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Since the World Health Organization has suggested the exploration of natural products for cancer management owing to the side effects of chemotherapy and irradiation on humans and breast cancer accounts for the highest number of cancer related deaths globally, this study has examined antiproliferative effects of the aqueous and methanol extracts of Hypsizygus tessellatus (brown and white var.) and Flammulina velutipes caps against two breast cancer cell lines. The antioxidant and antiproliferative activities of these mushroom extracts were evaluated in vitro using chemical-based (for antioxidant activity) and cell (for antiproliferative activity) approaches. Furthermore, the phytochemical composition of the mushroom extracts were identified using mass spectroscopy (UPLC-QTOF/MS). The obtained results showed aqueous extracts of F. velutipes (Enoki) and white H. tessellatus (Bunapi shimeji) caps to possess higher antiodixant activities against DPPH (IC50 = 0.202 and 0.573 mg/mL, respectively), and H2O2 (IC50 = 0.622 and 0.745 mg/mL, respectively) compared tothe methanol extracts. Aqueous extracts of the mushrooms also showed better ferric reducing antioxidant power (FRAP) values against ferric ions compared to the methanol extracts. Finally, the mushroom extracts showed good antiproliferative activities against human breast cancer cell lines. These findings suggest the presence of phytochemicals with antiproliferative and antioxidant acrtivities in the mushroom extracts studied.

Vernonia amygdalina leaves are mostly consumed in Asia and Africa, due to its potential as a good source of antioxidants. In this study, a two-level factorial design was used to evaluate the significant extraction parameters in achieving higher recovery yield of extract, total phenolic content, total flavonoid content, and antioxidants from Vernonia amygdalina leaf. Microwave-assisted extraction technique was employed using aqueous ethanol. The independent parameters were irradiation time (1–5 min), microwave power level (500–700 W), temperature (60–80 °C), feed-to-solvent ratio (1:8–1:12 g/ml), and ethanol concentration (40–80%). Amongst the examined parameters, ethanol concentration, irradiation time, microwave power level, and feed-to-solvent ratio were significant (p

The bioactive compounds in Vernonia amygdalina leaf were extracted using ethanol through Soxhlet and microwave-assisted extraction (MAE) techniques. The phytochemical analysis was carried out on the ethanolic extracts using the standard techniques. This analysis revealed the presence of flavonoids, alkaloids, steroids, terpenoids, glycosides, tannins, phenols, saponins, and the absence of anthraquinones. Furthermore, gas chromatography-mass spectroscopy (GC-MS) analysis results revealed the presence of more phytochemicals in the extract obtained through MAE compared to Soxhlet extraction technique, whereby phytol was present in a higher percentage. Fourier transform infrared spectroscopy analysis confirmed the presence of phytochemicals in the extracts. Moreover, the IC50 values of the extracts antioxidant activities were evaluated using DPPH and ABTS assays. There exists a clear correlation between total phenolic content, total flavonoid content and antioxidant activity of the extracts. Therefore, this study suggested that higher phenolic compounds responsible for natural antioxidant could be obtained from V. amygdalina leaf using the microwave-assisted extraction technique.

Hibiscus sabdariffa is a multi-cropping system endowed with wide ranges of benefits to humans. Being a plant rich in phenolic compounds, the process intensification of extraction method used for recovering the phenolic compounds from this essential plant is inevitable to easily proffer keen information on the extraction behaviours. Thus, the process intensification and kinetic behaviour of microwave-assisted extraction (MAE) for recuperating total phenolics (TP) content from H. sabdariffa calyces were investigated. The impacts of MAE factors such as solid/sample ratio, microwave power and temperature at varied irradiation time were studied. The effective diffusivity was also estimated. In addition, the extract was characterized to tentatively assign the phenolics using Liquid chromatography tandem mass spectrometry of quadrupole time-of-flight (LC-ESI-MS-MS). The achieved results clearly indicated that the MAE process intensification was acheived with TP content of 70.53 mg GAE/g extract in 3 min at solvent/sample ratio of 14:1 mL/g, microwave power of 500 W and 60 °C of temperature where the highest effective diffusivity coefficient was obtained. Out of the two considered kinetic models (second-order rate and power law), the second-order rate model best describes the MAE process intensification with higher coefficients of determination (R2 > 0.99). Moreover, an aggregate of 77 phenolic compounds was assigned in the extract of H. sabdariffa calyx; signifying the wider potentials of the extract industrially. Thus, this study clearly outlined that H. sabdariffa calyx is an embodiment of diverse phenolic compounds; indicating its potential in pharmaceutical and food industries.

