Dataset of Schinus terebinthifolius essential oil microencapsulated by spray-drying

Schinus terebinthifolius Raddi has been extensively studied due to its antioxidant, anti-inflammatory and antibiotic properties. Recently, its seeds have been tested against some insect pests as an insecticide, repellent and antifungal agent. Microencapsulation by spray-drying is widely used in the food and drug industries, as well as in the microencapsulation of essential oils, since it protects the oils against several effects, such as oxidation and thermal degradation, thus optimising its use. The aim was to microencapsulate S. terebinthifolius essential oil by spray-drying maltodextrin and arabic gum as encapsulating agents and SiO2 as a colloidal adjuvant. The morphology of the microcapsules was analysed by scanning electron microscopy (SEM), which evidenced mainly regular spherical-shaped particles with sizes between 5 and 10 µm. The thermal stability was studied by thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), and the microcapsules were stable at temperatures up to 200°C. The microencapsulating agents and the spray-drying technique produced microcapsules capable of protecting the essential oil against external effects, such as thermal degradation.


a b s t r a c t
Schinus terebinthifolius Raddi has been extensively studied due to its antioxidant, anti-inflammatory and antibiotic properties. Recently, its seeds have been tested against some insect pests as an insecticide, repellent and antifungal agent. Microencapsulation by spray-drying is widely used in the food and drug industries, as well as in the microencapsulation of essential oils, since it protects the oils against several effects, such as oxidation and thermal degradation, thus optimising its use. The aim was to microencapsulate S. terebinthifolius essential oil by spray-drying maltodextrin and arabic gum as encapsulating agents and SiO 2 as a colloidal adjuvant. The morphology of the microcapsules was analysed by scanning electron microscopy (SEM), which evidenced mainly regular spherical-shaped particles with sizes between 5 and 10 μm. The thermal stability was studied by thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), and the microcapsules were stable at temperatures up to 200 °C. The microencapsulating agents and the spray-drying technique produced microcapsules capable of protecting the essential oil against external effects, such as thermal degradation.

Value of the Data
• The seeds of Schinus terebinthifolius present activities in different areas, such as health, with antioxidant, anti-inflammatory, antibiotic and anticancer action [1] , in the food area for their antimicrobial, antibacterial and antifungal activity [ 2 , 3 ], and in the agronomic area for their repellent and insecticidal action against insect pests [4] . • The data provide a microencapsulated spray-drying formulation of the essential oil of S. terebinthifolius that protects the oil against external effects, such as temperature and oxidation, and presents controlled release of the essential oil [5] . • The data included in the article provide a broad characterization of the physicochemical properties of the microcapsules of essential oil of S. terebinthifolius, including the chemical composition of the essential oil, the morphology, and the thermal behaviour of the microcapsules. • The data provide the formulation of essential oil of S. terebinthifolius microcapsules, supporting research work in the areas of food technology, pharmaceuticals and agronomy, bringing benefits to the entire population. • Using the spray-drying technique to prepare the formulation allows the microencapsulation methodology to be scaled up using biodegradable and non-toxic agents. All food, pharmaceutical and agronomy professionals can use the material.

Objective
The aim was to microencapsulate S. terebinthifolius essential oil by spray-drying maltodextrin and arabic gum as encapsulating agents and SiO2 as a colloidal adjuvant.
Essential oils are characterized as complex mixtures of low molecular weight compounds, being highly volatile and responsible for flavors, aromas, and different biological activities such as antimicrobial, antifungal, insecticidal, and others [6] . The essential oil of S. terebinthifolius is cited in the literature for its antioxidant, anti-inflammatory and antibiotic properties, however its use is limited due to its volatility and rapid degradation under the influence of light, heat, and an oxidizing atmosphere [1] . The microencapsulation technique has been explored in sectors such as the food and pharmaceutical industries and is proposed for use in agriculture because it provides protection to active ingredients against external effects such as oxidation and degradation, in addition to providing controlled release of compounds [7] .

