199 Journal homepage: www.fia.usv.ro/fiajournal Journal of Faculty of Food Engineering, Ştefan cel Mare University of Suceava, Romania Volume XIX, Issue 3 - 2020, pag. 199 - 209 IMPACT OF MATURITY STAGE ON ANTIOXIDANT ACTIVITY AND PHYTOCHEMICAL PROPERTIES OF DIFFERENT PARTS FROM PAWPAW: CARICA PAPAYA L. VAR SOLO 8 Edwige Larissa KOFFI 1 , *Thierry Yapo MONNET 1 , Kouassi Hubert KONAN 1 , N’Guessan Jean Parfait Eugène KOUADIO 1 1 Laboratoire de Biocatalyse et des Bioprocédés, Université Nangui Abrogoua, 22 BP 801 Abidjan 22, Côte d’Ivoire, monnet_tieri@yahoo.ca, *Corresponding author Received 2nd June 2020, accepted 14th September 2020 Abstract: The purpose of this paper has been to study the antioxidant activities and phytochemical compounds at different stages of maturity from papaya (Carica papaya L. var solo 8) peel, pulp and seeds in order to understand the correlation throughout these parameters. Thereby, three parts of papaya such as peel, pulp and seeds were sampled fresh, dried in an oven at 45 °C for 48 hours, ground and analyzed according to standard procedures. Carica papaya L. var solo 8 peels, seeds and pulps were specifically rich in phytochemical content around 1/8 and ¼ advanced stage of maturity before decreasing at advanced maturity stage. Results showed high level of total phenolic (434.36 ± 0.10 mg (GAE)/100 g DW), flavonoids (23.74 ± 0.01 mg (QE)/100 g DW) and tannins (89.33 ± 0.06 mg (TAE)/100 g DW) respectively in seeds and peels. The DPPH, FRAP and ABTS assays of methanolic extracts from this papaya (Carica papaya L. var solo 8) showed that the antioxidant activity measured was high for the peels followed by pulp and seeds at immature stage. These data indicated that the whole parts of this papaya (Carica papaya L. var solo 8) could constitute a potential good source of natural antioxidant for local population. Keywords: Antioxidant activity, papaya Variety solo 8, Phytochemical composition, Maturity stage 1. Introduction Papaya is compared with other fruit such as the banana or the apple, it has been found a good natural source of macronutrients (carbohydrates and proteins) and macronutrients (vitamin A and vitamin C) 1. There is also a strong relationship between the intake of these antioxidant-containing plants and reduced mortality caused by diseases 2. Indeed, natural antioxidants warrant further scientific scrutiny given their activity against free radicals, which contribute to chronic degenerative diseases 3. Medicinal plants play important roles in preventing various diseases and have received much attention from many researchers over the last few decades. Studies on the antioxidant contents of fruits and vegetables are increasing because natural antioxidant consumption has been found to be related to decreased risk for cancer and heart diseases 4. Papaya contains a broad spectrum of phytochemicals including enzymes (in the latex), carotenoids (in fruits and seeds), alkaloids (in leaves), phenolics (in fruits, leaves, and shoots), and glucosinolates (in seeds and fruits). http://www.fia.usv.ro/fiajournal mailto:mariap@fia.usv.ro Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 200 During maturation, several variations (biochemical, physiological, and structural) take place and determine the fruit’s quality 5. To our knowledge there are no reports in one study about the influence of maturity stages on phytochemical content and antioxidant activity from different parts of C. papaya L. var solo 8. So, the goal of this work was to study the differences in amount and composition of phenolic compounds, total carotenoids, vitamin C and to estimate the antioxidant activities of C. papaya L. var solo 8 fruit harvested in Côte d’Ivoire with respect to different stages of maturity (Immature, 1/8 Advanced, 1/4 Advanced and Advanced) and fruit parts (Peel, pulp and seeds). The result of this study will form the basis of advising consumers and the biological world, when and how best to utilize this fruit. 