Este estudio fue financiado por la Universidad Mae Fah Luang. Los autores desean agradecer al Instituto de Té y Café de la Universidad Mae Fah Luang por facilitar la conexión entre los investigadores y los agricultores locales en relación con la adquisición de muestras de piel de plata de café.

Los detalles de los reactivos y el equipo utilizado en este estudio se enumeran en la Tabla de Materiales.
1. Preparación experimental
<ol><li>Preparación de muestras de plantas<ol><li>Recoger el café fresco (Coffea arabica) y secarlo a 60 °C en una bandeja secadora durante 72 h11.</li>
		<li>Muela el café seco Silverskin (CS) hasta convertirlo en un polvo fino con un molinillo y guárdalo a temperatura ambiente para su ...

Extracción asistida por microondas a base de polioles para rendimientos fenólicos y antioxidantes

<ol>
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Los autores no tienen nada que revelar.

Varios factores juegan un papel crucial en la implementación exitosa de MAE, como el contenido fitoquímico de los componentes de la planta, la duración de la extracción, la temperatura, la potencia de microondas, la relación sólido-líquido y la concentración de solvente13. Por lo general, las plantas exhiben diferentes perfiles de fitoquímicos; De ahí que la selección de plantas naturales ricas en antioxidantes y compuestos fenólicos sea fundamental23. Además, ...

