Seed samples were supplied from local orchards in the Aydın Region. The Sarilop variety of the figs was dried naturally, and their seeds were separated from the flesh and other impurities in its place by the grower. Seeds are extracted by using the cold press method. The oil extraction process was completed at Zade Vital Pharmaceuticals Inc. under GMP conditions. The process temperature was lower than 40 degrees Celsius and no heating application or any chemicals were used.

Chemicals were analytical or chromatographic grade, with trademarks J.T. Baker and Sigma–Aldrich. For all analysis Millipore ultrapure water (Type I) was used.

Total protein content was determined by using the Kjeldahl method. Protein content was calculated with the general factor (6.25). 19 Total ash analysis was completed according to EP 8.0 method 2.4.16 20 and for ash insoluble in hydrochloric acid analysis EP 8.0 method 2.8.1. 21

Trace elements analysis was conducted by ICP-OES using standard methods. 22 According to the method 0.5 g fig seed was weighed and 7 mL HNO₃ 65% and 1 mL H₂O₂ 30% was added. A microwave oven (Milestone Ethos One) was used for digestion of samples. The microwave digestion application was done with parameters which are shown in Table 1. The sample was cooled down for a period of time until the samples temperature reached 25⁰C. After dilution to 200 mL, the sample was analyzed by ICP-OES (Shimadzu ICPE-9000).

A fatty acid methyl esters (FAME) analysis was conducted according to COI/T.20/Doc. No 33 for olive oils method. 23 70 mg sample of oil was used for the analysis. Fatty acids were identified by retention time. The standard A 37 component mixture of FAME (Supelco) was used for determination of retention time. The area ratio, which is under the relevant peak, was used for the quantitative analysis. The calculation has been completed by using area normalization procedure. As an instrument the Shimadzu 2010 Plus GC-FID system was used. The column chosen was a Restek Rt 2560 capillary column (100 m x 0.25 mm ID x 0.2 µm). The injection and detector temperatures were set at 250^oC and 260^oC, respectively. The temperature program was as follows; the oven temperature was held at 140^oC for 1 min and then increased to 240^oC at a rate of 4^oC/min and held for 5 min. The split ratio was at 1:100. Sterol analysis was completed according to EP 8.0 2.4.23 sterols in fatty oil with the Shimadzu GC-2010 Plus. 24

Phenolic extraction has been conducted according to the method given by Ferhat et al.²⁵ The methanol extract has been prepared by weighing 1 g of fig seed oil into a centrifuge tube and adding 1 mL of methanol/water (80/20, v/v) into the tube. After stirring the mixture in a vortex apparatus (10 min), the tube was centrifuged (3800 rpm, 15 min) to separate the methanol layer. The extraction has been done twice.

Total phenolic content of the methanol extracts was determined by using the method given in the literature by Ferhat et al. 25 For determination of total phenolic content, 0.5 ml of methanolic extract solution, 5ml distilled water and 1 mL Folin–Ciocalteu reagent were added to the test tube respectively and the tube was shaken. After 4 minutes, 0.8 ml of Na₂CO₃(7.5%) solution was added into the tube. The mixture was left for 2 h with intermittent shaking. Absorbance of the mixture was measured at 640 nm. Each assay was carried out in triplicate.

The following equation which was obtained from the standard gallic acid graph is used to calculate the concentrations of phenolic compounds:

Absorbance = 0.006 gallic acid (mg) – 0.021 (R2=0.969)

For tocopherol analysis the method described by Celenk et al 26 was used. The column chosen was Lichrosorb Si 60, 250 x 4.0 mm for the HPLC analysis. The analysis was completed by using hexane/2-propanol (99,5/0,5) (v/v) as mobile phase, injection volume was 20 μL at 25±1 °C, the flow rate was 0,8 mL/min. All the injections were triplicate for each of the concentrations of tocopherols. The Tocopherol Set (Merck) was used as a standard which includes a four-vial pack containing α, β, γ, and δ-tocopherols. The data of peak areas are used for calibration graphs. The data from corresponding concentrations, the excitation at 290 nm wavelengths and the emission at 330 nm were used for calculation of the linear regression equations.

