Main Components of The Semboro Variety of Siam Orange Peel Essential Oil Prepared Using Water Distillation Method

The maximum production potential for low quality oranges is 15% or 9,057 tons/year, the potential for orange peel waste is 50% of the total weight of oranges or the equivalent of 4,500 tons of orange peel waste The average yield of orange peel essential oil is 0.6%, resulting in a potential of 27 tons/year. The aim of this research is to obtain information regarding the best heating temperature in the distillation process and to identify the main components of Siam orange peel essential oil of the Semboro variety. The research was carried out using a laboratory-scale water distillation system, with a distillation flask capacity of 1 liter, with 150 g of orange peel as raw material at a distillation process heating temperature of 250 ° C and 300 ° C. The yields of 1.9 mL and 0.9 mL of Siam orange peel essential oil were obtained 1.083% and 0.513% respectively. The specific gravity of Siam orange peel essential oil is 0.855 g/cm 3 and 0.886 g/cm 3 respectively, the main components are 29 and 18 components respectively. An important finding of this research is that at a distillation process with heating temperature of 250 ° C, yields a limonene content of 16.10%, whereas heating at 300 ° C results in 7.69% limonene content


INTRODUCTION
Jember Regency is known as the center of the Semboro Siam Oranges.The Siam orange plantation area is 3,500 ha out of 5,600 ha of the total area of orange peel plants with production reaching 65,145 tons.The average productivity of Semboro orange farmers is 172.93 quintals per hectare.The quality of oranges based on grain diameter is divided into 4 grades, namely: grade A (super) diameter > 73 mm, grade AB diameter 63 -73 mm, grade C diameter 56 -62 mm and grade D diameter 50 -55 mm (Setiawan & Suhendra, 2014).For grade D, is known as low grade quality oranges.The maximum production potential of low grade oranges is 15% or 9,057 tons/year.In general, low grade oranges have low prices, so to increase the selling value, it is necessary to diversify into processed orange juice.The potential for orange peel waste is 50% of the total weight of oranges or the equivalent of 4,500 tons of orange peel waste (Singh et al., 2020).Given the distillation provide essential oil of average 0.6%, then the potential of essential is 27 tons/year (Muhtadin et al., 2013).This can potentially improve the welfare of orange peel farmers, in particular.
The purpose of the study was to determine the chemical components of the essential oil of Siam Semboro sweet orange peel produced through a distillation process at a certain heating temperature (250 °C and 300 °C) and to determine the yield of the essential oil obtained.Research related to the yield and identification of the constituent components of Siam orange peel essential oil, Semboro variety, Jember Regency has not been done much.Therefore, this research is important as initial data for potential investors to find out the potential of essential oil extracted from Siam Semboro orange peel, especially by using water distillation method.

Materials and tools
The material used in this study was the fresh Siam Semboro sweet orange peel obtained from traditional market "Pasar Tanjung" in Jember.The equipment is a set of steam distillation apparatus, separating funnel, erlenmeyer, analytical balance, measuring cup, bottle containing essential oil, aluminum foil, filter paper disc, petri dish, micro pipette, electric heater, rotary evaporator, data logger, k term thermocouple and a set of Gas Chromatography-Mass Spectroscopy analyzer (GC-MS QP2010 Plus, Shimadzu).

Sample setup
Fresh orange peel was cut into 1 cm size as much as 150 grams and put into a distillation flask with a volume of 1000 mL.The set up of the distillation apparatus can be seen in Figure 1.T1 is condenser inlet temperature, T2 is condenser outlet temperature, T3 is boiling flask temperature and T4 is distillate temperature.

Essential oil distillation by steam distillation
A total of 300 g of fresh orange peel that has been cut into 1 cm size was distilled twice with a heating temperature of 250 °C and 300 °C.Steam distillation equipment includes stove, 1000 mL volume distillation flask, condenser, distillate container and separator funnel.Temperature measurements were carried out using a data logger, where the probe was placed in a distillation flask, inlet and outlet channels from the condenser, and in the distillate storage flask, then heated at a temperature of 250 °C and 300 °C.The resulting of distillate was separated using a separating funnel.The analysis was conducted descriptively.

Identification of essential oils
As much as 1 drop of essential oil is dropped on a piece of filter paper and allowed to stand for a few minutes.After a few minutes, the essential oil will evaporate completely without leaving a transparent stain (Guenther, 1972).

GC-MS Analysis
The essential oil of Siam Semboro orange peel obtained was then analyzed using gas chromatography-mass spectroscopy (GC-MS) with column oven temperature was 80 °C, injection temperature of 250 °C with pressure of 64.1 kPa, and column flow of 0.99 mL/min.This analysis is to determine the components of the chemical groups that make up essential oils and the mass spectrum obtained is compared with the mass spectrum of the comparison compounds known in the database that has been programmed on the GC-MS tool.

