Determination of some flavan-3-ols and anthocyanins in red grape seed and skin extracts by HPLC-DAD: Validation study and response comparison of different standards

2008 ◽  
Vol 628 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Susanna Muñoz ◽  
Montserrat Mestres ◽  
Olga Busto ◽  
Josep Guasch
Keyword(s):  
Validation Study ◽  
Grape Seed ◽  
Red Grape

Direct Determination of Boscalid in Grape Samples by Differential Pulse Voltammetry using a Carbon Paste Electrode

2021 ◽  
Author(s):  
Priscila Azevedo Liberato ◽  
Leonardo Luiz Luiz Okumura ◽  
Astréa Filomena de Souza Silva ◽  
Herbert Aleixo ◽  
Júnio Gonçalves Silva ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Direct Determination ◽  
Differential Pulse ◽  
Grape Seed ◽  
Carbon Paste ◽  
Vitis Labrusca ◽  
Pulse Voltammetry ◽  
Red Grape ◽  
Paste Electrode

A new methodology to determine direct the fungicide Boscalid (BSC) was developed and successfully applied in red grape 100% juice, peel extracts, pulp and purple grape seed (Vitis labrusca L.)...

scholarly journals Comparison of Flow Injection-MS/MS and LC-MS/MS for the Determination of Ochratoxin A

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 547
Author(s):  
Kai Zhang
Keyword(s):  
Ochratoxin A ◽  
Flow Injection ◽  
Internal Standard ◽  
Grape Juice ◽  
Tandem Mass ◽  
Triple Quadrupole ◽  
On Line ◽  
Red Grape Juice ◽  
Red Grape

Two methods for measuring ochratoxin A in corn, oat, and grape juice were developed and compared. Flow injection (FI) and on-line liquid chromatography (LC) performances were evaluated separately, with both methods using a triple quadrupole tandem mass spectrometer (MS/MS) for quantitation. Samples were fortified with 13C uniformly labeled ochratoxin A as the internal standard (13C-IS) and prepared by dilution and filtration, followed by FI- and LC-MS/MS analysis. For the LC-MS/MS method, which had a 10 min run time/sample, recoveries of ochratoxin A fortified at 1, 5, 20, and 100 ppb in corn, oat, red grape juice, and white grape juice ranged from 100% to 117% with RSDs < 9%. The analysis time of the FI-MS/MS method was <60 s/sample, however, the method could not detect ochratoxin A at the lowest fortification concentration, 1 ppb, in all tested matrix sources. At 5, 20, and 100 ppb, recoveries by FI-MS/MS ranged from 79 to 117% with RSDs < 15%. The FI-MS/MS method also had ~5× higher solvent and matrix-dependent instrument detection limits (0.12–0.35 ppb) compared to the LC-MS/MS method (0.02–0.06 ppb). In the analysis of incurred corn and oat samples, both methods generated comparable results within ±20% of reference values, however, the FI-MS/MS method failed to determine ochratoxin A in two incurred wheat flour samples due to co-eluted interferences due to the lack of chromatographic separation.

scholarly journals Determination of rheological behaviour of wine lees

2015 ◽  
Vol 29 (3) ◽  
pp. 307-311 ◽  
Author(s):  
Jaromír Lachman ◽  
Kazimierz Rutkowski ◽  
Petr Trávníček ◽  
Tomáš Vítěz ◽  
Patrik Burg ◽  
...  
Keyword(s):  
Dynamic Viscosity ◽  
Rheological Behaviour ◽  
Volatile Acid ◽  
Second Phase ◽  
Temperature Hysteresis ◽  
Chemical Background ◽  
Rate Test ◽  
Red Grape ◽  
Increasing Temperature

Abstract This study deals with the rheological properties of wine lees. Samples of wine lees of the Saint Laurent variety were used in this experiment. The investigated wine lees arose in the process of production red grape wine in 2013 (Czech Republic). At first, the chemical background was determined. The chemical background includes the following chemical parameters: total acidity, pH, alcohol content, reduced sugars, free SO2, total SO2, and volatile acid. In the second phase of the study, physical properties were determined. Specifically, a sample of wine lees was subjected to rheological tests. These tests consisted in determination of dependence of dynamic viscosity on the temperature, hysteresis loop tests, dependence of dynamic viscosity on the time and step-down in the shear rate test. The experiment demonstrated that the dynamic viscosity increased with increased temperature – this phenomenon is caused by thermolabile proteins – and the wine lees has rheopectic behaviour; the degree of rheopexy was found to rise with the increasing temperature.

