The Study on Extraction Process and Analysis of Components in Essential Oils of Black Pepper (Piper nigrum L.) Seeds Harvested in Gia Lai Province, Vietnam

Stability and bioactivity evaluation of black pepper essential oil nanoemulsion

Black pepper essential oil has the same disadvantages as other plant essential oils, such as volatilization, high sensitivity to light and heat and poor water solubility, which leads to great limitations in application. This study improved the stability and antibacterial properties of black pepper essential oil (BPEO) based on a nano-emulsification process. Tween 80 was selected as the emulsifier to prepare the BPEO nanoemulsion. Gas chromatograph - mass spectrometer (GC-MS) was used to analyze the composition of BPEO, of which d-limonene was the main component (37.41%). After emulsification, black pepper nanoemulsion was obtained (droplet size was 11.8 nm). The water solubility and stability of the emulsions at 25 °C were also improved with decreasing particle size. Antimicrobial properties of plant pathogens (Colletotrichum gloeosporioides, Botryodiplodia theobromae) and foodborne pathogens (Staphylococcus aureus, Escherichia coli) were evaluated by disk diffusion and other techniques for determining minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). With 12.5 mg mL^-1 MIC and 25 mg mL^-1 MBC, BPEO inhibited the growth of two tested plant pathogens and two foodborne pathogens. Essential oils (EO) were encapsulated in a nanoemulsion system to enhance the bacteriostatic effect of essential oils and reduce MIC and MBC concentrations. After emulsification, the biological activity (antimicrobial and antioxidant) of the BPEO nanoemulsion was considerably improved, nano-emulsification had certain significance for the study of EOs.

Pulsatile Controlled Release and Stability Evaluation of Polymeric Particles Containing Piper nigrum Essential Oil and Preservatives

Considerable efforts have been spent on environmentally friendly particles for the encapsulation of essential oils. Polymeric particles were developed to encapsulate the essential oil from Piper nigrum based on gelatin and poly-ε-caprolactone (PCL) carriers. Gas Chromatography ((Flame Ionization Detection (GC/FID) and Mass Spectrometry (GC/MS)), Atomic Force Microscopy (AFM), Nanoparticle Tracking Analysis (NTA), Confocal Laser Scanning Microscopy (CLSM), Attenuated Total Reflectance-Fourier-transform Infrared Spectroscopy (ATR-FTIR), and Ultraviolet-Visible (UV-VIS) spectroscopy were used for the full colloidal system characterization. The essential oil was mainly composed of β-caryophyllene (~35%). The stability of the encapsulated systems was evaluated by Encapsulation Efficiency (EE%), electrical conductivity, turbidity, pH, and organoleptic properties (color and odor) after adding different preservatives. The mixture of phenoxyethanol/isotialzoni-3-one (PNE system) resulted in enhanced stability of approximately 120 and 210 days under constant handling and shelf-life tests, respectively. The developed polymeric system presented a similar controlled release in acidic, neutral, or basic pH, and the release curves suggested a pulsatile release mechanism due to a complexation of essential oil in the PCL matrix. Our results showed that the developed system has potential as an alternative stable product and as a controlling agent, due to the pronounced bioactivity of the encapsulated essential oil.

Product diversification from pomelo peel. Essential oil, Pectin and semi-dried pomelo peel

Currently, agriculture has shifted to green production, in which the recycling of post-production by-products is a key issue. In the present work, by-products such as pomelos were studied to promote consumption and enhance the value of pomelo. From pomelo material, essential oils extracted from pomelo peels, pectin, and drying pomelo products have been diversified. In the extraction process of essential oils, the hydrodistillation method was applied in conjunction with the response surface method to obtain the optimal conditions of influence factors. These essential oils were quantified as well as determined for components by GC-MS. The pectin recognition process was done by immersion method in HCl acid (pH 2) and the drying process was made with a heat pump dryer under the effects of drying temperature, drying time and wind rate. The results of the essential oil products reached the highest (0.88 ±0.006 g) at the material size of 3 mm, the distillation time of 27 min, and the ratio of raw materials/solvents of 1/12 g/mL. The main components found in pomelo peeling essential oils included limonene (71.768%), γ-terponene (12,847%), α-Phellandrene (2.979%), β-myrcene (2.668%), 1R-α-pinene (2,656%), and β-pinene (1,191%). The pectin content was the highest under the temperature of 90 °C, extraction time of 60 min and ratio/solvent ratio of 1:32 g/mL. Under these extraction conditions, 48% of concentrated pectin content was obtained. Surveying conditions for drying white pomelo peels are capable of reversing: refunded drying pomelos are drying heat pumps in the following conditions: 50 °C drying temperature, the drying time of 90 min, and wind rate of 12 m/s. Product with hardness 309.862 N.