The nutraceutical potential of black and white pepper has drawn the attention of many researchers to unravel their pharmaceutical and nutritional properties. These properties could be attributed to the presence of some essential bioactive compounds and mineral elements. This study, therefore, investigated the phenolic and mineral element composition in their oleoresin extracts, using a set of physicochemical and characterization protocols. The result obtained at optimum condition gave a total of 17 and 20 phenolic compounds in black and white pepper extracts, respectively. Moreover, four essential mineral elements (Na, Mg, K, and Ca) were detected. The presence of hazardous elements such as Ar, Se, Pb, and Cr, below the detection limit (BDL) indicated the edibility of the oleoresin extracts. The total phenolic content (TPC) in both extracts was evaluated using Folin-Ciocalteu assay. The result showed that the white pepper extract exhibited higher total phenol content (63.40 ± 0.096 mg GAE/g d.w) than black pepper extract (51.95 ± 0.025 mg GAE/g d.w). The combined action of the mineral elements, total phenolic content and the phytochemical profiles confirmed the potential of oleoresin extracts as natural antioxidants in food and pharmaceutical industries.

Black and white peppers are important oil bearing commodity crop in tropical areas. They are highly beneficial in food industries and herbal medicine, due to their amazing aroma and therapeutic activities. In this study, heat reflux technique was employed to extract medicinal oleoresin from the two peppercorns. For this purpose, various extraction parameters were considered viz: extraction time, particle size and feed-solvent ratio. These extraction parameters were employed to optimize the extraction yield and absorbed energy via Taguchi methodology. The established optimal condition values of the yield and absorbed energy from the parametric study were 13.22 mg/g and 285.60 J/min, respectively in black pepper heat refluxation. Moreover, in white pepper refluxation, the extraction yield and absorbed energy were 14.04 mg/g and 264.82 J/min, respectively. Artificial neural network (ANN) was used for prediction purposes. This was achieved by comparing two algorithms, transfer functions and neurons. A good training and better prediction of the experimental data were observed using the Levenberg Marquardt (LM) feed forward backpropagation algorithm with log sigmoid transfer function as hidden layer and 3-4-5-1 as model topology. Furthermore, a total of 19 and 25 bioactive compounds were identified in black and white pepper extracts, respectively. The results from the Scanning Electron Spectrometry (SEM) showed a remarkable morphological changes during the heat refluxation process.

The integrated bacterial mixed culture consortium with disproportionate oxygen demand was discovered to mutually cooperate with one single biofilm in oxidizing sulfide at different concentration. The present work was carried out to verify the potential of bacterial mixed culture (BMC) in developing a predictive optimum condition for sulfide oxidation in a laboratory batch mode. A face centered central composite design (FCCCD) under response surface methodology (RSM) was employed to predict the synergistic effects of initial hydrogen sulfide concentration (100–500 ppm), temperature (30–40 °C) and aeration rates (50–250 vvm) on BMC sulfide oxidation. A total number of 20 experimental runs with 6 centre points were carried out. The obtained results were analyzed using design expert and statistical validation indices to check the adequacy of the obtained quadratic models. The analysis of variance showed that more than 99% of the variation was explained by the models. There was a good agreement between experimental and predicted data. The optimum sulfide removal of 448.75 ppm was achieved at the temperature of 32.4 °C, initial hydrogen sulfide of 500 ppm and aeration rates of 110.06 vvm in 8 h. Therefore, the finding depicts the adequacy of the obtained model in enhancing BMC sulfide oxidation conditions. The model is further affirmed through SEM-EDXS analysis, revealing oxidized sulfide product aggregate of the micrographs coupled with elemental identification and quantitative composition.

Fenugreek (Trigonella-Foenum Graecum) is known as one of the traditional and most promising medicinal herbs belongs to the leguminous family. The seeds of fenugreek have been extensively studied for the treatment of inflammation, cancer and diabetes. In this study, fenugreek seed oil was extracted and evaluated for its chemical compositions and bonding through gas chromatography coupled to mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR) analysis, respectively. The antioxidant activity against 2,2-diphenyl-picrylhydrazyl (DPPH) and 2,2′-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•) radicals, total phenolic content (TPC) and total flavonoid content (TFC) of the oil were also studied. The capacity of antioxidants detected by ABTS was stronger than that by DPPH. A total number of 23 chemical compounds were detected and identified in fenugreek seed oil comprising of 99% of the total oil through GC-MS analysis. The major compounds of the extracted oil were linoleic acid (54.13%), palmitic acid (16.21%), pinene (4.56%), 4-Pentyl-1-(4-propylcyclohexyl)-1-cyclohexene (3.87%) and linoleic acid methyl ester (3.19%). FTIR analysis confirmed the presence of carboxyl group in the oil which were more dominated by unsaturated essential fatty acids. Moreover, the oil of fenugreek seed indicated a strong antioxidant radical scavenging activity against both DPPH and ABTS assays with an IC50 of 172.6 ± 3.1 and 161.3 ± 2.21, respectively. The TPC and TFC of the oil were 38.97 ± 0.34 mg GAE/g. oil and 14.417 ± 0.23 mg QE/g.oil. Thus, this study suggests that the fenugreek seed oil could be used for pharmaceutical purposes. Keywords: Fenugreek seed oil, Gas chromatography-mass spectrometry, Unsaturated essential fatty acid, Antioxidant, Total phenolic content, DPPH, ABTS

