds fromAspergillus niger

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Paula Karina S. Uchoa ◽  
Leandro Bezerra de Lima ◽  
Antonia T. A. Pimenta ◽  
Maria da Conceição F. de Oliveira ◽  
Jair Mafezoli ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
High Performance ◽  
Chromatography Method ◽  
Relative Standard ◽  
Validation Parameters ◽  
Cytotoxic Compounds ◽  
Liquid Chromatography Method ◽  
Marine Strain

A high-performance liquid chromatography method was developed and validated for the quantification of the cytotoxic compounds produced by a marine strain ofAspergillus niger. The fungus was grown in malt peptone dextrose (MPD), potato dextrose yeast (PDY), and mannitol peptone yeast (MnPY) media during 7, 14, 21, and 28 days, and the natural products were identified by standard compounds. The validation parameters obtained were selectivity, linearity (coefficient of correlation > 0.99), precision (relative standard deviation below 5%), and accuracy (recovery > 96).

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