3.1. Phytochemical Analysis of Fig Fruit Extracts
Statistical analysis showed that TAC, total anthocyanins, TFC, and TPC were significantly different among selected fig varieties, as well as extracting solvent significantly affected their concentrations (Table 1).
3.1.1. Total alkaloids content (TAC)
It is evident from the results that 70% ethanol solvent was more efficient to recover the alkaloids from fruit compared to aqueous one (Table 1). The highest TAC was noted in ethanolic extract of Irani fig (12.55±0.98 mg/100g) followed by ethanolic extracts of Afghani fig (11.37±0.48 mg/100g) and aqueous extract of Afghani fig (10.59±0.78 mg/100g). The lowest TAC was present in the aqueous extract of Irani fig i.e., 6.14±0.49 mg/100g. Likewise, another researcher reported that dried figs from India showed the presence of 9.6% alkaloids in ethanolic extract in dried figs. Generally, alkaloids are considered anti-nutrients and toxins. These compounds are the active components of many anesthetics, relaxants, stimulants, sedatives, and tranquilizers. However, recent advances in research of functional and nutraceutical foods have shown that one of the subclasses of alkaloids named saponins is effective for lowering cholesterol levels [19]. Fig plant possesses diverse bioactive compounds mainly in leaves, followed by fruits, pulps, and peels [20]. Fresh fig fruit was compared for antioxidant activity, and phytochemicals content after microwave drying, sun drying, and freezing. Results revealed that TAC levels in all samples ranged between 7.80-7.60 mg/100g. The drying procedure reduced the TAC due to the thermal degradation of alkaloids, and the changes in cell structure integrity, which alters the migration of compounds from fruit cells to solvent. Moreover, TAC is observed to deteriorate by various chemical reactions including heat, light, and enzymes. Less degradation of TAC was noted in microwave drying, compared to sun drying because of low oxygen and no light [21].
3.1.2. Total anthocyanins content
It is evident from the results that water was more effective to extract anthocyanins from fig fruit. The highest anthocyanins were noted in aqueous extracts of Irani fig (3.47±0.23 mg/100g) followed by Afghani fig (3.46±0.15 mg/100g) and Turkish fig (3.40±0.42 mg/100g). The lowest anthocyanins content was observed in ethanolic extract of Afghani fig i.e., 1.45±0.28 mg/100g. In an earlier study, Ercisli et al. [1] reported total anthocyanin ranged from 0-42 μg/g in 24 fig genotypes from Northeastern Turkey. Likewise, another researcher reported anthocyanin content ranged from 0.21-2.01 mg/100 g in two fig varieties [22]. Six fig varieties from Turkey with various colors were compared for anthocyanin’s contents during different ripening states and fruit parts including skin and pulp. The dark skin figs were found to have more anthocyanins compared to other lighter varieties. In the skin, anthocyanins ranged from 0.7-27.3 mg/100g whereas 0.1-0.3 mg/100g were found in fruit pulp. However, the whole fig fruit has anthocyanins ranging from 0.3-10.9 mg/100g [7].
Previous studies have shown that figs contain greater anthocyanin levels than other atypical natural sources [23, 24]. In a study conducted by Wojdyło et al. [25], recovered 1.0 to 122 mg/100 g of anthocyanins from different fig varieties, using methanol as the extraction solvent. In another study, fresh figs from the Mediterranean region of Turkey were found to have anthocyanins ranging from 32.3-356.0 ug/g [26]. A higher concentration of anthocyanins 233.59-266.20 µg/g has been reported in Mexican fig paste [27]. Five different varieties from Spain were analyzed for the anthocyanin content in skin and pulp. In the skin, anthocyanins ranged from 32 to 97 ug/g than that pulp (1.5-15 ug/g), which is because of the color pigment in the skin [28]. These values are higher than those obtained in this study. The higher concentration obtained by these researchers could be partly attributed to the extraction solvent used, which led to an increased extraction efficiency. Moreover, further differences could be explained maturity stages chosen for harvest, the drying method used, and the origin of fig.
