Microwave Hydrodiffusion And Gravity Research Articles

Ultrasound combined with microwave hydrodiffusion and gravity for enhancement of caffeine extraction from guarana powder.

The extraction of valuable compounds from dried fruits and vegetables by microwave hydrodiffusion and gravity (MHG) requires previous hydration of the plant material. In this work, ultrasound was used to speed up the hydration of guarana powder before MHG extraction and increase caffeine recovery. The humidification step was speeded up with ultrasound taking only 15 min over 60 min without ultrasound. Water and 50% (v/v) ethanol were evaluated as green solvents for humidification, with a higher concentration of caffeine obtained for the hydroalcoholic solution. Ultrasound pretreatment allowed guarana extracts from MHG with two times more caffeine for both solvents evaluated. Therefore, ultrasound can be used in the hydration step before MHG extraction to reduce time and increase caffeine recovery from guarana powder.

Iberis sempervirens: Antiproliferative Potential from Our Garden

Glucosinolates (GSLs) extracted from various parts of Iberis sempervirens L., including seeds, stems, leaves, and flowers, were qualitatively and quantitatively assessed. The analyses of GSLs were performed by their desulfo counterparts using the UHPLC-DAD-MS/MS technique and by their volatile breakdown products, isothiocyanates, using the GC-MS technique. The GSL profile comprised various types, including those derived from: methionine, represented by methylsulfinylalkyl GSL (glucoiberin), and methylsulfanylalkyl GSL (glucoibervirin and glucoerucin); phenylalanine (glucotropaeolin); and tryptophan (4-methoxyglucobrassicin). Among these, the highest level of glucoiberin was detected in the leaves, reaching 35.37 µmol/g of dry weight (DW), while the highest level of glucoibervirin was detected in the seeds, reaching 18.51 µmol/g DW. To obtain GSL breakdown products, a variety of isolation methods were employed, including hydrodistillation in a Clevenger-type apparatus (HD), CH2Cl2 after myrosinase hydrolysis for 24 h (EXT), microwave-assisted distillation (MAD), and microwave hydrodiffusion and gravity (MHG). Volatile isolates were tested for their antiproliferative activity using an MTT assay against the human lung cancer cell line A549 and the human bladder cancer cell line T24 during an incubation period of 72 h. HD and MAD showed the best activity against T24, with IC50 values of 0.61 µg/mL and 0.62 µg/mL, respectively, while EXT was the most effective against the A549 cell line, with an IC50 of 1.46 µg/mL.

Significant Benefits of Environmentally Friendly Hydrosols from Tropaeolum majus L. Seeds with Multiple Biological Activities.

Tropaeolum majus L. is a traditional medicinal plant with a wide range of biological activities due to the degradation products of the glucosinolate glucotropaeolin. Therefore, the goals of this study were to identify volatiles using gas chromatography-mass spectrometry analysis (GC-MS) of the hydrosols (HYs) isolated using microwave-assisted extraction (MAE) and microwave hydrodiffusion and gravity (MHG). Cytotoxic activity was tested against a cervical cancer cell line (HeLa), human colon cancer cell line (HCT116), human osteosarcoma cell line (U2OS), and healthy cell line (RPE1). The effect on wound healing was investigated using human keratinocyte cells (HaCaT), while the antibacterial activity of the HYs was tested against growth and adhesion to a polystyrene surface of Staphylococcus aureus and Escherichia coli. Antiphytoviral activity against tobacco mosaic virus (TMV) was determined. The GC-MS analysis showed that the two main compounds in the HYs of T. majus are benzyl isothiocyanate (BITC) and benzyl cyanide (BCN) using the MAE (62.29% BITC and 15.02% BCN) and MHG (17.89% BITC and 65.33% BCN) extraction techniques. The HYs obtained using MAE showed better cytotoxic activity against the tested cancer cell lines (IC50 value of 472.61-637.07 µg/mL) compared to the HYs obtained using MHG (IC50 value of 719.01-1307.03 μg/mL). Both concentrations (5 and 20 µg/mL) of T. majus HYs using MAE showed a mild but statistically non-significant effect in promoting gap closure compared with untreated cells, whereas the T. majus HY isolated using MHG at a concentration of 15 µg/mL showed a statistically significant negative effect on wound healing. The test showed that the MIC concentration was above 0.5 mg/mL for the HY isolated using MAE, and 2 mg/mL for the HY isolated using MHG. The HY isolated using MHG reduced the adhesion of E. coli at a concentration of 2 mg/mL, while it also reduced the adhesion of S. aureus at a concentration of 1 mg/mL. Both hydrosols showed excellent antiphytoviral activity against TMV, achieving100% inhibition of local lesions on the leaves of infected plants, which is the first time such a result was obtained with a hydrosol treatment. Due to the antiphytoviral activity results, hydrosols of T. majus have a promising future for use in agricultural production.