Microwave-assisted extraction (MAE) of phenolic compounds from Chromolaena odorata leaves was investigated using one-factor-at-a-time (OFAT) and two-level factorial design. The MAE parameters studied were irradiation time (A: 1–5 min); microwave power level (B: 400-800 W); extraction temperature (C: 60–80 °C); solvent/feed ratio (D: 8:1–14:1 mL/g); and ethanol concentration (E: 20–60% v/v). The optima yields of TPC and TFC were 56.13 mg GAE/g d.w. and 44.78 mg QE/g d.w., respectively were achieved from MAE of C. odorata leaf at irradiation time of 2 min, microwave power of 600 W, temperature of 60 °C, solvent:feed ratio of 10:1 mL/g, and ethanol concentration of 40% v/v through one-factor-at-time (OFAT) experimental trials. The results obtained from a two-level factorial design experiments reflected that only ethanol concentration (20–60% v/v), irradiation time (1–5 min) and microwave power level (400–800 W) had significant effects on the yields of total phenolic content (TPC) and total flavonoid content (TFC) from C. odorata leaves (p < 0.05). However, temperature and solvent/feed ratio was not significant. In addition, the interactions AB (irradiation time and microwave power) and AE (irradiation time and ethanol concentration) contributed greatly to the recovery yields.

The high death rate associated with cancer has fuelled the search for complementary cancer treatment methods in recent times. Among the leading alternative methods is natural products which have attracted much attention due to their high body tolerance. In this study, the caps of Flammulina velutipes (commonly called Enoki), an edible mushroom, were extracted with different solvents and characterized for in vitro antioxidant and anticancer activities. The anticancer activity of the extract was studied against breast cancer cells (MCF-7 and MDA-MD-231) and normal or Vero breast cells (MCF-10a). The radical scavenging, metal reducing power, and anticancer properties of the extracts were investigated via in vitro chemical and cell-based methods. Furthermore, a phytochemical profiling process was performed on the extract fraction with the highest level of biological activities using Liquid chromatography-mass spectrometry coupled with quadrupole time of flight (LC-MS-QTof). The results showed acetone fraction of Enoki caps to exhibit more radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals (IC50 = 0.840 mg/mL) and hydrogen peroxide (H2O2) radicals (IC50 = 0.890 mg/mL) compared to the ethyl acetate fraction (IC50 = 0.97 mg/mL against DPPH and 1.180 mg/mL against H2O2). Additionally, acetone fraction showed a better metal reducing property in a concentration-dependent manner. The in vitro cytotoxicity study showed a preferential level of toxicity of the acetone extract to the studied cancer cell lines compared to the Vero cells. This extract showed more cytotoxicity against MCF-7 (IC50 value ranged from 17.7 µg/mL to 38.36 µg/mL) and MDA-MB-231 (IC50 value ranged from 114.5 µg/mL to 184.2 µg/mL) compared to MCF-10a (>250 µg/mL). These findings present F. velutipes caps as a potential natural source of antioxidant and anticancer agents. Keywords: Anticancer, Antioxidant, Breast cancer, F. velutipes, Phytochemicals

Black pepper is a functional plant with nutritional and medicinal benefits. Piperine being the major bioactive compound in black pepper has been applied for the treatment of many free radical-related diseases. This study determined a combination of operating parameters that optimize the microwave extraction of the piperine oil. The effect of irradiation time, microwave power level, feed particle size and feed-solvent ratio on piperine content and absorbed microwave energy were tested using a three-level L9-Taguchi parametric design. The results obtained placed the optimum extraction condition at 90 min of irradiation time, 350 W of microwave power, 0.1 mm of particle size and 1:12 of feed-solvent ratio. Under this optimal condition the optimal piperine oil and absorbed microwave energy of 5.64 w/w and 84.17 J/min were obtained, respectively. The optimal conditions can therefore be employed to design extraction process with higher efficiency and productivity. Keywords: Black pepper, Piperine, Microwave reflux extraction, Taguchi optimization, Signal-to-noise ratio