3.1.3. Total flavonoid contents
It is evident from the results that 70% ethanol was more effective to extract flavonoids from fig fruit (Table 1). The results showed that the highest TFC was noted in ethanolic extracts of Afghani fig (11.79±0.80 mg/g) followed by Irani fig (11.62±0.80 mg/g) and aqueous extract of Irani fig (10.92±0.40 mg/g). The lowest TFC was observed in the aqueous extract of Turkish fig i.e., 6.24±0.28 mg/g. Harzallah et al. [23], have reported 6.00-12.75 mg/g TFC in three Tunisia fig varieties. Whereas Amessis-Ouchemoukh et al. [16] reported 8.58 mg/g flavonoid content in white figs from Algeria. In another experiment, TFC ranged from 2.1 to 21.5 mg/100g in two different fig varieties [7]. In a study, the impact of different drying methods was assessed on TFC in fig fruit. The freeze-drying method showed the highest TFC content (0.23 mg/100g) due to the occurrence of higher derivatives of quercetin in frozen compared to fresh fruit [29]. Sun-dried samples have lower TFC because of thermal degradation, direct oxidation, or action of oxidizing enzymes i.e., (PPO) polyphenol oxidase. The degradation of flavonoids is also due to changes in pH [30]. TFC is concentrated in the peel of fruit followed by whole fruit and pulp. The peel of the dark fig variety has the highest TFC compared to the other light-colored variety.
In a study, Mahmoudi et al. [31] determined 254 µg/g of TFC in the fig’s peel compared to 37.41 µg/g in the pulp. However, Bucić-Kojić et al. [9] optimized different extraction conditions for the efficient recovery of the phenolic compounds from lyophilized fig fruits. The results revealed that high temperature (80°C) and solvent with higher ethanol concentration (80%) were more effective to extract TFC (2.5 mg/g) compared to 50% ethanol (0.44 mg/g), and lower temperature (25°C). Benmaghnia et al. [32] compared four solvents (50% acetone, 70% ethanol, 80% methanol, and water) to evaluate their efficiency to extract phytochemicals from dried figs. Acetone was most efficient to extract TFC (228.22 mg/100g) compared to methanolic extract (38.8 mg/100g). Crude polysaccharide extract of fig fruit was analyzed for immunomodulating and antioxidant activity. TFC ranged between 1.67 mg to 1.84 mg/g [33]. These values are lower than those obtained in this study. The higher concentration obtained by these researchers could be partly attributed to the extraction solvent used, which led to an increased extraction efficiency. Moreover, further differences could be due to several factors such as differences in the origin of the fruit, maturity stages when the fruit was harvested, the drying time, method, and temperature used.
3.1.4. Total phenolics content
The results of TPC are presented in Table 1. The highest TPC was noted in ethanolic extracts of Afghani fig (29.20±0.55 mg/g) followed by ethanolic extract of Turkish fig (26.87±0.65 mg/g) and aqueous extract of Turkish fig (26.07±0.42 mg/g). The lowest TPC was observed in the aqueous extract of Afghani fig i.e., 20.70±0.96 mg/g. The results of this experiment are similar to the findings of Amessis-Ouchemoukh et al. [16] and Yang et al. [33] who reported 21.90 mg/g and 12.5 mg to 8.74 mg TPC, respectively. In a study, the researcher compared the influence of different extraction conditions used for the efficient extractability of phenolic compounds from lyophilized fig fruits. Results revealed that higher temperatures (80°C) and solvents with higher ethanol concentration (80%) were more effective to extract TPC (3.7 mg/g) compared to the TPC (2.4 mg/g) extracted by 50% ethanol solvent and lower temperature (25°C) [9]. Mujić et al. [34], compared the impact of different extraction solvents for efficient extractability of phenolic compounds from fresh fig fruits. Results revealed that methanol solvent was more effective to extract TPC (11.17 mg/g) compared to the TPC (9.56 mg/g) extracted by ethanol solvent. Various fig plant parts from Pakistan, including pulp and peel of fruit and tree leaves, were evaluated for their phytochemical contents and antidiabetic potential. Leaf extracts have the highest TPC followed by peel and pulp (353.5, 187.5, and 62.5 mg/g of dried extract, respectively) [35].
