Microwave Irradiation Treatment Research Articles

A novel combined healing system for sustainable asphalt concrete based on loading-microwave dual responsive capsules

The cracked asphalt concrete with calcium alginate/Fe3O4 capsules can get partial strength recovery under cyclic loading or microwave irradiation. This paper introduced a novel combined healing system for sustainable asphalt concrete based on loading-microwave dual responsive capsules in different service condition. In this paper, the capsules were synthesized and their morphological structure, mechanical performance and thermal resistance were characterized respectively. The rejuvenator release ratio of the capsules and the healing level of asphalt concrete were evaluated after cyclic loading and microwave irradiation. Meanwhile, the rheological characteristic of extracted asphalt binder was explored after cyclic loading and microwave irradiation treatment. Besides, the surface temperature of asphalt concrete after microwave irradiation was observed. The results revealed that the mechanical strength and mass loss of prepared capsules were 11.8 N and 3.8% at 200 °C respectively. The capsules experiencing higher cycles of loading events released more rejuvenator during microwave irradiation period. The combined healing level of asphalt concrete with capsules could reach 91.7% after 64000 cycles of loading and 30s of microwave irradiation. Meanwhile, the released rejuvenator softened asphalt binder and improved its flow ability. The novel combined healing system provides a new way of pavement maintenance strategy under the background of low carbon maintenance.

ZnO-CdS-Ag2S double S-scheme heterojunctions with significant hydrogen evolution reaction and dye degradation properties

Here in, we report a new methodology for the fabrication of free template ternary ZnO-CdS-Ag2S nanohybrids with superior photocatalyst properties for the hydrogen evolution reaction (HER) and dye degradation. Firstly, ZnO nanorods (NRs) were synthesized using a solvothermal method and used as a seed template for the growth of CdS-Ag2S QDs. The CdS-Ag2S QDs were grown using two different methods of microwave irradiation and photochemical treatment using thioglycolic acid (TGA) as both capping agent and digestive reactant. Structural characterizations proved the formation of the ternary structure with both methods of synthesis. XPS analyses revealed that photochemical approach results in the formation of a ternary composite with higher ZnO nanoparticles concentration. Electrochemical studies inferred that samples prepared using photochemical treatment have the least of charge transfer resistance, large surface area of 132 m2/g, large electrochemical surface area and higher electrochemical performance. Linear sweep voltammetry obtained current densities of magnitude of 100 mA cm−2 at bias −0.475 V vs. RHE, onset potential of −0.238 V, and Tafel slope of 45 mV/dec. Moreover, samples prepared using photochemical approach showed also high cyclic HER stability and reproducibility of the same results from the same ink after storing for six months. This method of synthesis can be applied for the synthesis of multi-functional ternary metal oxide-QD-QD nanocomposites for energy conversion applications. A S-scheme band diagram is suggested to infer the internal charge separation mechanism and high HER and photocatalyst activities of the ternary compound.

Modeling the combined resistance to microwave treatments and salt conditions of Escherichia coli and Staphylococcus aureus.

In the present study, the efficiency of the combined effect of microwave irradiation treatments together with salt concentration was assessed against Escherichia coli and Staphylococcus aureus. Microbial survival has been modeled through a one-step Weibull equation considering the non-isothermal profiles during the heating treatments. Three sodium chloride concentrations 0.5%, 3.5%, and 8.5% (w/v) treated under three microwave power levels (450, 600, and 800 W) were studied. Predictive models were validated using the determination coefficient (R2), root mean squared error and the acceptable prediction zone with external data obtained from ultra high temperature milk. The results obtained suggested that increasing microwave power levels and decreasing salt concentrations led to a higher microbial inactivation, being the δ values (time for achieving a first decimal reduction) for E coli of 19.57 s at 800 W and 0.5% NaCl. In contrast, experimental data of S aureus showed a higher variability since it presented more resistance to the microwave treatments. The results obtained and generated models can be used as decision-making tools to set specific guidelines on microwave treatments for assuring food safety.

Shikonin-Loaded Hollow Fe-MOF Nanoparticles for Enhanced Microwave Thermal Therapy.

