Revalorization of Coffee Husk: Modeling and Optimizing the Green Sustainable Extraction of Phenolic Compounds

This study aimed to model and optimize a green sustainable extraction method of phenolic compounds from the coffee husk. Response surface methodology (RSM) and artificial neural networks (ANNs) were used to model the impact of extraction variables (temperature, time, acidity, and solid-to-liquid ratio) on the recovery of phenolic compounds. All responses were fitted to the RSM and ANN model, which revealed high estimation capabilities. The main factors affecting phenolic extraction were temperature, followed by solid-to-liquid ratio, and acidity. The optimal extraction conditions were 100 °C, 90 min, 0% citric acid, and 0.02 g coffee husk mL−1. Under these conditions, experimental values for total phenolic compounds, flavonoids, flavanols, proanthocyanidins, phenolic acids, o-diphenols, and in vitro antioxidant capacity matched with predicted ones, therefore, validating the model. The presence of chlorogenic, protocatechuic, caffeic, and gallic acids and kaemferol-3-O-galactoside was confirmed by UPLC-ESI-MS/MS. The phenolic aqueous extracts from the coffee husk could be used as sustainable food ingredients and nutraceutical products.

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Influence of Cooking Methods on Onion Phenolic Compounds Bioaccessibility

Foods ◽

10.3390/foods10051023 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1023

Author(s):

Alice Cattivelli ◽

Angela Conte ◽

Serena Martini ◽

Davide Tagliazucchi

Keyword(s):

Phenolic Compounds ◽

In Vitro Digestion ◽

Total Phenolic ◽

Cooking Methods ◽

Total Phenolic Compounds ◽

Main Compound ◽

Quercetin Derivatives ◽

Mass Spectrometry Identification ◽

The Impact

The impact of domestic cooking (baking, boiling, frying and grilling) and in vitro digestion on the stability and release of phenolic compounds from yellow-skinned (YSO) and red-skinned onions (RSO) have been evaluated. The mass spectrometry identification pointed out flavonols as the most representative phenolic class, led by quercetin-derivatives. RSO contained almost the double amount of phenolic compounds respect to YSO (50.12 and 27.42 mg/100 g, respectively). Baking, grilling and primarily frying resulted in an increased amount of total phenolic compounds, especially quercetin-derivatives, in both the onion varieties. Some treatments promoted the degradation of quercetin-3-O-hexoside-4′-O-hexoside, the main compound present in both the onion varieties, leading to the occurrence of quercetin-4′-O-hexoside and protocatechuic acid-4-O-hexoside. After in vitro digestion, the bioaccessibility index for total phenolic compounds ranged between 42.6% and 65.5% in grilled and baked YSO, respectively, and between 39.8% and 80.2% in boiled and baked RSO, respectively. Baking contributed to the highest amount of bioaccessible phenolic compounds for both the onion varieties after in vitro digestion. An in-depth design of the cooking process may be of paramount importance in modulating the gastro-intestinal release of onion phenolic compounds.

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Optimization of extraction conditions for polyphenols from the stem bark of Funtumia elastica (Funtum) utilizing response surface methodology

AAS Open Research ◽

10.12688/aasopenres.13284.1 ◽

2021 ◽

Vol 4 ◽

pp. 46

Author(s):

Theophilus Fadjare Frempong ◽

Nathaniel Owusu Boadi ◽

Mercy Badu

Keyword(s):

