Microwave Hydrodiffusion And Gravity Research Articles

Perbandingan Metode Microwave Hydrodiffusion and Gravity (MHG) dan Microwave Steam Diffusion (MSDf) untuk Mengekstrak Minyak Atsiri dari Kulit Jeruk (Citrus Aurantium L.)

Orange production in 2020 projected to reach more than 3.2 million tons, with an estimated growth of 4.93% per year. As a result, large amounts of orange peel are available as a by-product and are treated as waste, creating environmental problems. This problem can be turned into potential if essential oils can be extracted from orange peels. The purpose of this study is to compare the methods of Microwave Hydrodiffusion and Gravity (MHG) and Microwave Steam Diffusion (MSDf) in terms of extraction time velocity, yield, electricity consumption, environmental impact (CO2 gas emissions) and their chemical composition. In this study, 300 grams of fresh orange peel (Citrus aurantium L) used with three microwave power variations: 136 watt, 264 watt, and 440 watt and extraction time of 15 minutes, 30 minutes, 45 minutes, and 60 minutes. The MSDf method produces yields faster than the MHG method at an optimal power of 264 W. In the 20th minute, the MSDf method produces an essential oil yield of 1.95%, while the MHG method produces 1.93% yield at the 40th minute. The MSDf method provides the number of oxygenated compounds (1.4%) is higher than the MHG method (1.12%). This study shows that the MSDf method can produce better quality oils as like as the MHG method. Based on the electricity consumed ratio, the MSDf method is 50% more energy-efficient than the MHG method. Emissions of CO2 gas released into the air in the MSDf method (0.07 kg) are also less than MHG (0.14 kg), so the impact on the environment is not too significant.

Microwave hydrodiffusion and gravity model with a blend of high and low power microwave firing for improved yield of phenolics and flavonoids from oyster mushroom

Oyster mushrooms are a globally important entity both commercially and therapeutically with immense food value. The work describes a successful application of a unique method of microwave hydrodiffusion and gravity combining optimal mix of high and low power microwave firing for the extraction of phenolics and flavonoids principles from oyster mushroom for the first time. Initial firing of microwaves at higher power level (510 W for 2 min and 340 W for 2 min) was applied followed by sustained microwave firing at 170 W till the completion of the extraction as indicated by physical oozing out of the aqueous extract. Such a combination of microwave firing in microwave hydrodiffusion and gravity (MHG) method (26 min) successfully produced two times more yield of extract with 57.7% ± 2.8 and 82.3% ± 3.7 more content of phenolics and flavonoids, respectively, when compared to 5 h Soxhlet extraction and that too with a better reproducibility. Mapping of individual phenolics/flavonoids were carried out and SEM images were studied for better understanding of the operational aspects. The research aims towards canvassing green technologies as in the near future only those technologies shall survive which are in tandem with environment.

Microwave hydrodiffusion and gravity as pretreatment for grape dehydration with simultaneous obtaining of high phenolic grape extract

The present study aimed to verify the efficiency of microwave hydrodiffusion and gravity (MHG) by partially removing water from grapes while simultaneously obtaining a phenolic-rich extract. In addition, the effect of heating on phenolic compound degradation of pre-dehydrated grapes, the extract, and economic viability to produce both products were evaluated. Thus, a 50% reduction of moisture in the grapes was observed after 10 min while simultaneously obtaining a grape extract. Both products obtained by MHG presented high phenolic compound content and antioxidant capacity. In addition, the use of MHG on an industrial scale was found to be economically viable based on the analysis time, labor cost, and financial return of the products obtained. Thus, the method is efficient, fast, economically viable, and sustainable while simultaneously producing pre-dehydrated grapes and a phenolic-rich extract.

Tailoring hybrid carrageenans from Mastocarpus stellatus red seaweed using microwave hydrodiffusion and gravity

This work deals with the use of microwave hydrodiffusion and gravity (MHG) for the recovery of hybrid carrageenans with specific mechanical features together with bioactive compounds. For this purpose, Mastocarpus stellatus red seaweed was used as raw material and the most adequate MHG processing conditions were studied. The physicochemical properties of the algae and the corresponding biopolymers, the fundamental characterisation of the bioactive compounds from the extracts (antioxidant capacity, sulfate content, protein content, among others) and the rheological features of the formulated gels were analysed. Results indicated that MHG is an adequate technique for obtaining functional extracts with potential applications in the food and non-food fields. Hybrid carrageenans with a wide range of viscoelastic features were recovered by MHG, saving time compared to conventional methods. The yields obtained for the recovered hybrid carrageenans and bioactive fractions were comparable to those obtained in red algae with conventional techniques.