Microwave (MW) thermal therapy has been widely used for the treatment of cancer in clinics, but it still shows limited efficacy and a high recurrence rate owing to non-selective heat delivery and thermo-resistance. Regulating glycolysis shows great promise to improve MW thermal therapy since glycolysis plays an important role in thermo-resistance, progression, metabolism, and recurrence. Herein, we developed a delivery nanosystem of shikonin (SK)-loaded and hyaluronic acid (HA)-modified hollow Fe-MOF (HFM), HFM@SK@HA, as an efficient glycolysis-meditated agent to improve the efficacy of MW thermal therapy. The HFM@SK@HA nanosystem shows a high SK loading capacity of 31.7 wt %. The loaded SK can be effectively released from the HFM@SK@HA under the stimulation of an acidic tumor microenvironment and MW irradiation, overcoming the intrinsically low solubility and severe toxicity of SK. We also find that the HFM@SK@HA can not only greatly improve the heating effect of MW in the tumor site but also mediate MW-enhancing dynamic therapy efficiency by catalyzing the endogenous H2O2 to generate reactive oxygen species (ROS). As such, the MW irradiation treatment in the presence of HFM@SK@HA in vitro enables a highly improved anti-tumor efficacy due to the combined effect of released SK and generated ROS on inhibiting glycolysis in cancer cells. Our in vivo experiments show that the tumor inhibition rate is up to 94.75% ± 3.63% with no obvious recurrence during the 2 weeks after treatment. This work provides a new strategy for improving the efficacy of MW thermal therapy.

Algae biogas production focusing on operating conditions and conversion mechanisms – A review

Global warming is the result of traditional fuel use and manufacturing, which release significant volumes of CO2 and other greenhouse gases from factories. Moreover, rising energy consumption, anticipated limitations of fossil fuels in the near future, and increased interest in renewable energies among scientists, currently increase research in biofuels. In contrast to biomass from urban waste materials or the land, algae have the potential to be a commercially successful aquatic energy crop, offering a greater energy potential. Here we discuss the importance of Anaerobic Digestion (AD) for enhanced biogas yield, characterization, and comparisons between algae pretreatment methods namely, mechanical, thermal, microwave irradiation, and enzymatic and catalytic methods. The importance of anaerobic digestion enhances biogas yield, characterization, and comparisons between mechanical, thermal, microwave irradiation, and enzymatic and catalytic treatment. Additionally, operational aspects such as algal species, temperature, C/N ratio, retention period, and particle size impact biofuel yield. The highest algal biogas yield reported was 740 mL/gVS, subtracted from Taihu de-oiled algae applying thermos-chemical pretreatment under conditions of temperature, time, and catalyst concentration of 70 °C, 3 h, and 6%, respectively. Another high yield of algal-based biogas was obtained from Laminaria sp. with mechanical pretreatment under temperature, time, and VS concentration of 38 ± 1 °C, 15 min, and 2.5% respectively, with a maximum yield of 615 ± 7 mL/g VS. Although biofuels derived from algae species are only partially commercialized, the feedstock for biogas might soon be commercially grown. Algae and other plant species that could be cultivated on marginal lands as affordable energy crops with the potential to contribute to the production of biogas are promising and are already being worked on.

Microwave treatment effect on the enhanced basicity of porous clay heterostructured composites derived from Laponite

Porous clay heterostructured composites (PCH) derived from layered hydrous magnesium silicate, Laponite, were functionalized by Fe(NO3)3x9H2O with the use of mechano-chemical impregnation followed by microwave irradiation or hydrothermal treatment to evoke new base properties, active in CO2 sorption. It resulted in the progressive leaching of the Mg2+ from the octahedral sheets of the Laponite structure and their capture on the surface of PCH composites increasing the Mg/Si ratio. The increase of Mg/Si ratio was accompanied by the decline of the (Mg3OH) absorption bands intensity attributed to Laponite and discussed regarding the formation of dispersed nanostructured MgO moieties capable of adsorbing CO2. CO2-TPD temperature-programmed desorption technique revealed that sorption and stabilization of CO2 molecules are related to the coordination of oxygen sites in the formed MgO lattice and that edge and corner sites facilitate the interaction of CO2 molecules with O2− sites on MgO. Doping of PCH resulted also in the nucleation of nanocrystalline α-Fe2O3 able to capture CO2 with strength and stability higher than MgO. Microwave irradiation resulted in significant development of the surface basicity as part of the transformation of clay structure. This study confirms the importance of clay minerals in the uptake and retention of CO2.