TPC greatly varied according to the repining stage as well as the fruit part. Six fig varieties from Turkey with various colors were compared for their TPC during different ripening states and different fruit parts including skin and pulp. Dark fruit skins had more phenolics compared to purple or lighter varieties. The TPC in fruit skins ranged from 41.7-463.0 mg/100g whereas TPC was 36.5 to 100.6 mg/100g in fruit pulp. However, whole fig fruit has TPC ranging from 48.6-281.1 mg/100g [7]. In another study nine fig varieties from Spain were analyzed for TPC to see the impact of tissue type, and ripening stages. The highest TPC (169.5 mg/100g) was found in dark-colored varieties compared to 58.9 mg/100g in yellow-green and green-colored figs. Additionally, approximately 80% of TPC were concentrated in the skin than that of flesh. Furthermore, fruits at ripening stage 3 had the highest TPC compared to stage 1 [36]. Whereas lower TPC ranged between 10.1-14.8 mg/g of dried material reported by Loizzo et al. [37]. Caliskan and Polat [26] studied seventy-six fig varieties and reported 28.6 to 211.9 mg/100g TPC in the flesh. The drying method has a pronounced impact on the concentration of TPC. After drying fruit, the TPC can be decreased or increased, dependent on the cultivar, production system, method of drying, composition of TPC in fruit, oxygen availability, and many others [21, 38].
According to a study, TPC concentration was augmented after drying because of loss of moisture. Likewise, the drying process also facilitated the release of bound phenolic compounds from the cellular matrix [14]. Drying at low temperatures resulted in the reduction of the TPC [39] might be due to the longer drying time that has destroyed some TPC [40]. In microwave, less heating duration increased the TPC compared to sun drying. Moreover, during sun-drying fruit sample was exposed to the atmospheric O2 that might cause hydrolysis of phenolic compounds [41]. The quantity and composition of anthocyanins, TFC, and TPC in fig fruit are greatly affected by agronomic practices, climate (altitude, light, temperature), harvesting time, genetics (cultivar and variety), geological area and conditions, seasons of cultivation, plant parts (vegetable, fruit, or flower), processing method and the determination method used [42].
3.2. HPLC analysis
Accurate determination of biomolecules in extracts is important to assess their effective dose. For this purpose, all extracts obtained from different extracting solvents and fig varieties were subjected to HPLC analysis. The extracts were analyzed for their flavonoids (catechin, flavanone, iso-quercitrin, luteolin, and quercetin) and phenolics (4-hydroxy cinnamic, 7-hydroxy-coumarin, chlorogenic acid, gallic acid, and sinapic acid).
3.2.1. Flavonoids
Catechin ranged from 23.97±0.28 to 20.89±0.57 mg/100g. The highest catechin was noted in ethanolic extracts of Irani fig (23.97±0.28 mg) followed by aqueous extract of Irani fig (21.93±0.53 mg) and aqueous extract of Afghani fig (21.53±0.78 mg). (Table 2). Flavanone ranged from 8.79±0.68 to 12.49±0.66 mg/100g. The highest flavanone was noted in the aqueous extract of Turkish fig (12.49±0.66 mg). Iso-quercitrin ranged from 0.379±0.039 to 0.310±0.025 mg/100g. The highest Iso-quercitrin was noted in ethanolic extract of Irani fig (0.379±0.039 mg) followed by ethanolic extract of Turkish fig (0.366±0.034 mg). It is evident from the results that water was more efficient to extract luteolin from the fruit. Luteolin ranged from 2.113±0.043 to 0.927±0.025 mg/100g. The highest luteolin was noted in the aqueous extract of Afghani fig (2.113±0.043 mg) followed by the aqueous extract of Irani fig (0.980±0.066 mg). Luteolin was not detected in the ethanolic extract of Irani fig and Turkish fig. It is evident from the results that both solvents were equally efficient to extract quercetin from the fruit. Quercetin ranged from 1.031±0.025 to 0.616±0.053 mg/100g. The highest quercetin was noted in the aqueous extract of Afghani fig (1.031±0.025 mg/100g) followed by the aqueous extract of Irani fig (0.625±0.057 mg/100g). Quercetin was not detected in the aqueous extract of Turkish fig and ethanolic extract of Afghani fig.
