This research was supported by CARS-tea and the Innovation Project for the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-TRI).

1. Production of matcha-embedded suspension
<ol>
	<li>Place 4 g of carboxymethyl chitosan (see Table of Materials) in 100 mL of distilled water to prepare a 0.04 g/mL of carboxymethyl chitosan stock solution. To dissolve carboxymethyl chitosan heat to 60 &#176;C on constant temperature heating magnetic stirrer.</li>
	<li>Dissolve 4 g of whey protein (see Table of Materials) in 50 mL of distilled water to prepare a 0.08 g/mL of whey protein stock solution.</li>
	<li>After the solutions cool, store them in a freezer and refrigerate them overnight to fully saturate the polymer molecule.</li>
	<li>Place 8 g of matcha and 4 g NaCl (see Table of Materials) in a beaker and add 50 mL of sterile boiled water to prepare matcha slurry. Assist the dissolution process using a glass stirring rod. Sterile water is deionized water that has been boiled in a pot for 15 min.</li>
	<li>Mix matcha slurry with 50 mL of carboxymethyl chitosan solution and blend with a magnetic stirring apparatus at 300 rpm at room temperature.</li>
	<li>Drip 25 mL of whey protein into the mixture and stir at 300 rpm for 30 min to create an embedded suspension. (see Figure 1). The suspension should be prepared concurrently with the noodle production and stored at a temperature of 4 &#176;C on the same day. 
	NOTE: The pH of the matcha-embedded suspension solution was left unadjusted, thus solely influenced by the matcha or wall material.</li>
</ol>
2. Microwave treatment of wheat flour
<ol>
	<li>Distribute 300 g of wheat flour in a round plastic container. Cover the container with plastic wrap and place it in the microwave oven at 700 W for 60 s. Afterward, keep the container with flour outside until it feels cool.</li>
</ol>
3. Production of matcha noodles
<ol>
	<li>Dough mixing: Pour 125 mL of pre-formed matcha-embedded suspension and 15 mL of water into 300 g of microwave-treated wheat flour slowly. Gently pull the flour into the center, bit by bit, until the embedded suspension is incorporated.
	<ol>
		<li>For non-microwave-treated wheat flour, use 125 mL of water instead of matcha-embedded suspension to prepare noodles, which are labeled as blank noodles (control). Add 125 mL of water and 8 g of matcha to non-microwave-treated wheat flour to prepare noodles and designate these as matcha noodles (M-noodles).</li>
	</ol>
	</li>
	<li>Kneading the dough: Knead the noodle dough with a dough mixer for 7 min. The dough should be smooth and pliable, not wet or sticky when done.</li>
	<li>Resting: Return the ball of dough to its mixing bowl and cover it with a damp tea towel. Let it rest for 30 min at room temperature.</li>
	<li>Prepare noodles as described below.
	<ol>
		<li>Divide the dough into 4 equal pieces, then rewrap 3 and set aside. Lightly flour the unwrapped piece, lifting it occasionally to ensure that it does not stick.</li>
		<li>Adjust the press roller spacing of the dough press to 3.5 mm. Place the dough on a dough press to sheet, and then compound. Press the dough sheet repeatedly until it reaches a smooth and pliable consistency.</li>
		<li>Thin the dough sheet to 1 mm. Starting from 3.5 mm, adjust the press roller spacing to 2 mm and then 1 mm. Press the sheet 3x in each roller spacing.</li>
		<li>Cover loosely with clingfilm, and then repeat steps 3.4.1-3.4.3 with the remaining dough. 
		NOTE: In order to ensure that the pressing process of each batch of samples is consistent, the press roll spacing is adjusted once, and the next spacing is adjusted after each sample is passed.</li>
		<li>Slit the noodle strands into 22 cm long, 1 mm thick, and 3.0 mm wide samples (see Figure 2). Dust about 3.75 g semolina to make sure noodles do not stick together.</li>
	</ol>
	</li>
</ol>
4. Sensory evaluation and physical property analysis
<ol>
	<li>Sensory evaluation
	<ol>
		<li>Place 30 g of noodles in 600 mL of boiling water and cook for 5 min. Immerse cooked noodles in cold water immediately, before testing.</li>
		<li>Perform sensory evaluation of noodle samples using quantitative descriptive analysis (QDA) as outlined in Li et al.12. Ensure that the sensory characteristics of the samples are evaluated by 12 trained panelists using a nine-point hedonic scale with 9 denoting like extremely and 1 denoting dislike extremely.</li>
	</ol>
	</li>
	<li>Color measurement
	<ol>
		<li>Cut cooked as well as fresh samples into pieces of about 10 cm and place them under the instrumental aperture of the colorimeter.</li>
		<li>Press the instrumental button to measure the color of the fresh noodles and repeat the test 6x for each sample.</li>
	</ol>
	</li>
	<li>Texture analyzer
	<ol>
		<li>Determine the texture property of cooked as well as fresh noodles using a texture analyzer and calculate based on texture profile analysis (TPA).</li>
		<li>Place five strands of noodles on the test bench and repeat the test 6x for each sample.</li>
	</ol>
	</li>
</ol>
5. Data analysis
<ol>
	<li>Analyze the data by variance analysis (ANOVA) and consider the difference significant when p &#60; 0.05.</li>
</ol>