Distillation process temperature
The distillation process was carried out using a steam system employing a laboratory-scale distillation apparatus with 150 g of orange peel.The temperature distribution during the distillation process with heating temperatures of 250 °C and 300 °C, is shown in Figures 2. The distillation process with heating temperature of 250 °C starting to evaporate the liquid into the gas phase at 3,090 s or 51.5 min.It means that the liquid needs 51.5 min to reach its boiling point (100 °C).The distillation process was stopped when the distillation was reached at 23,890 s or at 6 h and 38 min or the extraction process took 5 h and 50 min.Figure 3 shows that the heating temperature at 300 °C changes the liquid phase to gas at 48.5 min.The distillation process was stopped after 5 h and 25 min or the extraction process for 4 h and 37 min.The higher the heating temperature, the faster the heat transfer and mass transfer that occur between the media and the material.Thus, the faster the material reaches its boiling point for the evaporation process (Hien et al., 2022).Several research results related to extraction time were reported by Haryanti et al., (2014), reporting the process of extracting orange fern oil in 3 h; Ikarini et al., (2021) reported that the distillation of Siamese oranges was carried out for 2 h; Febrina & Sigiro (2021) reported that the distillation of Siam Sambas oranges was carried out for 7 h; Fachriyah et al., (2002), reported distillation of Siamese orange peel essential oil for 10 h; Wibaldus et al., (2016) reported the distillation of lime for 4 h.The distillation time varies greatly also depending on the raw material, the thicker the orange peel, the longer the distillation time is needed.General, the Semboro Siamese orange peel with an average thickness of 1 mm.

Essential Oil Extraction
As many as 150 g of fresh Siam Semboro orange peel, cut into approximately 1 cm pieces, underwent steam distillation.Following separation with a separatory funnel, yields of 1.9 mL and 0.9 mL of yellow volatile oil were obtained, corresponding to 1.083% and 0.513% yields, with specific gravities of 0.855 g/cm 3 and 0.886 g/cm 3 , respectively.The extraction process at high temperatures causes heat transfer and mass transfer that occurs between the environment and the material to take place faster so that the extraction process takes place more effectively.However, if the temperature is too high, there are components in the material that are degraded, thus reducing the quality of the resulting extract (Teles et al., 2017).This is in line with research conducted by Hien et al.,(2022) on orange essential oil obtained at an extraction temperature of 130 °C resulting in a yield of 1.7 mL/g, but at a temperature of 150 °C the yield of essential oil decreased to 1.63 mL/g.

Identification of Siam Semboro orange peel essential oil
Identification is done as an effort to ensure that the oil produced is an essential oil.The identification results showed that there were no transparent stains on the filter paper, this proves that the oil obtained is an essential oil.Further analysis was performed using Gas Chromatography and Mass Spectroscopy (GC-MS).The results of the GC-MS analysis obtained two data, namely chromatograms from gas chromatography (GC) analysis and mass spectra from mass spectroscopy (MS) analysis.The essential oil chromatogram of orange peel oil is shown in Figure 4 for heating at 250 °C.The chromatograms shows 29 peaks of compounds.The suspected volatile compounds in the essential oil of Semboro orange peel chromatogram are shown in Table 1.The identification results of Siam Semboro orange peel essential oil with heating at 250°C produced 29 components with 10 main components (area >2.50%), including:   Treatment at 300 °C heating produced 18 components with the main components (% area above 2.5%) including: (1) Linalool; ( 2 The heating process at high temperatures and prolonged extraction time causes oxidation and degradation reactions in the compounds contained in orange peel oil.This caused the number of compounds identified on GC-MS for the 300°C heating temperature to be lower (Sulaiman et al., 2017).This is in line with research conducted by Yusoff et al., (2013) which showed that at an evaporation temperature of 95 °C the number of compounds contained in kaffir lime oil was 19 compounds while at an evaporation temperature of 90 °C, 24 compounds were found.In steam distillation, the yield of chemical compounds in the orange peel oil is still higher than cold press-assisted aqueous extraction that was conducted by Labrath & Gaikar (2020).The research found that the total yield of orange peel oil was 0.79% which contained 7 types of chemical compounds including Tangeritin, Sinensetin, Nobiletin, Tocotrienol, Tocopherol acetate, Xanthophyll, and 3-hydroxyl α-carotene.

CONCLUSIONS
The 250 °C and 300 °C heating temperatures resulted in yields of 1.083% and 0.513%, respectively, the specific gravity at 18°C was 0.855 g/cm 3 and 0.886 g/cm 3 , and the main components were 29 and 18 components, respectively.Treatment with heating at a temperature of 250 °C resulted in higher Siam orange peel essential oil yields, while the specific gravity value was smaller and the number of chemical compounds was greater than heating at a temperature of 300 °C.The 250 °C treatment was chosen to be used as a reference for further research related to the initial treatment of materials with High Pulsed Electric Field (HPEF) treatment and application to vacuum distillation.

Figure 1 .
Figure 1.The set up of the distillation apparatus

Figure 2 .
Figure 2. Temperature distribution during distillation with heating temperature at 250°C and 300°C

Table 1 .
Alleged essential compounds in the chromatogram of essential oils of Siam Semboro orange peel based on database

Table 2 .
Alleged essential compounds in the chromatogram of essential oils of Siam Semboro orange peel based on database