Olusegun Abayomi Olalere

Parametric optimization of microwave reflux extraction of spice oleoresin from white pepper ( Piper nigrum )

BackgroundWhite 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.MethodsThe 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 experimentalxa0trials.ResultsThe 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 correspondingxa0optimum extraction yield of 4.278xa0(v/w)% was obtained. Moreover, the percentage contribution of each extraction factor on the response settings resulted in the decreasing order: irradiation timeu2009>u2009molar ratiou2009>u2009power levelu2009>u2009particle 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 groupsxa0with an observable structural transformation.ConclusionsThe result of optimum design, phytochemical screening, and structural characterization thereforexa0provided a better understanding on the potential of microwave refluxation in extracting spice oleoresin from white Piper nigrum.

Characterization and effect of extraction solvents on the yield and total phenolic content from Vernonia amygdalina leaves

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 (19.45u2009±u20090.22% g/g) and total phenolic content (96.25u2009±u20092.52xa0mg GAE/g d.w.) were achieved using 60% v/v aqueousxa0ethanol solution. In addition, there exist a significant correlation between total phenolic content and antioxidant activities usingxa0DPPH (R2 = 0.9397, pu2009<u20090.05) and ABTS scavenging activity (R2 = 0.7700, pu2009<u20090.05). More so, the FTIR analysis confirmed the presence of functional groups attributed to its antioxidant property. There was a significant damage in the cell wall of V. amygdalina leaf after extracted with 60% v/v ethanol solution. Therefore, V. amygdalina leaf can be a good source of antioxidants.

Extraction, radical scavenging activities and physicochemical fingerprints of black pepper ( Piper nigrum ) extract

Black pepper (Piper nigrum) is an essential tropical crop which doubled as spice in food industries and medicine in the treatment of free radical related disorders. For this study, microwave reflux method was employed in the extraction of bioactive oleoresin from black peppercorns. Extraction parameters such as irradiation time, microwave power, feed particle size and molar ratio were optimized. The effects of these parameters onxa0the oleoresin yield and antiradical activities were investigated using a multi-level Taguchi methodology. The results obtained placed the optimum extraction condition at 120xa0min irradiation time, 350xa0W microwave power, 0.105xa0mm feed particle size and 12xa0g/ml molar ratio. Under this optimal condition, the oleoresin yield was obtained as 5.64% (w/w). However, the optimum percentage inhibitions of the extracted spice oleoresins on the stable DPPH and hydrogen peroxide radicals were estimated to be 88.75 and 90.31%, respectively. Moreover, the Fourier transform infraredxa0(FTIR) analysis confirmed the presence of unsaturated amide groups, whichxa0validated the antioxidant potential of the black pepper extract. The scanning electronic microscopyxa0(SEM) further elucidated the structural transformation of black pepper from the pulsed microwave heating effect.

Ethanolic extraction of bioactive compounds from Vernonia amygdalina leaf using response surface methodology as an optimization tool

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 (1‒5xa0min), microwave power level (500‒700xa0W), feed-to-solvent ratio (1:8‒1:12xa0g/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 (pu2009<u20090.05), whereas the feed-to-solvent ratio was insignificant. The validated optimal yields of TPC (113.76xa0mg GAE/g d.w.), TFC (94.08xa0mg QE/g d.w.), DPPH (97.98%), and ABTS (99.34%) were obtained at extraction conditions, viz, 4xa0min of irradiation time, 558xa0W of microwave power, feed-to-solvent ratio of 1:10xa0g/ml, and ethanol concentration of 76%. In addition, the phytochemical profiling of the extract at optimal conditions confirmed the presence of phenolic and flavonoid compounds.

Parameter study, antioxidant activities, morphological and functional characteristics in microwave extraction of medicinal oleoresins from black and white pepper

ABSTRACT 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 107.57u2009µg/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 94.71u2009µg/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.

Application of orthogonal optimization and feedforward backpropagation model in the microwave extraction of natural antioxidants from tropical white pepper

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 120xa0min, microwave power level of 350xa0W, particle size of 0.300xa0mm, and liquid-to-solid ratio of 6xa0mL/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.

Data article on elemental and metabolomic-based alkaloidal composition in black pepper oleoresin using a positive ESI-mode LC-QToF and ICP-mass spectroscopy

This paper contains data from the elemental and phytochemical profiling of black pepper oleoresin extracts using the LC–MS QToF and ICP-MS analysis. In recent years studies have shown the medicinal properties of extracts from these two cultivars of Piper nigrum. The medicinal properties are attributed to the presence of many secondary metabolites and mineral element in them. The phytochemical profiling was conducted using a Liquid Chromatography equipped with an electrospray time-of-flight mass spectrometer detectors. The mass spectrometer was equipped with an electrospray ionization sources operated in positive ion mode. The alkaloid compounds in the optimized black pepper extract were tentatively characterized in accordance with their ions׳ mass fragmentation.