Microwave hydrodiffusion and gravity versus conventional distillation for Acacia dealbata flowers. Recovery of bioactive extracts for cosmetic purposes

Natural extracts recovered from underutilized wild Acacia dealbata flowers using microwave hydrodiffusion and gravity (MHG) were compared with those obtained from conventional steam distillation. Several irradiation powers (50–125 W) were studied. MHG solid phases were treated by solid-liquid extraction (SLE) with ethanol solvent. Their total phenolic content, antioxidant capacity, total carotenoid content, color characteristics, pH value and solar protection factor (SPF) were tested. Selected extracts were incorporated to an oil-in-water emulsion cosmetic model made with three thermal spring waters and preliminary sensory analysis was made. These creams were chemically and rheologically analyzed jointly with their bioactive capacity by an acceleration oxidation test. The optimum MHG extract was collected at 75 W for 180 min, since this flower liquor exhibited the highest total phenolic content (around 0.15 mg GAE/g flower dry weight) and antioxidant capacities (about 0.39 mg Trolox eq/g flower dry weight and 0.36 μg β-carotene/g flower dry weight) of microwave extracts. Distillation extracts presented higher concentrations (about 0.20 mg GAE/g flower dry weight and around 0.58 mg Trolox eq/g flower dry weight), but with larger (two times) estimated specific energy requirements. Selected extracts provided sunscreen creams with similar chemical (i.e., pH and SPF values) and bioactive properties (i.e., thiobarbituric acid reactive substance outcomes) that cosmetics prepared with BHT or (±)-α-tocopherol commercial antioxidants. The viscosity features of the different cosmetic samples were similar, except for those sun creams elaborated with one thermal spring water. This sample presented lower apparent viscosity profiles, which could be an important advantage from the skin application point of view.

Jabuticaba peel extract obtained by microwave hydrodiffusion and gravity extraction: A green strategy to improve the oxidative and sensory stability of beef burgers produced with healthier oils

Hydrogelled emulsions (HE) from chia and linseed oils (1:1) were made with different concentrations (0, 6, 8, and 10%) of jabuticaba peel extract (JPE) obtained by microwave hydrodiffusion and gravity (MHG) extraction. Burgers (20% fat) were produced with the replacement of 60% of fat by HEs. The oxidative profile and the sensory quality of raw and cooked burgers were evaluated for 120 days (−18 °C). The JPE exhibited 1.72 mg/mL of phenolic compounds and 57,741.67 μmol TE/mL of antioxidant capacity. In addition, the MHG extraction eliminated the mesophilic bacteria from the jabuticaba peel. The burgers made with HE and without the addition of JPE showed a 5-fold increase in TBARS values when compared to the control. On the other hand, the addition of 10% JPE to HE was effective to maintain the lipid oxidation similar to the control until the 60th day of storage. Besides, the incorporation of JPE into HE reduced the sensory defects caused by the lipid reformulation.

Clean technologies applied to the recovery of bioactive extracts from Camellia sinensis leaves agricultural wastes

This study deals with the valorisation of tea leaves from the agricultural pruning remains using clean technologies with low environmental impact. Leaves with null commercial interest were dismissed during the pruning season, however with a sequential combination of microwave hydrodiffusion and gravity (MHG), ultrasound-assisted (US) and pressurized hot water (AH) extractions was possible to recover bioactive compounds. An initial pre-treatment was performed using MHG at selected irradiation powers to facilitate the liberation of antioxidants through the cell membrane. The solid phases were processed by three ways: i) ultrasound bath system (80°C, 80KHz, from 15 to 60min); ii) AH technology (non-isothermal treatment with maximum temperature from 140 to 200°C); and iii) a sequence of the three aforementioned technologies. Both raw material and liquors were analysed to determine fundamental physicochemical, phytochemical or biological properties. Leaves debris showed positive results in bioactive compounds with a maximum value of total phenolic around 130mg GAE/g extract in the sequential combination. Antioxidant capacity ranged from 0.3 to 0.9g Trolox/g extract. The combination of green extraction technologies guarantees an efficient recovery of bioactive compounds, creating the possibility of new products that improve the wellbeing.