Emerging evidence has revealed the functional characteristics of black pepper extracts for both nutritional and medicinal purposes. The medicinal properties of this important commodity crop are due to the presence of active piperine which it a viable drug potential in ethnomedicine for the treatment of many degenerative free-radical related diseases. In this study, the microwave-enhanced technique was employed in the extraction of alkaloid oleoresins at optimum condition. The metabolomics-based approach was employed to determine the alkaloid profiles using LC-MS-Quadrupled time of flight mass spectrometer. At optimum microwave condition, a total of 21 bioactive alkaloids were identified with piperine being the most abundant with a mass to charge ratio of 286.1442 m/z. The result from the SEM-monograph and BET-surface characterization showed a remarkable transformation in the micro-cellular matrix as a result of the applied microwave electromagnetic heating.

Cancer management is associated with serious side-effects due to the harmful nature of radiation and chemotherapy on the body cells. These side-effects have necessitated the need for diversifying the alternative or complementary sources of cancer therapy. Natural products have been on the front line as alternative sources of anticancer agents and have attracted much attention in recent times. In this study, the anticancer activity of Hypsizygus tessellatus (white var.) caps (also known as Bunapi shimeji) extracted with acetone and ethyl acetate was evaluated in vitro against MDA-MB-231 and MCF-7 (breast cancer cell lines) and MCF-10a (Vero or normal breast cells). Likewise, the free radical scavenging and metal reducing activities of the extract were evaluated through in vitro chemical-based methods. Furthermore, the phytochemical compositions of the extracts were determined through LC–MS-QTOF-assisted mass spectroscopy. The results of this study indicated that acetone fraction had better radical scavenging activity against DPPH (IC50 = 0.76 mg/mL) and H2O2 (IC50 = 0.84 mg/mL) than ethyl acetate fraction against DPPH (IC50 = 1.10 mg/mL) and H2O2 (IC50 = 1.26 mg/mL) (p

Diabetes mellitus is a metabolic disorder disease emanating from the inability of body’s response to high glucose levels in the blood. However, the side-effects from consuming synthetic drugs have reduced the effectiveness, thus, the potential of purple fleabane (Vernonia cinerea) leaf was investigated using microwave-assisted extraction (MAE) in this study. The influences of extraction factors such as irradiation time, microwave power level, feed/solvent, and ethanol concentration on the recovery yields of polyphenol and flavonoids were as well studied. Thirty experimental runs using a face-centered central composite design (FCCCD) with six centre points were employed and optimal yields were obtained by generating quadratic models based on response surface methodology. The obtained optimal MAE conditions were as follows: irradiation time, 2 min; microwave power level, 444 W; feed/solvent, 1:14 g/mL; and ethanol concentration, 47% v/v. There was an insignificant difference between the predicted and experimental data (p > 0.05), showing good predictive models for the extraction of phenolic compounds from V. cinerea leaves using MAE. Also, the results confirmed that MAE can recover higher phenolic compounds, antioxidant, and anti-diabetic activities from V. cinerea leaves in shorter extraction time. In addition, the phenolic compounds in V. cinerea leaf extract were identified using liquid chromatography-mass spectrometry quadrupole time of flight (LC–MS-Q-TOF) and Fourier transform infrared spectroscopy (FTIR). The extracts showed higher anti-diabetic activity using alpha-amylase and alpha-glycosidase assays which suggested its exploration in pharmaceutical and functional food industries.

The most daunting challenge in microwave extraction is the variability in the output quality due to inherent uncontrollable temperature factors. This study focused on how to optimize the energy absorption and reduce the effects of temperature fluctuations on extracts quality in microwave extraction of white pepper. The Taguchi Orthogonal Optimization array was employed to simultaneously study the effects of four parameter settings on energy absorption. The result obtained from the three-level setting confirmed solvent-to-plant ratio (D) as the most significant factor in the optimization of absorbed microwave energy. This suggests that solvent-to-plant ratio provided a higher contribution to the extraction process with a decreasing significance level of D > A>B > C. The result from the microstructural analysis showed a 40.02% decline in the BET-surface area. The cumulative area decline and morphological changes indicated textural and dispersive transformation from the intermittent microwave electromagnetic heating. Moreover, The LC–MS/QToF analysis shows the presence of 25 and 186 bioactive compounds for negative (–ve) and positive (+ve) electrospray (ESI) ionization modes, respectively. These compounds are responsible for various biological activities of oleoresin oil which has a potential use in many medicinal applications.

