Glycerol as Alternative Co-Solvent for Water Extraction of Polyphenols from Carménère Pomace: Hot Pressurized Liquid Extraction and Computational Chemistry Calculations

Glycerol is a co-solvent for water extraction that has been shown to be highly effective for obtaining polyphenol extracts under atmospheric conditions. However, its efficacy under subcritical conditions has not yet been studied. We assessed different water-glycerol mixtures (15%, 32.5%, and 50%) in a hot pressurized liquid extraction system (HPLE: 10 MPa) at 90 °C, 120 °C, and 150 °C to obtain extracts of low molecular weight polyphenols from Carménère grape pomace. Under the same extraction conditions, glycerol as a co-solvent achieved significantly higher yields in polyphenols than ethanol. Optimal extraction conditions were 150 °C, with 32.5% glycerol for flavonols and 50% for flavanols, stilbenes, and phenolic acids. Considering gallic acid as a model molecule, computational chemistry calculations were applied to explain some unusual extraction outcomes. Furthermore, glycerol, methanol, ethanol, and ethylene glycol were studied to establish an incipient structure–property relationship. The high extraction yields of gallic acid obtained with water and glycerol solvent mixtures can be explained not only by the additional hydrogen bonds between glycerol and gallic acid as compared with the other alcohols, but also because the third hydroxyl group allows the formation of a three-centered hydrogen bond, which intensifies the strongest glycerol and gallic acid hydrogen bond. The above occurs both in neutral and deprotonated gallic acid. Consequently, glycerol confers to the extraction solvent a higher solvation energy of polyphenols than ethanol.

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Hot Pressurized Liquid Extraction of Polyphenols from the Skin and Seeds of Vitis vinifera L. cv. Negra Criolla Pomace a Peruvian Native Pisco Industry Waste

Agronomy ◽

10.3390/agronomy11050866 ◽

2021 ◽

Vol 11 (5) ◽

pp. 866

Author(s):

Erik E. Allcca-Alca ◽

Nilton C. León-Calvo ◽

Olivia M. Luque-Vilca ◽

Maximiliano Martínez-Cifuentes ◽

José Ricardo Pérez-Correa ◽

...

Keyword(s):

Bioactive Compounds ◽

Ethanol Concentration ◽

Liquid Extraction ◽

Grape Pomace ◽

Pressurized Liquid Extraction ◽

Vitis Vinifera L ◽

Solvent Mixtures ◽

Total Polyphenol ◽

Industry Waste ◽

Potential Applications

The pisco industry in Peru generates large amounts of grape pomace, which is a natural source of bioactive compounds with potential nutraceutical applications. Hot pressurized liquid extraction (HPLE) with water-ethanol solvent mixtures (20–60%) at high temperatures (100–160 °C) was applied to recover polyphenols from the skin and seeds of a Peruvian pisco-industry grape-pomace waste. At the same HPLE conditions (60% ethanol, 160 °C), the seed fraction extracts contained ~6 times more total polyphenol and presented ~5 times more antioxidant activity than the extract from the skin fraction. The lowest ethanol concentration (20%) and the highest temperature (160 °C) achieved the highest recovery of flavanols with 163.61 µg/g dw from seeds and 10.37 µg/g dw from skins. The recovery of phenolic acids was maximized at the highest ethanol concentration and temperature with 45.34 µg/g dw from seeds and 6.93 µg/g dw from skins. Flavonols were only recovered from the skin, maximized (17.53 µg/g dw) at 20% of ethanol and the highest temperature. The recovery of specific polyphenols is maximized at specific extraction conditions. These conditions are the same for seed and skin extractions. This alternative method can be used in other agroindustrial wastes in order to recover bioactive compounds with potential applications in the pharmaceutical and food industry.

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Recovery of Aromatic Aglycones from Grape Pomace Winemaking By-Products by Using Liquid-Liquid and Pressurized-Liquid Extraction

Food Analytical Methods ◽

10.1007/s12161-013-9597-5 ◽

2013 ◽

Vol 7 (1) ◽

pp. 47-57 ◽

Cited By ~ 12

Author(s):

Carolina Muñoz-González ◽

Juan J. Rodríguez-Bencomo ◽

Pedro J. Martín-Álvarez ◽

M. Victoria Moreno-Arribas ◽

M. Ángeles Pozo-Bayón

Keyword(s):

Liquid Extraction ◽

Grape Pomace ◽

Pressurized Liquid Extraction ◽

By Products

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Comparisons of Soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and subcritical water extraction for environmental solids: recovery, selectivity and effects on sample matrix

Journal of Chromatography A ◽

10.1016/s0021-9673(00)00091-1 ◽

2000 ◽

Vol 892 (1-2) ◽

pp. 421-433 ◽

Cited By ~ 275

Author(s):

Steven B Hawthorne ◽

Carol B Grabanski ◽

Esther Martin ◽

David J Miller

Keyword(s):

Supercritical Fluid Extraction ◽

Supercritical Fluid ◽

Subcritical Water ◽

Soxhlet Extraction ◽

Liquid Extraction ◽

Water Extraction ◽

Pressurized Liquid Extraction ◽

Fluid Extraction ◽

Subcritical Water Extraction ◽

Sample Matrix

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Evaluation of Pressurized Liquid Extraction and Pressurized Hot Water Extraction for Tanshinone I and IIA in Salvia miltiorrhiza Using LC and LC-ESI-MS