Data Description
The essential oil of Schinus terebinthifolius Raddi fruits was obtained from hydrodistillation in a modified Clevenger-type apparatus. Table 1 presents the chemical composition of the essential oil by gas chromatography/mass spectrometry using a GCMS-QP2010 Ultra (Shimadzu, Tokyo, Japan). Fourteen compounds were identified in the essential oil of S. terebinthifolius fruits, corresponding to 96.13% of the total oil.
The morphology of the microcapsules was analysed by scanning electron microscopy (SEM). Fig. 1 shows images of the metallised MD:AG:SiO 2 :EO sample, where MD is maltodextrin, AG is arabic gum, SiO 2 is silicon dioxide, and EO is essential oil. The microcapsules presented a circular shape and an apparent absence of pores. The evident lack of fissures in the walls or porosity in the surface of the particles indicates complete coverage of the nucleus by the wall materials. Fig. 2 shows an SEM image of the MD:AG:SiO 2 :EO microcapsule obtained without metallisation (A) and the particle size distribution (B). The particle size distribution shows that 84% of the microcapsules present diameters between 5 and 10 μm.
Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) analyses of the MD:AG:SiO 2 :EO microcapsule without metallisation were performed to investigate whether the SiO 2 is only present in the formulation as a dispersing agent, that is, to know whether the microparticles were formed by silicon or by carbon from the carbohydrates (maltodextrin and     total mass, respectively. The raw and analysed data are available as supplementary documents ( https://data.mendeley.com/datasets/nz4g5kz766/2 ) [6] .

Obtaining pink pepper tree ( S. terebinthifolius ) essential oil
The fruits of the pink pepper tree ( S. terebinthifolius ) were collected in the A. C Simões Campus of Alagoas Federal University, Brazil (9 °33' 11.08'' S, 35 °46' 30.02'' W; 9 °33' 10.63'' S, 35 °4 6' 30.22'' W) in October 2017. The vegetal material was identified by Rosângela P. Lyra Lemos of the MAC herbarium of the Environment Institute of Alagoas (IMA-AL), where a botanical exsiccate was deposited with register number 63595. The EOs were extracted from the fruits by hydrodistillation, according to the method used by the AOAC [7] , using a modified Clevengertype apparatus coupled to a 12 L volumetric flask. The dry fruits were crushed and submitted to steam distillation (10 0 0 g in 7 L of distilled water) for 4 h. After separation of the aqueous phase, the oil portion was stored in amber glass and refrigerated (-4 °C) until required.
The extraction was performed in quadruplicate, and the oil yield was calculated by the mass ratio of obtained oil and crushed vegetal material ( Eq. (1 )). (1)

Chemical characterisation of the pink pepper essential oil by gas chromatography
The samples were analysed by gas chromatography using a GC-2010 Plus (Shimadzu, Tokyo, Japan) equipped with a DB-5 capillary column (30 m x 0.25 mm x 0.25 μm Agilent Technologies, USA) and FID detector. The samples were diluted with double-distilled HPLC grade hexane (Merck, Darmstadt, Germany) to 10 ppm. The samples (1 μL) were injected in splitless mode. The carrier gas was H 2 with a pressure of 77.6 kPa, the injector temperature was 260 °C, and the detector temperature was 360 °C. The temperature program was initiated at 60 °C, kept for 3 min, then increased to 300 °C (8 °C/min) and held for 10 min.
The proportion between compounds was calculated by the peak area percentage ( Eq. (2 )). The compounds were identified through the comparison of their retention times (RTs), and their linear retention indexes (KI) were determined by injecting a standard solution of n-alkanes with carbon numbers in the range C7-C30 and calculated using Eq. (3 ).
where i = compound of interest where: The qualitative analysis of the compounds of the selected oils was performed in a GCMS-QP2010 Ultra (Shimadzu, Tokyo, Japan) equipped with a DB-5 capillary column (30 m x 0.25 mm x 0.25 μm i.d. Agilent Technologies, USA) and a quadrupole mass spectrometer. The samples (1 μL) were injected with a split ratio of 1:3 and an injector temperature of 260 °C. The carrier gas was He with a pressure of 72.8 kPa. The temperature program used was the same program used for the GC-FID analysis. The ionisation was conducted by electron impact with an ionisation voltage of 70 eV, the ion source temperature was 290 °C, and the detection was performed in scan mode from 35 to 400 m/z. The mass spectra were compared to those available in the commercial libraries NIST08, NIST08s and Wiley 275 L and those corresponding to synthetic patterns.

