Ultrasound-assisted Process Research Articles

Ultrasound-assisted process to improve proteins recovery from industrial canola and soybean byproducts

AbstractAn ultrasound-assisted process is proposed to obtain protein isolates from canola and soybean byproducts. A laboratory-scale probe system (24 kHz, 400W) was used for protein extraction and six levels of energy density were analyzed. Different mixtures of solvents (water, ethanol, methanol, acetone) and temperatures were tested for removing phenolic compounds, and the best results were obtained with ethanol-water (8:2 v/v) and energy density of 104 kJ/L, which minimize protein losses at that step. After extraction of phenolic compounds, samples were alkalinized (pH 12 or 9.5), subjected to ultrasound treatment and the protein precipitated at the isoelectric pH. The highest yield on protein extraction was obtained with 1:20 meal: NaOH solution ratio, applying 150 kJ/L at constant temperature (30 °C), increasing the protein recovery, 72.5% for canola meal and 37.5% for soybean meal, compared to the conventional method. The solubility of both isolates obtained with ultrasound improved ~ 50% at a pH close to neutral and basic, with an increase in free sulfhydryl groups, without significant effects of ultrasound treatment on the subunit fractions of the proteins. These results provide alternatives to develop protein isolates from an undervalued by-product, with better techno-functional properties that can be employed in the food industry.

Ultrasound-assisted process of dough for noodle production: Textural properties, moisture distribution, microstructure and cooking quality

To address certain issues in noodle processing, a self-designed vibrating plate ultrasound equipment was implemented in dough processing. This study investigated the effects of ultrasound on the disulfide bond, secondary structures, and microstructures of noodles, as well as their qualities including texture, tensile strength, and cooking characteristics. The objective was to uncover the underlying mechanisms by which ultrasound assistance enhances dough processing. The findings indicated that ultrasonic treatment enhanced noodle quality, especially under the action of medium-intensity ultrasound treatment (MUS, 330 W; 30 s). After undergoing MUS, the noodles exhibited a notable enhancement in tensile force and stretching distance by 21.2% and 49.3% compared with the control group. MUS treatment facilitated the transformation of loosely bound water to tightly bound water during dough processing. LUS, MUS, HUS treatment led to a notable increase in β-turn and β-sheet contents. Moreover, the microstructure of noodles exhibited enhanced stability and orderliness, characterized by reduced exposed starch particles and smaller pore size. Noodles treated with MUS received the highest sensory scores. Overall, the vibrating plate ultrasonic-assisted dough processing technology demonstrated improvement in the quality of noodles, offering an innovative strategy for enhancing flour product production.

Flexible, biodegradable ultrasonic wireless electrotherapy device based on highly self-aligned piezoelectric biofilms.

Biodegradable piezoelectric devices hold great promise in on-demand transient bioelectronics. Existing piezoelectric biomaterials, however, remain obstacles to the development of such devices due to difficulties in large-scale crystal orientation alignment and weak piezoelectricity. Here, we present a strategy for the synthesis of optimally orientated, self-aligned piezoelectric γ-glycine/polyvinyl alcohol (γ-glycine/PVA) films via an ultrasound-assisted process, guided by density functional theory. The first-principles calculations reveal that the negative piezoelectric effect of γ-glycine originates from the stretching and compression of glycine molecules induced by hydrogen bonding interactions. The synthetic γ-glycine/PVA films exhibit a piezoelectricity of 10.4 picocoulombs per newton and an ultrahigh piezoelectric voltage coefficient of 324 × 10-3 volt meters per newton. The biofilms are further developed into flexible, bioresorbable, wireless piezo-ultrasound electrotherapy devices, which are demonstrated to shorten wound healing by ~40% and self-degrade in preclinical wound models. These encouraging results offer reliable approaches for engineering piezoelectric biofilms and developing transient bioelectronics.