Journal of Chromatographic Science ◽

10.1093/chromsci/42.4.211 ◽

2004 ◽

Vol 42 (4) ◽

pp. 211-216 ◽

Cited By ~ 21

Author(s):

E. S. Ong ◽

S. M. Len

Keyword(s):

Salvia Miltiorrhiza ◽

Liquid Extraction ◽

Hot Water ◽

Water Extraction ◽

Pressurized Liquid Extraction ◽

Hot Water Extraction ◽

Pressurized Hot Water Extraction ◽

Tanshinone I ◽

Esi Ms

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Chemical Properties of Vitis Vinifera Carménère Pomace Extracts Obtained by Hot Pressurized Liquid Extraction, and Their Inhibitory Effect on Type 2 Diabetes Mellitus Related Enzymes

Antioxidants ◽

10.3390/antiox10030472 ◽

2021 ◽

Vol 10 (3) ◽

pp. 472

Author(s):

Nils Leander Huamán-Castilla ◽

David Campos ◽

Diego García-Ríos ◽

Javier Parada ◽

Maximiliano Martínez-Cifuentes ◽

...

Keyword(s):

Diabetes Mellitus ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Pure Water ◽

Liquid Extraction ◽

Grape Pomace ◽

Pressurized Liquid Extraction ◽

Water Glycerol ◽

Synthetic Drug

Grape pomace polyphenols inhibit Type 2 Diabetes Mellitus (T2DM)-related enzymes, reinforcing their sustainable recovery to be used as an alternative to the synthetic drug acarbose. Protic co-solvents (ethanol 15% and glycerol 15%) were evaluated in the hot pressurized liquid extraction (HPLE) of Carménère pomace at 90, 120, and 150 °C in order to obtain extracts rich in monomers and oligomers of procyanidins with high antioxidant capacities and inhibitory effects on α-amylase and α-glucosidase. The higher the HPLE temperature (from 90 °C to 150 °C) the higher the total polyphenol content (~79%, ~83%, and ~143% for water-ethanol, water-glycerol and pure water, respectively) and antioxidant capacity of the extracts (Oxygen Radical Absorbance Capacity, ORAC), increased by ~26%, 27% and 13%, while the half maximal inhibitory concentration (IC50) decreased by ~65%, 67%, and 59% for water-ethanol, water-glycerol, and pure water extracts, respectively). Water-glycerol HPLE at 150 and 120 °C recovered the highest amounts of monomers (99, 421, and 112 µg/g dw of phenolic acids, flavanols, and flavonols, respectively) and dimers of procyanidins (65 and 87 µg/g dw of B1 and B2, respectively). At 90 °C, the water-ethanol mixture extracted the highest amounts of procyanidin trimers (13 and 49 µg/g dw of C1 and B2, respectively) and procyanidin tetramers of B2 di-O-gallate (13 µg/g dw). Among the Carménère pomace extracts analyzed in this study, 1000 µg/mL of the water-ethanol extract obtained, at 90 °C, reduced differentially the α-amylase (56%) and α-glucosidase (98%) activities. At the same concentration, acarbose inhibited 56% of α-amylase and 73% of α-glucosidase activities; thus, our grape HPLE extracts can be considered a good inhibitor compared to the synthetic drug.

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Biobased Solvents for Pressurized Liquid Extraction of Nannochloropsis gaditana Omega-3 Lipids

Marine Drugs ◽

10.3390/md19020107 ◽

2021 ◽

Vol 19 (2) ◽

pp. 107

Author(s):

Cristina Blanco-Llamero ◽

F. Javier Señoráns

Keyword(s):

Lipid Extraction ◽

Isochrysis Galbana ◽

Liquid Extraction ◽

Pressurized Liquid Extraction ◽

Solvent Mixtures ◽

Omega 3 ◽

Ultrasound Assisted Extraction ◽

Microalgal Biomass ◽

Nannochloropsis Gaditana ◽

Lipid Species

To develop greener extraction alternatives for microalgae biomass, ultrasound assisted extraction (UAE) and pressurized liquid extraction (PLE) with different biobased solvents were investigated, demonstrating that both techniques are useful alternatives for algal lipid extraction. Specifically, Nannochloropsis gaditana lipids were extracted by UAE and PLE at different temperatures and extraction times with sustainable solvents like 2-Methyltetrahydrofuran (2-MeTHF) and its mixtures with ethanol and other alcohols. The best oil yields for both PLE and UAE of N. gaditana were achieved with the mixture of 2-MeTHF:ethanol (1:3), reaching yields of up to 16.3%, for UAE at 50 °C and up to 46.1% for PLE at 120 °C. Lipid composition of the extracts was analyzed by HPLC-ELSD and by GC-MS to determine lipid species and fatty acid profile, respectively. Different fractionation of lipid species was achieved with PLE and solvent mixtures of different polarity. Thus, for the extraction of glycolipids, ethanolic extracts contained higher amounts of glycolipids and EPA, probably due to the higher polarity of the solvent. The optimized method was applied to microalgae Isochrysis galbana and Tetraselmis chuii showing the potential of mixtures of biobased solvents like 2-methyl-THF and ethanol in different proportions to efficiently extract and fractionate lipids from microalgal biomass.

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