Microwave-assisted Extraction Method Research Articles

Chemical Composition of Hydrodistillation and Solvent Free Microwave Extraction of Essential Oils from <i>Plectranthus amboinicus </i>and <i>Melaleuca cajupati</i> Leaves and their Repellent Activity

Extraction of the native plants Plectranthus amboinicus and Melaleuca cajupati leaves have been carried out using traditional hydrodistillation (steam distillation) and solvent free microwave-assisted extraction methods at different temperatures and microwave irradiation powers. The chemical compositions of the essential oils extracted were identified using gas chromatography analysis. The ideal extraction time for Pletranthus amboinicus and Melaleuca cajupati were 120 min with microwave power 200 W and 400 W, respectively with the calculated extraction yield were 0.034 % and 0.276 %, respectively. In this paper, the results of the selected microwave powers, first oil drops, and extraction time are presented as well as the findings of the chemical compositions present in both plants are also discussed.

Proximate Composition, Phytochemical Analysis and Toxicity Assessment of Extracts of Caulerpa lentillifera using Autoclave- and Microwave-Assisted Extractions

Caulerpa lentilliferais a marine alga widely cultured and consumed in Asia and Oceania. Emerging green techniques are currently popular for phytochemical extraction. Therefore, this study aimed to investigate the proximate compositions, phytochemicals, and antioxidant properties of the C. lentilliferaextracts using autoclave-assisted and microwave-assisted extraction methods (A-CLE and M-CLE, respectively). The toxicity of extracts was tested against human normal colon cells and freshwater crustacean Daphnia magna. We found that crude lipid, ash and moisture contents in A-CLE were lower than those in M-CLE, while crude protein and crude carbohydrate were higher in A-CLE. Total flavonoid content in A-CLE (1.474 ± 0.046 mg QE g-1 extract) was higher than that in M-CLE (1.179 ± 0.054 mg QE g-1 extract). There was no difference in total phenolic contents, triterpenoid contents and antioxidant activities between the extracts. The IC50 of A-CLE (12,260 ± 197 µg mL-1) was higher than that of M-CLE (10,950 ± 169 µg mL-1). In the acute toxicity test, the LC50 of A-CLE against D. magna (7.50 ± 0.28 g L-1) was lower than LC50 of M-CLE (8.76 ± 0.26 g L-1). This study suggest that autoclave-assisted and microwave-assisted extractions are effective green methods of extracting C. lentillifera. This study will be useful for further studies of C. lentillifera extracts to improve human and animal health.

Microwave-assisted extraction of pectin from onion and garlic waste under organic, inorganic and dual acid mixtures

This study aims to investigate pectin extraction from garlic (GW) and onion waste (OW) by microwave-assisted (MAE) and sequential microwave assisted-hot acid extraction (MAHE) methods. All extractions were performed under three different media including organic acids [citric (CA) and acetic (AA)], inorganic acids [sulfuric (H2SO4) and hydrochloric (HCl)] and their mixtures. GW provided more pectin yields compared with OW. While the highest pectin yields from GW and OW by MAE in H2SO4 were respectively 24.62 ± 0.65 and 24.93 ± 0.59%, these yields under MAHE were 27.99 ± 0.36 and 28.43 ± 0.42%, respectively. Higher pectin yields and galacturonic acid (Gal-A) contents were mostly achieved in inorganic acids. However, degree of esterification (DE), methoxyl content (MeO) and equivalent weight (EW) values were higher for the pectins extracted under organic acids. Extraction of pectin from GW and OW was also accomplished in dual acidic media by MAE. Addition of inorganic acids to the organic acid solutions resulted in increasing pectin yields. The highest pectin yields from GW and OW under dual acid solutions were respectively 23.36 ± 0.66 and 21.88 ± 0.52%, and achieved in 1/3 HCl-H2SO4 and 1/3 CA-H2SO4 mixtures by MAE. While increasing inorganic acid contents in dual acid solutions resulted in enhanced Gal-A contents, increasing organic acid volume also generated higher DE and MeO values of the pectins. Obtained successful outcomes indicate that MAHE method could be used as an efficient extraction technique for the higher pectin yields, and utilization of organic-inorganic dual acid mixtures during MAE provides enhanced yields and controlled physicochemical properties of pectin.Graphical abstract

Microwave and ultrasound assisted extraction techniques with citric acid of pectin from Pomelo (Citrus maxima) peel