Thermal processing induced changes on molecular structure spectral profile of carbohydrates and ruminal degradation and intestinal digestion characteristics of oat grains (Avena sativa) in dairy cows: comparison among dry heating vs. moisture heating vs. microwave irradiation

In this study, the objectives were to ( i) identify the magnitude of differences between dry heating, moisture heating, microwave irradiation, and no-heated treatments on chemical profiles, energy values, the Cornell Net Carbohydrate and Protein System fractions, rumen degradation, and intestinal digestion of newly developed oat ( Avena sativa) varieties; ( ii) investigate heating induced changes in the molecular structure of the grains with the use of vibrational attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy; and ( iii) predict rumen degradability of the nutrients based on the molecular spectral profile obtained from ATR-FTIR. Duration and temperature for each processing treatment were established based on previous studies. Results showed that heat processing treatments altered CHO fractions with undegradable CHO fraction (CC) increased by moisture heating. The ATR-FTIR spectroscopy was successful in detecting the processing induced CHO molecular structure changes in oat grain. The CHO molecular profiles were correlated to chemical profile and in situ rumen degradation characteristics. Lastly, multiple regressions with best model variable selection for prediction of nutritional value were obtained. In conclusion, heat processing methods tended to affect both energy values and rumen degradation features. The CHO molecular structure spectral profiles could be used as potential predictors for heated oat grain degradation.

Improving the Structural Ordering and Particle-Size Homogeneity of Li-Rich Layered Li1.2Ni0.13Co0.13Mn0.54O2 Cathode Materials through Microwave Irradiation Solid-State Synthesis

Li1.2Ni0.13Co0.13Mn0.54O2 (LNCM) has been intensively investigated owing to its high capacity and large voltage window. However, despite its high performance, the synthesis of LNCM can be challenging as it usually contains structural disorders and particle-size inhomogeneities, especially via a solid-state method. This work introduces microwave irradiation treatment on the LNCM fabricated via a solid-state method. The as-treated LNCM has low structural disorders, as indicated by the smaller cation mixing, better hexagonal ordering, and higher c/a ratio compared to the non-treated LNCM. Furthermore, the particle-size homogeneities of as-treated LNCM improved, as characterized by scanning electron microscopy (SEM) and particle size analyzer (PSA) measurements. The improved structural ordering and particle-size homogeneity of the treated sample enhances the specific capacity, initial Coulombic efficiency, and rate capability of the cathode material. The LNCM sample with 20 min of microwave treatment exhibits an optimum performance, showing a large specific capacity (259.84 mAh/g), a high first-cycle Coulombic efficiency (81.45%), and good rate capability. It also showed a stable electrochemical performance with 80.57% capacity retention after 200 cycles (at a charge/discharge of 0.2C/0.5C), which is 13% higher than samples without microwave irradiation.

Producing Refuse Derived Fuel with Refining Industry Oily Sludge and Mushroom Substrates

The sludge in this study was obtained from refinery crude oil storage tanks. It contained a high proportion of hydrocarbon composition and harmful substances (such as polycyclic aromatic hydrocarbons and benzene). Through the microwave irradiation treatment process, the harmful substances were removed from the sludge which was then recycled and combined with agricultural waste mushroom substrates to produce refuse derived fuel (RDF). The results showed that the calorific value of RDF was 7279 cal/g when the blending ratio (wt/wt) of oil sludge and mushroom substrates was 5:5. On the other hand, when the portion of the mushroom substrates was increased, the sludge became easier to ignite with better combustion reaction. When the blending ratio (wt/wt) was changed from 8:2 to 5:5, the ignition index and comprehensive performance index were increased by 51.9 and 50.2%. Therefore, mixing the sludge with agricultural waste mushroom substrates is in line with the concept of waste recycling and circular economy.

Microwave treatment to optimize physicochemical properties of modified Busil (Xanthosoma sagittifolium) starch

COVID-19 pandemic encourages the utilization of local food sources to ensure food availability. Busil (Xanthosoma sagittifolium) was readily available and affordable in Banjarnegara Regency in the Province of Central Java in Indonesia. However, the busil starch utilization was still rare due to the low functional properties of the native busil starch. The objective of this study was to explore busil starch physicochemical characterization enhancement after microwave irradiation treatment, especially on the stability of heat processing. This research was conducted in two steps. First, microwave treatment (with a variation of energy and irradiation time) of native busil starch (NBS), and the second was modified busil starch (MBS) physicochemical characterization. A rise in amylose was observed on MBS. SEM analysis was shown MBS granules are breakdown. Through viscosity, final viscosity, setback viscosity, peak time, and the pasting temperature of MBS generally were increased. Meanwhile, peak viscosity and breakdown viscosity of MBS was decreased. Thermal properties of MBS like onset (To), peak (Tp), and conclusion (Tc) temperatures were also increased. The degree of whiteness index (DW) of MBS was decreased. FTIR analysis has shown that microwave treatment did not cause functional group alteration. XRD analysis has also demonstrated no change in the diffraction pattern but a slight change in the crystallinity index. Generally, microwave treatment leads to MBS thermal stability and potentially broaden MBS utilization on food processing product.