Phenolic Compounds ◽

Response Surface ◽

Response Surface Method ◽

Phenolic Content ◽

Stem Bark ◽

Total Phenolic ◽

Liquid Ratio ◽

Surface Method ◽

Solid Liquid ◽

The Impact

Background: The recovery of phenolic compounds is seen as an arduous task because phenolic compounds are available as free aglycones, as sugar or ester conjugates, or as polymers with several monomeric components. Furthermore, phenolic compounds do not disperse evenly and may be connected to cell walls, carbohydrates, or proteins. This study looks at the optimization of factors that affect the efficiency for the extraction of phenolic compounds from the stem-bark of Funtumia elastica. Methods: Five independent variables (solvent concentration, time, the temperature, solid-liquid ratio, and pH) of the extraction process were selected. Single factor analysis as well as the response surface method was used to evaluate the impact of the selected factors on the total phenolic content. The effect of the extraction factors on the phenolic content was statistically significant (p <0.05). For the response surface method, a five/factor, five/level central composite design used, and a fitted second-order polynomial regression model equation was used to show how the extraction parameters affected the total phenolic recovery. Results: The predicted value (R² of 0.5917) agreed with the adjusted value (R² of 0.7707). The residuals for response predictions were less than 5%. The optimal factors for the extraction were ethanol concentration of 75.99% v/v, extraction time of 193.86 minutes, temperature of 63.66°C, pH of 5.62, and solid-liquid ratio of 1:21.12 g/mL. Actual overall content of the phenolic compounds was validated at 82.83 ± 3.335 mg gallic acid equivalent (GAE) /g weight of extract, which agreed with the predicted response of 89.467 mg GAE/g of the dried extract under the optimal factors. Conclusions: The rich phenolic content of stem-bark of Funtumia elastica points to its potential as a functional medicinal product to alleviate diseases caused by oxidative stress such as asthma, breathing disorders, inflammation, and cardiovascular diseases.

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Phytochemical and Functional Characterization of Phenolic Compounds from Cowpea (Vigna unguiculata (L.) Walp.) Obtained by Green Extraction Technologies

Agronomy ◽

10.3390/agronomy11010162 ◽

2021 ◽

Vol 11 (1) ◽

pp. 162

Author(s):

M. Victoria Avanza ◽

Gerardo Álvarez-Rivera ◽

Alejandro Cifuentes ◽

José A. Mendiola ◽

Elena Ibáñez

Keyword(s):

Phenolic Compounds ◽

Vigna Unguiculata ◽

Phenolic Content ◽

Functional Characterization ◽

Extraction Yield ◽

Added Value ◽

Total Phenolic ◽

Factors Affecting ◽

Quercetin Glycosides

This work presents a green, downstream process, from extraction to phytochemical characterization and bioactivity testing, to obtain and evaluate the functional properties of phenolic compounds from cowpea (Vigna unguiculata (L.) Walp.) seeds and pods. Phenolic-rich extracts were obtained by pressurized liquid extraction (PLE). The main factors affecting the extraction conditions (temperature and solvent) were optimized in order to attain extracts with the highest extraction yield, antioxidant capacity, and total phenolic content. The optimal extraction conditions were 1:1 ethanol:water at 170 °C with one extraction cycle for seeds and three extraction cycles for pods. Phenolic compounds of optimal extract were analyzed by UHPLC-q-TOF-MS/MS (quadrupole-time of flight tandem MS). The obtained PLE-extracts exhibited higher phenolic content and antioxidant activity compared to conventional extraction procedures. The in vitro anti-neurodegenerative potential of extracts was measured through Acetylcholinesterase (AChE) inhibition assay. The results revealed the higher bioactivity observed in cowpea pod samples compared to seed extracts, which might be related to higher levels of quercetin and quercetin glycosides, kaempferol diglucoside, and other tetrahydroxylated flavones and flavonols identified in these samples. These results also provide an added-value benefit to the cultivation of this legume, considering the high potential of cowpea phenolic extracts as nutraceutical and functional ingredients in food formulations.

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Phytochemical composition and antioxidant activity of Malus baccata (L.) Borkh. fruits

Food Science and Applied Biotechnology ◽

10.30721/fsab2020.v3.i1.46 ◽

2020 ◽

Vol 3 (1) ◽

pp. 47

Author(s):

Nadezhda Petkova ◽

Manol Ognyanov ◽

Blaga Inyutin ◽

Petar Zhelev ◽

Panteley Denev

Keyword(s):

Phenolic Compounds ◽

Antioxidant Activities ◽

Ethanol Extract ◽

Titratable Acidity ◽

Total Phenolic ◽

Total Phenolic Compounds ◽

Frap Assay ◽

Phytochemical Composition ◽

Malus Baccata

Crab apple (Malus baccata (L.) Borkh.) was mainly distributed in Europe as an ornamental plant, but the nutritional properties of its edible fruits were not fully revealed. The aim of the current study was to characterize the phytochemical composition of ripen carb apple fruits and to evaluate their nutritional and antioxidant potentials. The fruits were assayed for moisture and ash content, proteins, lipids, carbohydrates, titratable acidity (TA), pH, total phenolic compounds and natural pigments. Among the analyzed carbohydrates cellulose was found in the highest content (6% dw), followed by sugars (sucrose, glucose and fructose) and 1.8 % dw uronic acids. The total chlorophylls and carotenoids contents in their fruits were 6.51 and 4.80 μg/g fw, respectively. Total monomeric anthocyanins were not detected. The highest content of total phenolic compounds (2.67 mg GAE/g fw) was found in 95 % ethanol extract from fruits, while the total flavonoids were relatively low – 0.1 mg QE/g fw. DPPH assay (17.27 mM TE/g fw) and FRAP assay (14.34 mM TE/g fw) demonstrated in vitro antioxidant activities of crabapple. Malus baccata fruits were evaluated as a rich source of dietary fibers and phenolic compounds with significant antioxidant potential that could be used in human nutrition.