This current research attempted to obtain pectin from Pomelo (Citrus maxima) peels using conventional heating, microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE) techniques with organic citric acid. In order to characterize pectin extracted using conventional heating, MAE, and UAE, yield, pH, solubility, ash content, equivalent weight, anhydrouronic acid content, degree of esterification methoxyl content were taken into consideration. On physicochemical properties, the extraction techniques had a significant effect. The findings demonstrated that the MAE method produced the highest amount of pectin (26.63 ± 0.21 %). On the basis of the Degree of Esterification (DE) value, pectins were all classified as high-methoxypectins (HMP). According to anhydrouronic acid (AUA) content, the extracted pectins were extremely pure. Fourier transform infrared (FT-IR) spectroscopy was used to structurally characterize pectin that was extracted using three different methods, and the results revealed that pectin has functional groups between 1740 and 800 cm-1 spectrally.

Cellulose nanocrystals from marine algae Cladophora glomerata by using microwave-assisted extraction

Algae of the order Cladophorales are the source of a unique nanocellulose with high crystallinity and a large aspect ratio, enabling broad surface modification. Cellulose nanocrystals (CNCs) are obtained via acid hydrolysis of nanocellulose, which is highly crystalline. However, the production of CNCs from Cladophorales algae is limited and still uses a conventional heating method. Thus, this study aimed to develop a microwave-assisted extraction (MAE) method for fast and efficient extraction of CNCs from Cladophora glomerata algae. Additionally, we replaced the use of hypochlorite with H2O2, which is more environmentally friendly, and compared the CNCs obtained from the conventional methods with our new method. The functional structure of CNCs was confirmed by Fourier-transform infrared spectroscopy. Single-step H2O2 bleaching with MAE yielded the smallest-sized CNCs. Our developed method resulted in the production of CNCs with a high crystallinity index, high thermal stability, and high purity of native cellulose. Additionally, none of the CNCs were toxic to primary normal human dermal fibroblasts. The properties of the isolated CNCs may make them useful materials in pharmaceutical and cosmetic formulations.

Effects of different extraction methods on the physico-chemical characteristics and biological activities of polysaccharides from Clitocybe squamulosa

This study comparatively evaluated the effects of the commonly used six extraction methods (acidic, alkaline, enzymatic, ultrasonic, high-pressure, and microwave) on the physico-chemical properties, processing characteristics, and biological activities of polysaccharides from Clitocybe squamulosa (CSFPs). The results show that polysaccharides extracted using an enzyme-assisted extraction method has a relatively high extraction yield (4.46 ± 1.62 %) and carbohydrate content (70.79 ± 6.25 %) compared with others. Furthermore, CSFPs were all composed of glucose, galactose, mannose, xylose, and glucosamine hydrochloride. Only ultrasonic-assisted extraction of polysaccharides (CSFP-U) has a triple helix chain conformation. Scanning electron microscopy (SEM) revealed significant differences in the microstructure of polysaccharides prepared using different methods. Besides that, the polysaccharides prepared by alkali extraction (CSFP-B) and high-pressure assisted extraction (CSFP-H) have good water (2.86 ± 0.29 g/g and 3.15 ± 0.29 g/g) and oil (8.13 ± 0.32 g/g and 7.97 ± 0.04 g/g) holding properties. The rheological behavior demonstrated that CSFPs solutions were typical non-Newtonian fluid. Apart from this, the antioxidant capacity (clearing DPPH (IC50 = 0.29) and ABTS free radicals (IC50 = 0.19), total reduction ability (IC50 = 3.02)) of polysaccharides prepared by the microwave-assisted extraction (CSFP-M) method was significantly higher than that of other extraction methods. By contrast, the polysaccharide prepared by acid extraction (CSFP-A) has the optimum binding capacity (bile acid salt (71.30 ± 6.78 %) and cholesterol (57.07 ± 3.26 mg/g)). The antibacterial activity of CSFPs was positively correlated with their concentration. Thus, the research results can provide a theoretical basis for the development and utilization of polysaccharides from C. squamulosa.