Optimization of Microwave Hydrodiffusion and Gravity (MHG) for Pre-treatment of Dehydration and Obtaining a Jaboticaba Extract

Optimization of Microwave Hydrodiffusion and Gravity (MHG) for Pre-treatment of Dehydration and Obtaining a Jaboticaba Extract

Extraction of Vegetable Oil from Candlenut Seeds (Aleurites Moluccana L. Willd.) Using the Microwave Hydrodiffusion and Gravity (MHG) Method

Extraction of Vegetable Oil from Candlenut Seeds (Aleurites Moluccana L. Willd.) Using the Microwave Hydrodiffusion and Gravity (MHG) Method

Methodology for Extraction of Essential Oils: A Review

The majority of concentrated and volatile Essential oils are extracted from various parts of the plants. Essential oils contain hundreds of organic constituents such as natural elements, vitamins, hormones, etc., widely used in the perfumery and pharmaceutical industries. Different techniques are available for the extraction of essential oil, such as hydro and steam distillation, cold pressing/expression, Maceration, solvent extraction, Effleurage, Carbon Dioxide Extraction, Hydro Diffusion, etc., and innovative techniques like Supercritical Fluid Extraction (S.F.E.), Microwave Assisted Hydro distillation (MAHD), Ultrasound-Assisted Extraction (U.A.E.), Solvent-free Microwave Extraction (SFME), Microwave hydro diffusion and Gravity (M.H.G.). This review paper summarizes the research on various methods for essential oil extraction for various raw materials. The summary of this paper included information on different plant materials, the most suitable extraction method with operating conditions, advantages, and disadvantages of extraction methods, etc.

Microwave Hydrodiffusion and Gravity Extraction of Vitamin C and Antioxidant Compounds from Rosehips (Rosa canina L.).

Rosehips, Rosa canina L. (Rosaceae family), have been used for a long time for their beneficial effects on health, and they are largely exploited in the food and nutraceutical supplement sectors. The aim of this work was to apply and optimize for the first time the microwave hydrodiffusion and gravity (MHG) extraction of rosehips, as a novel application of solvent-free microwave extraction, previously conducted in a similar way only on mulberry, strawberry, and onion. The optimization was performed through a central composite design (CCD) by evaluating the effect of the experimental parameters on the yield; total polyphenol, flavonoid, and anthocyanin contents; radical scavenging activity; and content of vitamin C in the obtained extracts. As a result, the water moistening pretreatment was clearly revealed to possess a pivotal role in the quality of the rosehip extracts. Among the evaluated responses, the yield, the anthocyanin content, and the antioxidant activity were well described by the statistical model. Notably, the optimized MHG extract was compared with the ones obtained by conventional solvent extraction showing higher amounts of vitamin C, polyphenols, flavonoids, and anthocyanins, while the traditional extracts performed better in terms of yield. In conclusion, MHG represents a promising alternative to standard extraction methods for obtaining rosehip extracts rich in vitamin C and antioxidant compounds. In this respect, the results of our research support the employment of MHG on an industrial level for the production of rosehip-based food supplements enriched in vitamin C.

A Comparative Study between Microwave Hydrodiffusion and Gravity (MHG) and Ultrasound-Assisted Extraction (UAE): Chemical and Biological Characterization of Polyphenol-Enriched Extracts from Aglianico Grape Pomace.

The wine industry produces large amounts of grape pomace (GP), a waste that needs to be disposed of properly. Bioactive compounds with high added value can be recovered from GP as an interesting strategy to reduce the environmental impact. Here, two different technologies were employed to recover polyphenol compounds from GP: microwave hydrodiffusion and gravity (MHG) and ultrasound-assisted extraction (UAE). The further purification of UAE and MHG extracts was carried out through solid-phase extraction (SPE) to obtain three fractions, F1, F2 and F3. ATR-FTIR analysis confirmed the presence of sugar and polysaccharide components in F1, as well as non-anthocyanin and anthocyanin compounds in F2 and F3, respectively. Also, the chemical profile was determined by HPLC-UV-DAD, identifying the presence of catechin in F2, and malvidin-3-O-glucoside chloride and cyanidin chloride derivative as the main anthocyanin compounds in F3. The fractions and their parental extracts were characterized for total phenolic content (TPC) and scavenger activity by in vitro assays. We found that F2-MHG and F3-MHG contained phenol contents 6.5 and 8.5 times higher than those of the parental non-fractionated extracts. Finally, F3-MHG (100 μg/mL, w/v) was shown to reduce the proliferation of HT-29 cells.