Advancements in Production of Color-Stable Matcha Fresh Noodles

<ol>
	<li>Yu, K., Zhou, H. M., Zhu, K. X., Guo, X. N., Peng, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increasing+the+physicochemical+stability+of+stored+green+tea+noodles:+Analysis+of+the+quality+and+chemical+components.">Increasing the physicochemical stability of stored green tea noodles: Analysis of the quality and chemical components.</a> Food Chem. 278, 333-341 (2019).</li><li>Nguyen, T. T. L., Gilbert, R. G., Gidley, M. J., Fox, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+contribution+of+&#946;-glucan+and+starch+fine+structure+to+texture+of+oat-fortified+wheat+noodles.">The contribution of &#946;-glucan and starch fine structure to texture of oat-fortified wheat noodles.</a> Food Chem. 372, 131291 (2022).</li><li>Baskaran, D., Muthupandian, K., Gnanalakshmi, K. S., Pugazenthi, T. R., Ayyadurai, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+properties+of+noodles+enriched+with+whey+protein+concentrate+(wpc)+and+skim+milk+powder+(smp).">Physical properties of noodles enriched with whey protein concentrate (wpc) and skim milk powder (smp).</a> J Stored Prod Postharvest Res. 2 (6), 127-130 (2011).</li><li>Chen, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+starch+noodles+made+from+three+typical+Chinese+sweet-potato+starches.">Evaluation of starch noodles made from three typical Chinese sweet-potato starches.</a> J Food Sci. 67 (9), 3342-3347 (2002).</li><li>Reshmi, S. K., Sudha, M. L., Shashirekha, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noodles+fortified+with+citrus+maxima+(pomelo)+fruit+segments+suiting+the+diabetic+population.">Noodles fortified with citrus maxima (pomelo) fruit segments suiting the diabetic population.</a> Bioactive Carb Dietary Fibre. 22, 100213 (2020).</li><li>Phuah, Y. Q., Chang, S. K., Ng, W. J., Lam, M. Q., Ee, K. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+on+matcha:+Chemical+composition,+health+benefits,+with+insights+on+its+quality+control+by+applying+chemometrics+and+multi-omics.">A review on matcha: Chemical composition, health benefits, with insights on its quality control by applying chemometrics and multi-omics.</a> Food Res Int. 170, 113007 (2023).</li><li>Hou, G. 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N., Indrani, D., Anandharamakrishnan, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microencapsulation+of+green+tea+polyphenols+and+its+effect+on+incorporated+bread+quality.">Microencapsulation of green tea polyphenols and its effect on incorporated bread quality.</a> LWT - Food Sci Tech. 64, 289-296 (2015).</li><li>Li, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+superfine+green+tea+powder+on+the+thermodynamic,+rheological+and+fresh+noodle+making+properties+of+wheat+flour.">Effect of superfine green tea powder on the thermodynamic, rheological and fresh noodle making properties of wheat flour.</a> LWT - Food Sci Techn. 46 (1), 23-28 (2012).</li><li>Kun Yu, K., Zhou, H. M., Zhu, K. X., Guo, X. N., Peng, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physicochemical+changes+in+the+discoloration+of+dried+green+tea+noodles+caused+by+polyphenol+oxidase+from+wheat+flour.">Physicochemical changes in the discoloration of dried green tea noodles caused by polyphenol oxidase from wheat flour.</a> LWT - Food Sci Tech. 130, 109614 (2020).</li><li>Doxastakis, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technological+properties+and+non-enzymatic+browning+of+white+lupin+protein+enriched+spaghetti.">Technological properties and non-enzymatic browning of white lupin protein enriched spaghetti.</a> Food Chemistry. 101 (1), 57-64 (2007).</li><li>Xu, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+heat+treatment+on+polyphenol+oxidase+activity+and+textural+properties+of+jackfruit+bulb.">Effects of heat treatment on polyphenol oxidase activity and textural properties of jackfruit bulb.</a> J Food Process Preserv. 40 (5), 943-949 (2016).</li><li>Yadav, D. 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The authors have nothing to disclose.