Ultrasound and pulsed electric field treatment effect on the thermal properties, oxidative stability and fatty acid profile of oils extracted from berry seeds

AbstractThe seeds of berry fruits which are considered as a by-product may be valorized by recovering the oil they content. Nevertheless, the conventional extraction methods are time, energy and organic solvents consuming. In order to make extraction more environmental-friendly, alternative methods, like ultrasound-assisted and pulsed electric field-assisted processes, are being developed. The procedure of extraction may however influence the quality of obtained oil. The following study aims to define the effects of ultrasound and pulsed electric field application in the extraction process on the thermal properties, i.e., oxidative stability, melting and cyclic heating/cooling profiles, thermal decomposition characteristics. Additionally, fatty acid profile assessment was included in the study. Seeds of blackberries, blackcurrants, chokeberries, raspberries and redcurrants were used to extract oil. Based on the results, it can be summarized that extraction method influenced the resistance of oils to oxidation. Ultrasound-assisted process resulted in oils with the highest oxidation induction times. Melting profile was slightly influenced by extraction method, with peak temperatures indicating the presence of low-melting and middle-melting triacylglycerol fractions. Differential scanning calorimetry with heat/cool/heat procedure let determine crystallization peak temperatures around − 60 °C, which could be associated with the specific triacylglycerol profile of berry seed oils. The courses of thermogravimetric analysis curves were comparable for all the tested samples. The fatty acid profile study revealed that all the studied thermal properties were affected by the unique fatty acid percentage share, with a great predominance of polyunsaturated fatty acids. Obtained results allowed to conclude that extraction method influenced oxidative stability, thermal properties and fatty acid profile only to some extent. The most promising extraction method among analyzed seems to be ultrasound-assisted extraction as it provided oil with high oxidative stability, typical thermal properties and unchanged fatty acid profile, without being harmful to natural environment due to possible reduction in solvent and time consumption.

Optimizing Fucoidan Encapsulation in a W1/O/W2 Double Emulsion through an Ultrasound-Assisted Process and Response Surface Methodology

Optimizing Fucoidan Encapsulation in a W₁/O/W₂ Double Emulsion through an Ultrasound-Assisted Process and Response Surface Methodology

Eco-friendly Chrome Tanning of Leather using Ultrasound Technique

This article describes the development of an environmentally friendly chrome tanning process of leather using ultrasound. Most of the leathers are tanned by the conventional method using basic chromium sulfate. It is one of the most polluting and time-consuming steps in leather processing. Investigations were carried out on ultrasound assisted eco-friendly tanning process so that the chrome tanning agent could provide better quality leather. Effects of using ultrasound in chrome tanning process were studied at different pH, tanning time, tanning agent dosage, and then compared with that of conventional method. Tanned leathers were characterized by scanning electron microscopy (SEM), photomicrographic analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and energy dispersive X-ray (EDX). SEM analyses of the surface and cross-section of the tanned leather showed that fiber structures were not affected by ultrasound. It was also found that the shrinkage temperature of leather tanned with ultrasound was increased by about 5-29 °C. Chrome uptake and content were found to increase by 30-50% and 1-7%, respectively. Tanning time was shortened from 6 hours to 2 hours and the quantity of leachable chromium in ultrasound assisted chrome tanned leather was also decreased significantly. The noteworthy enhancing effects have been attributed largely because of the increased penetration of tanning agents into pickled leather. Photomicrographic analysis of the cross-section of the tanned leather also showed a higher penetration of tanning agents in presence of ultrasound.

Ultrasonic-Assisted Extraction of Bioactive Extract from Napier Grass (Pennisetum purpureum), Evaluation of Its Bioactivity, Antimutagenicity and Cytotoxicity