The microwave-assisted extraction conditions for the optimal yield of extracts and total phenolic content (TPC) from Vernonia amygdalina leaf were optimized using a face-centered central composite design of response surface methodology. The independent parameters were viz: irradiation time (5–15 min), microwave power (400–600 W), temperature (90–110 °C), and feed-to-solvent ratio (1:8–1:12 g/mL). The optimal conditions for highest yield of extract (22.34% w/w) and TPC (102.24 mg GAE/g d.w.) were obtained at irradiation time of 8 min, microwave power of 416 W, temperature of 100 °C, and feed-to-solvent ratio of 1:8 g/mL. The quadratic model significantly (p

Despite response surface methodology (RSM) has been the most preferred statistical tool for optimizing extraction processes, artificial neural network (ANN) has been one of the most effective tools used for optimization and empirical modelling since the last two decades, most especially for non-linear equations. Thus, this study was carried out to compare the performance of RSM and ANN in optimizing the extraction yield and antioxidant capability of extract from Vernonia cinerea leaves using microwave-assisted extraction (MAE) techniques. The responses (extraction yield and antioxidant capabilities) were modelled and optimized as functions of four independent MAE parameters (irradiation time, microwave power level, ethanol concentration, and feed-to-solvent ratio) using RSM and ANN. The coefficient of determination (R2), root mean square error (RMSE) and absolute average deviation (AAD) were employed to compare the performance of both modelling tools. ANN model has a higher predictive potential compared to RSM model with higher correlation coefficients of 0.9912, 0.9928 and 0.9944 for extraction yield, DPPH and ABTS scavenging activities, respectively. Thus, ANN model could be a better alternative in data fitting for the MAE of antioxidants from Vernonia cinerea leaves. Keywords: Extraction yield, Vernonia cinerea, Artificial neural network, Antioxidants, Response surface methodology

The study investigated the effects of extraction parameters on the yield, antioxidant activities, morphological and functional group characteristics of black and white pepper oleoresin extracts. Optimized oleoresin yields of 5.64 and 8.72 w/w% were obtained as black and white pepper extracts, respectively. Moreover, from the antioxidant assay, the concentration of black and white pepper extracts required to scavenge half of stable DPPH radicals were 94.92 and 107.57 µg/ml, respectively. From the complementary antioxidant assay; the concentration of black and white pepper extracts required to scavenge half of the stable ABTS free radicals were 82.36 and 94.71 µg/ml, respectively. This indicated that extracts from white pepper exhibited higher antioxidant capacity than the black pepper extracts. The results from the untargeted compositional GC-MS analysis identified a total of 23 and 31 bioactive compounds in black and white oleoresin extracts, respectively. This study, therefore, revealed the potential of microwave extraction in obtaining high-quality extracts.

The leaves of Vernonia cinerea are widely used for medicinal purposes. Although, different studies have reported on the biological activities of the plant extracts whereas the tentative assignment ...

Mushrooms are rich in pharmacologically-important phytochemicals with reported medicinal values. In this study, the antibacterial activity of Flammulina velutipes (Enoki), Hypsizygus tessellatus (brown (Buna shimeji) and white (Bunapi shimeji) variants) stem extracts prepared with different solvents (water, methanol, acetone, and ethyl acetate) was investigated against Escherichia coli (E. coli ATCC 25922), Serratia marscenscens (S. marscenscens ATCC14756), Bacillus subtilis (B. subtilis ATCC 23857), and Staphylococcus aureus (S. aureus ATCC 25923). Their antioxidant activities were evaluated using radical scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) and ferric reducing power (FRP). The water extracts of Enoki, Buna shimeji, and Bunapi shimeji showed bacterial growth inhibition in a concentration-dependent manner. From the obtained results, all the Enoki extracts showed a significant inhibition of the gram positive bacterial species (E. coli and S. marcescens > 68%) and a reduced inhibition of the gram negative bacterial species (B. subtilis and S. aureus

The drying behavior of Vernonia amygdalina leaves was investigated using open sun and shade drying. The effective diffusivity coefficients for both methods were evaluated. Eight drying kinetics models were fitted to the experimental data obtained from the two drying methods; the goodness of fit was evaluated using three statistical tools, and the best model was selected. The Midilli and Kucuk model, which gave higher values of the coefficient of determination and lower values of the reduced chi-square and root mean square error was considered the best for predicting the drying behavior of open sun-dried and shade-dried V. amygdalina leaves with values of R of 0.99951 and 0.99981, RMSE of 0.00243 and 0.00253 and reduced chi-square of 0.000511 and 0.000428, respectively. The values of the effective diffusivity coefficients for open sun and shade drying were 26.58 × 10−10 m2/s and 52.77 × 10−11 m2/s, respectively. Furthermore, open sun drying resulted in severe deformity of the leaf morphology which may lead to degradation of the phytochemicals. Thus, shade drying was the better way of drying V. amygdalina leaves to preserve the nutrients compared to open sun drying. Keywords: Mathematical model, Shade drying, Sun drying, Vernonia amygdalina