Glucosinolates and Cytotoxic Activity of Collard Volatiles Obtained Using Microwave-Assisted Extraction.

Glucosinolates (GSLs) in Brassica oleracea L. convar. acephala var. viridis (collard) flower, leaf, stem, and root were analyzed qualitatively and quantitatively via their desulfo-counterparts using UHPLC-DAD-MS/MS. Twelve GSLs were identified, including Met-derived GSLs (sinigrin, glucoibervirin, glucoerucin, glucoiberin, glucoraphanin, progoitrin), Trp-derived GSLs (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin), and Phe-derived GSLs (glucotropaeolin and gluconasturtiin). Total GSL content was highest in the root, having 63.40 μmol/g dried weight (DW), with gluconasturtiin (34.02 μmol/g DW) as the major GSL, followed by sinigrin and glucoibervirin (12.43 and 7.65 μmol/g DW, respectively). Total GSL contents in the flower, leaf, and stem were lower than in root, having 6.27, 2.64, and 1.84 μmol/g DW, respectively, with Trp and/or Met-derived GSLs as the predominant ones. GSL breakdown products were obtained via microwave hydrodiffusion and gravity (MHG) and volatile breakdown products were analyzed using GC-MS techniques. Volatile isolates were tested for their cytotoxic activity using MTT assay. MHG volatile extract from the root demonstrated the best cytotoxic activity against human bladder cancer cell line T24 and breast cancer cell line MDA-MB-231 during an incubation time of 72 h (IC50 21.58, and 11.62 μg/mL, respectively). The activity of the root extract can be attributed to its major volatile, 2-phenylethyl isothiocyanate (gluconasturtiin breakdown product).

Relevance of drying treatment on the extraction of high valuable compounds from invasive brown seaweed Rugulopteryx okamurae

The present paper is focused on the dehydration of the invasive brown seaweed Rugulopteryx okamurae comparing conventional and innovative techniques to maximize the alga potential. The optimized microwave hydrodiffusion and gravity (MHG) treatment allowed an adequate drying of the seaweed together with the recovery of antioxidant and gelling fractions. Chemical and structural profiles of the fresh and dried raw material, dehydration kinetics and the corresponding modelling, antioxidant characteristics of the gathered liquid phases or mechanical properties of the developed formulations were determined. Results indicated that MHG treatment (600 W for 5 min and 200 W for 15 min) involved a dramatic reduction in processing time (from 180 h for sunlight dehydration to 30 h for conventional oven drying and to 20 min for MHG treatment). All drying kinetics were successfully (R2 > 0.94) fitted with two-model parameters, being Page's model (R2 > 0.96) the one that provided the best fits. MHG suggested the recovery of liquid fractions with higher yields and antioxidant potential when compared with those obtained after ethanolic solid liquid extraction of conventionally dried seaweed. Slightly lower mineral content was identified in solid phases remained after MHG treatment. Alginates present in MHG liquid phases exhibited similar structural profiles to their commercial counterparts, featuring lower molecular weight distributions. It was possible to prepare alginate-based hydrogels with smoother viscoelastic properties than those commercially available, incorporated with microparticulate selected extracts after spray-drying treatment.

Microwave-Assisted and Conventional Extractions of Volatile Compounds from Rosa x damascena Mill. Fresh Petals for Cosmetic Applications.