The antioxidant characteristics of Napier grass (Pennisetum purpureum) can vary significantly depending on the age of the plant, species, and environmental constraints. In this study, ultrasonic extraction was performed to obtain the bioactive extract from Napier grass. Napier grass at different growth periods (50, 70, and 90 days) was evaluated for phenolic and flavonoid quantity followed by antioxidant activity. The effect of extraction parameters was evaluated using response surface methodology (RSM) with Box-Behnken design. The optimum condition for extraction of bioactive compounds from Napier grass was selected through RSM as 10 mL of ethanol (47.68% v/v) and 50 min of extraction time with ultrasound assisted process (100% amplitude and 20 kHz). The extract from 50 days old grass showed excellent antioxidant properties (68.4 μm Fe (II)/g, 5.1 mg AAE/g, 56.7% of DPPH activity), higher phenolic (8.5 mg GAE/g), flavonoid (3.9 mg QE/g) and protein content (14.9% w/w) which also good antimicrobial and antimutagenic activity. The bioactive extract from 50 days of grass demonstrated strong antimutagenicity (>60%) against sodium azide-induced mutation in S. typhimurium TA 100 strain and did not exhibit a cytotoxic effect on Vero and Caco-2 cells at the concentration of 250 µg/mL and 500 µg/mL, respectively. Keywords: Napier grass, Ultrasonic extraction, Antioxidant, Antimutagenicity, Cytotoxicity

Ecofriendly Preparation of Rosmarinic Acid-poly(vinyl alcohol) Biofilms Using NADES/DES, Ultrasounds and Optimization via a Mixture-Process Design Strategy.

Green chemistry emphasizes the isolation of biologically active compounds from plants and biomass to produce renewable, bio-based products and materials through sustainability and circularity-driven innovation processes. In this work, we have investigated the extraction of rosmarinic acid (RA), a phenolic acid with several biological properties, from aromatic herbs using ultrasounds and low environmental risk natural deep eutectic solvents (NADES). Various solvent mixtures have been investigated, and the parameters influencing the process have been studied by a mixture-process experimental design to identify the optimal RA extraction conditions. The extraction yield has been calculated by HPLC-diode array analysis. The lactic acid:ethylene glycol mixture using an ultrasound-assisted process has been found to be the most versatile solvent system, giving RA yields 127-160% higher than hydroalcoholic extraction (70% ethanol). The deep eutectic solvent nature of lactic acid:ethylene glycol has been demonstrated for the first time by multi-technique characterization (1H-NMR and 13C-NMR, DSC, and W absorption properties). The aqueous raw extract has been directly incorporated into poly(vinyl alcohol) to obtain films with potential antibacterial properties for applications in the field of food and pharmaceutical packaging.

Ultrasound assisted phytochemical extraction of red cabbage by using deep eutectic solvent: Modelling using ANFIS and optimization by genetic algorithms

The present investigation studied the effect of process parameters on the extraction of phytochemicals from red cabbage by the application of ultrasonication and temperature. The solvent selected for the study was deep eutectic solvent (DES) prepared by choline chloride and citric acid. The ultrasound assisted extraction process was modeled using adaptive neuro-fuzzy inference system (ANFIS) algorithm and integrated with the genetic algorithm for optimization purposes. The independent variables that influenced the responses (total phenolic content, antioxidant activity, total anthocyanin activity, and total flavonoid content) were ultrasonication power, temperature, molar ratio of DES, and water content of DES. Each ANFIS model was formed by the training of three Gaussian-type membership functions (MF) for each input, trained by a hybrid algorithm with 500 epochs and linear type MF for output MF. The ANFIS model predicted each response close to the experimental data which is evident by the statistical parameters (R2>0.953 and RMSE <1.165). The integrated hybrid ANFIS-GA algorithm predicted the optimized condition for the process parameters of ultrasound assisted extraction of phytochemicals from red cabbage was found to be 252.114 W for ultrasonication power, 52.715 °C of temperature, 2.0677:1 of molar ratio of DES and 25.947 % of water content in DES solvent with maximum extraction content of responses, with fitness value 3.352. The relative deviation between the experimental and ANFIS predicted values for total phenolic content, antioxidant activity, total anthocyanin activity, and total flavonoid content was found to be 1.849 %, 3.495 %, 2.801 %, and 4.661 % respectively.