In this study, ethanolic microwave-assisted extraction of total phenolic content (TFC), total flavonoid content (TFC) and antioxidant from Vernonia amygdalina leaf was investigated using response surface methodology. Four extraction variables, including irradiation time (1‒5 min), microwave power level (500‒700 W), feed-to-solvent ratio (1:8‒1:12 g/ml), and ethanol concentration (60‒80%) were optimized to obtain optimal yields. The analysis of variance results showed that ethanol concentration, microwave power level and irradiation time mostly affected the TFC, TPC and antioxidant activities significantly (p

In this study, the microwave-assisted extraction (MAE) variables were optimized using a face-centered central composite design of response surface methodology for optimal recoveries of total flavonoid content (TFC) and antioxidant capacities (DPPH and ABTS) of Vernonia amygdalina leaf extract. The independent variables were irradiation time (5–15 min), microwave power level (400–600 W), temperature (90–110 °C), and feed-to-solvent ratio (0.08–0.13 g/ml). The ANOVA results showed that TFC, DPPH and ABTS radical scavenging activities were significantly (p

In this study, the effects of extraction solvents on the yield and total phenolic content of Vernonia amygdalina leaf were examined. The considered solvents were water, 20% v/v ethanol, 40% v/v ethanol, 60% v/v ethanol, 80% v/v ethanol, and 100% v/v ethanol using Soxhlet extraction technique. Highest extraction yield (19.45 ± 0.22% g/g) and total phenolic content (96.25 ± 2.52 mg GAE/g d.w.) were achieved using 60% v/v aqueous ethanol solution. In addition, there exist a significant correlation between total phenolic content and antioxidant activities using DPPH (R2 = 0.9397, p

Phaleria macrocarpa locally known as Mahkota Dewa is one of the important medicinal plants that originates from Papua Island, Indonesia and grows in tropical areas. Mangiferin is one of the major bioactive compounds of Phaleria macrocarpa. The effect of extraction time (4–6 h) and extraction temperature (90–110 °C) on the mangiferin yield were investigated using Face Centered Central Composite Design (FCCCD) with five centre points under Response Surface Methodology (RSM). The presence of mangiferin in the extract was confirmed using HPLC-DAD and the functional groups were identified through FTIR analyses. A second order polynomial model was employed in predicting the response. The regression analysis showed that more than 98% of the variation was explained by the models with the optimum of 38.7 mg/g mangiferin yield at 105 °C and 6 h extraction time. The experimental values show good accuracy with those predicted (1.1% deviation), thus indicating the suitability of the model employed and the success of FCCCD in optimizing the extraction conditions.

Hibiscus sabdariffa comprises calyx which is rich in flavonoids and numerous phytochemical compounds. Nevertheless, the extraction parameters can influence the recoveries of these bioactive compounds. It is then important to investigate the contributing effects of the process parameters and optimized their conditions to achieve higher recovery yield. Hence, this study was carried out to examine the contributing effects of microwave‐assisted extraction (MAE) process factors (irradiation time, ethanol concentration, solvent/sample ratio, temperature, and microwave power) on the yield of total flavonoid (TF) contents from H. sabdariffa calyces using one‐variable‐at‐a‐time. The significant MAE process parameters were further optimized using Box Behnken design. At the MAE optimal conditions, the extract was analyzed to identify the flavonoid compounds using liquid chromatography‐mass spectrometry quadrupole time of flight. An optimum TF content of 94.32 mg QE/g extract from H. sabdariffa calyces was obtained at the following MAE conditions: Irradiation time of 4 min; ethanol concentration of 52% vol/vol; microwave power of 450 W and solvent/sample ratio 15:1 ml/g. Moreover, 95 flavonoid compounds were tentatively identified in the extract at optimized MAE conditions. Thus, these flavonoids can be further isolated in future studies to unveil embedded potentials of H. sabdariffa calyx extract. PRACTICAL APPLICATION: The procedure described the microwave‐assisted extraction (MAE) which can serve as a guideline for extracting flavonoids from Hibiscus sabdariffa calyx. Moreover, the liquid chromatography‐mass spectrometry quadrupole time of flight analysis provided the developed conditions for identifying flavonoids from the calyces. The results obtained suggested the exact MAE conditions to achieve an optimum yield of flavonoids from H. sabdariffa calyces. Most importantly, the tentatively identified flavonoids can further be isolated and purified in future studies to unveil the embedded biological potentials.