Hoy en día, existe una tendencia mundial hacia la concienciación medioambiental en la industria de la belleza, lo que ha llevado a los fabricantes a centrarse en la tecnología verde para la extracción de componentes vegetalesutilizando alternativas sostenibles. Por lo general, los solventes tradicionales como el etanol, el metanol y el hexano se utilizan para extraer componentes fenólicos de las plantas y antioxidantes naturales2. Sin embargo, la presencia de residuos de disolventes en los extractos de plantas supone un riesgo potencial para la salud humana, ya que provoca irritación de la piel y los ojos3, especialmente en lo que respecta a su aplicación prevista en los cosméticos. En consecuencia, es un desafío eliminar estos residuos de solventes de los extractos, un proceso que exige una inversión considerable en tiempo, energía y recursos humanos4. Recientemente, el agua sobrecalentada, los líquidos iónicos, los disolventes eutécticos profundos y los disolventes bioderivados han surgido como enfoques prometedores para la extracción con disolventes verdes5. Sin embargo, su uso sigue estando limitado por la separación de productos en procesos acuosos. Para hacer frente a estos desafíos, el desarrollo de extractos listos para usar surge como una solución viable6.
Los polioles se utilizan a menudo en formulaciones cosméticas como humectantes debido a su buena polaridad y capacidad para retener la humedad del medio ambiente7. Además, se pueden utilizar polioles como la glicerina, el propilenglicol, el butilenglicol, el metilpropanodiol, el isopentildiol, el pentilenglicol, el 1,2-hexanodiol y el hexilenglicol para las extracciones de plantas. Se consideran disolventes no tóxicos, biodegradables, respetuosos con el medio ambiente, no reactivos y seguros para su uso en la extracción de plantas8. Además, los polioles pueden soportar el calor generado durante la extracción asistida por microondas (MAE) debido a sus elevados puntos de ebullición y polaridad9. La Administración de Alimentos y Medicamentos de los Estados Unidos (FDA, por sus siglas en inglés) reconoce generalmente a estos polioles como productos químicos seguros (GRAS). A diferencia de los disolventes convencionales, como el etanol o el metanol, que pueden requerir una eliminación rigurosa del extracto debido a sus efectos potencialmente nocivos, los polioles ofrecen la ventaja de minimizar la energía, el tiempo y los costes asociados alos procesos de eliminación de disolventes. Esto no solo agiliza el proceso de extracción, sino que también mejora la eficiencia general y la sostenibilidad del método de extracción. Investigaciones anteriores han empleado polioles como el propilenglicol y el butilenglicol como disolventes en la extracción de compuestos bioactivos de flores de Camellia sinensis 10 y pulpa de café11, lo que revela un potencial significativo por su papel como disolventes alternativos sostenibles en el proceso de extracción de plantas. Por lo tanto, el desarrollo y la optimización continuos de un sistema de solventes polioles y agua tienen el potencial de avances significativos en química verde y prácticas industriales sostenibles.
Generalmente, los compuestos bioactivos que se encuentran en las plantas se sintetizan como metabolitos secundarios. Estos compuestos se pueden clasificar en tres grupos principales: terpenos y terpenoides, alcaloides y compuestos fenólicos12. Se utilizan varios métodos de extracción en diferentes condiciones para aislar compuestos bioactivos específicos de las plantas. Los compuestos bioactivos de los materiales vegetales pueden extraerse utilizando técnicas convencionales o no convencionales. Los métodos tradicionales incluyen la maceración, la extracción por reflujo y la hidrodestilación, mientras que los métodos no convencionales consisten en la extracción asistida por ultrasonidos, la extracción asistida por enzimas, la extracción asistida por microondas (MAE), la extracción asistida por campo eléctrico pulsado, la extracción con fluidos supercríticos y la extracción con líquidos presurizados13. Estos métodos no convencionales están diseñados para mejorar la seguridad mediante la utilización de solventes y auxiliares más seguros, mejorando la eficiencia energética, evitando la degradación de los componentes bioactivos y reduciendo la contaminación ambiental14.
Además, MAE es una de las sofisticadas tecnologías verdes para extraer compuestos bioactivos de las plantas. Los procedimientos de extracción convencionales requieren cantidades significativas de tiempo, energía y altas temperaturas, que con el tiempo pueden degradar los compuestos bioactivos sensibles al calor13. A diferencia de las extracciones térmicas convencionales, MAE facilita la extracción de compuestos bioactivos al generar un calentamiento localizado dentro de la muestra, alterando las estructuras celulares y mejorando la transferencia de masa, aumentando así la eficiencia de la extracción de compuestos. El calor se transfiere desde el interior de las células vegetales mediante microondas, que operan sobre las moléculas de agua dentro de los componentes de la planta13. Además, MAE ha avanzado para mejorar la extracción y separación de compuestos activos, aumentando el rendimiento del producto, mejorando la eficiencia de la extracción, requiriendo menos productos químicos y ahorrando tiempo y energía, al tiempo que evita la destrucción de compuestos bioactivos15.