Compared to instant noodles, fine-dried noodles, and other similar products, fresh noodles have a greater capacity to preserve their original taste and flavor, making them highly promising in the market. A previous study has shown that green tea could enhance the overall quality of fresh noodles to a certain degree16. Therefore, incorporating tea into the flour product system of fresh noodles aims to prioritize both high quality and health benefits, in line with the contemporary trend of promoting...

Noodles are a staple of traditional grain-based cuisine in China, with approximately 40% of the wheat production in Asian countries being utilized for noodle processing1. Nevertheless, the basic nutritional component of wheat flour is insufficient to satisfy the increasing nutritional needs of consumers. Therefore, several investigators have opted to replace a portion of the wheat flour in noodles with alternative natural ingredients, such as oat bran2, milk protein3, sweet potato4, and citrus maxima5, in order to enhance the nutritional and functional qualities of the noodles. Matcha is an abundant bioactive compound possessing antioxidant and anti-inflammatory properties, which have the potential to mitigate the risk of cardiovascular disease and prevent chronic illnesses6. Consequently, there has been a burgeoning interest in investigating the integration of matcha into traditional culinary fare, including Chinese steamed bread, rice cake, and particularly fresh noodles.
However, fresh noodles are prone to time-dependent darkening, leading to unfavorable changes in the visual appearance of the product, which poses a significant challenge to the storage of fresh noodles7. It is widely agreed that the discoloration observed during the storage of fresh noodles is mainly caused by the presence of polyphenol oxidase (PPO)7,8. Additionally, it was indicated that the soluble protein fraction is involved in the process of non-polyphenol oxidase (non-PPO) darkening9. Extensive efforts have been devoted in recent years to mitigate the darkening of PPO during storage. Previous studies have suggested that acid inhibitors and heat treatment applied to raw noodles could effectively achieve this objective by denaturing proteins and consequently inhibiting enzyme activity10,11. Chlorophyll is susceptible to changes in pH, temperature, and heat, and the vibrant green hue of green tea noodles is primarily attributed to chlorophyll10. It is evident that there are limitations in effectively controlling the color of green tea noodles through the direct addition of acid inhibitors and heat treatment.
In addition to the thermal processing of wheat flour, the preservation of chlorophyll in matcha noodles is a critical factor to consider. Several methods have been proposed to prolong the storage time of chlorophyll and preserve its pigment, including the use of alkalinizing agents, copper complexations, and low-temperature storage12. Unfortunately, the majority of processes necessitate a pH level close to nature in order to reduce the occurrence of unfavorable chemical reactions. The stability concern may be potentially mitigated by the copper complex of chlorophyll derivatives, which exhibit a green color reminiscent of natural chlorophyll. However, individuals exhibit a preference for natural chlorophyll over artificial colors. Microencapsulation techniques have emerged as a viable solution to the challenge of improving bioactive compounds&#39; stability by providing barriers against environmental conditions such as oxygen, pH, ionic strength, and temperature13,14,15. Until now, tea extract, catechins, and chlorophyll have been continuously studied for their stability and controlled release properties when embedded in different wall materials14. However, the incorporation of microcapsules into noodles has not yet been proposed15.
In this study, we described a method that embeds matcha with whey protein and carboxymethyl chitosan and microwave-treating wheat flour to obtain color-stable matcha fresh noodles. The addition of microencapsulated bioactive compounds to food facilitates the creation of novel functional food products while preserving the inherent qualitative attributes. We present the results obtained using this processing protocol to investigate alterations in color values of matcha noodles following storage. The specific objective of the study was to determine the optimal approach for preparing matcha noodles that demonstrate both exceptional color and flavor.