Background: Black- and white pepper extracts are natural products, which had been extensively used in food industries as a seasoning agent, and in herbal medicine for the treatment of many free radical-related diseases. Owing to the medicinal and nutritive benefits of this functional spice, the need then arises to find a way of extracting its fixed oil at optimum condition. Objectives: The aim of this study was to investigate the effect of extraction parameters on the extraction yield, antioxidant activities, microstructure, functional group characteristics, and elemental composition of fixed oils extracted from the two cultivars. Methods: Extraction of fixed oil was carried out using a heat reflux extraction technique. The dietary elemental composition was conducted using Energy Dispersive Spectroscopy (EDS). The effect of localized heating on the extracts was evaluated to determine the structural changes in the pepper sample using Brunauer-Emmett-Teller (BET) and Scanning Electron Microscopy (SEM). Results: The optimal fixed oil yields under the optimum condition were 10.38 mg/g for the black pepper and 15.27 for the white pepper. The antiradical powers (ARP) of 0.007985 and 0.009046 mL/µg were obtained for black- and white pepper fixed oil, respectively. This suggests that the fixed oil from white pepper exhibited higher antiradical characteristics than black pepper fixed oil. The results of BET-parameters revealed the percentage of deformations related to the black- and white pepper under the localized heating was 21.47% and 29.14%, respectively. Conclusions: The results revealed a greater deformation on the microstructure of white pepper than black pepper. Moreover, rich dietary elements present in the extracts succinctly unveiled the potential of fixed oil extracts in curative applications and preventive traditional medicine.

Carica papaya leaf is one of the considered agricultural waste; nevertheless, this leaf has been reported to contain diverse health benefits to humans. In as much as natural-based oils are of higher demands because of their aromatherapy property, this study focused on the extraction of oil from C. papaya leaf using microwave-assisted extraction (MAE) technique. Then, the extracted oil was analysed using gas chromatography-mass spectrometry. The influences of MAE parameters which include time of irradiation, microwave power, volume of solvent, and temperature on the extracted oil were investigated. The considered parameters were time of irradiation (30–180 min), microwave power (400–700 W), volume of the solvent used (distilled water) within the range of 100 to 300 mL, and temperature (40–100 °C). The outcomes from this finding showed that time of irradiation, microwave power and volume of solvent significantly altered the oil yield from C. papaya leaves. At the apex points of the considered parameters (time of irradiation, 120 min; microwave power, 500 W; volume of solvent, 200 mL; and temperature of 100 °C); the major identified compounds were n-Hexadecanoic acid; 9, 12, 15-Octadecatrienoic acid; phytol; 9-Octadecenoic acid; 9, 17-Octadecadienal; Oleic acid; and Octadecanoic acid. Therefore, C. papaya leaf is an embodiment of oil rich in fatty acid which can be employed as aromatherapy agent.

Lubricating oils are made from base oil mixed with other chemicals (additives) to improve its properties. Engine oil is used to lubricate moving engine parts, reduce friction, protect against wear, and remove contaminants. Moreover, it can acts as a cleaning, anticorrosive and cooling agent. This study aimed to refine used engine oil by using single and composite solvents. Isopropyl alcohol was used as a single solvent, while the composite solvent was made up of ethanol, isopropyl alcohol and toluene. Extractions were carried out with different parameters such as temperature (40 and 60°C) and solvent-to-oil ratio (1:1 and 2:1). Thereafter, different properties including viscosity, calcium and zinc content, and total base number for determining the degree of treatment of the regenerated oil and waste oil were analysed. The regenerated oil was compared with virgin base oil (SN 500) via Fourier transform infrared (FTIR) spectroscopy to determine their correlations. Based on the experimental results, the calcium and alkalinity contamination from the detergent additive and zinc from the anti-wear additive decreased using both the single and composite solvents. The results from the viscosity, viscosity index, and FTIR analyses showed different degrees of improvement compared to the virgin base oil (SN 500). Then, the best results were observed with isopropyl alcohol as a single solvent and an extraction temperature of 40°C. The regenerated oil could be improved through further metal removal processing using a metal adsorption agent such as zeolite. Thus, further investigations may be warranted in the future to compare the present studied parameters.