Esta investigación se centra en la extracción de compuestos fenólicos vegetales y antioxidantes naturales mediante extracción asistida por microondas (MAE) utilizando diferentes tipos de polioles como disolventes. Se determina el contenido fenólico total (TPC), el contenido total de flavonoides (TFC) y las actividades antioxidantes (DPPH, ABTS y FRAP) de los extractos de MAE a base de polioles. Además, el MAE a base de polioles se compara con el MAE utilizando disolventes convencionales como el agua y el etanol. Se espera que esta investigación contribuya al desarrollo de una tecnología de extracción ambientalmente sostenible para componentes naturales, promoviendo la sostenibilidad al reducir la dependencia de productos químicos peligrosos, acortando los tiempos de procesamiento y minimizando el consumo de energía en la producción de materias primas para aplicaciones potenciales dentro de la industria cosmética.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1,2-Hexanediol</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>2,2 -Azino-bis 3 ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS)</td>
			<td>Sigma</td>
			<td>A1888</td>
			<td></td>
		</tr>
		<tr>
			<td>2,2-Diphenyl-1-picrylhydrazyl (DPPH)</td>
			<td>Sigma</td>
			<td>D9132</td>
			<td></td>
		</tr>
		<tr>
			<td>2,4,6-Tri(2-pyridyl)-s-triazine (TPTZ)</td>
			<td>Sigma</td>
			<td>93285</td>
			<td></td>
		</tr>
		<tr>
			<td>2-Digital balance</td>
			<td>Ohaus</td>
			<td></td>
			<td>Pioneer</td>
		</tr>
		<tr>
			<td>4-Digital balance</td>
			<td>Denver</td>
			<td>SI-234</td>
			<td></td>
		</tr>
		<tr>
			<td>6-hydroxy-2,5,7,8 tetramethylchroman -2-carboxylic acid (Trolox)</td>
			<td>Sigma</td>
			<td>238813</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well plate</td>
			<td>SPL Life Science</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Absolute ethanol</td>
			<td>RCI Labscan</td>
			<td>64175</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic acid</td>
			<td>RCI Labscan</td>
			<td>64197</td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum chloride</td>
			<td>Loba Chemie</td>
			<td>898</td>
			<td></td>
		</tr>
		<tr>
			<td>Automatic pipette</td>
			<td>Labnet</td>
			<td></td>
			<td>Biopett</td>
		</tr>
		<tr>
			<td>Butylene glycol</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethos X advanced microwave extraction</td>
			<td>Milestone Srl, Sorisole, Italy</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ferrous sulfate</td>
			<td>Ajex Finechem</td>
			<td>3850</td>
			<td></td>
		</tr>
		<tr>
			<td>Folin-Ciocalteu&#39;s reagent</td>
			<td>Loba Chemie</td>
			<td>3870</td>
			<td></td>
		</tr>
		<tr>
			<td>Freezer SF</td>
			<td>Sanyo</td>
			<td>C697(GYN)</td>
			<td></td>
		</tr>
		<tr>
			<td>Gallic acid</td>
			<td>Sigma</td>
			<td>398225</td>
			<td></td>
		</tr>
		<tr>
			<td>Grinder</td>
			<td>Ou Hardware Products Co.,Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hexylene glycol</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric acid (37%)</td>
			<td>RCI Labscan</td>
			<td>AR1107</td>
			<td></td>
		</tr>
		<tr>
			<td>Iron (III) chloride</td>
			<td>Loba Chemie</td>
			<td>3820</td>
			<td></td>
		</tr>
		<tr>
			<td>Isopentyldiol</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>RCI Labscan</td>
			<td>67561</td>
			<td></td>
		</tr>
		<tr>
			<td>Methylpropanediol&#160;</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pentylene glycol</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium persulfate</td>
			<td>Loba Chemie</td>
			<td>5420</td>
			<td></td>
		</tr>
		<tr>
			<td>Propylene glycol</td>
			<td>Chanjao Longevity Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Quercetin</td>
			<td>Sigma</td>
			<td>Q4951</td>
			<td></td>
		</tr>
		<tr>
			<td>Refrigerated centrifuge</td>
			<td>Hettich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium acetate</td>
			<td>Loba Chemie</td>
			<td>5758</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium carbonate</td>
			<td>Loba Chemie</td>
			<td>5810</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>RCI Labscan</td>
			<td>AR1325</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium nitrite</td>
			<td>Loba Chemie</td>
			<td>5954</td>
			<td></td>
		</tr>
		<tr>
			<td>SPECTROstar Nano microplate reader</td>
			<td>BMG- LABTECH</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>SPSS software</td>
			<td>IBM SPSS Statistics 20</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tray dryer</td>
			<td>France Etuves</td>
			<td>XUE343</td>
			<td></td>
		</tr>
	</tbody>
</table>