Response surface methodology for optimization studies of hydro-distillation of essential oil from pixie mandarin (Citrus reticulata Blanco) peels

Essential oil extraction technique from mandarin pixie peels by hydro-distillation is optimized by response surface methodology (RSM). Mathematical techniques were used in experimental design to evaluate the impacts of factors that affect the extraction process and improve the yield of the extraction process. A central mixed design based on influencing variables such as water ratio (3–5 mL/g), temperature (110–130 °C) and extraction time (90–150 min) was adopted with essential oil yield as the target function. Correlation analysis of the mathematical regression model showed that the quadratic polynomial model can be used to optimize hydro-distillation of pixie mandarin oil. The results showed that under the optimum extraction conditions, the highest quantity of essential oils was achieved (7.28 mL/100 g materials). In terms of statistical analysis, the significance levels (p-value <0.05) of the model showed that the experimental results had a good impact between factors. The coefficient of determination indicating the match between the experimental value and the predicted value of the model was high (R2>0.9). The chemical composition of the essential oil was analyzed by Gas Chromatography-Mass Spectrometry, revealing the dominance of limonene content (97.667%), which implies that the essential oil of pixie mandarin could be an alternative source of limonene.

Central Composite Design, Kinetic Model, Thermodynamics, and Chemical Composition of Pomelo (Citrus Maxima (Burm.) Merr.) Essential Oil Extraction by Steam Distillation

Pomelo peel-derived essential oils have been gaining popularity due to greater demand for stress relief therapy or hair care therapy. In this study, we first performed optimization of parameters in the pomelo essential oil extraction process on a pilot scale to gain better insights for application in larger scale production. Then extraction kinetics, activation energy, thermodynamics, and essential oil quality during the extraction process were investigated during the steam distillation process. Three experimental conditions including material mass, steam flow rate, and extraction time were taken into consideration in response surface methodology (RSM) optimization. The optimal conditions were found as follows: sample weight of 422 g for one distillation batch, steam flow rate of 2.16 mL/min and extraction time of 106 min with the coefficient of determination R2 of 0.9812. The nonlinear kinetics demonstrated the compatibility of the kinetic model with simultaneous washing and unhindered diffusion with a washing rate constant of 0.1515 min−1 and a diffusion rate constant of 0.0236 min−1. The activation energy of the washing and diffusion process was 167.43 kJ.mol−1 and 96.25 kJ.mol−1, respectively. The thermodynamic value obtained at the ΔG° value was −35.02 kJ.mol−1. The quality of pomelo peel essential oil obtained by steam distillation was characterized by its high limonene content (96.996%), determined by GC-MS.

Thermal decomposition and oxidation of β-caryophyllene in black pepper during subcritical water extraction

Subcritical water extraction is an efficient technique for extracting components from various plants by changing the polarity of water. β-caryophyllene is a natural bicyclic sesquiterpene with the highest content found among black pepper essential oils. In this study, the efficiency of extraction and yield of β-caryophyllene from black pepper were investigated using a subcritical water extraction technique. The optimal conditions of β-caryophyllene (1.19 ± 0.38 mg/g), and caryophyllene oxide (0.82 ± 0.38 mg/g) were obtained from black pepper under extraction conditions of 170 °C/10 min, and 200 °C/15 min, respectively. As the extraction temperature was increased, β-caryophyllene oxidation proceeded and the extraction content of caryophyllene oxide increased. It is anticipated that both β-caryophyllene and caryophyllene oxide with high biological activity can be used to selectively extract compounds using subcritical water extraction, which will be helpful in industrial applications.