Grain refinement of NiTi alloys during ultrasound-assisted wire-arc directed energy deposition

ABSTRACTAchieving grain refinement in the wire-arc directed energy deposition (DED) process of NiTi alloy is highly challenging. We have successfully obtained NiTi alloy with a fine microstructure and observed an improvement in superelastic recoverability by introducing an ultrasound-assisted field during the deposition process. The results show that the average grain size of the NiTi alloy samples decreased from 147.3 to 72.2 μm. Additionally, the recoverable strain of the samples increased significantly from 3.7% to 4.4%. This is attributed to the ultrasonic cavitation and acoustic streaming phenomena during the ultrasound-assisted process, which promotes the columnar-to-equiaxed transition (CET) during the solidification process. Fundamentally, the key to the enhancement of recoverable strain after ultrasound-assisted is that the formation of equiaxial grains provides more strain compatibility to the grain boundaries, which reduces the formation of dislocations during deformation.

Characteristics and molecular properties of crude hemeproteins extracted from Asian seabass gills using an ultrasound-assisted process.

The development of a safe and effective iron supplement is important for the treatment of iron-deficient anemia. Therefore, the crude hemeprotein extract (CHPE) from Asian seabass gills wasextracted without (CON) and with ultrasound (US)-assisted process, followed by freeze-drying. The resulting freeze-dried crude hemeprotein extract (FDCHPE) powders were determined for trace mineral content, color, secondary structure, protein pattern, size distribution, volatile compounds, and amino acid composition. The extraction yields of CON-FDCHPE and US-FDCHPE were 6.76% and 13.65%, respectively. Highest heme iron (0.485 mg/mL) and non-heme iron (0.023 mg/mL) contents were found when US at 70% amplitude for 10 min (US 70/10) was applied. Both CON-FDCHPE and US-FDCHPE had no heavy metals, but higher iron content (432.8 mg/kg) was found in US-FDCHPE (P < 0.05). Typical red color was observed in CON-FDCHPE and US-FDCHPE with a*-values of 9.72 and 10.60, respectively. Ultrasonication affected protein structure, in which β-sheet upsurged, whereas random coil, α-helix, and β-turn were reduced. Protein pattern confirmed that both samples had myoglobin as the major protein. US-FDCHPE also showed a higher abundance of volatile compounds, especially propanal, hexanal, heptanal, and so forth, compared to CON-FDCHPE. Amino acid composition of US-FDCHPE was comparable to Food and Agriculture Organization of the United Nations (FAO) values. Overall, FDCHPE extracted using ultrasonication could be safe and effective for fortification in food products as an iron supplement to alleviate iron-deficient anemia. Additionally, gills as leftovers could be better exploited rather than being disposed. © 2023 Society of Chemical Industry.

Enhancing biodiesel production from waste date seed oil through ultrasonic-assisted optimization: A sustainable approach using non-edible feedstocks

Using non-edible materials as feedstocks in the production of biodiesel is a promising alternative to fossil fuels. Date seed oil (DSO) is an emerging and promising source for biodiesel production owing to its environmental benefits. In this work, ultrasonic-assisted biodiesel production from DSO was investigated using the Box-Behnken design (BBD) approach to optimize the critical reaction variables for a high product yield. A maximum biodiesel yield of 97.3 % was obtained at optimized conditions of 6.1:1 Methanol:DSO ratio, 0.47 wt.% KOH loading, and 52 °C for a batch reaction time of 10 min. Analysis of variance (ANOVA) studies showed that all the input variables and their interaction terms had a significant effect on the biodiesel yield. Further, the predicted quadratic model exhibited a significant correlation with experimental results with a correlation coefficient (R2) value of 0.9897. Kinetic studies showed the superiority of ultrasonics over mechanical stirring for DSO's triglycerides conversion that followed pseudo-first-order kinetics. The physical and chemical properties of the produced biodiesel were closely aligned with ASTM D6751 standards. Thus, the results of this study can be used for the development of biodiesel production from waste date seed oil on a larger scale using the ultrasound-assisted process.