2. Material and methods Biological material Biological material is composed of the peel, epicarp and seeds of harvested Carica papaya L. var solo 8 at four stages of maturity which are immature, 1/8 advanced, 1/4 advanced and advanced yellow skin (Figures 1 to 3). These stages follow those proposed by Yao 6 to investigate pectinolytic activities. The fruits were harvested from a farm near Thomasset (Azaguié), a village located at about 50 km north of Felix Houphouet Boigny Airport, Abidjan, Cote d’Ivoire. Immature 1/8 Advanced 1/4 Advanced Advanced Fig. 1. Carica papaya L. var solo 8 peels at different stages of maturity Immature 1/8 Advanced 1/4 Advanced Advanced Fig. 2. Carica papaya L. var solo 8 pulps at different stages of maturity Immature 1/8 Advanced 1/4 Advanced Advanced Fig. 3. Carica papaya L. var solo 8 seeds at different stages of maturity Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 201 Methods Collection and sampling from different parts of papaya The sampled papaya fruits were previously washed and rinsed with bleach and separated according to the stage of maturity. The peel, pulp and seeds were then separated from each other using a knife, peeler, and spatula. A quantity of 500 g of each part of the papaya (peel, pulp, and seeds) at the various stages of ripeness was spread out on aluminium film and then dried in a ventilated MEMMERT oven at 45 °C for 2 days. After drying, the parts were crushed in a mill type Mill IKA (Germany/Deutschland). The resulting grind of each sample formed the papaya powder (flour) used at different analyses. These grindings were then packaged in glass bottles which were previously dried in an oven at 45 °C and then stored in a desiccator. Phytochemical Composition Extraction of phenolic compounds Extraction of phenolic compounds was determined using Singleton et al. method 7. A sample (10 g) of fine dried papaya sample flour was extracted by stirring with 50 ml of methanol 80 % (v/v) at 25 °C for 24 hours and filtered through Whatman n°4 paper. The residue was then extracted with two additional 50 ml portions of methanol. The combined methanolic extracts were evaporated at 35 °C (rotary evaporator HEILDOLPH Laborata 4003 Control, Schwabach, Germany) until 25 ml, prior to phenolic compound contents determination. Determination of total phenolic compounds content Contents of total phenolic compounds were estimated according to the Folin- Ciocalteu method 7. A volume of 1 ml of methanolic extract of each sample was added to 1 ml of Folin-Ciocalteu solution in a test tube. After 3 minutes, 1 ml of 20 % sodium carbonate solution was added to the mixture and adjusted to 10 ml with distilled water. The mixture was let to stand at room temperature in a dark environment for 30 min. Absorbance was measured against the blank reagent at 725 nm. Gallic acid was used for the calibration curve with a concentration range of 50 - 1000 μg/ml. Results were expressed as mg gallic acid equivalent (GAE)/100g DW (Dry Weight). Determination of tannins: Tannin content was determined using the method described by Bainbridge et al. 8. A volume of 1 ml of each methanolic extract was collected and mixed with 5 ml of reaction solution [vanillin 0.1mg/ml in sulphuric acid 70 % (v/v)]. The mixture could stand at room temperature in a dark environment for 20 min. The absorbance was measured at 500 nm against a blank (without extract). Tannic acid was used for the calibration curve with a concentration range of 0 - 100 μg/ml. The results were expressed as mg of tannic acid equivalents (TAE)/100 g DW. Determination of total flavonoid content The total flavonoids content was determined using the Dowd method 9. 5 ml of 2 % aluminum trichloride (AlCl3) in methanol was mixed with the same volume of the methanolic extract solution (0.4 mg/ml). After ten minutes the absorbance was measured at 415 nm using PerkinElmer UV-VIS Lambda. Blank sample consisting of a 5 ml extract solution with 5 ml methanol without AlCl3. The total flavonoid content was determined using a standard curve with catechin (0 – 100 mg/l) as the standard. Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 202 Total flavonoids content is expressed as mg of catechin equivalents (CE)/100 g DW. Determination of total carotenoid content (TCC) and estimation of vitamin C The TCC and vitamin C was determined using the spectrophotometric method as described by these authors 10. Optical density was measured at 450 nm and 491 nm respectively in a spectrophotometer with the appropriate blank (PE:DE: 2:1, v, v). The amount of carotenoid and vitamin C in mg/100 g of dry weight (DW) was calculated using LambertBeer equation (as described in Rocheford’s Lab protocol). Antioxidant Activities DPPH Assay The antioxidant activity of the extracts was evaluated by DPPH radical scavenging assay which was described by 11. DPPH is solubilized in absolute ethanol to have a solution of 0.3 mg/mL. Different ranges of concentrations in the order of the microgram of each extract are prepared (2 mg/ml, 1 mg/ml, 0.25 