The tropical white peppercorns are common commodity crops which have been traditionally used for the treatment of many free radical-related diseases. These medicinal properties are due to the presence of natural antioxidants. This study investigated the combination of microwave extraction parameters for the recovery of natural antioxidants from the white pepper matrix. Microwave-assisted technique was used for the extraction of bioactive oleoresin from white pepper. Taguchi experimental design was employed to investigate the combination of independent extraction parameters for optimal recovery of natural antioxidants. The feed backpropagation artificial neural network model was thereafter applied to optimally predict the result for the different combination of operating parameters. This was achieved by evaluating different algorithms, transfer functions, and neurons. The result obtained from the orthogonal parametric study gave an optimal antioxidant activity of 91.02% at irradiation time of 120 min, microwave power level of 350 W, particle size of 0.300 mm, and liquid-to-solid ratio of 6 mL/g. The gradient descent (GD) algorithm, tansigmoid transfer function, and 4-x-3 topology were used to model the experimental data. A better prediction was then obtained with an overall coefficient (R) and mean square error (MSE) of 0.9595 and 1.4381, respectively. In this study, the feedforward backpropagation neural network was successfully applied to optimally evaluate the complex relationship between the input extraction parameters and the response.

Background White Piper nigrum is an important commodity crop containing a number of essential bioactive components with nutritional and medicinal properties when sufficiently extracted. Microwave refluxation is therefore a novel technique employed in the extraction of bioactive components from natural products of plant origin. This method doubled as classical and traditional solvent extraction techniques with reduced extraction time, higher selectivity, low solvent consumption, and higher extraction rate. Methods The Taguchi L9-orthogonal design was employed to determine a combination of extraction factors that jointly optimized the extraction yield. The use of this para metric design was due to its ability to mitigate inherent noise factor with minimal experimental trials. Results The optimal extraction condition was attained at 90 min of irradiation time, 300 W of microwave power, 0.105 mm of particle size, and 10 ml/g of molar ratio. Under this condition, the corresponding optimum extraction yield of 4.278 (v/w)% was obtained. Moreover, the percentage contribution of each extraction factor on the response settings resulted in the decreasing order: irradiation time > molar ratio > power level > particle size. Phytochemical screening was condcuted on the oleoresin extracts and a total number of 26 bioactive compounds were identified. Also, the Fourier Transform Infrared Analysis (FTIR) and the Scanning Eectron Microscopy (SEM) confirmed the presence of seven presence of seven functional groups with an observable structural transformation. Conclusions The result of optimum design, phytochemical screening, and structural characterization therefore provided a better understanding on the potential of microwave refluxation in extracting spice oleoresin from white Piper nigrum.

Phaleria macrocarpa, commonly known as Mahkota dewa is a well-known medicinal plant native to Malaysia and Indonesia. P. macrocarpa has been used as traditional medicine for the treatment of many diseases for a long time. In this study, P. macrocarpa peels’ bioactive compounds were extracted using microwave-assisted extraction method. The effects of different process parameters such as irradiation time (0.5, 1, 3, 5, and 10 min), microwave temperatures (60, 70, 80, 90, and 100 °C) and microwave power (200, 300, 400, 500, and 600 W) on the extraction yield were investigated. Moreover, the antioxidant activity and total phenolic (TPC) content of the extract were estimated. The results reflected that the extraction yields, antioxidant activity and total phenolic content increased with increasing levels of process parameters to certain conditions where highest yields were attained. However, the best conditions of processing parameters that resulted to the highest amount of yield (61.25%) were 1 min, 80 °C and 300 W. The highest amount of antioxidant activity and TPC yield were 61.15±0.93% and 102.60±1.17 mg GAE/g d.w, respectively. These illustrated that P. macrocarpa peels can serve as a good source of antioxidant.

Fatty acids are reduced carbon chains mostly found in nature with different usages in the industrial feedstock, pharmaceutical and food industries. Plants are embodiments of substantial amounts of fatty acids. In this study, gas chromatography-mass spectrometry (GC–MS) analysis was employed to identify the chemical compositions of oils from Hibiscus sabdariffa flower, Stigma maydis; Chromolaena odorata leaf extracted through microwave-assisted hydrodistillation method. In addition, the oils from the three plant samples were characterized using Fourier transform infrared spectroscopy (FTIR) analysis to evaluate the fingerprints. A total number of 16, 13 and 13 chemical compounds were identified in the oils from H. sabdariffa flower, S. maydis and C. odorata leaf, respectively. The main identified compounds were fatty acids and esters. Moreover, the FTIR characterization reflected the presence of hydroxyl group, cellulose-fatty acids, methyl carboxylic acid, nucleic acid, and carbohydrate. This finding has fully demonstrated that the oils from H. sabdariffa flower, S. maydis and C. odorata leaf can serve as the potential sources of fatty acids.