<table><tbody><tr><td>Carboxymethyl chitosan</td><td>Mackin</td><td></td><td></td></tr><tr><td>Colorimeter</td><td>3nh</td><td>NH-300+</td><td></td></tr><tr><td>Dough mixer</td><td>ACA</td><td>AM-CG108</td><td></td></tr><tr><td>Freezer</td><td>Haier</td><td>BCD-252KS</td><td></td></tr><tr><td>Heating magnetic stirrer</td><td>Yuhua</td><td>DF-101S</td><td></td></tr><tr><td>Magnetic stirrer</td><td>Keezo</td><td>KMS-521D</td><td></td></tr><tr><td>Matcha</td><td>Jinhua Feicui</td><td></td><td></td></tr><tr><td>Microwave</td><td>Panasonic</td><td>NN-GF351X</td><td></td></tr><tr><td>NaCl</td><td>China National Salt Industry Corporation</td><td></td><td></td></tr><tr><td>Noodle maker</td><td>Tianxi</td><td>JCD-10</td><td></td></tr><tr><td>Texture analyzer</td><td>Lotun Science</td><td>TA-XT plus</td><td></td></tr><tr><td>Wheat flour</td><td>Queen</td><td></td><td></td></tr><tr><td>Whey protein</td><td>Yuanye</td><td></td><td></td></tr></tbody></table>

preparation of matcha fresh noodles with stable color using embedding method and microwave treatment

Matcha, as a healthy food additive, has been widely utilized in traditional foods such as noodles, cookies, and bread. However, there are several challenges that must be addressed in the quality of matcha-incorporated foods, with the most significant being the prevention of matcha discoloration. In this study, we introduce a novel approach involving the incorporation of matcha with whey protein (0.08&#160;g/mL) and carboxymethyl chitosan (0.04&#160;g/mL), accompanied by microwave treatment at 700 W for 60 s of wheat flour to produce color-stable matcha fresh noodles. All steps involved in the production process of matcha fresh noodles are presented in the article, including matcha embedding treatment, microwave treatment of wheat flour, kneading the dough, leaving to prove, dividing the dough, rolling out the dough and slicing the sheets by noodle press. The findings revealed a 72.13% reduction in discoloration of fresh matcha noodles following embedding and microwave treatment, compared to untreated fresh matcha noodles. Moreover, the combined process did not have any detrimental impact on the sensory attributes of matcha noodles, including their aroma and taste. Therefore, the novel method proposed in this study holds significant potential for enhancing the color stability of fresh matcha noodles during preparation.

This protocol allowed for the sensory and physical property analysis of processed matcha-incorporated foods and noodles, beginning with matcha treatment and continuing through the intermediate stages of processing to the final product. This protocol was coupled with embedding and microwave to produce matcha noodles (Figure 3). The fresh noodles with unencapsulated matcha, with embedded matcha and microwave treatment, and without any matcha were marked as M-Noodles, ME-Noodle...

Author Spotlight: Enhancing Flavor Interaction of Food Using Matcha Microcapsules 

The protocol describes a method for embedding matcha with whey protein and carboxymethyl chitosan and microwave-treating wheat flour to obtain color-stable matcha fresh noodles.

Preparation of Matcha Fresh Noodles with Stable Color using Embedding Method and Microwave Treatment

Matcha, as a healthy food additive, has been widely utilized in traditional foods such as noodles, cookies, and bread. However, there are several ...

preparation-matcha-fresh-noodles-with-stable-color-using-embedding

Research

JoVE Journal

Chemistry

559 Views.  Tea Research Institute Chinese Academy of Agricultural Sciences. The protocol describes a method for embedding matcha with whey protein and carboxymethyl chitosan and microwave-treating wheat flour to obtain color-stable matcha fresh noodles. 

Video: Author Spotlight: Enhancing Flavor Interaction of Food Using Matcha Microcapsules 

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan &#948; solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials&#39; morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by St&#246;ber&#39;s methods, which have smooth surfaces.

Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle ...