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Delivery of Phenolic Compounds, Peptides and β-Glucan to the Gastrointestinal Tract by Incorporating Dietary Fibre-Rich Mushrooms into Sorghum Biscuits

Foods ◽

10.3390/foods10081812 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1812

Author(s):

Juncai Tu ◽

Margaret Anne Brennan ◽

Gang Wu ◽

Weidong Bai ◽

Ping Cheng ◽

...

Keyword(s):

Phenolic Compounds ◽

Dietary Fibre ◽

Lentinula Edodes ◽

Phenolic Content ◽

Antioxidant Activities ◽

In Vitro Digestion ◽

Total Phenolic ◽

Soluble Peptide ◽

Insoluble Dietary Fibre

Sorghum biscuits were enriched with mushroom powders (Lentinula edodes, Auricularia auricula and Tremella fuciformis) at 5%, 10% and 15% substitution levels. An in vitro gastrointestinal digestion was used to evaluate the effect of this enrichment on the phenolic content and soluble peptide content as well as antioxidant activities of the gastric or intestinal supernatants (bio-accessible fractions), and the remaining portions of phenolic compounds, antioxidants and β-glucan in the undigested residue (non-digestible fraction). The phenolic content of the gastric and intestinal supernatants obtained from digested mushroom-enriched biscuits was found to be higher than that of control biscuit, and the phenolic content was positively correlated to the antioxidant activities in each fraction (p < 0.001). L. edodes and T. fuciformis enrichment increased the soluble protein content (small peptide) of sorghum biscuits after in vitro digestion. All mushroom enrichment increased the total phenolic content and β-glucan content of the undigested residue and they were positively correlated (p < 0.001). The insoluble dietary fibre of biscuits was positively correlated with β-glucan content (p < 0.001) of undigested residue. These findings suggested that enriching food with mushroom derived dietary fibre increases the bioavailability of the non-digestible β-glucan and phenolic compounds.

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Honeybee Pollen Extracts Reduce Oxidative Stress and Steatosis in Hepatic Cells

Molecules ◽

10.3390/molecules26010006 ◽

2020 ◽

Vol 26 (1) ◽

pp. 6

Author(s):

Juan Esteban Oyarzún ◽

Marcelo E. Andia ◽

Sergio Uribe ◽

Paula Núñez Pizarro ◽

Gabriel Núñez ◽

...

Keyword(s):

Antioxidant Activity ◽

Phenolic Compounds ◽

Cell Model ◽

Radical Scavenging ◽

Central Zone ◽

Total Phenolic ◽

Nonalcoholic Fatty Liver ◽

Bee Pollen ◽

Quercetin Concentration

Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. Additional therapies using functional foods and dietary supplements have been investigated and used in clinical practice, showing them to be beneficial. Honeybee pollen from Chile has shown a large concentration of phenolic compounds and high antioxidant activity. In this work, we characterized twenty-eight bee pollen extracts from the central zone of Chile according to botanical origin, phenolic profile, quercetin concentration, and antioxidant activity (FRAP and ORAC-FL). Our results show a statistically significant positive correlation between total phenolic content and antioxidant capacity. Selected samples were evaluated on the ability to reverse the steatosis in an in vitro cell model using Hepa1-6 cells. The pollen extracts protected Hepa1-6 cells against oxidative damage triggered by 2,2′-azo-bis(2-amidinopropane) dihydrochloride (AAPH)derived free radicals. This effect can be credited to the ability of the phenolic compounds present in the extract to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. Additionally, bee pollen extracts reduce lipid accumulation in a cellular model of steatosis. In summary, our results support the antioxidant, hepatoprotective, and anti-steatosis effect of bee pollen in an in vitro model.

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In Vitro Gastrointestinal Digestion Impact on the Bioaccessibility and Antioxidant Capacity of Bioactive Compounds from Tomato Flours Obtained after Conventional and Ohmic Heating Extraction

Foods ◽

10.3390/foods10030554 ◽

2021 ◽

Vol 10 (3) ◽

pp. 554

Author(s):

Marta C. Coelho ◽

Tânia B. Ribeiro ◽

Carla Oliveira ◽

Patricia Batista ◽

Pedro Castro ◽

...