The free radical scavenging activity was determined by the DPPH assay spectrophotometrically. 25 According to the method, 1.95 ml of DPPH (0.025 mg/ml) prepared in anhydrous methanol was added into 50 μl of sample methanolic solution. The absorbance was measured thirty minutes later, at 515 nm. In the results, higher free radical scavenging activity was found related to lower absorbance of the reaction mixture. The following equation is used to calculate the capability of scavenging the DPPH radical:

DPPH radical scavenging effect %= A control-A sample A control x 100 

With respect to the terms of the formula above, “A_control” is defined here as the first concentration of the DPPH and “A_sample” is defined here as the absorbance of the remaining concentration of DPPH with the extract.

Volatile compounds were identified by using the gas chromatography technique coupled with mass spectrometry (GC–MS). The instrument employed was a Shimadzu GC-MS with mass selective detector which is the QP 2010 plus model. The chromatographic column was Restek Rxi-5ms, thickness was 0.25 µm, length was 30 m, and the internal diameter was 0.25 mm. The used oil sample amount was not less than 1 mL, and the compounds were identified by comparing the database library of the GC with the mass spectra obtained. The amounts of volatile components were determined by the analysis instrument, using the area of each peak for integration and calculation results were given as percentages. Chromatographic conditions were set as column oven temperature to 40°C, injection temperature to 250 °C, injection mode was split, total flow was 40,8 mL/min, column flow was 1,80 mL/min and split ratio was 20. The oven temperature program was as follows: the oven temperature was held at 40^oC for 3 min. It was then increased to 240^oC at a rate of 4^oC/min and held stationary for 5 min.27

The free fatty acid (FFA) content was analyzed according to EP 8.0 method 2.5.1 28, and the peroxide value (PV) was calculated with EP 8.0 method 2.5.5. 29 The refractive index was determined by using EP 8.0 method 2.2.6 30 and Rudolph J57WR, and for p-Anisidine value A.O.C.S Official Method Cd 18-90 was used. 31 The p-Anisidine values were calculated using the following equation: p-A.V.=25*(1,2As-Ab)/m. 32

F. carica seeds have been evaluated for their cold pressed oil content, protein, ash, ash insoluble in hydrochloric acid, potassium, calcium, sodium, magnesium and iron. The oil yield of fig seed with the cold press method was found at 22.7 %. Protein, ash and ash insoluble in hydrochloric acid values were found in our study as 14.65%, 2.6 g and 0.2 g, respectively. Potassium, magnesium and calcium were the main trace elements in the dried fig seeds (Table 2).

Fig seed oil fatty acid methyl esters (FAME) composition are found most abundantly in polyunsaturated fatty acids (PUFA) and monounsaturated fatty acid (MUFA) with 41.27% alpha linolenic acid, 30.06 % linoleic acid and 18.10% oleic acid (Table 3). 33

Total phenolic content of the cold pressed fig seed oil was found to be 79.5 mgGAE/100 g in our study and sterol analysis showed that beta-sitosterol was the most abundant components and total sterol was 6519.40 mg kg-1 (Table 4).

F. carica seeds oil have been analyzed for their tocopherol content and in the results α, β, γ, δ-tocopherol were detected. The results were for α-tocopherol 6.088 mg kg^-1, β-tocopherol 0.18 mg kg^-1, γ-tocopherol 634 mg kg^-1, δ-tocopherol 18 mg kg^-1 and total tocopherol was 658.27 mg kg^-1. γ-tocopherol has the most abundant content exceptionally while β-tocopherol has the lowest range. According to the free radical scavenging activity (DPPH) analysis the antioxidant capacity of the oil was determined at 52.54%.

Ninety-fourdifferent components are determined in the Cold pressed oil of F. carica seeds and major volatiles are shown in Table 5.