microwave-assisted extraction of phenolic compounds and antioxidants for cosmetic applications using polyol-based technology

La utilización de polioles como disolventes verdes para la extracción de compuestos bioactivos de materiales vegetales ha ganado atención debido a su seguridad y comportamiento inerte con los productos químicos bioactivos de las plantas. Este estudio explora la extracción sostenible de compuestos fenólicos y antioxidantes naturales de la piel de plata del café utilizando el método de extracción asistida por microondas (MAE) con solventes a base de poliol: glicerina, propilenglicol (PG), butilenglicol (BG), metilpropanodiol (MPD), isopentildiol (IPD), pentilenglicol, 1,2-hexanodiol y hexilenglicol (HG). Se realizó un análisis comparativo de extracciones de solventes convencionales y no convencionales, centrándose en su impacto sobre los compuestos bioactivos de MAE, abarcando parámetros como el contenido fenólico total (TPC), el contenido total de flavonoides (TFC) y las actividades antioxidantes como el ensayo de barrido de radicales 1,1-difenil-2-picrilhidrazilo (DPPH), el ensayo de barrido de radicales 2,2'-azino-bis(-3-etilbenzotiazolina-6-sulfónico) (ABTS) y el ensayo de poder antioxidante reductor férrico (FRAP). Los valores más altos se observaron para TPC con extracción acuosa de 1,2-hexanodiol (52,0 ± muestra de 3,0 mg de GAE/g), TFC con extracción acuosa de 1,2-hexanodiol (muestra de 20,0 ± 1,7 mg de QE/g), DPPH con extracción acuosa de HG (muestra de 13,6 ± 0,3 mg de TE/g), ABTS con extracción acuosa de pentilenglicol (muestra de 8,2 ± 0,1 mg TE/g) y FRAP con extracción acuosa de HG (muestra de 21,1 ± 1,3 mg de Fe (II) E/g). Esta investigación tiene como objetivo avanzar en la tecnología de extracción ecológica a través de componentes naturales de plantas, promoviendo la sostenibilidad al minimizar el uso de productos químicos peligrosos y reducir el consumo de tiempo y energía, con aplicaciones potenciales en cosméticos.

Nowadays, there is a global trend towards environmental awareness in the beauty industry, leading manufacturers to focus on green technology for extracting plant components using sustainable alternatives1. Typically, traditional solvents such as ethanol, methanol, and hexane are used to extract plant phenolic components and natural antioxidants2. Nevertheless, the presence of solvent residues within plant extracts poses a potential risk to human health, inducing skin and eye irritation3, particularly concerning their intended application in cosmetics. Consequently, it is challenging to eliminate such solvent residues from the extracts, a process that demands considerable investment in time, energy, and human resources4. Recently, superheated water, ionic liquids, deep eutectic solvents, and bio-derived solvents have emerged as promising approaches for green solvent extraction5. However, their use is still limited by product separation in aqueous-based processes. To address these challenges, the development of ready-to-use extracts emerges as a viable solution6.
Polyols are often used in cosmetic formulations as humectants because of their good polarity and ability to retain moisture from the environment7. In addition, polyols such as glycerin, propylene glycol, butylene glycol, methylpropanediol, isopentyldiol, pentylene glycol, 1,2-hexanediol, and hexylene glycol can be utilized for plant extractions. They are considered non-toxic, biodegradable, environmentally friendly, non-reactive, and safe solvents for use in plant extraction8. Additionally, polyols can withstand the heat generated during microwave-assisted extraction (MAE) due to their elevated boiling points and polarity9. These polyols are generally recognized as safe (GRAS) chemicals by the United States Food and Drug Administration (FDA). Unlike conventional solvents such as ethanol or methanol, which may require rigorous removal from the extract due to their potentially harmful effects, polyols offer the advantage of minimizing the energy, time, and costs associated with solvent removal processes10. This not only streamlines the extraction process but also enhances the overall efficiency and sustainability of the extraction method. Previous investigations have employed polyols such as propylene glycol and butylene glycol as solvents in the extraction of bioactive compounds from Camellia sinensis flowers10 and coffee pulp11, revealing significant potential for their role as sustainable alternative solvents in the plant extraction process. Thus, the continued development and optimization of a polyols-water solvent system holds the potential for significant advancements in green chemistry and sustainable industrial practices.
Generally, bioactive compounds found in plants are synthesized as secondary metabolites. These compounds can be categorized into three primary groups: terpenes and terpenoids, alkaloids, and phenolic compounds12. Various extraction methods are utilized under different conditions to isolate specific bioactive compounds from plants. Bioactive compounds from plant materials can be extracted using either conventional or non-conventional techniques. Traditional methods include maceration, reflux extraction, and hydro-distillation, while non-conventional methods consist of ultrasound-assisted extraction, enzyme-assisted extraction, microwave-assisted extraction (MAE), pulsed electric field-assisted extraction, supercritical fluid extraction, and pressurized liquid extraction13. These non-conventional methods are designed to enhance safety by utilizing safer solvents and auxiliaries, improving energy efficiency, preventing degradation of the bioactive components, and reducing environmental pollution14.
Furthermore, MAE is among the sophisticated green technologies for extracting bioactive compounds from plants. Conventional extraction procedures require significant amounts of time, energy, and high temperatures, which over time might degrade heat-sensitive bioactive compounds13. In contrast to conventional thermal extractions, MAE facilitates the extraction of bioactive compounds by generating localized heating within the sample, disrupting cell structures, and enhancing mass transfer, thereby increasing the efficiency of compound extraction. Heat is transferred from inside the plant cells by microwaves, which operate on the water molecules within the plant components13. Moreover, MAE has advanced to improve the extraction and separation of active compounds, increasing product yield, enhancing extraction efficiency, requiring fewer chemicals, and saving time and energy while preventing the destruction of bioactive compounds15.
This research focuses on the extraction of plant phenolic compounds and natural antioxidants through microwave-assisted extraction (MAE) using different types of polyols as solvents. The total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (DPPH, ABTS, and FRAP) of polyol-based MAE extracts are determined. Additionally, polyol-based MAE is compared with MAE using conventional solvents such as water and ethanol. This research is expected to contribute to the development of environmentally sustainable extraction technology for natural components, promoting sustainability by reducing reliance on hazardous chemicals, shortening processing times, and minimizing energy consumption in raw material production for potential applications within the cosmetics industry.