Microencapsulation of pink pepper tree essential oil
Maltodextrin DE-20 (Advanced Nutrition), arabic gum (LabSynth) and Aerosil® 200 (colloidal silicon dioxide -LabSynth) were used as encapsulating agents. A solution of 20% ethanol in MiliQ® ultrapure water was used as a solubilising agent.
To prepare the emulsions, the wall materials were dissolved in the water/ethanol solution at 25 °C, and this mixture was agitated until complete dissolution. The total concentration was set at 30%, of which 70% was maltodextrin, 25% arabic gum and 5% silicium dioxide. The pink pepper essential oil was added to the hydrated wall material at a concentration of 20% relative to the total solids. An emulsion was formed under magnetic stirring at 10 0 0 rpm (magnetic stirrer IPAS, model IKA® C-MAG HS 7).
Atomisation drying was performed in a spray dryer (LabMaq, model MSDi 1.0; Ribeirão Preto, Brazil) with a dual fluid atomising nozzle of 1.0 mm diameter, air flow of 30 L/min, air pressure of 3.0 bar and an airflow of the dryer of 3040 L/min. The dryer was fed at a flow of 0.32 L/h, with clockwise rotation. The air inlet temperature was 140 ± 2 °C and the outlet temperature was 104 ± 3 °C.
The prepared sample was named MD:AG:SiO 2 :EO, referring to the maltodextrin -arabic gum -silicium dioxide -pink pepper essential oil composition. A second sample was prepared using only the encapsulating agents and named MD:AG:SiO 2 (maltodextrin -arabic gum -silicium dioxide).

Morphological characterisation by scanning electron microscopy (SEM) and by Energy Dispersive Spectroscopy (EDS)
For the morphological characterisation, the microcapsules were metallised in a QUORUM Q150R ES with a current of 45 mA for 200 s. The SEM images of the metallised samples were obtained at the Microscopy Laboratory of the Alagoas Federal Institute (Maceió, Brazil) in a TES-CAN VEGA3, working in accelerating voltages between 5 and 30 kV in different magnifications.
To confirm the walls of the microcapsule, SEM images were also obtained without metallisation in a JEOL JSM 7100F microscope equipped with an emission field electron source, with an accelerating voltage between 1 and 15 kV in different magnifications. Additionally, elemental analysis was performed by X-ray energy dispersive spectroscopy (EDS) using a solid state detector (SSD).
The average particle diameter was measured in 250 microcapsules in PixelPro software.

Thermogravimetric analysis-differential scanning calorimetry (TGA-DSC)
The thermal degradation of the samples was performed at the laboratory of the Catalysis and Chemical Reactivity Group of the Alagoas Federal University (Maceió, Brazil) using SDT650 equipment (TA Instruments). The MD:AG:SiO 2 and MD:AG:SiO 2 :EO samples (7.809 mg and 3.834 mg, respectively) were submitted to a heating ramp from 35 to 650 °C (10 °C/min) using synthetic air with a flow of 50 mL/min.

Ethics Statements
None.

Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data Availability
Data on spray-drying microencapsulation of Schinus terebinthifolius essential oil (Original data) (Mendeley Data).