Physicochemical properties of fig seed cold pressed oil found for free fatty acid (FFA), the peroxide value (PV), the refractive index (RI)(40 ^oC) and p-anisidine were 0,90% oleic acid, 2.2 meq O₂/kg oil, 1.4721 and 2.22 respectively. Peroxide value, free fatty acid and p-anisine levels were within the acceptance levels for edible oils

Polyunsaturated fatty acids (PUFA) and monounsaturated fatty acid (MUFA) 33 were the most abundant components in FAME composition. Comparing this study with the other studies of dried figs, linolenic acid was found to be the most predominant fatty acid with 53.1%, linoleic acid 21.1%, palmitic acid 13.8%, and oleic acid at 9.8%. 4 The studies with latex showed that the fatty acid composition mostly contains palmitic (21.4%), arachidic (44.1%), and behenic acids (13.1%). Latex contains mostly saturated fatty acids (161.77 mg/kg), MUFA (5.89 mg/kg), PUFA (14.59 mg/kg). [1. 5] Our results are compatible with two other studies about fig seed oil. These studies showed that the main saturated fatty acids were palmitic acid (3.57-7.40% and 8.53-9.05%) and stearic acid (2.97-3.73% and 2.59-3.30%). Arachidic, behenic, margaric and lignoceric acids were determined to exist in trace levels. In terms of unsaturated fatty acids, linolenic acid (37.87-41.80% and 38.43-43.57%), linoleic acid (31.80-37.95% and 28.90-34.51%) and oleic acid (16.82-17.79% and 13.43-15.64%) were found with the highest values, similar to our study. MUFA value (18.42%) of this study was higher than the other two studies, PUFA (71.54%) was lower and TSFA (9.99%) was within the ranges of the other two studies. 15, 36 The saturated fatty acid profile of this study was similar to guava and melon seeds oil 38, 45 and linolenic acid content of the fig seed oil might be considered to be similar to raspberry, bilberry and elderberry. 37 Since the ω-6/ω-3 rate (0.72) was lower, fig seed oil might be recommended for a healthy diet and can be evaluated as a new source for ω-3 fatty acids.

Unsaturated fatty acids (89.96%) and a lower rate of ω-6/ω-3 are responsible for many important functions in the body. The studies show that linoleic and linolenic acids, which are included with polyunsaturated fatty acids, are responsible for converting the eicosanoids-hormone like-substances to be in different physiological reactions such as the immune response and blood clotting. 4 By reducing low-density lipoprotein cholesterol and blood pressure level, oleic acid also has an important supportive function with coronary heart problems. 46 Even though the fatty acids ranges are different, the unsaturated and saturated fatty acids ratios were found similar with other studies. These differences can be related to different environmental conditions such as geographical difference, climate change and other factors like genetics, and plant species.

Total phenolic content of the cold pressed fig seed oil was found to be 79.5 mg GAE/100 g in our study. Other studies’ results from different cultivars of dried fig extract were 11.7, 10.1 and 14.8 mg chlorogenic acid equivalents/g, 47 from stem 539.17 ± 3.21 mg GAE/100 g, from root 573.06 ± 2.74 mg GAE/100 g , from leaves 531.76 ± 4.90mg GAE/100 g, 48 from overall fresh fruit 1,090–1,110 mg GAE/100 g. 40 Another study, which subjected the peel and pulp separately, found the total phenolic content for peel in the range of 4.78-5.76 mgGAE/g sample and 1.92-2.67 mgGAE/g sample 42 and level of total phenolics for F. carica stem extracts was 133 mg GAE/g. 10 In a study from a Turkish region for different F. carica fruits, total phenolic content was analyzed for Bursa siyahi, Karabakunya, Sarilop and Sultan Selim and these were 37.29±1.558, 33.55±1.559, 28.25±1.446, 25.47±0.936 mg GAE g-1 respectively. 49 A study from Turkey determined the total phenolic content of fresh and dried figs and the results were 199.52-307.64 mg GAE/100 g and 81.77-212.36 mg GAE/100 g respectively. 50 Hssaini et al. 15 reported the phenolic content of four different cultivars’ seed soil between the range of 69.83 and 100.99 mg GAE/100 g and Ozyurt 51 reported phenolic content of commercial fig seed oil as 654.73 mg GAE/Loil. Our results were similar to dried fig and fig seed oil phenolic contents. As can be seen in different studies, which are conducted with different parts of figs (roots, root bark, stem wood and bark, leaves, branches, fruits, and seeds), phenolic compounds are found to be very widely different. These compounds are responsible in fruits for specific functions and sensory properties such as color and flavor. At the same time phenolic compounds are very important and popular with their health-promoting effects especially for their antioxidant, free-radical scavenging, and antiproliferation/antiprogression actions properties. 5, 40 Ficus species are an excellent source of phenolic compounds. 11 Especially fig fruits are accepted as having higher amounts of phenolic compounds compared with tea and red wine which are two well-publicized sources for phenolics 49 and some studies demonstrated that fresh figs contain lower phenolic amounts than dried figs 47 while some others showed that the phenolic content of dried figs is lower than fresh figs. 50