Silicon doped graphene as high cycle performance anode for lithium-ion batteries

Silicon/carbon composite is discovered as a prevailing strategy to prevent the deterioration of silicon material during battery cycling. Herein, we report a novel silicon doped graphene material (SiG) through a facile synthetic route and investigate its application in lithium-ion battery. The microwave irradiation treatment successfully realizes the doping of Si heteroatoms into the graphene lattice, which results in a twice specific capacity of pristine graphene. More importantly, the SiG demonstrates an improvement in Li+ storage and diffusion after cycle, as well as enhanced energy density and power density, which is attributed to the Si heteroatoms dispersed on the surface and a more ordered graphene lattice. Full cell assembled with SiG/LiFePO4 achieves 86% retention after 200 cycles. The novel silicon doping strategy paves the way for the practical application in high-performance lithium-ion batteries.

Evaluation of microwave heating on the mechanical properties, β-glucan, and fiber content of barley kernels.

Microwave heating may affect some non-starch polysaccharides of cereal kernels. This microwave effect can be positive for functional properties and the final product. Therefore, the purpose of this work was to explore the effects of microwave heating on mechanical properties, malt extract yield, wort viscosity, β-glucan of wort, and soluble, insoluble, and total dietary fiber in malting and feed barley. The barley kernels were microwave heated for 4 and 8 s and compared with a control (0 s) with no microwave irradiation treatment. The mechanical properties were measured by compressive loadings; an Environmental Scanning Electron Microscopy was used for kernel layers. β-glucan content in the barley kernel and wort was measured with a Mixed Linkage beta-glucan (K-BGLU Megazyme International; Wicklow, Ireland). Insoluble, soluble, and total dietary fiber was determined using 32-07 of AACC method. The thickness of barley kernel bran layers was related to the mechanical properties. The modulus of elasticity decreased after 4 s of heating but increased after 8 s. Irradiation affected non-starch polysaccharides, such as β-glucan and fiber. β-glucan decreased after 4 s as did wort viscosity. The insoluble and total dietary fiber followed the same trend as β-glucan, but the soluble fiber content increased with prolonged microwave heating. A few seconds of microwave heating is enough to increase barley’s value in the brewing industry and improve health benefits due to minor changes in the biochemical grain components.

Application of E/Z-Isomerization Technology for Enhancing Processing Efficiency, Health-Promoting Effects, and Usability of Carotenoids: A Review and Future Perspectives.

Carotenoids are naturally occurring pigments whose presence in the diet is beneficial to human health. Moreover, they have a wide range of applications in the food, cosmetic, and animal feed industries. As carotenoids contain multiple conjugated double bonds in the molecule, a large number of geometric (E/Z, trans/cis) isomers are theoretically possible. In general, (all-E)-carotenoids are the most predominant geometric isomer in nature, and they have high crystallinity and low solubility in various mediums, resulting in their low processing efficiency and bioavailability. Technological developments for improving the processing efficiency and bioavailability of carotenoids utilizing the Z-isomerization have recently been gaining traction. Namely, Z-isomerization of carotenoids induces a significant change in their physicochemical properties (e.g., solubility and crystallinity), leading to improved processing efficiency and bioavailability as well as several biological activities. For the practical use of isomerization technology for carotenoids, the development of efficient isomerization methods and an acute understanding of the changes in biological activity are required. This review highlights the recent advancements in various conventional and unconventional methods for carotenoid isomerization, such as thermal treatment, light irradiation, microwave irradiation, and catalytic treatment, as well as environment-friendly isomerization methods. Current progress in the improvement of processing efficiency and biological activity utilizing isomerization technology and an application development of carotenoid Z-isomers for the feed industry are also described. In addition, future research challenges in the context of carotenoid isomerization have been elaborated upon.

Combustion Kinetics of Coal Treated by Microwave Irradiation Combined with Hydrochloric Acid Pickling.