Keyword(s):

Gastrointestinal Tract ◽

Phenolic Compounds ◽

Antioxidant Capacity ◽

Bioactive Compounds ◽

Solid Fraction ◽

Ohmic Heating ◽

Coumaric Acid ◽

Insoluble Dietary Fiber ◽

The Impact

In times of pandemic and when sustainability is in vogue, the use of byproducts, such as fiber-rich tomato byproducts, can be an asset. There are still no studies on the impact of extraction methodologies and the gastrointestinal tract action on bioactive properties. Thus, this study used a solid fraction obtained after the conventional method (SFCONV) and a solid fraction after the ohmic method (SFOH) to analyze the effect of the gastrointestinal tract on bioactive compounds (BC) and bioactivities. Results showed that the SFOH presents higher total fiber than SFCONV samples, 62.47 ± 1.24–59.06 ± 0.67 g/100 g DW, respectively. Both flours present high amounts of resistant protein, representing between 11 and 16% of insoluble dietary fiber. Furthermore, concerning the total and bound phenolic compounds, the related antioxidant activity measured by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolorization assay presented significantly higher values for SFCONV than SFOH samples (p < 0.05). The main phenolic compounds identified in the two flours were gallic acid, rutin, and p-coumaric acid, and carotenoids were lycopene, phytofluene, and lutein, all known as health promoters. Despite the higher initial values of SFCONV polyphenols and carotenoids, these BCs’ OH flours were more bioaccessible and presented more antioxidant capacity than SFCONV flours, throughout the simulated gastrointestinal tract. These results confirm the potential of ohmic heating to modify the bioaccessibility of tomato BC, enhancing their concentrations and improving their antioxidant capacity.

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Impact of Specialty Malts on Wort and Beer Characteristics

Fermentation ◽

10.3390/fermentation7030137 ◽

2021 ◽

Vol 7 (3) ◽

pp. 137

Author(s):

Luis F. Castro ◽

Abigail D. Affonso ◽

Renata M. Lehman

Keyword(s):

Phenolic Compounds ◽

Free Amino ◽

Amino Nitrogen ◽

The Other ◽

Fermentable Sugars ◽

Total Phenolic ◽

Total Phenolic Compounds ◽

Polyphenol Content ◽

The Impact

Specialty malts are commonly used in brewing to provide flavor, aroma, and color to wort and beer. The use of specialty malts contributes to the variety of beer products; therefore, it is important to understand their effect on the characteristics of wort and beer. This study investigates the impact of various specialty malts on wort and beer properties. A control beer was prepared with 100% base malt, and four beer treatments were prepared with the addition of kilned, roasted, and caramel specialty malts. For each treatment, 20% of the base malt was substituted with the various specialty malts when preparing the wort. The fermentable sugars and free amino nitrogen (FAN) content for each wort were analyzed. Alcohol by volume (ABV), international bitterness units (IBU), diacetyl, and polyphenol content of each prepared beers were subsequently analyzed. Results showed that wort prepared with the addition of roasted and caramel malts contained a lower concentration of fermentable sugars and FAN than wort prepared with the base and kilned malts. Beers prepared with the addition of roasted and caramel malts exhibited the lowest levels of ABV, as well as the lowest levels of diacetyl. These beers also exhibited higher levels of total phenolic compounds compared to the other beer samples. No change was observed in IBU levels as a result of brewing with the different specialty malts. This study illustrates how the use of specialty malts impacts wort and beer properties, providing useful information to aid in the production of quality beer products.

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Characterization, Stability, and Bioaccessibility of Betalain and Phenolic Compounds from Opuntia stricta var. Dillenii Fruits and Products of Their Industrialization

Foods ◽

10.3390/foods10071593 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1593

Author(s):

Iván Gómez-López ◽

Gloria Lobo-Rodrigo ◽

María P. Portillo ◽

M. Pilar Cano

Keyword(s):