Total sterol was found 6519.40 mg kg-1 in our study with some other sterol components (Table 4). Other studies which are focused on different parts of fig fruits’ sterol compositions have demonstrated different results. A study which was focused on the extract of F. carica latex composition found betulol (327 mg/kg), lupeol (2827 mg/kg), lanosterol (2634 mg/kg), lupeol acetate(1989 mg/kg), β-amyrin (1197 mg/kg), β-sitosterol (10567 mg/kg), and α-amyrin (76 mg/kg). Within the results, β-sitosterol (54%) was the highest sterol compound while α-amyrin (0,4%) was the lowest 5 In another study, which subjected San Francesco, Citrullara, and Dottato cultivars of dried F. carica, sterol composition was found to contain campesterol (0.2-1.0%), stigmasterol (1.6-1.9%), stigmasta-5,23-dien-3-ol (0.2-2.4%) and β-sitosterol (1.5-10.3%) with the highest rates. 47 Jeong and Lanchance‘s study 4 about different parts of the figs (fruit, bark, stem, pith) found four sterols as campesterol, stigmasterol, sitosterol and fucosterol. While fucosterols were analyzed only in fruits, sitosterol had the highest level in all parts of the fig. Total sterol contents of some seeds oils also show similarity to our results such as date palm kernel oil (336.1-788.4 mg 100 g^-1), gooseberry seed oil (586 mg 100 g^-1) and grape seed oil (156-10596.2 mg 100 g^-1). 37 Comparing the other results with our study, the sterol composition ranges were similar with the dominance of beta-sitosterol. The sterols also have been reported in seeds, seed oils, roots, stems and branches, leaves and blossoms in different studies and the total amounts of sterols were not equal and the proportions were different in various parts of a plant or a tree. 4 As the phytosterols are important for cholesterol elimination in the body, cellular processes and also participation in cellular differentiation and proliferation, 47 fig seed oil can be considered as a valuable source for sterols.

F. carica seeds have been analyzed for their tocopherol content and in the results α, β, γ, δ-tocopherol were detected in different levels. The results were similar in order of contents with the Baygeldi et al. study but slightly different in amounts in which γ-tocopherol was 391.89 mg/100g, δ-tocopherol was 7.65 mg/100g, α-tocopherol was 4.6 mg/100 g. 35 Some studies about tocopherols also have been conducted for different parts of the fig plant. The fig leaves have been found with a low level of α-tocopherol on dried weight (0.0570%). 52 The fig fruit α-tocopherol content was 0.34 mg/100 g and γ-tocopherol was 0.38 mg/100 g. 53 Although fig fruits can be considered as being with a low level of tocopherols compared with the other fruits such as raspberries or peaches, fig seeds oil can be classified as a good source of tocopherol similar to with some other seeds such as blueberry (260.6 mg/kg) and marionberry (978 mg/kg). 54 Since the tocopherols have beneficial effects on health along with other components of oils such as phenolics, sterols and fatty acids, 37 with its phytochemical structure fig seed oil can be a functional component in different food applications.38