Bioactive extracts from edible nettle leaves using microwave hydrodiffusion and gravity and distillation extraction techniques

Microwave hydrodiffusion and gravity (MHG) was compared with conventional steam distillation from edible nettle leaves. The optimum MHG-extract was collected at 100 W, with the lowest energy consumption (∼788 kJ) and the highest total phenolic content or antioxidant capacities (∼0.04 mg GAE/g nettle leaves dry weight or 0.11 mg Trolox eq/g nettle leaves dry weight). Similar chemical, bioactive and stability features were obtained for creams with added nettle leave extracts and commercial antioxidants. Rheology of emulsions with different type of water did not present differences apart from samples made with thermal water 3 and MHG-extract. The addition of MHG-extract in the shampoo provided an increase of their foaming ability and stability jointly with an initial positive change of the lightness on the volunteer’s natural hair (ΔL*∼2.6).

Biological Effects of Glucosinolate Degradation Products from Horseradish: A Horse that Wins the Race.

Horseradish degradation products, mainly isothiocyanates (ITC) and nitriles, along with their precursors glucosinolates, were characterized by GC-MS and UHPLC-MS/MS, respectively. Volatiles from horseradish leaves and roots were isolated using microwave assisted-distillation (MAD), microwave hydrodiffusion and gravity (MHG) and hydrodistillation (HD). Allyl ITC was predominant in the leaves regardless of the isolation method while MAD, MHG, and HD of the roots resulted in different yields of allyl ITC, 2-phenylethyl ITC, and their nitriles. The antimicrobial potential of roots volatiles and their main compounds was assessed against sixteen emerging food spoilage and opportunistic pathogens. The MHG isolate was the most active, inhibiting bacteria at minimal inhibitory concentrations (MICs) from only 3.75 to 30 µg/mL, and fungi at MIC50 between <0.12 and 0.47 µg/mL. Cytotoxic activity of volatile isolates and their main compounds were tested against two human cancer cell lines using MTT assay after 72 h. The roots volatiles showed best cytotoxic activity (HD; IC50 = 2.62 μg/mL) against human lung A549 and human bladder T24 cancer cell lines (HD; IC50 = 0.57 μg/mL). Generally, 2-phenylethyl ITC, which was tested for its antimicrobial and cytotoxic activities along with two other major components allyl ITC and 3-phenylpropanenitrile, showed the best biological activities.

Blanching impact on pigments, glucosinolates, and phenolics of dehydrated broccoli by-products

Because of high water content, the valorisation of broccoli by-products requires dehydration that can preserve bioactive compounds. Blanching pre-treatment has been reported to improve the drying rate of broccoli. As a thermal treatment, it promotes also enzyme inactivation. Therefore, in this study, the impact of pre-dehydration blanching step, freeze-drying, air-drying at 40 °C, and microwave hydrodiffusion and gravity (MHG) dehydration on the levels of pigments, glucosinolates, and phenolics, was evaluated by UHPLC-DAD-ESI/MSn. When compared to freeze-drying, a technique known to preserve compounds, a pre-blanching step increased the extractability of both pigments and phenolics, while air-drying only retained 49% of the pigments and 70% of phenolics, both without affecting glucosinolates. However, when air-drying was preceded by blanching, less than 50% of compounds were retained. On the other hand, MHG dehydration increased the phenolics extractability by 26%, particularly that of kaempferol derivatives while also retaining the amount of the glucosinolate glucoraphanin, when compared to freeze-drying. Nevertheless, only 23% of indole glucosinolates were recovered and pigments were severely reduced, with lutein accounting only for 32% and only chlorophyll b was observed in trace amounts after MHG dehydration. Therefore, to valorise broccoli by-products as ingredients, different drying technologies may be used when targeting different composition richness: freeze-drying is suitable for pigments and glucosinolates, air-drying is suitable for glucosinolates, while MHG promotes the extractability of phenolic compounds.