The findings of this experiment are supported by the results of Wojdyło et al. [25] where 10 Spanish fig cultivars were quantified for phenolic content. Resulted revealed that catechin (20.6 to 95.7 mg/100g) and epicatechin (43.1 to 8.95 mg/100g) were found in higher concentrations. Other derivatives of quercetin, i.e., quercetin-3-O-galactoside (4.6-14.2 mg/100g), quercetin-3-O-(malonyl)-galactoside (5.3-58.0 mg/100g), and quercetin-3-O-rutioside (42.9-328.3 mg/100g) were found in fig fruits. Another researcher reported similar catechin content in fig fruit pulp (4.58- 9.53 mg/100g), and peel (6.10-12.48 mg/100g) in two fig varieties. Fig peel was more concentrated in catechin compared to the pulp. However, luteolin and rutin are present in fig fruit pulp (0.08-0.10 and 1.07-2.82 mg/100g), and peel (14.20-15.34 and 0.05-0.06 mg/100g), respectively. Fig peel was concentrated with catechin compared to pulp [22]. Slatnar et al. [14] evaluated the impact of drying on phenolic compounds. He reported that dried (sun or oven) fig fruit has higher catechin, and quercetin-3-O-glucoside (19.75 and 0.56-3.35 mg/100g) compared to fresh fig (1.36, and 0.18-0.60 mg/100g). However, luteolin-8-C-glucoside was present in dried fig fruit (0.13- 0.45 mg/100g), whereas luteolin was not detected in the fresh fig.
Another researcher reported catechin as the most abundant phenolic compound in the fig fruit (21.2 mg) compared to peel (17.1 mg) and whole fruit (16.7 mg/100g). Whereas quercetin was reported only in leaves of fig plant was approximately 8.4 mg/100g [43]. In another study, nine fig varieties from Spain were analyzed for phenolics for each tissue type, and ripening stage. The highest catechin concentration (20.6 mg/100g) was found in the peel compared to the flesh (7.1 mg/100g). Additionally, fruits at the higher ripening stage had more catechin compared to stage 1. Quercitin-3-O-rutinoside was also found in fig fruit (0.1-1.9 mg/100g) [36]. Veberic et al. [4] stated 1.07-4.03 mg/100g of catechin and 4.89-28.7 mg/100g of flavanol. Whereas Piga et al. [44] analyzed two fig cultivars, black and green, and detected quercetin-3-O-rutinoside in green figs and cyanidin-3-O-rutinoside in black figs. Similarly, Vallejo et al. [24] reported quercetin glucoside (2.5 mg/100g) with higher quercetin rutinoside (13.0 mg/100g). Oliveira et al. [8] reported quercetin 3-O-glucoside (30.8-31.4 mg), and quercetin 3-O-rutinoside (629.6-499.1 mg/Kg). Luteolin was concentrated in the peel (0.1-1.9 mg/100g) among different fig crops.
In another experiment, three fig types of dark in color were evaluated for the sun-drying effect on physicochemical parameters. In fresh and dried fig fruit catechin (1.72-8.63, and 1.80-5.78 mg/100g), quercetin (3.22-16.53 and 0.64-3.43 mg/100g), quercetin 3-glucoside (5.03-14.18, and 0.49-3.20 mg/100g), and quercetin 3-rutinoside (31.70-38.17, and 3.49-10.82mg/100g) was founded [45]. The concentration of TPC metabolites in plants is significantly affected by genetics, environmental conditions, specific cultivar, and agroecological conditions. The antioxidant efficacy of catechins is exerted by direct ROS scavenging activity or through indirect mechanisms i.e., increasing activity of antioxidant enzymes, hindering pro-oxidant enzymes (lipoxygenase, xanthine oxidase, NADPH oxidase) activity, and suppressing stress-related signaling pathways (TNF-a, and NF-kB) [46].