Determination of Oxadixyl in Wines by Liquid Chromatography-Tandem Mass Spectrometry: Single-Laboratory and Interlaboratory Validation Study

2014 ◽  
Vol 97 (6) ◽  
pp. 1701-1706
Author(s):  
Armen Mirzoian ◽  
Jeffrey R Ammann
Keyword(s):  
Validation Study ◽  
High Throughput Screening ◽  
Multiple Reaction Monitoring ◽  
Direct Injection ◽  
Ionization Source ◽  
Minimal Sample ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Interlaboratory Validation

Abstract A direct injection LC/MS/MS method for the determination of the pesticide oxadixyl in wines was developed and validated. A sample divert valve was used to deliver the fraction that contained oxadixyl to the mass spectrometer's electrospray ionization source. Oxadixyl was monitored and quantitated using two transitions in multiple reaction monitoring mode. The method demonstrated recoveries of 99.2 ± 2.0 and 96.7 ± 5.2% for red and white wines, respectively, a linearity range of 2–20 μg/L, LOD at 0.7 μg/L, LOQ of 2.0 μg/L, and precision values of 8.2% (RSDr) and 6.2% (RSDR). Direct injection of the wine onto a C18 ultra-performance LC column allowed automation and high throughput screening. Benefits of this approach include minimal sample preparation, short (3 min) run times, and the use of matrix-matched calibration standards, which minimize the matrix effect due to interferences from wine phenolics, sugars, and various other components. The method's performance characteristics were not statistically different for white and red wines. An additional interlaboratory validation study involved 12 laboratories and demonstrated good data agreement with HorRat values ranging from 0.23 to 0.52.

scholarly journals Application of Advanced Drying Technologies for Obtaining Bioactive Beer Yeast and Grape Seed Extract Powders

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Alina NICULA ◽  
Alexandru. T. NICULA ◽  
Carmen SOCACIU ◽  
Pierre DuBREUCQ
Keyword(s):  
Bioactive Compound ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Seed Extract ◽  
Outlet Temperature ◽  
Drying Process ◽  
Fluid Bed ◽  
High Concentrations ◽  
Beer Yeast

As the food industry is interested to recuperate the valuable waste such as beer yeast (Saccharomyces cervisiae) and grape seed (Vitis vinifera), both with high nutritional and health promotion effects, new products and processes are expected to be released on the market. The new modern drying technologies used to process natural compounds and extracts aim a protected evaporation under controlled temperatures and immobilization on matrices, in order to keep high concentrations of bioactive compound in the final products. One of the most important technological parameter during the drying process is the Inlet and Outlet Temperature Using Spray Drying (SD) and Fluid Bed Drying (FBD) optimized technologies we obtained beer yeast (BY) and the grape seed extract (GSE) solid forms, demonstrating that functionality is well preserved (by determination of vitamins B and phenolics, respectively) in the final products comparing with the initial, genuine extracts. Beer yeast and grape seed concentrated forms (stabilized powders and granulated formulas) have emerging consequences in this context and attract the modern consumer for their positive action on health.

scholarly journals Recovery of Oligomeric Proanthocyanidins and Other Phenolic Compounds with Established Bioactivity from Grape Seed By-Products

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 677 ◽  
Author(s):  
Federica Pasini ◽  
Fabio Chinnici ◽  
Maria Caboni ◽  
Vito Verardo
Keyword(s):  
Phenolic Compounds ◽  
Grape Seed ◽  
Grape Pomace ◽  
Grape Seeds ◽  
Esi Ms ◽  
Oligomeric Proanthocyanidins ◽  
Main Class ◽  
Normal Phase Hplc ◽  
By Products

Grape seeds are a copious part of the grape pomace produced by wine and juice industry and they represent an interesting source of phenolic compounds. Proanthocyanidins (PAs) are the main class of grape seed phenols and are important dietary supplements for their well-known beneficial properties. In this study enriched extracts obtained from Chardonnay and Pignoletto grape seeds were characterized for their proanthocyanidins and other minor phenolic compounds content and composition. Seed PAs were fractionated using Sephadex LH-20, using different ethanol aqueous solutions as mobile phase and analysed by normal phase HPLC-FLD-ESI-MS. Monomers, oligomers up to dodecamers and polymers were recorded in all samples. For both cultivars, the extracts showed a high content in PAs. The determination of other phenolic compounds was carried out using a HPLC-QqQ-ESI-MS and Chardonnay samples reported a greater content compared to Pignoletto samples. Contrary to PAs fraction, extracts obtained with ethanol/water 50/50 (v/v) presented a significant higher phenolic content than the others.

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