Solvent-free simultaneous extraction of volatile and non-volatile antioxidants from rosemary (Rosmarinus officinalis L.) by microwave hydrodiffusion and gravity

The demand for more efficient environmentally friendly extraction processes is increasing and microwave technology has emerged as remarkable alternative. In this way, microwave hydrodiffusion and gravity (MHG) was purposed as a fast and solvent-free simultaneous extraction of two antioxidant fractions from rosemary (Rosmarinus officinalis L.). The wetted plant material was placed inside the microwave oven, and the extraction conditions optimised using central composite design. The most suitable conditions found for the simultaneous extraction of both volatile and non-volatile fractions from 100 g of plant were 400 W of microwave power, 20 min of extraction and 250 mL of water added for plant wetting. The essential oil yield of 2.32 % was comparable to that obtained by hydrodistillation (HD) of 2.35 %. The profile of extracts obtained by HD and MHG presented differences, with more oxygenated compounds in the essential oil obtained by MHG. In addition, the antioxidant activity of the oil obtained by MHG reached 430 versus 211 μmol Trolox equivalent/g oil for HD. The aqueous extract recovered by MHG presented a total phenolic content similar to 1 h of maceration and also displayed higher antioxidant activity. Phenolic compounds with known antioxidant activity were identified in the aqueous extract from rosemary using high-resolution time-of-flight mass spectrometry with electrospray ionisation. The proposed MHG extraction recovered both volatile and non-volatile fractions in only 20 min and can be considered a clean alternative for antioxidants extraction without the use of solvents.

Antioxidant capacity of the extracts from flowers of Erica australis L.: Comparison between microwave hydrodiffusion and gravity (MHG) and distillation extraction techniques - Formulation of sunscreen creams

Microwave hydrodiffusion and gravity (MHG) extraction of Erica australis flowers was optimized evaluating different microwave irradiation powers (25−200 W). Collected extracts were compared with the liquid phase obtained by conventional distillation. Their total phenolic content, antioxidant capacity and color features were evaluated. Microscopical properties of the flower tissues allowed assessing the distinct effects of the extraction processes. The cosmetic application of the collected bioactive extracts in the formulation of sunscreen creams with waters from three different thermal spring waters and the corresponding characterization (e.g. chemical, bioactive and rheological features) and sensory analysis were also made. For cosmetic comparative purposes, extracts from Ulex europaeus flowers obtained by MHG procedure was also analyzed. The stability of these oil-in-water model emulsions was tested during accelerated oxidation conditions. Results indicated that MHG at 50 W for 130 min was the most adequate work conditions for the extraction of antioxidant compounds from these wild flowers (around 0.27 mg Trolox eq/g flower dry weight and 0.01 mg ascorbic acid/g flower dry weight or 0.04 mg FeSO4 * 7H2O/g flower dry weight). This procedure also led a drop of energy consumption environmental impact (about 8 times less) in comparison with distillation method. Small total color differences were detected between the gathered extracts. The incorporation of flower extracts produced similar effects when compared with added commercial antioxidants except for viscous behavior. Sensorially, E. australis extract incorporated with thermal waters displayed a positive effect on the skin cream application of the formulated cosmetic, mainly with thermal water 3.

Microwave Hydrodiffusion and Gravity (MHG) Extraction from Different Raw Materials with Cosmetic Applications.

Microwave hydrodiffusion and gravity (MHG) and ethanolic solid-liquid extraction were compared using selected plant sources. Their bioactive profile, color features, and proximate chemical characterization were determined. MHG extracts, commercial antioxidants, and three distinct types of thermal spring water were used in a sunscreen cream formulation. Their bioactive capacity, chemical and rheological properties were evaluated. MHG Cytisus scoparius flower extract provided the highest bioactive properties. Pleurotus ostreatus MHG liquor exhibited the highest total solid extraction yield. The Brassica rapa MHG sample stood out for its total protein content and its monosaccharide and oligosaccharide concentration. Quercus robur acorns divided into quarters supplied MHG extract with the lowest energy requirements, highest DPPH inhibition percentage, total lipid content and the highest enzyme inhibition. The chemical and bioactive capacities stability of the sunscreen creams elaborated with the selected MHG extracts and the thermal spring waters showed a similar behavior than the samples containing commercial antioxidants.