Innovative ultrasound sonication pretreatment sparger-based microwave assisted extraction method for enhanced essential oil extraction from lemon grass

This study introduces an innovative approach, Ultrasonic Sonication Pretreatment Sparger-based Microwave Assisted Extraction (U Sp-MAE), designed to enhance lemongrass essential oil extraction. Addressing the challenge of maximizing yield and quality, our work systematically optimized key extraction parameters. Results demonstrated a significant improvement over conventional methods, with the highest yield of 1.89% achieved under specific conditions: a Sparger Flow rate of 4 L/min, Ultrasound Power of 700 W, Sonication Time of 5 min, and Liquid-to-Solid Ratio of 5 mL/g. This method not only advances essential oil extraction but holds promise for broader applications in society, showcasing its potential impact on sustainable and efficient resource utilization.

Microwave-assisted extraction of Lawsonia inermis L. leaves: Method validation, optimization, and tyrosinase-stimulating activity

Vitiligo is a long-term skin condition characterized by the development of pale white patches due to a lack of melanin. Lawsonia inermis L. leaves, which contain lawsone, have been explored as a potential alternative treatment for vitiligo. This study aimed to optimize the microwave-assisted extraction of L. inermis leaves and evaluate its ability to stimulate tyrosinase activity, which is relevant to vitiligo treatment. The Box-Behnken design was employed, with three factors being varied: microwave power, time, and cycle. Two responses were monitored: extraction yield and lawsone content. To determine the lawsone content, validated high-performance liquid chromatography was utilized, which demonstrated good linearity, specificity, precision, and accuracy. The optimal conditions that provided the highest extraction yield and lawsone content were then used to evaluate the extract’s ability to stimulate tyrosinase activity. The results revealed that a microwave power of 300 W and a microwave time of 20 s for one cycle yielded an extraction yield of 12.99% ± 0.10% and a lawsone content of 94.85 ± 3.12 mg/g extract. The accuracy of the prediction, with a percent error of less than 10%, confirmed the reliability of the computer program used for data prediction. Furthermore, the extract exhibited significant stimulation of tyrosinase activity, indicating its potential usefulness in vitiligo treatment. The optimal microwave-assisted extraction method identified in this study holds promise for maximizing extraction yield and lawsone content in L. inermis leaves extract. This extract could serve as a basis for developing topical products for the treatment of vitiligo.

Identification of Flavonoid Content of Noni Fruit Alcohol Extraction (Morinda citrifolia L) Using Microwave Assisted Extraction (MAE) Method as a Pilot Study of Herbs

Flavonoids are phenolic compounds most commonly found in many plants, including noni fruit. Noni fruit also has many benefits for the pharmaceutical and herbal industries. Microwave-assisted extraction (MAE) is an effective and rapid method for obtaining bioactive compounds from plant materials. This research is a laboratory experimental study using noni-fruit samples and aims to identify flavonoid compounds in noni-fruit extract. Noni fruit was dried before being processed into simplisia powder. Using 96% ethanol and 70% alcohol solvents, the MAE method concentrated the extract for two minutes at 50 C. Using HCL solvent, the noni extract was then identified as having flavonoids. The results showed that flavonoid compounds were present in a 70% alcohol extract of noni fruit.

Microwave‐Assisted Extraction of Polysaccharides From the Abelmoschus sagittifolius: Optimization, Structure, and Bioactivity

The aim of this study was to extract polysaccharides from Abelmoschus sagittifolius using the microwave‐assisted extraction (MAE) method. Three independent variables, including extraction temperature, microwave power, and microwave time, were chosen for investigation through single‐factor experiments. Response surface methodology (RSM) based on a Box‐Behnken design (BBD) was utilized to optimize the extraction conditions. The study found that the optimal conditions for polysaccharide extraction were a temperature of 63°C, a microwave power of 650 W, and a duration of 58 min. The polysaccharide yield under these conditions was 29.8 g/100 g, closely matching the experimental yield of 30.1 g/100 g. This yield was approximately 1.15 times higher than the yield achieved through conventional extraction methods (heat reflux extraction (HE) method). The study also demonstrated that polysaccharides extracted using the MAE method exhibited improved antioxidant capacity and enzyme inhibition and displayed significant inhibitory effects on HepG2 cells compared to the conventional extraction method. Moreover, the polysaccharides obtained from the optimized MAE process had a lower molecular weight and higher polydispersity than the HE method. These findings indicate that MAE is a promising, efficient, and environmentally friendly technology for extracting polysaccharides from A. sagittifolius.