Investigation and optimization of ultrasound-assisted process of carbon dioxide absorption into amine-based nanofluids

In this study, the effect of the simultaneous application of the nanofluids and ultrasound waves on the carbon dioxide (CO2) absorption process has been investigated in a batch system. For this purpose, the methyl diethanolamine (MDEA)-based nanofluids containing zinc oxide (ZnO) nanoparticles were prepared through a two-step procedure and used as the liquid absorbents. The absorption experiments were carried out using the pressure drop method in an isothermal reactor equipped with a high-frequency (1.7 MHz) ultrasound transducer. The effects of various factors, including the temperature, initial pressure, MDEA concentration, nanoparticle concentration, and ultrasonic power upon the absorption process, were investigated using the design-of-experiments (DOE) method. At first, a parameter screening was applied to determine the significant factors affecting the process. After removing the insignificant parameters, the process optimization was performed using the response surface method (RSM). The results indicated that the employment of high-frequency ultrasound waves had a great effect on improving the CO2 absorption rate. By using a small amount of ultrasonic power (3.9 W), the absorption rate was increased by 632%. The results of the screening revealed that among the mentioned input factors, the effects of the ultrasound power, MDEA concentration, and initial pressure on the process were significant, and the effects of the other factors were insignificant. Based upon the results, among the input factors, the ultrasonic power had the greatest impact on the CO2 absorption rate. The results also revealed that the utilization of ZnO nanoparticles in the ultrasound-assisted process of CO2 absorption, could lead to a slight reduction in the absorption rate, resulting from attenuation of the ultrasonic wave propagation in the liquid due to the presence of nanoparticles. The results of RSM optimization demonstrated that the best model to describe the process behavior was the quadratic model. A polynomial relation was also presented in terms of the factors affecting the process. Additionally, the optimal values of the input factors were determined to attain the maximum absorption rate by using RSM optimization.

Sonochemically prepared bismuth doped titanium oxide-reduced graphene oxide (Bi@TiO2-rGO) nanocomposites for effective visible light photocatalytic degradation of malachite green

In the present work, rGO (reduced graphene oxide) was used as a support material for the preparation of Bi@TiO2-rGO nanocomposites with uniform morphology with using ultrasound assisted process. Bi@TiO2-rGO nanocomposites samples at various loading of Bi were prepared by a facile sol-gel method assisted by ultrasound waves and their performance was compared with nanocomposites prepared by conventional stirring method. Formation of Bi and Ti based nanoparticles supported with rGO sheet was confirmed by scanning electron microscopy. The successful incorporation of rGO, Bi and Ti in Bi@TiO2-rGO nanocomposites was confirmed by XRD, Raman spectroscopy and EDAX. The XRD study showed phases corresponding to Bi, Ti and rGO and indicated the formation of crystalline Bi@TiO2-rGO nanocomposite. From the morphological analysis of nanocomposites, uniformly decorated layered morphology was observed. XRD and Raman analyses confirmed the presence of Bi, Ti and formation of rGO during preparation of Bi@TiO2-rGO nanocomposite using ultrasound assisted and conventional method. Prepared Bi@TiO2-rGO nanocomposite was applied for the degradation of malachite green dye. The photocatalytic degradation experiments were carried out in sunlight using Bi@TiO2-rGO nanocomposites prepared with varied loading of Bi using ultrasound and conventional method. At the optimum condition, degradation was found to be 93.34 % in sunlight.

Ultrasound assisted Sono-Fenton process including FeMnO3 nanocatalysts for degradation of phenazopyridine

This study describes the synthesis of FeMnO3 magnetic nanocatalysts using a hydrothermal method. The nanocatalysts were used to degrade phenazopyridine hydrochloride (PhP) through the Sono-Fenton method, an advanced oxidation technique. The fabricated FeMnO3 nanocatalysts underwent various characterization techniques, including field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), and Brunauer Emmett Teller (BET) analysis. Based on the XRD pattern and FE-SEM images, the cubic crystal structure and particle uniformity were confirmed. The catalytic performance of FeMnO3 nanocatalysts was examined in terms of their ability to remove PhP. Additionally, the impact of various parameters on the degradation rate of phenazopyridine was investigated. The optimal values for pH, nanocatalyst dosage, H2O2 concentration, and sonication time were found to be 10, 1 g/L, 1.2 mol/L, and 30 min, respectively. The degradation efficiency was eventually found to be 97 %. The most significant advantages of these nanocatalysts include their reusability without any significant decrease in reaction efficiency, rapid reaction time, ease of synthesis, and lack of requirement for complex systems.