Manufacturing of Three-dimensionally Microstructured Nanocomposites through Microfluidic Infiltration

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite in&#64257;ltration of 3D interconnected microfluidic networks. The manufacturing of the reinforced beams begins with the fabrication of microfluidic networks, which involves layer-by-layer deposition of fugitive ink filaments using a dispensing robot, filling the empty space between filaments using a low viscosity resin, curing the resin and finally removing the ink.&#160;Self-supported 3D structures with other geometries and many layers (e.g.&#160;a few hundreds layers) could be built using this method. The resulting tubular micro&#64258;uidic networks are then infiltrated with thermosetting nanocomposite suspensions containing nanofillers (e.g.&#160;single-walled carbon nanotubes), and subsequently cured. The infiltration is done by applying a pressure gradient between two ends of the empty network (either by applying a vacuum or vacuum-assisted microinjection). Prior to the infiltration, the nanocomposite suspensions are prepared by dispersing nanofillers into polymer matrices using ultrasonication and three-roll mixing methods. The nanocomposites (i.e.&#160;materials infiltrated) are then solidified under UV exposure/heat cure, resulting in a 3D-reinforced composite structure. The technique presented here enables the design of functional nanocomposite macroscopic products for microengineering applications such as actuators and sensors.

Three-dimensional (3D) microstructured composite beams are fabricated through the directed and localized infiltration of nanocomposites into 3D porous microfluidic networks. The flexibility of this manufacturing method enables the utilization of different thermosetting materials and nanofillers in order to achieve a variety of functional 3D reinforced nanocomposite macroscopic products.

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite ...

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for Cu(II) Through Microwave Pre-Pyrolysis

An environment-friendly technique for synthesizing biomass-based mesoporous activated carbon with high nitrogen-/oxygen-chelating adsorption for Cu(II) is proposed. Bagasse impregnated with phosphoric acid is utilized as the precursor. To pyrolyze the precursor, two separate heating modes are used: microwave pyrolysis and conventional electric-heating pyrolysis. The resulting bagasse-derived carbon samples are modified with nitrification and reduction modification. Nitrogen (N)/oxygen (O) functional groups are simultaneously introduced to the surface of activated carbon, enhancing its adsorption of Cu(II) by complexing and ion-exchange. Characterization and copper adsorption experiments are performed to investigate the physicochemical properties of four prepared carbon samples and determine which heating method favors the subsequent modification for doping of N/O functional groups. In this technique, based on analyzing data of nitrogen adsorption, Fourier transform infrared spectroscopy, and batch adsorption experiments, it is proven that microwave-pyrolyzed carbon has more defect sites and, therefore, time-saving effective microwave pyrolysis contributes more N/O species to the carbon, although it leads to a lower specific surface area. This technique offers a promising route to synthesis adsorbents with higher nitrogen and oxygen content and a higher adsorption capacity of heavy-metal ions in wastewater remediation applications.

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for CuII Through Microwave Pre-Pyrolysis

Here, we present a protocol to synthesize nitrogen/oxygen dual-doped mesoporous carbon from biomass by chemical activation in different pyrolysis modes followed by modification. We demonstrate that the microwave pyrolysis benefits the subsequent modification process to simultaneously introduce more nitrogen and oxygen functional groups on the carbon.

An environment-friendly technique for synthesizing biomass-based mesoporous activated carbon with high nitrogen-/oxygen-chelating adsorption for Cu(II) is ...

Environment

Nanosponge Tunability in Size and Crosslinking Density

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with controlled dimensions. This approach begins with synthesis of a functionalized lactone which is key to the pendant functionalization of the resulting polymer. Valerolactone (VL) and allyl-valerolactone (AVL) are then copolymerized using ring-opening polymerization. Post-polymerization modification is then used to install an epoxide moiety on some or all of the pendant allyl groups. Epoxy-amine chemistry is employed to form nanoparticles in a dilute solution of both polymer and small molecule diamine crosslinker based on the desired nanosponge size and crosslinking density. Nanosponge sizes can be characterized by transmission electron microscopy (TEM) imaging to determine the dimension and distribution. This method provides a pathway by which highly tunable polyesters can create tunable nanoparticles, which can be used for small molecule drug encapsulation. Due to the nature of the backbone, these particles are hydrolytically and enzymatically degradable for a controlled release of a wide range of hydrophobic small molecules.

This article describes a process for tuning the size and crosslinking density of covalently crosslinked nanoparticles from linear polyesters containing pendant functionality. By tailoring synthesis parameters (polymer molecular weight, pendant functionality incorporation, and crosslinker equivalents), a desired nanoparticle size and crosslinking density can be achieved for drug delivery applications.

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with ...