Antibacterial film-forming spray containing Caesalpinia sappan L. extract obtained through eco-friendly microwave-assisted extraction

The heartwood of Caesalpinia sappan L. contains brazilin, which exhibits excellent antibacterial activity. Its extract shows potential for incorporation into topical antibacterial products. This study aimed to optimize the conditions of an eco-friendly microwave-assisted extraction method to maximize brazilin content and antibacterial activity. It also optimized the film-forming antibacterial spray containing C. sappan heartwood extract using a Box–Behnken design. Ethanol concentration, microwave power, and microwave time were varied for microwave-assisted extraction. The optimized conditions of 28 % ethanol, 800 W microwave power, and 70-s microwave time maximized the extraction yield, brazilin content, and clear zones against Staphylococcus aureus and Staphylococcus epidermidis. The optimized extract was then incorporated into a film-forming spray. The film-forming spray formula's hydroxypropyl methylcellulose, glycerin, and ethanol contents were varied. Based on the design space, the optimized formulation comprised 0.6 % hydroxypropyl methylcellulose, 1.25 % glycerin, and 28 % ethanol. Approximately 97 % of the brazilin was released from the formulation during an 8-h release experiment. Moreover, approximately 25 % of the brazilin accumulated in the synthetic human skin-like membrane during an 8-h permeation experiment. In summary, this study successfully prepared, characterized, optimized, and verified a film-forming spray containing the optimized C. sappan heartwood extract obtained through microwave-assisted extraction.

An extraction technique to reach the effective radical scavenging constituents from the leaves of Indonesian malva nut tree (Scaphium macropodum): A comparative study of maceration, heat-assisted, ultrasound-assisted, and microwave-assisted extraction

Scaphium macropodum (Miq.) Beumée ex K. Heyna is an Indonesian commodity that has been widely used as an herbal medicine. This study examined the total phenolic content (TPC), flavonoid content (TFC), and antioxidant properties of Scaphium macropodum leaves. The leaves were extracted by several methods, including maceration, heat-assisted (HAE), ultrasound-assisted (UAE), and microwave-assisted extraction (MAE) using water, methanol, and ethanol solvents. The TPC value varied within the range of 14.03–97.34 mg GAE/g extract, while the TFC was not detected in water extract and ranged from 61.99 to 88.15 mg QE/g extract for alcohol solvents. The tested extracts showed great antioxidant properties by DPPH (1,1-Diphenyl-2-picrylhydrazyl) and ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging with the inhibition percentage ranging from 3.21 to 48.62% at the concentration 25 μg/mL for DPPH and 19.48–97.44% at the concentration 20 μg/mL for ABTS assays. The statistical analysis and PCA (Principal component analysis) were conducted to obtain the proper extraction technique. The MAE method using ethanol solvent was the most suitable technique for extracting the valuable compounds of Scaphium macropodum leaves. These findings suggest the potential uses of Scaphium macropodum leaves as an alternative natural medicine with useful bioactive constituents providing good antioxidant activity.

Characterization of Andrographis Paniculata Extract Obtained by Microwave-Assisted Extraction (MAE) Method with Radiation Time

The purpose of this research was to extract Andrographis paniculata using the Microwave Assisted Extraction (MAE) method at 4 radiation (4 minutes, 6 minutes, 8 minutes, and 10 minutes) and characterize the extract on phenolic content, flavonoid content, andrographolide content, antioxidant activity, and functional group using Fourier Transform Infrared Spectroscopy (FTIR). Radiation times of the MAE method had a significant effect on phenolic content, flavonoid content, andrographolide content, and antioxidant activity of Andrographis paniculata. Radiation time for 10 minutes of MAE gave higher phenolic, flavonoid, andrographolide, and antioxidant activity of Andrographis paniculata. The IR spectra of the Andrographis paniculate extract increased as the radiation time increased. The optimum radiation time was at 8 minutes with the result of phenolic content at 57.2 mg GAE /g, flavonoid content at 113.07 ppm, andrographolide at 763.47 µg/ml, antioxidant activity at 71.66% and the IR spectra at 1031.92 cm-1, 2945.3 cm-1, 3346.5 cm-1.