mg/ml, 0.125 mg/ml, 0.0625 mg/ml). Absolute ethanol was used as the dilution solvent. In dry, sterile tubes, 2.5 mL of extract solution to be analyzed and 1 mL of DPPH solution are added. After stirring, the tubes are placed in the dark for 30 min and the absorbance of the mixture is measured at 517 nm against a blank of 2.5 mL pure ethanol and 1 mL DPPH solution. The percentage of inhibition of DPPH radical formation is calculated as follows according to the formula: I = [(Ab – As) / Ab] × 100 With I, the percentage of inhibition, Ab, the absorbency of blank As, the absorbance of the sample. ABTS Assay The Trolox Equivalent Antioxidant Capacity (TEAC) test described in 11 was used to assay the antioxidant activities. The ABTS + radical cation was produced by mixing a solution of ABTS (8 mmol. L-1) and a solution of K2S2O8 (3 mmol. L-1) (1 / 0.5, v / v). The mixture was then incubated for 16 h in the dark at room temperature (25 °C). Then, 0.1 mL (standard or extract) diluted in methanol (1/10, v / v), was added to 3.9 mL of the diluted ABTS solution. The mixture was vigorously vortexed for 2 min following by incubation for 6 min in the dark at room temperature (25 °C). The absorbance of the mixture was read in the Jasco V-530 UV- visible spectrophotometer at 734 nm. The results were expressed in μmol. g-1 TE (Trolox Equivalents). The percent degradation of ABTS by Trolox was compared to that of the sample. Percentage degradation A (%) of ABTS was expressed by using following mathematical formula, A(blank) = blank absorbance after incubation. A(extract) = extract absorbance at 734 nm after incubation FRAP Assay Reducing Power Determination The ferric reducing capacity of extracts was investigated by using the potassium ferricyanide-ferric chloride method 11. Briefly, 0.2 mL of each of the extracts at different concentrations, 2.5 mL of phosphate buffer (0.2 M, pH 6.6), and 2.5 mL of potassium ferricyanide K3Fe(CN)6 (1 %) were mixed and incubated at 50 °C for 20 min, to reduce ferricyanide into ferrocyanide. The reaction was stopped by adding 2.5 mL of 10 % (w/v) trichloroacetic acid followed by centrifugation at 1000 rpm for 10 min. Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 203 Finally, 2.5 mL of the upper layer was mixed with 2.5 mL of distilled water and 0.5 mL of FeCl3 (0.1 %) and the absorbance was measured at 700 nm. Statistical Analysis All the chemical analyses and assays were performed in triplicate, unless otherwise indicated. The results were expressed as mean values • ± standard deviation (SD). Analysis of variance (ANOVA) followed by Duncan’s test was performed to test the differences between means by using Kyplot (version 2.0 beta 15, c1997-2001, Koichi Yoshioka) statistical software. 3. Results and discussion Phenolic contents Estimation of polyphenol, flavonoids, and tannins Phenolic compounds, as secondary metabolites, are a large group of molecules widely distributed in fruits and vegetables. They are considered the main actors for the antioxidant capacity of plants and have also many benefits for human health, as free radical scavenger. Recently, universal importance is given to the identification of maturity stages with the best levels of polyphenols targeting increased functional properties of fruits and vegetables. But it is hard to estimate the real content of the phenolic compounds, due to the fact that the phenolic content of fruits and vegetables is largely influenced by many factors, such as biotic and abiotic stress, senescence, cultivar, tissue, harvesting time, post-harvest treatment and also extraction techniques 11. The maturity stage is an important factor that influences the compositional quality and the quantity of fruits. Table 1 shows the content of estimated polyphenols, flavonoids, and tannins in different parts of Carica papaya L. var solo 8 fruits harvested at several stage of maturity. Polyphenols: The levels of total phenolic content (TPC) in the evaluated parts of the papaya fruits varied significantly from 149.85 to 434.36 mg GAE / 100 g of dry weight (DW). The seeds contained the highest phenolic content (434.36 ± 0.10), followed by the peel (350.34 ± 0.68) and the pulp (254.41 ± 0.04) at immature to 1/8 advanced stage. Obviously, seeds have higher content at the stage of ¼ advanced maturity followed by peel and pulp with a peak at 1/8 and ¼ of advanced maturity, respectively. Decrease is observed for all the parts of fruits at advanced maturity stage. Nonetheless, in comparison with several