Degradation of binary mixtures of dyes by step-scheme quaternary photocatalyst in continuous flow-loop ultrasound assisted micro-photoreactor

The development and design of micro-scale photocatalytic systems to achieve the degradation of organic pollutants such as dyes to improve environmental conditions is very desirable. In the current study, a microfluidic-based ultrasound-assisted photocatalytic microreactor was used for degradation of a mixture of cationic dyes including RhB and MB in binary mode by quaternary CeO2/Co3O4/Ag/Ag3PO4 step-scheme (S- scheme) photocatalyst under visible LED light. Various characterizations were performed to determine the morphology and structure of the photocatalyst. The ultrasound-assisted photocatalytic micro-photoreactor shows a much higher degradation performance than the simple micro-photoreactor for the degradation of cationic dyes. Besides, the batch process shows higher photocatalytic activity compared to the micro-photoreactor under ultrasound-assisted process. In addition, the reaction constant of CeO2/Co3O4/Ag/Ag3PO4 composite in ultrasound assisted micro-photoreactor are about 0.0087 1/s and 0.0081 1/s (RhB and MB) which are almost 2.3 and 1.7 times higher than micro-photoreactor due to free radicals, ultrasonic waves and Dean vortices. The observation of findings illustrated the photocatalytic degradation of dyes by the as-prepared composite in various processes were in the order of batch mode > ultrasound assisted micro-photoreactor > micro-photoreactor. The strategy of micro-photoreactor with ultrasonic waves using photocatalytic composite to improve dye degradation performance can lead to the development of advanced micro-photoreactor based on photocatalytic composites with high performance for wastewater treatment applications.

Characterization and recycling of raw fly ash derived through stems of Sesamum indicum as a proficient adsorbent for chlorazol black E from wastewater

Coal fly ash (CFA) is an anthropogenic industrial byproduct that is expected to increase exponentially to fulfill the needs of energy using coal and agro-waste as a cheap fuel. The disposal of this classified human carcinogen is a major concern in developing and underdeveloped economies due to lack of resources. Recycling and value addition of industrial waste, coherence with sustainable development goals is a viable solution. Zeolitization of coal fly ash is an ideal approach for recycling this waste into superior products to be used in a variety of industrial applications. This study was aimed to recycle CFA to useful zeolites using ultrasound assisted hydrothermal process. Sesamum indicum plant stems based fly ash (rFA) was found to belong to class “F" and has very low moisture and carbon contents. To investigate the morphology and elemental composition of rFA and UHSZ, SEM/EDX was used along with XRD, FTIR and Raman spectroscopy which confirmed the existence of quartz, mullite and anhydrite. SEM/EDX results revealed the presence of Al, Si, S, K, Sb, Mg and Ta in raw ash. Adsorption studies of both rFA and synthesized zeolite(UHSZ) were conducted to determine the quintessential parameters of pH, time, initial dose of adsorbent for optimum results. Fabricated zeolites (2 ​g/100 ​mL) from raw fly ash removed 90–98% of chlorazol black E (DB38) from 100 ​mg/L solution within 40 ​min at pH ​≈ ​7. Both Langmuir and Freundlich isotherms gave best fit, which validated that the adsorption of DB38 to UHSZ was a blended process rather than a simple monolayer adsorption mechanism. Pseudo 1st-order and 2nd-order kinetic models were adopted to fit the obtained kinetic data. The pseudo 2nd-order kinetic model was found to be most related.

Antioxidant Potential of Spray- and Freeze-Dried Extract from Oregano Processing Wastes, Using an Optimized Ultrasound-Assisted Method.