Comparison of extraction methods on anthocyanin pigment attributes from mangosteen (Garcinia mangostana L.) fruit rind as potential food colourant

The mangosteen fruit is mostly consumed for its pulp, and the rind, which accounts for more than 60 % of the total fruit weight, is discarded making it poor economic worth. The dark purple rind of mangosteen fruit is a rich source of anthocyanin pigment that can be used for food application if extracted using eco-friendly solvents. The aim of the study was to come up with an efficient, cheap and environmentally friendly method of anthocyanin pigment extraction from mangosteen fruit rind. Acidified solvent has shown to have higher recovery percentage of the pigment concentrate having higher TMAC (17,652.54 mg/L), colour density (1596.30 AU), polymeric colour (997.80 AU). Significantly highest recovery percentage (55.03), antioxidant activity measured by DPPH (2.29 l/ml), FRAP (2.83 l/ml), and ABTS (2.02 l/ml), total phenolics (32.25 mgGAE/100 g), total flavonoid content (40.02 mgQE/100 g), as well as the instrumental colour values indicating bright reddish-purple, were observed in microwave assisted extraction method with acidified solvent. By LC-MS/MS analysis, it was also evident that the rind contains a number of beneficial and health-promoting compounds, such as anthocyanins, xanthones, phenolics, flavonoids, coumarins, phoroglucinol derivatives, lignans, retinoids.

The Extraction of Oxalate Acid from Porang Flour (Amorphophallus oncophyllus) using Microwave-Assisted Solvent Extraction

Porang (Amorphophallus oncophyllus) is one of the local annual plants that contain high levels of oxalate. Oxalates are undesirable compounds in porang flour, and their levels must be removed or reduced to obtain high quality porang flour as a food ingredient. In this research, the extraction of oxalate acid was conducted using microwave-assisted solvent extraction and mechanical separation methods. This study aims to analysis the parameters that influence the extraction of oxalate acid using microwave-assisted solvent extraction such as the effect of microwave power, extraction time, feed-to-solvent ratio (F/S) and material size. The mechanical separation process will be studied the effect of material size for extraction of oxalate acid. The optimum yield obtained for oxalate acid extraction with microwave-assisted solvent extraction was microwave power of 600 W, extraction time of 30 min, feed-to-solvent ratio of 0.05 g/mL and porang size of 100 mesh obtained by oxalate acid yield of 24.78%. Porang size of 100 mesh was the optimum yield obtained for extraction of oxalate acid using mechanical separation method. The result of physical properties test using SEM-EDX and FTIR shows that extraction of oxalate acid from porang using microwave extraction method could produce oxalic acid which has good quality. In addition, extraction using microwave offers an environment-friendly extraction method, which can accelerate and increase the oxalate acid extraction yield.

Effect of microwave assisted extraction on total phenolic, flavonoids, and antioxidant from Stenochlaena palustris leaves

Degenerative disease is a disease caused by too many free radicals in the body. To neutralize, reduce, and inhibit the formation of new free radical compounds in the body, antioxidant compounds are needed. One source of antioxidants can come from plants that contain phenolic compounds. S. palestris plant is one of the plants from Bangka Belitung which contains phenolic compounds. The purpose of this study was to determine the effectiveness of the microwave assisted extraction method for the total phenolic and flavonoid content and antioxidants in the chloroform, acetone, and methanol extracts of S. palustris leaves with MAE times of 5, 10, 15, and 30 minutes (60° C, 1200 Watts). Based on the results of the analysis of the average yield values, total phenolics, total flavonoids, and antioxidant activity of the leaves of S. palustris using the MAE method had higher results compared to maceration. Based on the time difference used, the 5 minute MAE time has a higher value than the 10, 15, and 30 minute time. In terms of the extraction time used and the results obtained, the MAE method is more efficient and effective than the maceration method.

Extraction and Comparison of Anthocyanin Content in Seeds of Different Black Rice Varieties Using Water Bath Solution Extraction Method

Black rice, rare colored rice, is rich in anthocyanins. Black rice anthocyanin is a kind of natural plant pigment, which has the important effects of anti-oxidation, anti-inflammation and anti-cancer, protecting eyesight and promoting cardiovascular health. Fifteen representative black rice seeds in Southern Henan were used as test materials, and were determined and analyzed by using rice huller, visible light spectrophotometer and water bath solution extraction method and microwave assisted extraction method. The results showed that the anthocyanin content of different varieties of black rice varies greatly, among which the anthocyanin content of black fragrant glutinous rice No. 2 was the highest (0.4258%), and that of black fragrant glutinous rice No.4 was the lowest (0.0207%). The average content of anthocyanin in seeds of black rice varieties tested in Southern Henan Province was 0.1925%. Therefore, the above research results provide important clues for the genetic breeding and improvement of high-quality black rice varieties in Southern Henan. At the same time, varieties with higher anthocyanin content in black rice can be considered as backbone parents for new breeding high-quality black rice.