Antioxidant capacity of fig seed oil was found at 52.54%. Hssaini et al. 15 evaluated the DPPH radical scavenging activity of four different fig cultivars’ oil (C11A21, Bourjassotte noir, C7A14 and White Adriatic) and the results were in a range between 226.46-294.36 mg Trolox equivalent/g oil. In the study of Imran 48 for F. benjamina they found the DPPH, IC₅₀ analysis results for stems at 50.10 ± 3.23 μg mL^-1, for roots at 58.81 ± 4.50 μg mL^-1 and for leaves at 49.86 ± 3.39 μg mL^-1. Loizzo 47 found the DPPH assays results for three different cultivars of the fig at 22.6, 38.2, 41.3 µgmL^-1 and for its honey at 11.6 µgmL^-1. Ersoy and others 49 have studied four different F. carica cultivars in Turkey and found the DPPH values for the fruits as 1.20, 1.26, 1.42, 1.49 mg sample mg^-1. The study with the co-products of fig found the DPPH (for 100mg/mL) for peel between 57.56-87.35% and for the pulp between 28.97-46.03%. 42Following the results above, F. carica seed oil showed similar antioxidant activity with elderberry seeds. 55 The DPPH radical scavenging assay is commonly used on free radicals to determine the scavenging potential of an antioxidant. The studies generally employed this analysis for different parts of figs but not for oil. Comparing with other results, which are shown, the antioxidant capacity of fig and its cold pressed oil can be considered to be a good antioxidant with its capacity. Since the antioxidants are accepted to decrease the risks of chronic diseases, a fig seed oil rich diet with natural antioxidants might be a proper choice for preventing oxidative damages and degenerative diseases. 15

Ninety-four different components are determined in F. carica seeds oil in this study (Table 5). The other studies isolated different volatile compounds for fig fruits (pulps and peels) such as “aldehydes: 2-methylbutanal, 3-methyl-butanal, hexanal, heptanal, (E)-2-pentanal, nonanal, and octanal, alcohols: 3-methylbutanol, 1-penten-3-ol, (E)-2-nonenol, benzyl alcohol, and phenylethyl alcohol, ketone: 6-methyl-5-hepten-2-one, esters: ethyl salicylate, methyl salicylate, and methyl hexanoate, monoterpenes: α-pinene, limonene, β-pinene, menthol, eucalyptol, linalool, sesquiterpenes: copaene, α-cubenene, τ-muurolene, β-caryophyllene, germacrene D, and τ-cadinene, norisoprenoid: β-cyclocitral, and miscellaneous compounds: eugenol”. 1, 3, 47 The leaves of F. carica have different volatile compounds which are classified as follows: “Aldehydes: methylbutanal, (E)-2-pentanal, hexanal, and 2-methylbutanal, (E)-2-hexanal, alcohols: 3-methyl-1-butanol, 1-penten-3-ol, heptanol, 2-methylbutanol, (E)-2-nonen-1-ol, benzyl alcohol, and phenylethyl alcohol, ketone: 3-pentanone, esters: methyl butanoate, methyl hexanoate, hexyl acetate, ethyl benzoate, and methyl salicylate, sesquiterpenes: α- guaiene, α-cubenene, copaene, α-ylangene, β-elemene, α-gurjunene, β-bourbonene, β-cubebene, β α-caryophyllene, α-caryophyllene, aromadendrene, τ-cadinene, τ-muurolene, germacrene D, α-muurolene, and (+)-ledene, monoterpenes: limonene and menthol, norisoprenoid: β-cyclocitral, and miscellaneous compounds: psoralen”. 5 Each study shows different volatile compounds for different parts of figs and these studies generally focused on leaves and fruits. Considering the analyses employed for fruits, the results that we found in our study show similar and also some different compounds at the same time.

Physicochemical properties of fig seed oil were within the acceptance levels for edible oils in the current study. Comparing with other cold pressed seed oils, peroxide value was lower than cherry seed oil (18.80 mEqO₂/kg oil), pomegranate seed oil (9.20 mEqO₂/kg oil), apricot seed oil (25 mEqO₂/kg oil) and coffee bean oil (26.34 mEqO₂/kg oil). Free fatty acid value of fig seed oil was also lower than the cold pressed oils mentioned above. 51 The refractive index was very similar with other fruit seed oils. 56, 57