3.2.2. Phenolics
70% ethanol was more efficient to extract 4-hydroxy cinnamic from the fruit (Table 3). It ranged from 1.225±0.053 to 0.763±0.096 mg/100g. The results showed that the highest 4-hydroxy cinnamic was noted in both ethanolic extracts of Irani fig and Turkish fig (1.225±0.053 mg) followed by an aqueous extract of Irani fig (1.022±0.064 mg). Similarly, 70% ethanol was more efficient to extract 7-hydroxy-coumarin. It ranged from 1.865±0.070 to 1.369±0.083 mg/100g. The highest 7-hydroxy-coumarin was noted in ethanolic extracts of Turkish fig (1.865±0.070 mg) followed by ethanolic extract of Irani fig (1.863±0.031 mg). The aqueous solvent was more efficient to extract chlorogenic acid. It ranged from 0.913±0.064 to 0.316±0.021 mg/100g. The highest chlorogenic acid was noted in the ethanolic extract of Irani fig (0.913±0.064 mg) followed by the aqueous extract of Irani fig (0.635±0.029 mg). Chlorogenic acid was not detected in the ethanolic extract of Turkish fig. Aqueous as well as ethanolic solvents were equally effective to extract gallic acid. It ranged from 33.35±0.70 to 32.52±0.34 mg/100g. The highest gallic acid was noted in the ethanolic extract of Turkish fig (33.35±0.70 mg) followed by the ethanolic extract of Irani fig (33.26±0.53 mg). 70% ethanol was more efficient to extract sinapic acid from the fruit. It ranged from 1.024±0.042 to 0.830±0.092 mg/100g. The highest sinapic acid was noted in ethanolic extracts of Irani fig (1.024±0.042 mg) followed by Turkish fig (1.022±0.064 mg).
The finding of this experiment is supported by the findings of Pereira et al. [36] who stated 0.1-1.4 mg/100g chlorogenic acid. Another researcher reported similar chlorogenic acid content in fig fruit pulp and peel (0.92-3.51, and 1.43-2.67 mg/100g, respectively) in two fig varieties. Fig peel was concentrated with catechin compared to pulp [22]. Moreover, Vallejo et al., [24] reported chlorogenic acid ranged from 2.0-5.8 mg/100g. Veberic et al. [4] suggested that chlorogenic acid and gallic acid were present in fig fruits (0.46-1.71, and 0.14-0.38 mg/100g, respectively). Nakilcioğlu and Hışıl [47] reported 0.40-2.21 mg/100g chlorogenic acid and 1.15-6.98 mg/100g gallic acid in dry figs, whereas higher content is reported in fresh fig (2.97-6.54 mg/100g). Wojdyło et al. [25] analyzed 10 different Spanish fig cultivars to identify and quantify their phenolic content. The concentration of chlorogenic acid ranged from 8.8-124.5 mg/100g. However, most of the fig cultivars showed chlorogenic acid less than 50 mg/100g. Slatnar et al. [14] investigated the effect of drying on phenolic compounds. He reported that dried (sun or oven) fig fruit has higher chlorogenic acid (3.42-32.42 mg/100g) compared to fresh fig (1.33-4.91 mg/100g). Unlike the present study lower gallic acid concentration is reported in fig fruits.