Efficient extraction of quassinoids and alkaloids from Eurycoma longifolia Jack roots using natural deep eutectic solvents and microwave-assisted extraction

Eurycoma longifolia Jack (EL) extracts have immunomodulatory and anti-inflammatory effects and are utilized in the treatment of male sexual dysfunctions. Water-based extraction methods for hydrophobic and bioactive components of EL are often inefficient and energy-intensive. Therefore, this study aimed to develop an efficient and environmentally friendly method for extracting EL quassinoids and alkaloids using natural deep eutectic solvents (NADESs) and microwave-assisted extraction (MAE). The NADES-based MAE method employed an optimized NADES comprising choline chloride, citric acid, glucose, and water (CCGW). CCGW provided higher extraction yields of eurycomanone (EU, 1.608 ± 0.004 mg/g) and 9-methoxy-canthin-6-one (9MCO, 0.3022 ± 0.0007 mg/g) than water-based extraction under optimal MAE conditions, as determined using Box–Behnken Design of Response Surface Methodology. CCGW effectively extracted both polar quassinoids and less-polar alkaloids from EL roots. While concentrated NADES had an impact on RAW264.7 cell viability, the use of diluted CCGW did not enhance the cytotoxicity of both EU and 9MCO compared to their preparation in water. The anti-inflammatory activity of 9MCO, prepared in diluted CCGW, was equivalent to that of the compound prepared in water. The cytotoxicity of both compounds in Vero cells was higher when coupled with CCGW than their preparation in water. The NADES-based MAE method is an efficient approach for extracting bioactive components from EL.

Purification and separation of glucomannan from porang tuber flour (Amorphophallus muelleri) using microwave assisted extraction as an innovative gelatine substituent

Gelatine is frequently used as a food ingredient. However, Indonesia imports almost all of its gelatine, totaling 3990152 tons annually. Gelatine could be replaced with glucomannan compound which was found in porang tubers. However, it also contains calcium oxalate, which is harmful for the human body. In this study, calcium oxalate was first eliminated by the purification process using 10 % NaCl (w/w). Moreover, the microwave-assisted extraction method was used to extract the glucomannan compound by applying 300 W of microwave power with different extraction times (5, 10, 15, and 20 min) and different ethanol concentrations (60, 70, 80, and 96 %). Statistical analysis was used to optimize and identify significant parameters influencing the glucomannan concentration. The best conditions for glucomannan extraction were an extraction time of 10 min and an ethanol concentration of 80 % (v/v), resulting in a glucomannan yield of ≥96 %. Machine learning was successfully applied for data modelling using a Long Short-Term Memory block with an average R-square of 0.9772 (97.72 % accuracy) and an average MSE of 4.7719. Furthermore, physical and chemical characteristics of the extracted porang flour were accorded with SNI gelatine standards 06–3735 in 1995, which consisted of glucomannan (96.359 ± 1.164 %), calcium oxalate (0.009 ± 0.001 %), water (2.290 ± 0.986 %), ash (0.018 ± 0.002 %), fat (0.0235 ± 0.120 %), heavy metals (not identified), and pH (6.455 ± 0.191). Finally, the extracted glucomannan can be used as a potential regional substitute for gelatine production.

Transesterification of Microalgae from Food Waste via Acid Catalyst for Biodiesel Production

Recently, numerous studies have presented the potential of various feedstock of biodiesel catalysed with acid catalysts and its performance. This study examines the potential of microalgae from food waste for biodiesel production by a homogeneous acid catalyst in a transesterification reaction. Initially, lipid was extracted from the microalgae using the microwave-assisted extraction (MAE) method. Then, the lipid was transesterified using a sulphuric acid catalyst under different conditions to decide the optimum condition. About 50% of the lipid was extracted from the microalgae when 400 W of microwave power was used for 15 minutes. The biodiesel yield of 76% has been attained from transesterifying the extracted lipid with methanol using 9:1 of methanol to oil molar ratio, 2.5 wt% of catalyst dosage for 3 hours at 65°C. Overall, this study has shown the potential of microalgae from food waste as one of the options for biodiesel’s feedstock catalysed by acid.
 Keywords: Biodiesel, food waste, microalgae, transesterification, acid catalyst, microwave assisted extraction (MAE)