Control and Disposal of Invasive Japanese Knotweed Reynoutria japonica Houtt. Using Microwave Treatment

The study aims to assess the effectiveness of microwave treatment (MWT) at a frequency of 2.45 GHz and a power of 800 W to control Japanese knotweed (Reynoutria japonica Houtt.) using a self-propelled device that was built in the in-house facility. The MWT was applied in the field population of knotweed in July 2022. First, plants were mechanically moved from the area of 1 m2, and next, the cut shoots around 4 cm high were microwave-treated for 25 min, 20 min, and 15 min. The control treatments were: 1) only cut plants and 2) rhizomes dug out to 30 cm deep. The effectiveness of the microwave treatments was observed for the next 11 months by counting the number of newly grown shoots. The results showed that a 25 min MWT was 100% effective in Japanese knotweed loss of vitality, while a 15 min MWT microwave treatment stimulated plant growth by around 50%, compared to controls. Rhizomes were dug out in a separate in vitro experiment for laboratory testing. The rhizomes were categorized by thickness and subjected to a 60 s MWT using a commercial microwave, after which their temperature and vitality were assessed. The temperature of rhizomes following MWT depended on their thickness. Those rhizomes that warmed to temperatures above 42 &#176;C were effectively destroyed. Summing up, the time plants are exposed to microwaves plays a major role in the effectiveness of this method. The longer the exposure to MWT, the better control. The thinner the rhizomes, the more effective the in vitro MWT rhizomes disposal.

This protocol provides a method for microwave control of Japanese knotweed in the field and disposal of dug-up rhizomes in laboratory conditions. The advantages and disadvantages of both methods are discussed. Future research directions are also suggested to optimize the use of microwaves for controlling Japanese knotweed.

The study aims to assess the effectiveness of microwave treatment (MWT) at a frequency of 2.45 GHz and a power of 800 W to control Japanese knotweed ...

Triplet Fusion Upconversion Nanocapsule Synthesis

Triplet fusion upconversion (UC) allows for the generation of one high energy photon from two low energy input photons. This well-studied process has significant implications for producing high energy light beyond a material's surface. However, the deployment of UC materials has been stymied due to poor material solubility, high concentration requirements, and oxygen sensitivity, ultimately resulting in reduced light output. Toward this end, nanoencapsulation has been a popular motif to circumvent these challenges, but durability has remained elusive in organic solvents. Recently, a nanoencapsulation technique was engineered to tackle each of these challenges, whereupon an oleic acid nanodroplet containing upconversion materials was encapsulated with a silica shell. Ultimately, these nanocapsules (NCs) were durable enough to enable triplet fusion upconversion-facilitated volumetric three-dimensional (3D) printing. By encapsulating upconversion materials with silica and dispersing them in a 3D printing resin, photopatterning beyond the surface of the printing vat was made possible. Here, video protocols for the synthesis of upconversion NCs are presented for both small-scale and large-scale batches. The outlined protocols serve as a starting point for adapting this encapsulation scheme to multiple upconversion schemes for use in volumetric 3D printing applications.

This protocol details the synthesis of upconversion nanocapsules for subsequent use in photopolymerizable resins for triplet fusion upconversion-facilitated volumetric 3D printing.

Triplet fusion upconversion (UC) allows for the generation of one high energy photon from two low energy input photons. This well-studied process has ...

Engineering

Microwave Synthesis and Characterization of Nickel Hydroxide Nanosheets

Effect of Microwave Synthesis Conditions on the Structure of Nickel Hydroxide Nanosheets

A protocol for rapid, microwave-assisted hydrothermal synthesis of nickel hydroxide nanosheets under mildly acidic conditions is presented, and the effect of reaction temperature and time on the material&#39;s structure is examined. All reaction conditions studied result in aggregates of layered &#945;-Ni(OH)2 nanosheets. The reaction temperature and time strongly influence the structure of the material and product yield. Synthesizing &#945;-Ni(OH)2 at higher temperatures increases the reaction yield, lowers the interlayer spacing, increases crystalline domain size, shifts the frequencies of interlayer anion vibrational modes, and lowers the pore diameter. Longer reaction times increase reaction yields and result in similar crystalline domain sizes. Monitoring the reaction pressure in situ shows that higher pressures are obtained at higher reaction temperatures. This microwave-assisted synthesis route provides a rapid, high-throughput, scalable process that can be applied to the synthesis and production of a variety of transition metal hydroxides used for numerous energy storage, catalysis, sensor, and other applications.