Origanum vulgare is recognized worldwide for its numerous applications, in the food industry and beyond. However, the extraction of its essential oils generates a significant amount of waste. The aim of this research was to achieve the valorization of solid waste from oregano hydro-distillation, by (i) optimizing the ultrasound extraction of antioxidants, (ii) evaluating the effect of spray and freeze drying on the extract's physicochemical properties, and (iii) characterizing the obtained powder by its antioxidant capacity. A central composite design of experiments was used to optimize the sample/solvent ratio, ethanol/water ratio, and extraction time. The extract was analyzed for its antioxidant potential by determining the percentage of DPPH inhibition, FRAP, and total phenolic content (TPC). The GAB model best fit the data for the moisture sorption isotherm of the resulting powder. The antioxidant activity of the powders was tested in a ground-beef food system. The TPC was maximized at times longer than 58 min, a sample/solvent ratio between 0.058 and 0.078, and a ratio of ethanol/water around 1. Neither drying method significantly affected the antioxidant properties of the extract, even though the resulting powders from each showed a different morphology (determined using SEM). Encapsulation with maltodextrin protected the spray-dried extract during a 6-month storage period. Powders from both drying methods equally retarded lipid oxidation, and were comparable to the synthetic antioxidant BHT. It is concluded that oregano processing waste is a potent source of antioxidants, and that its dried extract, via an ultrasound-assisted process, can potentially be used as a natural alternative to synthetic antioxidants.

Statistical optimization of ultrasound‐assisted biodiesel production from Moringa oleifera oil – waste cooking oil mixture using modified conch shell catalyst

AbstractBiodiesel is a potential alternative fuel that offers several environmental benefits and can be used in conventional engines. However, high feedstock cost poses a challenge for its commercial viability. This study focuses on producing biodiesel using waste cooking oil (WCO) and Moringa oleifera oil (MOO) as feedstock, with a specific emphasis on the use of modified conch shell as solid catalyst under ultrasonic conditions. Different mixtures of WCO and MOO were evaluated for their suitability in a two‐stage esterification transesterification process, and the acid value of the WCO‐MOO blend was reduced through an ultrasound‐assisted esterification process. Additionally, a calcium oxide‐based catalyst was developed from conch shells (CS) through calcination for 3 h at 900°C and further modified using water and methanol. The characterization studies confirm the successful development and modification of the CS catalyst and also demonstrates excellent catalytic activity. The ultrasound assisted transesterification process parameters were optimized using response surface methodology (RSM) based Box–Behnken design (BBD). By employing a catalyst loading of 5.8 wt%, methanol to esterified oil volumetric ratio of 0.37:1, and an ultrasonication time of 57 min, a maximum predicted methyl ester conversion of 94.7% was achieved. Therefore, this work provides valuable insights into the use of modified conch shell catalyst for biodiesel production from WCO and MOO mixtures thereby contributing to the advancement of cost‐effective and environmentally friendly biodiesel production methods.

Evaluation of ultrasound-assisted process as an approach for improving the overall quality of unsmoked bacon

Our previous study has found that ultrasonic application on raw meat could improve the flavor of unsmoked bacon. For comprehensively evaluating the impacts of ultrasonic pretreatment (0, 250, 500 or 750 W, 20 kHz) on the overall quality of unsmoked bacon during processing, the following indicators were determined including salt and water content, pH, shear force, color, water distribution, texture and myofibril microstructure. Results manifest that ultrasonic pretreatment could significantly improve the salt and water content, pH and redness of unsmoked bacon. The water retention capacity was obviously enhanced by ultrasonic pretreatment proved by increased immobile water and decreased free water. Meanwhile, the shear force, the hardness and the chewiness were notably ameliorated after ultrasonic pretreatment, suggesting a better tenderness verified by the observation results of transmission electron microscope. However, no significant differences were found on the brightness, yellowness, springiness, cohesiveness and resilience of unsmoked bacon after ultrasonic pretreatment. Consequently, ultrasound could be considered as a potential tool for the overall-quality improvement of unsmoked bacon.