Preparation of Hydrogels Composed of Bioactive Compounds from Aqueous Phase of Artichoke Obtained by MHG Technique

This work deals with the valorisation of artichoke industrial wastes from natural and blanched processed samples to prepare innovative functional gelling matrices. For this purpose, the recovery of bioactive liquid phases using microwave hydrodiffusion and gravity (MHG) in a broad range of irradiation powers and the corresponding phytochemical and colour characterisations were conducted. Liquid phases with the highest bioactive compounds were used to formulate functional hydrogels. These gelled systems were mechanically characterised. Phytochemical analyses indicated that the highest bioactive features were identified for liquors collected from both natural and blanched samples MHG-treated at 500 W. The blanching pre-treatment favoured the bioactive compound recovery, without notable differences in terms of colour properties. In general, no significant differences (p > 0.05) were observed in energy consumption when MHG treatments for natural and blanched artichoke extractions were compared. In all selected cases, typical gel spectra were observed for bioactive liquid phases gelled using both alginate and gelatine. Softening of the gelled matrices was identified in the presence of bioactive extracts. Texture profile analyses for natural and blanched artichoke samples were consistent with the results obtained by rheology. Phytochemical and colour analyses indicated that frozen storage was an adequate method to preserve the bioactive properties of the samples for at least 3 years.

Valorisation of edible brown seaweeds by the recovery of bioactive compounds from aqueous phase using MHG to develop innovative hydrogels

Abstract The effect of microwave hydrodiffusion and gravity (MHG) treatment (over the range of 50 to 800 W) on the recovery of liquid phases with bioactive compounds from two edible brown seaweeds, and the corresponding colour characteristics, were studied. For comparative purposes, conventional distillation technique was performed. The potential application of the collected bioactive liquid phases in the formulation of functional hydrogels was evaluated. The obtained results indicated that liquid phases collected from both Undaria pinnatifida and Laminaria ochroleuca seaweeds MHG-treated at 300 W or selected optimized combination of microwave irradiation powers and times (CPT) exhibited the highest phenolic content or antioxidant capacities. The distillation methodology did not improve the antioxidant liquid features. No notable differences were identified in terms of colour of the liquid phases for both algae. Mechanical spectra and textural profiles of the selected hydrogels exhibited typical gel behaviour and suggested that liquid phases with the highest bioactive properties involves the hydrogels softening. It was found that the liquid phases collected by MHG technology from edible brown seaweed would be a suitable resource for the formulation of functional hydrogels with bioactive properties with potential development in food and other industries.

Microwave hydrodiffusion and gravity for rapid extraction of essential oil from Tunisian cumin (Cuminum cyminum L.) seeds: Optimization by response surface methodology

Recently, microwave hydrodiffusion and gravity (MHG) pushed the confines of the microwave assisted extraction (MAE) further toward an innovative, quick, efficient, and eco-friendly process for plant secondary metabolites extraction. The goal of this study was to optimize the microwave hydrodiffusion and gravity (MHG) process for the extraction of the essential oils (EO) from Tunisian cumin (Cuminum cyminum L.) seeds. The effects of different parameters: microwave irradiation time (8, 12, and 16 min), microwave irradiation power (150, 200, and 250 W), and moisture content (40, 50, and 60%), on the extraction yield were achieved using the response surface methodology (RSM) with central composite design (CCD). In order to elucidate the efficiency of the MHG, it was compared with conventional hydrodistillation (HD) in terms of kinetic, quantity and quality of obtained EO, environmental impact, and energy consumption. Results showed that, under the optimum conditions defined by the central composite face-centered (CCF) and calculated by the analysis of variance (ANOVA) (16 min of microwave irradiation time, 203.30 W of microwave irradiation power, and 44.67% of moisture content), the yield of cumin essential oil obtained with MHG was 1.579 ± 0.05%. Meanwhile, compared with the HD process, the MHG successfully improved the EO yield (1.579 ± 0.05% versus 1.550 ± 0.07% with HD) in shorter extraction time (16 min versus 150 min with HD), less electrical consumption, lower carbon dioxide emissions (CO2), and smaller volume of waste water. Using the GC-FID and GC–MS analysis, the MHG provided more valuable EO with high amount of oxygenated compounds compared with the HD. Scanning electron micrograph (SEM) confirmed the efficiency of MHG for EO extraction. Thus, MHG appeared like rapid process, green technology, and desirable alternative protocol to enhance the quantity and the quality of the essential oil extracted from the medicinal and aromatic plants (MAPs).