Rosa x damascena Mill. essential oil is mainly used in the cosmetics and perfumery industry, but it also finds application in the food industry as a flavoring agent. The chemical composition of essential oils is affected by environment, soil, harvesting technique, storage condition, and extraction methods. Nowadays, the study and design of greener, more efficient, and sustainable extractive procedures is the main and strategic focus in the chemical research and development of botanical derivatives, especially as regards fragrances and essential oils. Several technologies are available, and the best method to use depends on the desired chemicals, but conventional extractive processes are often laborious and time-consuming, involve large amounts of solvents, and may cause the partial loss of volatiles, affecting the quality of the final product. In the last decade, microwave irradiation has been successfully applied to classical techniques, often improving the general extractive efficiency and extract quality. In the present paper, as a preliminary analytical screening approach, two microwave-mediated techniques, Solvent-Free Microwave Extraction (SFME) and Microwave Hydrodiffusion and Gravity (MHG), and two conventional procedures, Hydrodistillation (HD) and Steam Distillation (SD), were applied and compared for the extraction of volatile compounds from R. x damascena fresh petals to highlight differences and advantages of the selected procedure and of the obtained extracts useful in a cosmetic context as fragrances or active ingredients. The chemical composition of the extracts was investigated by GC-MS and GC-FID. Sixty-one components, distributed in the four techniques, were identified. SD and HD are dominated by oxygenated terpenes (59.01% and 50.06%, respectively), while MHG and SFME extracts are dominated by alcohols (61.67% and 46.81%, respectively). A relevant variability in the composition of the extracts relating to the extraction techniques used was observed. To point out the correlation between the process and composition of the obtained natural products, principal component analysis (PCA) of the data extracted from GC-FID was used. Taking into account a cosmetic application, SFME shows several advantages when compared with the other procedures. The extract (obtained in a significantly higher amount) contains a meaningful lower level of potential fragrance allergenic compounds and quite a double amount of benzyl alcohol and 2-phenyl ethanol that can also enhance the preservative action in personal care products.

Microwave hydrodiffusion and gravity model with a unique hydration strategy for exhaustive extraction of anthocyanins from strawberries and raspberries

This study aimed to verify if microwave hydrodiffusion and gravity (MHG) could efficiently extract anthocyanins from strawberries and raspberries with low environmental impact and costs. Our findings revealed that it was possible to extract 69 and 64% anthocyanins from the strawberries and raspberries in a single extraction step, respectively. When the co-product (product remaining after extracting in natura fruits) was hydrated with green solvents and subjected to re-extraction, it was possible to exhaustively extract the anthocyanins from both fruits. Using the Green Analytical Procedure Index (GAPI), the MHG proved to cause low environmental impact due to the solvents used, enabling the reuse of the co-product for food and pharmaceutical products application. Moreover, the MHG was economically viable, and the sample pretreated with distilled water was the most indicated re-extraction method. The MHG process proved to be exhaustive for strawberry and raspberry anthocyanins, thus demonstrating to be an excellent alternative for sustainable extraction.

Comparative evaluation of physicochemical profile and bioactive properties of red edible seaweed Chondrus crispus subjected to different drying methods

Dehydration of the edible seaweed Chondrus crispus was performed by freeze-drying, conventional oven-drying and emerging microwave hydrodiffusion and gravity (MHG). In this work, the drying kinetics and modelling, estimating specific energy consumption and environmental impact of distinct processes were tested. Color and microstructural features of the dried macroalgae were also evaluated, as well as their nutritive characterization, chemical profile and bioactive potential (antioxidant and antimicrobial activities). Moreover, collected liquid phases from both the defrosted and MHG treated samples were also characterized. All methodologies provided solid phases with an adequate final moisture content. MHG significantly reduced the needed time, specific energy consumption and environmental impact, providing C. crispus with intermediate color and histological structure characteristics. Overall, this trend was also defined to tested chemical parameters and bioactivities. MHG provided aqueous extracts with potential bioactive compounds from this red alga, increasing the efficiency of this drying method.

Optimization of Solvent-Free Microwave-Assisted Hydrodiffusion and Gravity Extraction of Morus nigra L. Fruits Maximizing Polyphenols, Sugar Content, and Biological Activities Using Central Composite Design.

Black mulberry, Morus nigra L. (family: Moraceae), is a healthy food and medicinal plant. Microwave hydrodiffusion and gravity (MHG) is one of the most innovative applications of solvent-free microwave extraction. The aim of this study was to optimize for the first time the MHG solvent-free extraction of polyphenols and sugars from M. nigra fruits. Optimization was carried out using a central composite design (CCD) with selected responses such as extraction yield, total polyphenol (TPC), flavonoid (TFC), anthocyanin (TAC), and sugar (TSC) contents, in addition to DPPH radical scavenging, and α-glucosidase (AGHi), lipase (Li), and xanthine oxidase (XOi) inhibition as tools to evaluate the best parameters for efficient and rapid extraction of black mulberry. The optimized extract was characterized in terms of the aforementioned parameters to validate the models, and was further analyzed for 36 individual polyphenols using HPLC-MS/MS. The optimized MHG extract was finally compared with traditional extracts, and demonstrated much better performance in terms of TPC, TAC, and Li, while the traditional extracts showed better XOi and AGHi. In conclusion, MHG is a valuable green technique for the production of non-degraded black mulberry polyphenol-rich extract and we suggest its larger use in the pharmaceutical and food industries.