Multistage Extraction of Star Anise and Black Pepper Derivatives for Antibacterial, Antioxidant, and Anticancer Activity

Recently, natural resources have attracted considerable interest for their applications in food security and human health problems. Traditional natural spices, such as star anise and black pepper, played important roles in the pharmaceutical and food industries due to their strong pharmacological activity, antioxidant potential and rare complications. In order to achieve biomasses from the natural product with multiple bioactivities, we developed the multistage extraction method to extract and separate various bioactive compounds from these natural plants. Our work demonstrated that various bioactive-rich extractives were achieved using steam distilled- or oxidative-extraction methods with high extraction yields and purity. Furthermore, the extractives in each step can be used not only as bioactive compounds, but also as a resource to further prepare different derivatives during the next extractive step, providing biomass-saving to a great extent. The extractives obtained with high yields and purities (>82%) were identified by ¹H NMR, ¹³C NMR, FTIR, UV-vis, fluorescence spectroscopy, and high-performance liquid chromatography (HPLC). Moreover, these biomasses display potent antibacterial activities against some types of microorganisms such as S.aureus, S.pyogenes, E.coli, and S.typhi with a lowest MIC of 400 μg/ml for the development of antibacterial agents, significant antioxidant activity as the natural antioxidant for enhancing food shelf-life, and excellent anticancer activity that induces significant cancer cell apoptosis. This work showed the different multistage extracts from natural products, which enable them to be applied in the fields of the pharmaceutical industry and the food industry.

Repellent and acaricidal activity of essential oils and their components against Rhipicephalus ticks in cattle

Ticks, particularly the Rhipicephalus which are the most prevalent and invasive affect 80 % of the cattle population worldwide. Through transmission of pathogens, tick worry and physical damage to the hides, ticks cause economic loss of billions of dollars each year with 1 billion US dollars loss per annum reported only in Latin-America. These losses can be minimized only by successful management of Rhipicephalus ticks. Various strategies like chemical control, vaccination and biological control are aimed at control of Rhipicephalus ticks. There are some serious limitations associated with them like tick resistance, drug toxicity, antigenic variations etc. In contrast to these issues related with chemical tick control, the botanicals particularly the essential oils obtained from aromatic plants of medicinal importance are eco-friendly and non-toxic to most host. In recent years, essential oils-based control of cattle ticks has gained considerable attraction of scientists all over the world as depicted from this review. A comprehensive effort has been made to critically analyze the role of essential oils in controlling Rhipicephalus ticks with particular emphasis on the mode of action of bioactive compounds both as repellents and acaricides. Furthermore, we have pointed out the most important challenges which need to be addressed for development and commercialization of an essential oil based anti-tick product.

Formulation of black pepper (Piper nigrum L.) essential oil nano-emulsion via phase inversion temperature method

Recent trends in preservation of processed foods involve the use of natural compounds, rather than chemically synthesized additives, to simultaneously confer antimicrobial properties and prevent fat oxidation. In this regard, black pepper essential oils, due to its diversity in biological activities, have been increasingly popular. The compounds are often used in relatively low amounts and in the form of nanoparticles to permit well blending into foods or uniform dispersion on the surface of fresh meat. The purpose of this study is to determine experimental parameters of a nano-emulsion formation process from black pepper essential oil via the phase inversion temperature (PIT) technique. The study results showed that the system achieved the optimal nano-emulsion under following condition: the ratio by weight of water: Tween-80: oil = 86:9.7:4.3, the stirring speed of nano-emulsions at 500 rpm for 45 min (heating at 75°C for 30 min and then rapidly cooling at 5°C for 15 min).

Green Separation and Extraction Processes: Part I

Supercritical fluid extraction comprises a known technology applied to obtain volatile compounds from flowers, i [...]

Antivirulence properties and related mechanisms of spice essential oils: A comprehensive review

In recent decades, reduced antimicrobial effectiveness, increased bacterial infection, and newly emerged microbial resistance have become global public issues, leading to an urgent need to find effective strategies to counteract these problems. Strategies targeting bacterial virulence factors rather than bacterial survival have attracted increasing interest, since the modulation of virulence factors may prevent the development of drug resistance in bacteria. Spices are promising natural sources of antivirulence compounds owing to their wide availability, diverse antivirulence phytochemical constituents, and generally favorable safety profiles. Essential oils are the predominant and most important antivirulence components of spices. This review addresses the recent efforts of using spice essential oils to inhibit main bacterial virulence traits, including the quorum sensing system, biofilm formation, motility, and toxin production, with an intensive discussion of related mechanisms. We hope that this review can provide a better understanding of the antivirulence properties of spice essential oils, which have the potential to be used as antibiotic alternatives by targeting bacterial virulence.