Nine dried fig cultivars from Tunisia were evaluated for fatty acid and phytochemical composition along with the antioxidant activity. Gallic acid ranged from 0.07-0.54 mg/100g, p-coumaric acid ranged from 0.23-0.89 mg/100g, and trans-cinnamic 0.28-0.85 mg/100g. The dark-colored varieties had higher phenolic compounds compared to those of light-colored ones [51]. A total of 116 compounds including flavanols, flavanones, flavones, flavonols, hydroxybenzoic acids, isoflavones, hydroxycinnamic acids, hydroxycoumarins, and their derivatives were characterized in the leave and fruit of the fig plant [52]. Three fig types of dark in color were evaluated for the impact of sun-drying on physicochemical parameters. In fresh fig fruit chlorogenic acid (0.44-2.09 mg/100g), cinnamic acid (0.83 mg/100g), o-coumaric acid (1.12-2.73 mg/100g), and gallic acid (1.40-1.76 mg/100g) found to be lower compared to dried fig (chlorogenic acid: 0.17-0.34, cinnamic acid: 0.59-2.63, o-Coumaric acid: 0.82-1.05, and gallic acid: 2.76-5.04 mg/100g) [45].
3.3. Antioxidant Potential of Extract
Statistical analysis showed that ABTS, DPPH, FRAP, and H2O2 were significantly different among selected fig varieties, as well as extracting solvent (Table 4). Mean values for ABTS showed that extract obtained through 70% ethanol has more ability to reduce ABTS compared to aqueous extract. ABTS values ranged from 33.86±0.70 to 44.47±0.33%. The highest ABTS reducing ability (44.47±0.33%) was noted by ethanolic extracts of Afghani fig followed by aqueous Afghani fig (40.97±0.58%). The lowest ABTS reducing ability was observed in the ethanolic extract of Turkish fig i.e., 33.86±0.70%. It is evident from mean values for DPPH that extract prepared with 70% ethanol has more ability to reduce DPPH compared to aqueous extract (Table 4). Overall, DPPH ranged from 77.88±0.61 to 66.37±0.70%. The results showed the highest DPPH reducing ability in ethanolic extracts of Afghani fig (77.88±0.61%) followed by aqueous Irani fig (75.03±0.77%). The lowest DPPH was observed in ethanolic extract of Turkish fig i.e., 66.37±0.70%. It is evident from the mean values for FRAP that both extracts from aqueous and 70% ethanol have a similar ability to reduce FRAP (Table 4).
It can be deduced from the present study that the extract with higher TPC and TFC had higher ABTS, DPPH, FRAP, and H2O2 reducing ability. 70% ethanol has more ability to inhibit H2O2 compared to aqueous extract. The results showed that the highest H2O2 inhibiting ability was noted by ethanolic extracts of Afghani fig (20.26±0.91%) followed by Irani fig (16.37±0.55%). The higher H2O2, inhibiting activity in ethanolic extract of Afghani fig might be due to higher TPC and TFC content (Table 1). In an earlier study Amessis-Ouchemoukh et al. [16], has reported 68.98% ABTS reducing activity in the fig sample. In another study, three sun-dried fig cultivars along with their honey were analyzed for their antioxidant activity. The results showed that the variety with the highest phenolic and flavonoid ratio also exhibited the highest ABTS reducing activity [37]. A similar trend has been reported by Hoxha et al. [48], who determined the TPC, total anthocyanin content, TFC, and antioxidant activity of five dried fig cultivars from Albania. The cultivar with higher flavonoids showed the highest ABTS reducing capacity.
The total oxidant capacity of hydrophilic (flavonoids and vitamins) and lipophilic (carotenoids) fractions of pulp and skin of nine fig varieties from Spain. Hydrophilic fractions showed higher antioxidant activity compared to the lipophilic fractions. Furthermore, the skin was found to have approximately 2 to 10 times higher antioxidant activity compared to the pulp. Moreover, dark-skinned figs have higher antioxidant activity compared the light-colored ones. Peel is the chief part of the fruit contributing to TPC, and TFC which is why it is advisable to consume whole figs [36]. Solomon et al. [7] determined the correlation between phytochemicals and antioxidant potential in 6 fig types (black, green, red, and yellow). Caliskan and Polat [26], found a positive relation between antioxidant potential and anthocyanin contents. The ABTS reducing activity for fresh and sun-dried varieties was observed for dark fig varieties. Sun-drying of figs reduced the ABTS reducing activity by 29% [45]. Contrary to this Loizzo et al. [37] reported that the drying of fruit improved the radical scavenging ability, and reduced lipid peroxidation. However, the extract that showed such a response has similar phenol and flavonoid content, but much higher anthocyanin content compared to other extracts. Martínez-García et al. [52] analyzed half-cut and ground Mexican figs for their phytochemical’s concentration and antioxidant activity at three different temperatures. Results showed that drying improved the TPC with a small reduction of anthocyanins. Overall, the antioxidant potential of dried fig fruit was improved. High hydrostatic pressure was applied on Mexican fig paste to see its effect on anthocyanin content and antioxidant potential. An increase in anthocyanins concentration resulted in the improvement of ABTS reducing capacity.