Operational efficiencies of six microwave based extraction methods for orange peel oil

Microwave is a very efficient energy carrier for the extraction of essential oils from aromatic plants in unit operations intended for distillation. The aim of this work was to compare six extraction processes: four Microwave Assisted Extraction (MAE) and two conventional processes for the extraction of orange essential oils. The comparison was based on different processing and qualitative criteria such as extraction yield, power efficiency, biochemical and sensorial attributes. Two multiple criteria methods were developed to select the most efficient process.The first method is based on the income over energy cost index. The results show that among the set of extraction processes studied only Microwave Hydrodiffusion and Gravity (MHG) would be operational cost efficient. The second method combines both processing and qualitative criteria. The results show that the extraction processes with combination of microwaves and steam are best ranked followed by those with just microwaves.

Microwave hydrodiffusion and gravity (MHG) processing of Laminaria ochroleuca brown seaweed

Abstract Microwave hydrodiffusion and gravity (MHG) technique was proposed for the dehydration of edible Laminaria ochroleuca brown seaweed and the recovery of the bioactive compounds. The effect of irradiation power (50, 300 and 800 W) and time (below 180 min) on the drying kinetics and its modelling, shrinkage, energy consumption, microstructural and colorimetric features were studied for the solid phase. In parallel, the phenolic content and scavenging capacity were determined for the solid phase. Results showed that the increase in irradiation power from 50 to 800 W led to the drop of the drying times from 180 to 5 min, although with high final moisture contents (20.78 ± 1.20 and 58.24 ± 3.75% wet basis, w.b., respectively). MHG proposed treatment to obtain the optimum L. ochroleuca drying conditions (9.90 ± 0.81% w.b.) was a four steps protocol: 300 W for 5 min followed by 100 W for 10 min, 50 W for 35 min and 25 W for 90 min. All drying kinetics were successfully (R2 > 0.95) fitted with the Page model. An adequate lineal dependence (R2 > 0.94) between shrinkage and moisture content was found. The energy consumption for MHG proposed method was about two decades lower than the values reported for conventional convective air drying of other brown seaweeds. The method settled down provided microstructural, colorimetric and antioxidant capacity properties comparable to the commercially dehydrated seaweed.

Microwave assisted dehydration of broccoli by-products and simultaneous extraction of bioactive compounds

Broccoli by-products from frozen-food industry account for 45% of the initial broccoli heads. They consist on stalks, inflorescences, and leaves, blanched and non-blanched, sharing the nutritional value and bioactive compounds of commercial broccoli heads. However, their high perishability prevents further valorisation. Therefore, in this study microwave hydrodiffusion and gravity (MHG) technology was used to dehydrate broccoli by-products and simultaneously recover the water-soluble diffused compounds for food ingredients use. The hydrodiffusion allowed to obtain a dried material with 12% moisture in 43 min when 550 g of broccoli by-products were used, preserving polysaccharides and proteins. Diffused water contained up to 317 µg/mL gallic acid equivalents of phenolic compounds, 11 mg/mL free sugars, 9 mg/mL amino acids, and 356 µg/mL glucosinolates, depending on the type of by-product used. These results show the potential of MHG technology for valorisation of broccoli by-products by its simultaneous stabilization by dehydration and extraction of bioactive compounds.

Integrating Microwave-Assisted Extraction of Essential Oils and Polyphenols from Rosemary and Thyme Leaves

The extraction of essential oils (EOs) and polyphenols from rosemary and thyme has been done using an integrated process: microwave hydro-diffusion and gravity (MHG) for EOs and microwave-assisted extraction (MAE) for polyphenols. The innovative installation based on the MHG principle allows uniform microwave irradiation field due to a mechanical stirring and experiments done at low pressure. The results of quantitative analysis of the EOs extracted by MHG after 10 min were similar with those obtained by traditional methods (conventional hydro-distillation (CHD) and microwave-assisted hydro-distillation (MHD)) after 150 and 105 min, respectively. The specific energy for MHG was 5–15 times lower compared with these classical methods. The MHG extraction of EOs is also an effective method for plant material pretreatment before polyphenol extraction. Total phenolic content increased from 35 to 55 mg GAE/g DM for rosemary and from 23 to 38 mg GAE/g DM for thyme.