Chemical Composition and Biological Activity of Essential Oil and Extract from the Seeds of Tropaeolum majus L. var. altum.

Plant Tropaeolum majus L. (garden nasturtium) belongs to the family Tropaeolaceae and contains benzyl glucosinolate. The breakdown product of benzyl glucosinolate, benzyl isothiocyanate (BITC), exhibits various biological activities such as antiproliferative, antibacterial and antiinflammatory. In order to optimize the content of biologically active volatile compounds in plant extract and essential oil, the use of appropriate extraction technique has a crucial role. The current study investigates the effect of two modern extraction methods, microwave-assisted distillation (MAD) and microwave hydrodiffusion and gravity (MHG), on the chemical composition of volatile components present in the essential oil and extract of garden nasturtium (T. majus L. var. altum) seeds. Investigation of the biological activity of samples (essential oil, extract and pure compounds) was focused on the antiproliferative effect against different cancer cell lines: cervical cancer cell line (HeLa), human colon cancer cell line (HCT116) and human osteosarcoma cell line (U2OS), and the antibacterial activity which was evaluated against the growth and adhesion of Staphylococcus aureus and Escherichia coli to polystyrene surface. Essential oil and extract of garden nasturtium (T. majus) seeds were isolated by two extraction techniques: MAD and MHG. BITC and benzyl cyanide (BCN) present in the extract were identified by gas chromatography-mass spectrometry. Essential oil of T. majus showed higher antiproliferative activity (IC50<5 µg/mL) than T. majus extract (IC50<27 µg/mL) against three cancer cell lines: HeLa, HCT116 and U2OS. BITC showed much higher inhibitory effect on all tested cells than BCN. The essential oil and extract of T. majus showed strong antimicrobial activity against S. aureus and E. coli. This work represents the first comparative report on the antiproliferative activity of the essential oil and extract of T. majus seeds, BITC and BCN against HeLa, HCT116 and U2OS cells as well as their antimicrobial activity against S. aureus and E. coli. This study demonstrates that the essential oil of T. majus seeds exhibits stronger antiproliferative and antimicrobial activity than the plant extract.

Recovery of phenolic compounds from grape pomace (Vitis vinifera L.) by microwave hydrodiffusion and gravity

Food processing has been gradually adopting the use of clean technologies that aim to minimize the generation of by-products. The use of winemaking by-products for the extraction of phenolic compounds is still incipient due to the lack of fast and efficient techniques. Thus, the aim of this study was to use the Microwave Hydrodiffusion and Gravity (MHG) technique to extract phenolic compounds from a winemaking by-product, the grape pomace (GP). The phenolic content of the extracts was analyzed by High Performance Liquid Chromatography (HPLC). Physicochemical and antioxidant properties were evaluated in the MHG extracts and in the GP before and after (co-product - CP) extraction. The GP had significant antioxidant properties and good yields in operating conditions of 2 W/g. Hydroxybenzoic acid, procyanidins, flavan-3-ols, and one flavanol were the phenolic compounds identified. The CP maintained the physicochemical and antioxidant properties similar to the GP.

Extraction of bioactive compounds from Senecio brasiliensis using emergent technologies.

The online version contains supplementary material available at 10.1007/s13205-021-02845-1.

Microwave hydrodiffusion and gravity as a sustainable alternative approach for an efficient apple pomace drying

Apple pomace valuation has been impaired by its high perishability and absence of fast drying approaches demanded by industry. This work aimed to assess the feasibility of Microwave Hydrodiffusion and Gravity (MHG) process applied for apple pomace drying using discrete delivery powers (300–900 W) and comparison with hot-air drying (40–100 °C). To dry 0.4 kg of apple pomace (81% moisture), hot-air drying required 3.6–9.9 h with estimated water evaporation flux of 1.0–3.5 mL/min. For MHG, which processed 1.2 kg, these corresponded to 1.0–2.6 h and 5.1–13.9 mL/min. Furthermore, MHG allowed water recovery containing part of apple pomace phenolic compounds and carbohydrates. The dried pomace was stable for 2 years, after which phenolic compounds and polysaccharides were still recoverable by hot water extractions. These results pave the way for MHG to be used for apple pomace and other by-products preservation, boosting their conversion into valuable co-product for valuation of its components.

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.