Autor destacado: Extracción ecológica de compuestos bioactivos mediante técnicas asistidas por microondas basadas en polioles

Extracción asistida por microondas de compuestos fenólicos y antioxidantes para aplicaciones cosméticas mediante tecnología basada en polioles

This research talks about finding eco-friendly ways to extract plant bioactive compounds. We are testing how well microwave assisted extraction with the polyol-based solvents work for extracting plants bioactive substances, especially phenol compounds. Additionally, exploring this method could lead to more efficient and effective extraction technique for the cosmetic industries.Today's cosmetic research is also about using green technology and green chemistry. Nonconventional extraction techniques such as microwave-assist extraction, and extraction, have been interestingly employed to extract plants bioactive compounds. However, organic solvents are still commonly utilized for bioactive component extraction.Using polyol-based solvent for microwave assistant extraction turned out to be more effective than using traditional solvent like water and ethanol. The results show that the plant extract obtained with polyol have higher level of phenolic content for the flavanoid content and antioxidant activity. Compared to those extracted with conventional solvent.Our procedure stands out because it is beneficial, environmentally friendly and safe for human health. It is also more energy efficient and cost effective than traditional processes, making it an excellent alternative for sustainable and simple production. Our finding show that polyols combined with unconventional extraction methods can extract phenol compounds.The next challenge is whether this extraction method can be used to extract other plant, secondary metabolized, and if it can be commercialized to extract bioactive compounds for cosmetic purposes.

Efecto de los disolventes polioles y los disolventes convencionales sobre el contenido fenólico total, el contenido total de flavonoides, los ensayos antioxidantes DPPH, FRAP y ABTS La polaridad del disolvente debe ser compatible con la de las moléculas activas objetivo para mejorar la eficiencia de extracción de las sustancias bioactivas de las plantas22. Se realizaron experimentos utilizando varios solventes (agua, etanol, glicerina, propilenglicol, butilenglicol, metilpro...

Este protocolo detalla la utilización de un método de extracción asistido por microondas a base de polioles para extraer compuestos fenólicos y antioxidantes naturales, lo que representa un enfoque práctico y ambientalmente sostenible para el desarrollo de extractos listos para usar.

The utilization of polyols as green solvents for extracting bioactive compounds from plant materials has gained attention due to their safety and inert ...

microwave-assisted-extraction-phenolic-compounds-antioxidants-for

Research

JoVE Journal

Chemistry

Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology

504 Views.  Mae Fah Laung University. This research talks about finding eco-friendly ways to extract plant bioactive compounds. We are testing how well microwave assisted extraction with the polyol-based solvents work for extracting plants bioactive substances, especially phenol compounds. Additionally, exploring this method could lead to more efficient and effective extraction technique for the cosmetic industries.Today's cosmetic research is also about using green technology and green chemistry. Nonconventional extractio...