Phenolic Compounds ◽

Phenolic Acids ◽

Total Phenolic ◽

Antioxidant Compounds ◽

Gastrointestinal Digestion ◽

Fruit Peel ◽

Full Characterization ◽

In Vitro Gastrointestinal Digestion ◽

Quercetin Glycoside

The aim of the present study was the full characterization, quantification, and determination of the digestive stability and bioaccessibility of individual betalain and phenolic compounds of Opuntia stricta, var. Dillenii fresh fruits (peel, pulp, and whole fruit) and of the products of the industrialization to obtain jam (raw pressed juice (product used for jam formulation), by-product (bagasse), and frozen whole fruit (starting material for jam production)). Opuntia stricta var. Dillenii fruits and products profile showed 60 betalain and phenolic compounds that were identified and quantified by HPLC-DAD-ESI/MS and HPLC-DAD-MS/QTOF, being 25 phenolic acids (including isomers and derivatives), 12 flavonoids (including glycosides), 3 ellagic acids (including glycosides and derivative), and 20 betanins (including degradation compounds). In vitro gastrointestinal digestion was performed by INFOGEST® protocol. Fruit pulp showed the greater content of total betalains (444.77 mg/100 g f.w.), and jam only showed very low amounts of two betanin degradation compounds, Cyclo-dopa-5-O-β-glucoside (and its isomer) (0.63 mg/100 f.w.), and two Phyllocactin derivatives (1.04 mg/100 g f.w.). Meanwhile, fruit peel was the richer tissue in total phenolic acids (273.42 mg/100 g f.w.), mainly in piscidic acid content and total flavonoids (7.39 mg/100 g f.w.), isorhamnetin glucoxyl-rhamnosyl-pentoside (IG2) being the most abundant of these compounds. The stability of betalains and phenolic compounds during in vitro gastrointestinal digestion is reported in the present study. In Opuntia stricta var. Dillenii pulp (the edible fraction of the fresh fruit), the betanin bioaccessibility was only 22.9%, and the flavonoid bioaccessibility ranged from 53.7% to 30.6%, depending on the compound. In non-edible samples, such as peel sample (PE), the betanin bioaccessibility was 42.5% and the greater bioaccessibility in flavonoids was observed for quercetin glycoside (QG1) 53.7%, the fruit peel being the most interesting material to obtain antioxidant extracts, attending to its composition on antioxidant compounds and their bioaccessibilities.

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Obtaining Bioactive Compounds from the Coffee Husk (Coffea arabica L.) Using Different Extraction Methods

Molecules ◽

10.3390/molecules26010046 ◽

2020 ◽

Vol 26 (1) ◽

pp. 46

Author(s):

Mariana de Oliveira Silva ◽

John Nonvignon Bossis Honfoga ◽

Lorena Lucena de Medeiros ◽

Marta Suely Madruga ◽

Taliana Kênia Alencar Bezerra

Keyword(s):

Phenolic Compounds ◽

Bioactive Compounds ◽

Extraction Methods ◽

Water Bath ◽

Raw Material ◽

Total Phenolic ◽

Total Phenolic Compounds ◽

Ethanol Mixture ◽

Coffee Husk ◽

Coffea Arabica L

Coffee husks (Coffea arabica L.) are characterized by exhibiting secondary metabolites such as phenolic compounds, which can be used as raw material for obtaining bioactive compounds of interest in food. The objective of this study is to evaluate different methods for obtaining the raw material and extracting solutions of bioactive compounds from coffee husks. Water bath and ultrasound-assisted extraction methods were used, using water (100%) or ethanol (100%) or a mixture of both (1:1) as extracting solutions and the form of the raw material was in natura and dehydrated. The extracts were evaluated by their antioxidant potential using DPPH radicals, ABTS, and iron reduction (ferric reducing antioxidant power (FRAP)), and later total phenolic compounds, total flavonoids, and condensed tannins were quantified the phenolic majority compounds were identified. It was verified that the mixture of water and ethanol (1:1) showed better extraction capacity of the compounds with antioxidant activity and that both conventional (water bath) or unconventional (ultrasound) methods showed satisfactory results. Finally, a satisfactory amount of bioactive compounds was observed in evaluating the chemical composition (total phenolic compounds, total flavonoids, condensed tannins, as well as the analysis of the phenolic profile) of these extracts. Corroborating with the results of the antioxidant activities, the best extracting solution was generally the water and ethanol mixture (1:1) using a dehydrated husk and water bath as the best method, presenting higher levels of the bioactive compounds in question, with an emphasis on chlorogenic acid. Thus, it can be concluded that the use of coffee husk as raw material to obtain extracts of bioactive compounds is promising. Last, the conventional method (water bath) and the water and ethanol mixture (1:1) stood out among the methods and extracting solutions used for the dehydrated coffee husk.

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