Furthermore, a direct relationship was observed between anthocyanins concentration, pressure applied, time, and anthocyanins concentration [27]. A higher FRAP value means higher antioxidant activity [50]. Viuda-Martos et al. [22] have reported DPPH and FRAP in fig fruit peel (9.50-87.35, and 0.66-3.60%, respectively), and pulp (4.12- 46.03, and 0.56-2.18%, respectively). It can be noticed that fig peel showed higher DPPH reducing potential compared to the pulp. Similar results have been reported by Benmaghnia et al. [32], from dried figs extracts using 4 types of solvents (50% acetone, 70% ethanol, 80% methanol, and water). The ethanolic extract showed the highest DPPH reducing activity (65.1-88.1%), followed by methanolic extract (78.6-84.6%), acetonic extract (78.2-81.3%), and aqueous extract (73.1-80.6%). However, the acetonic extract showed the highest FRAP reducing activity (68.6-88.3), followed by aqueous extract (59.8.1-87.9), methanolic extract (60.3-86.6), and ethanolic extract (61.3-62.7). A similar trend was noticed in TPC, TFC, and total tannin content. Higher the concentration of these compounds higher the antioxidant activity. Fresh fig fruits were compared for antibacterial, antioxidant activity, and phytochemicals after microwave, sun, and freeze-drying. The results revealed DPPH ranged from 71.66 to 75.84%. The drying procedure reduced the TAC due to thermal destruction of the alkaloids, and change in cell integrity, which alters the migration of compounds from fruit cells to solvents. These losses are further accelerated in the presence of numerous enzymatic reactions. However, in microwave drying, TAC losses were less because of less O2 and darkness [21]. Moreover, the microwave dried fig showed higher antioxidant potential because of the higher concentration of the free phenolic compounds.
Turkmen and Velioglu [53] have reported that microwave processing increased the antioxidant potential of the fruit. Fresh fig fruit was compared for antibacterial, antioxidant activity, and phytochemicals content after microwave drying, sun drying, and freezing. Radical scavenging potential was improved after heat treatment as it inhibited the oxidative enzymes and releases the antioxidant compounds from the cells. The higher release of TPC in microwave drying resulted in the increased antioxidant potential of fruit extracts [54]. Contrary to this Nakilcioğlu and Hışıl [47] reported that the drying process reduces the content of phytochemicals along with the reduction in the ability of FRAP reducing capacity. Kalt et al. [55] reported lower antioxidant potential in frozen fruits compared to fresh due to cell disruption, which leads to the release of hydrolytic and oxidative enzymes. In another study, an increase in hydrostatic pressure showed a significant increase (49.3 to 60%) in anthocyanins concentration, as well as antioxidant capacity. A direct relationship was also observed in anthocyanins concentration, pressure applied, time, temperature, and anthocyanins concentration [27]. Water and crude polysaccharide extract exhibited the -OH scavenging activity that ranged between 31.0% to 43.4%, respectively at the concentration of 4.0 mg/mL. The polysaccharide extract has higher antioxidant activity compared to water extract. However, the TPC and TFC of the polysaccharide extract were lower compared to the water extract. It can be suggested from the results that other components possibly have radical scavenging activity [33]. In another study, nine dried fig varieties from Algeria were investigated for antioxidant potential, results revealed that varieties having dark skin color showed better H2O2 inhibiting activity compared to light color fig. H2O2 inhibiting activity was directly proportional to the flavonoids in fruit [56].