The desulfurization efficiency, combustion properties, combustion kinetics, and structural changes of Kentucky coal under microwave irradiation (MI) combined with hydrochloric acid solution pickling were investigated and compared using a thermogravimetric analyzer coupled to a Fourier transform infrared spectrometer. The results show that the desulfurization rate increases with the concentration of hydrochloric acid solution. The introduction of MI can effectively improve the desulfurization efficiency. After desulfurization, the ignition temperature and burnout temperature of coal samples increase, the combustion index decreases, and the combustion performance deteriorates. The maximum weight loss rate decreases with the increase of the concentration of hydrochloric acid solution, and the activation energy of the coal sample after microwave treatment increases, and the reaction difficulty increases. The infrared analysis results show that MI and hydrochloric acid pickling treatment have little effect on the functional group structure of coal samples.

Enhancing oxidative stability of tocopherol-enriched edible oils using short-term exposure to microwave irradiation.

The effect of microwave irradiation on the oxidative stability of tocopherol-enriched corn oil at temperatures of 60 or 100°C was evaluated using the Rancimat assay. Short durations of microwave treatment (1min) on 10-g oil aliquots were found to increase the induction period of corn oil samples containing 500 and 1000ppm tocopherol by 7.7% and 9.9%, respectively compared to control oils. The moisture content of tocopherol-enriched corn oil decreased by 15% compared to that of corn oil after 1min of microwave treatment. At 100°C, 1000ppm tocopherol-enriched corn oil received 3min of microwave treatment had 5.8% and 9.9% lower primary and secondary oxidation products than control groups, respectively while this effect was not clearly observed for oils stored at 60°C. However, 15min of microwave irradiation accelerated the rates of lipid oxidation in corn oils irrespective of the addition of tocopherol. Content of α- and γ-tocopherols in 1min of microwave irradiated samples remained more by 28.8 and 5.8%, respectively than those of controls after 9h heat treatment at 100°C. Overall, microwave irradiation within 3min can increase the oxidative stability of 10g-corn oils, especially at 100°C, which could be due to the reduced moisture content in the bulk oil matrix. Practical Application: A microwave oven is an irreplaceable home appliance and is widely used in households. Short time exposure to microwave irradiation can remove moisture efficiently from edible oils without the formation of oxidation products, which could increase the oxidative stability of these oils, especially under frying conditions. The results of this study can be utilized to ensure a longer shelf-life of fried products in the food industry by short time treatment of microwave irradiation.

A laboratory investigation into the effect of waste non-tire rubber particles on the performance properties of terminal blend rubberized asphalt binders

Non-tire rubber products (e.g. hoses, weather strips, vibration insulators, and miscellaneous parts) are progressively increasing as scrapped and repaired vehicles rise, and are abundantly discarded due to various reasons, such as high-cost recycling, complex rubber components, and poor mechanical properties. The non-tire rubber products have similar chemical components as scrap tires that have been widely applied in the field of road engineering, so it is anticipated that waste non-tire rubber products can be pretreated and used in road engineering as scrap tires. Hence, the purpose of this study was to gain a comprehensive understanding of asphalt binders modified with waste non-tire rubber with or without a microwave and/or waste engineering oil (WEO) treatment by using the terminal blend (TB) process as crumb rubber. A variety of laboratory tests were conducted, including scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric coupled with FTIR (TG-FTIR), storage stability, high-temperature performance, fatigue, and other basic rheological properties. It was found that microwave irradiation and WEO treatment can accelerate the pyrolysis and decomposition of waste non-tire rubber particles while there were no obvious differences between the pyrolysis gaseous products of waste non-tire rubber particles with or without the microwave or/and WEO treatment. Additionally, the microwave or/and WEO treatment enhanced the thermal stability and fatigue resistance of TB rubberized asphalt, especially for that with 100% WEO and 40 mesh of non-tire rubber particles. The microwave or/and WEO treatment reduced the viscosities and high-temperature properties of TB rubberized asphalt, especially for TB rubberized asphalt with fine rubber particles. In general, it is feasible to use waste non-tire rubber particles to produce TB asphalt binders and offer a cleaner way of using waste non-tire rubber products. The method of microwave and WEO treatment can be used to prepare TB asphalt with high content of non-tire rubber particles in the future.