Author Spotlight: A Rapid, Microwave-Assisted Hydrothermal Synthesis Of Nickel Hydroxide Nanosheets 

Nickel hydroxide nanosheets are synthesized by a microwave-assisted hydrothermal reaction. This protocol demonstrates that the reaction temperature and time used for microwave synthesis affects the reaction yield, crystal structure, and local coordination environment.

A protocol for rapid, microwave-assisted hydrothermal synthesis of nickel hydroxide nanosheets under mildly acidic conditions is presented, and the effect ...

Food Sample Homogenization and Digestion for Multi-Element Analysis

Preparation of Food Samples Using Homogenization and Microwave-Assisted Wet Acid Digestion for Multi-Element Determination with ICP-MS

Sample preparation is crucial for elemental determination, and various techniques are available, one of which involves homogenization followed by acid digestion. Special care is required during sample handling in the preparation stage to eliminate or minimize potential contamination and analyte loss. Homogenization is a process that simultaneously reduces particle size and uniformly distributes sample components. Following homogenization, the sample undergoes acid digestion, wherein it is digested with acids and auxiliary chemicals at elevated temperatures, transforming solid samples into a liquid state. In this process, metals in the original sample react with acids to form water-soluble salts. Samples prepared through acid digestion are suitable for elemental analysis using techniques such as inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectroscopy, atomic absorption spectroscopy, electrochemical methods, and other analytical techniques. This work details the preparation of food samples for multi-element determination using inductively coupled plasma mass spectrometry. The step-by-step procedure involves the homogenization process using a laboratory-sized mixer with ceramic blades, followed by acid digestion in closed vessels using microwave-assisted wet acid digestion. A mixture of 5.0 mL of 68 wt% HNO3 and 1.0 mL of 30 wt% H2O2 serves as an auxiliary reagent. This guide provides an explanation of the processes involved in both stages.

Author Spotlight: Technologies and Challenges in Elemental Analysis of Food Samples

The presented protocol describes sample homogenization with a laboratory mixer, acid digestion of food samples using a mixture of 68 wt% HNO3 and 30 wt% H2O2&#160;via microwave-assisted wet acid digestion, and multi-element determination performed with inductively coupled plasma mass spectrometry.

Sample preparation is crucial for elemental determination, and various techniques are available, one of which involves homogenization followed by acid ...

Polyol-Based Microwave-Assisted Extraction for Phenolic and Antioxidant Yields

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

The utilization of polyols as green solvents for extracting bioactive compounds from plant materials has gained attention due to their safety and inert behavior with plant bioactive chemicals. This study explores the sustainable extraction of phenolic compounds and natural antioxidants from coffee silverskin using the microwave-assisted extraction (MAE) method with polyol-based solvents: glycerin, propylene glycol (PG), butylene glycol (BG), methylpropanediol (MPD), isopentyldiol (IPD), pentylene glycol, 1,2-hexanediol, and hexylene glycol (HG). A comparative analysis was conducted on conventional and non-conventional solvent extractions, focusing on their impact on the bioactive compounds of MAE, encompassing parameters such as total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities like the 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay (DPPH), the 2,2&#8242;-azino-bis(-3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging assay (ABTS), and the ferric reducing antioxidant power assay (FRAP). The highest values were observed for TPC with aqueous-1,2-hexanediol extraction (52.0 &#177; 3.0 mg GAE/g sample), TFC with aqueous-1,2-hexanediol extraction (20.0 &#177; 1.7 mg QE/g sample), DPPH with aqueous-HG&#160;extraction (13.6 &#177; 0.3 mg TE/g sample), ABTS with aqueous-pentylene glycol extraction (8.2 &#177; 0.1 mg TE/g sample), and FRAP with aqueous-HG extraction (21.1 &#177; 1.3 mg Fe (II) E/g sample). This research aims to advance eco-friendly extraction technology through natural plant components, promoting sustainability by minimizing hazardous chemical use while reducing time and energy consumption, with potential applications in cosmetics.

Author Spotlight: Eco-Friendly Extraction of Bioactive Compounds Using Polyol-Based Microwave-Assisted Techniques

This protocol details the utilization of a polyol-based microwave-assisted extraction method for extracting phenolic compounds and natural antioxidants, representing a practical and environmentally sustainable approach to the development of ready-to-use extracts.

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