In Ukrainian

Microwave irradiation (MWI) in the synthesis of materials has been an actively developing branch of science for the last three decades. Structures based on calcium phosphates (CaP) are one of the most well-known and widely used synthetic biomaterials in orthopedics and dentistry. The main topic of this review is the use of MWI in the formation of biomaterials based on calcium phosphate phases and their complexes with biopolymers (chitosan, alginate, silk fibroin). The physical bases of MW interaction with different materials are considered, including the influence of this irradiation on the structure, physicochemical and mechanical properties of biomaterials (crystallite size, porosity, strength, capability to absorb and release drugs). The main heating mechanisms during MWI are described, namely: the dipolar losses, and losses of conductivity. Important advantages of MWI treatment are reducing processing time, reducing electricity use, reducing waste and improving quality of the synthesized biomaterials. A list and comparison is made of articles describing the production of HA crystals with different morphology (nanowires, spherical, needle- and rod-shaped) with all the initial conditions and their effect on the synthesized material. The latest developments in the field of biomaterials conducted based on the laboratory “Bionanocomposite” of Sumy State University are considered. The original synthesis method of CaP-biopolymer materials is described, as well as the advantages of the synthesized scaffolds over foreign developments. It is expected that this review of the interdisciplinary topic will contribute to the further study of other new applications of microwave technologies in the synthesis of the latest modern biomaterials created by scientists, biomedical engineers in other laboratories and institutions in Ukraine and around the world.

Enhancement of Electrical Properties of Sol-Gel Indium-Tin-Oxide Films by Microwave Irradiation and Plasma Treatment.

We proposed the enhancement of the electrical properties of solution-processed indium–tin–oxide (ITO) thin films through microwave irradiation (MWI) and argon (Ar) gas plasma treatment. A cost- and time-effective heat treatment through MWI was applied as a post-deposition annealing (PDA) process to spin-coated ITO thin films. Subsequently, the sheet resistance of MWI ITO thin films was evaluated before and after plasma treatment. The change in the sheet resistance demonstrated that MWI PDA and Ar plasma treatment significantly improved the electrical properties of the ITO thin films. Furthermore, X-ray photoelectron spectroscopy and X-ray diffraction analyses showed that the electrical properties of the ITO thin films were enhanced by the increase in oxygen vacancies due to the ion bombardment effect of high-energy plasma ions during Ar plasma treatment. Changes in the band gap structure of the ITO thin film due to the ion bombardment effect were also analyzed. The combination of MWI PDA and Ar plasma treatment presents new possibilities for improving the high-conductivity sol–gel ITO electrode.

Effects of microwave processing parameters on the properties of nanohydroxyapatite: Structural, spectroscopic, hardness, and toxicity studies

This paper analyzed the effects of the processing parameters on the structural, spectroscopic, and hardness properties and toxicity of nanohydroxyapatite (nanoHAP) materials, specifically in terms of low-power short-duration microwave irradiation. NanoHAP compounds were synthesized from duck eggshells (a bio-based calcium source) and phosphoric acid via a wet precipitation method and subsequent treatment by microwave irradiation. Three different power inputs of 40, 200, and 400 W were used for the microwave tests, which were conducted for durations of 35, 40, and 45 min. The results confirmed the benefits of microwave treatments in terms of rapid heating, reduced reaction time, and high throughput. The existence of pure nanoHAP was confirmed by an X-ray diffractogram, and the high energy emitted by the microwave irradiation combined with an extended reaction time was proven to further transform eggshell calcium (CaO) into nanoHAP. The shift toward narrower and smaller particles with increasing irradiation power and treatment duration was confirmed via scanning electron microscopy, and an increase in hardness with extended irradiation was demonstrated. A toxicity analysis conducted on human embryonic cells confirmed high cell viability after incubation with nanoHAP. This indicates that nanoHAP obtained from microwave irradiation treatment has the potential to be used as a biomaterial.

Microwave irradiation treatment improved the structure, emulsifying properties and cell proliferation of laccase-crosslinked α-lactalbumin

Influence of microwave irradiation heating (MH) and water bath heating (WH) pretreatments (70, 80 and 90 °C) on the structure, emulsifying properties and cell proliferation of laccase-crosslinked α-La was investigated. Compared with WH pretreatment, MH pretreatment can further promote the formation of polymers in laccase-crosslinked α-La. Also, MH treatment further unfolded the secondary structure, increased the surface hydrophobicity, and induced more formation of dityrosines in laccase-crosslinked α-La solution than that of WH pretreatment. Compared with untreated laccase-crosslinked α-La, its emulsifying activity index (EAI) was increased by 28.87% and 25.01% after MH and WH pretreatment at 90 °C. Gel hardness and water holding capacity of laccase-crosslinked α-La was increased by 30.20% and 18.37% after MH at 90 °C compared to untreated laccase-crosslinked α-La. Cell viability of laccase-crosslinked α-La (2 mg/mL) was increased by 18.12% at 90 °C with MH pretreatment. These findings indicated that MH pretreatment could ameliorate the crosslinking degree of α-La and laccase, thus improving its emulsifying, gel properties, and cell viability.