studies, Carica papaya Linn var. solo 8 seemed to have the highest level of total phenolic compound (12; 13 ). These high contents of phenolic compounds found in papaya (Carica papaya L. var solo 8) could constitute interesting data for population nutrition since it is well-known that these bioactive compounds found in human diet act as the antioxidant compounds and play a role in stabilizing lipid peroxidation 14. Flavonoids: The peel and seeds have important level respectively at 1/8 advanced maturity and immature stage, followed by pulp at ¼ advanced maturity one. Accumulation of flavonoids in investigated parts from papaya fruits ranged from 9.46 to 23.74 mg (QE) / 100 g DW. A high level of flavonoids was determined in the peel accounting for 23.74 ± 0.01, followed by 23.28 ± 0.01 and 16.61 ± 0.05 mg (QE) / 100 g DW in the seeds and the pulp, respectively. The lowest flavonoid accumulation was determined for the pulp (9.46 ± 0.02 mg (QE) / 100 g DW) at immature stage. However, no significant Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 204 difference was observed at risk (p < 0.05) between peel and seeds flavonoids content at 1/4 advanced maturity. Considering these data, consuming pulp at immature stage is not interesting due to the known beneficts of flavonoids. Fortunately, people consume papaya pulp beyond the immature stage. It is well known that flavonoids endow a wide range of pharmacological and biochemical properties, such as antimicrobial activities, anti-inflammatory, and inhibition of platelet aggregation 14. There was a significant variation in the accumulation of total flavonoids. Tannin: The condensed tannin amount determined was significantly different through the maturity stages besides the investigated parts in the fruits of Carica papaya L. var solo 8. High level was observed for the peel (89.33 ± 0.06 at ¼ advanced maturity) and the seeds (87.92 ± 0.02 at immature stage) with no significant difference at the level p < 0.05. Tannin content of the peel remains interesting during the maturation process (immature to advanced mature) accounting from 75.05 to 56.70 mg (TAE) / 100 g DW. Whereas the peel, pulp and seeds have lower tannin levels at ¼ and advanced maturity stage with 18.32 to 13.09 and 17.73 mg (TAE) / 100 g DW, respectively. Indeed, regardless of fruit parts and maturity stage, our results confirmed that fruits of C. papaya were an excellent source of phenolic compounds when comparing to other varieties, Maradol variety 15. Table 1 Polyphenol, flavonoid and tannin compounds in C. papaya L. var solo 8 Parameters Analyzed parts of the fruits Stage of maturity Immature 1/8 Advanced 1/4 Advanced Advanced Polyphenols Peel 235 ± 1.01d 350.34 ± 0.68g 266.74 ± 3.24e 261.23 ± 1.15e Pulp 149.85 ± 0.75a 203.03 ± 0.48b 254.41 ± 0.04e 218.74 ± 0.42c Seeds 211.73 ± 0.11c 240.44 ± 1.51d 434.36 ± 0.10h 339.2 ± 0.23f Flavonoids Peel 19.79 ± 0.05d 23.74 ± 0.01f 21.62 ± 0.01e 19.18 ± 0.03d Pulp 9.46 ± 0.02a 16.32 ± 0.02c 16.61 ± 0.05c 12.29 ± 0.01b Seeds 23.28 ± 0.01f 18.93 ± 0.01d 21.57 ± 0.02e 19.82 ± 0.05d Tannins Peel 75.05 ± 0.03g 79.70 ± 0.17g 89.33 ± 0.06h 56.70 ± 0.05d Pulp 25.98 ± 0.07c 68.61 ± 0.02f 18.32 ± 0.01b 13.09 ± 0.01a Seeds 87.92 ± 0.02h 69.29 ± 0.01f 62.29 ± 0.01e 17.73 ± 0.02b Values are expressed as mean ± standard deviation (n = 3). Means with different letters within a column were significantly different at the level P < 0.05. Total carotenoids and vitamin C contents Estimation of total carotenoid and vitamin C C. papaya L. var solo 8 is a red-fleshed papaya. During fruit maturity process, the most visible change of papaya is the color of exocarp turning from green to yellow whilst the pulp and seeds changing from Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 205 white to orange red and black (Figures 1 to 3). The content of major carotenoids was determined during the ripening of papaya fruit (Table 2). A large amount of carotenoid, as well as a small amount of lycopene was detected in the peel. The highest content was observed in the peel (93.50 ± 0.41 mg /100 g DW) and the pulp (91.50 ± 0.64 mg /100 g DW) followed by the seeds (72.49 ± 0.61 mg /100 g DW) at ¼ , immature and 1/8 advanced stage of maturity, respectively. An important content of ß-carotene, as well as small amount of lycopene were detected in the pulp at advanced stage of maturity. The content of lycopene increased, while and the content of ß-carotene decreased in the peel during papaya ripening. The highest content was 8.03 ± 0.27 mg /100 g DW for the pulp at ¼ advanced stage of maturity whereas the lowest amount occurred at advanced stage of maturity with the seeds accounting 0.03 ± 0.03 mg /100 g DW. The results were in contrast with those obtained by the variety Maradol by some authors 16, 17, 18. Indeed, ß-carotene accumulation from C. papaya L. var solo 8 is still higher than lycopene, which content remained important 19. The positive health benefits of lycopene contained in different fruits and vegetables have been widely reported, including reduction of cardiovascular problems 20. Therefore, the possible benefits of papaya consumption fruit could be compared to those reported by other vegetables rich in lycopene such as tomatoes. However, the concentration of other phytochemical present in these products that contribute to health needs is to be considered. Vitamin C, measured by spectrophometer at 491 nm, both in the peel, the pulp and the seeds was higher in peel than in the pulp at ¼ advanced maturity stage, and seeds at 1/8 advanced maturity (Table 2). Significant differences (P ≤ 0.05) were found in vitamin C between different parts. The largest amount of vitamin C in the peel was 22.5 ± 0.04 mg/100 g DW (at ¼ advanced maturity) and it remained stable. However, pulp had lower vitamin C values with 07.50 ± 0.02mg/100 g DW (at 1/8 advanced maturity satge) papaya fruit. In previous reports, papaya vitamin C content was higher than in this study and ranged from 60 to 84 mg/100 g 21. Solo type (Kapoho or Sunrise) papayas obtained from retail markets were analyzed in those studies. The content of vitamin C could vary, mainly because of the type of fruit cultivation, type of soil, weather and level of fruit ripeness 21. Vitamin C or ascorbic acid is a powerful hydrosoluble antioxidant that protects body against oxidative stress, due to its ability of trapping hydroxyl and superoxide radicals. In addition, a regular daily intake of vitamin C ranged from 250–500 mg reduces oxidative damage by removing free radicals 22 Antioxidant activities In this study, three complementary tests were used to assess the antioxidant activity of Carica papaya L. var Solo 8 from different fruit parts harvested at several stages of maturity: DPPH free radical- scavenging activity, Trolox equivalent antioxidant capacity (TEAC) and reducing power assays. Antioxidant activity is a complex procedure usually happening through several mechanisms and is influenced by many factors, which cannot be fully described with one single method. Therefore, it is essential to perform more than one type of antioxidant capacity measurement to consider the various mechanisms of antioxidant action [11; 12]. Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 206 Estimation of DPPH As summarized in Table 3, the rank order of antioxidant potency was the same for all assays, namely stage, in decreasing order, immature, followed by 1/8 advanced, ¼ advanced, and advanced stage of maturity. All the extracts were able to reduce the stable, purple coloured radical DPPH into yellow-coloured DPPH-H. The water extract obtained from seeds at a concentration of 2 mg/mL exhibited a percentage inhibition of 90.03 ± 0.45 % at ¼ advanced stage of maturity. On the other hand, the lowest capacity to reduce DPPH was observed in pulp water extract (I = 23.01 ± 0.44 %) by immature stage. Table 2 Total carotenoid and vitamin C compound in C. papaya L. var solo 8 Values are expressed as mean ± standard deviation (n = 3). Means with different letters within a column were significantly different at the level P < 0.05. Table 3 Effet of maturity stage on antioxidant measured by DPPH assays from different parts of C. papaya L. var solo 8 Stages of maturity Evaluated parts of fruits DPPH C 0.0625 C 0.125 C 0.25 C 0.5 C 1 C 2 Immature Peel 31.52 ± 0.66c 36.43 ± 0.63e 44.06 ± 0.88i 49.10 ± 0.57k 65.25 ± 0.45m 84.01 ± 0.93p Pulp 23.01 ± 0.44a 31.64 ± 0.33d 39.22 ± 0.49f 42.33 ± 0.38h 60.17 ± 0.48n 81.05 ± 0.61o Seeds 29.29 ± 0.68b 34.26 ± 0.74d 41.09 ± 0.14g 45.22 ± 0.43 j 62.01 ± 0.97 n 82.53 ± 0.55o 1/8 Advanced Peel 38.22 ± 0.61d 41.1 ± 0.37e 49.08 ± 0.32h 53.72 ± 0.39i 69.25 ± 0.28k 85.66 ± 0.58n Pulp 36.16 ± 0.83c 39.26 ± 0.83d 45.17 ± 0.53f 49.26 ± 0.66h 54.11 ± 0.57i 72.24 ± 0.49l Seeds 31.63 ± 0.57a 35.07 ± 0.95b 46.01 ± 0.89g 46.29 ± 0.78g 64.21 ± 0.76j 80.24 ± 0.52m 1/4 Advanced Peel 35.45 ± 0.35b 37.74 ± 0.49c 41.26 ± 0.75e 47.18 ± 0.34g 50.02 ± 0.63i 60.21 ± 0.89k Pulp 35.47 ± 0.71b 39.32 ± 0.76d 41.44 ± 0.98e 46.74 ± 0.64g 50.01 ± 0.34i 55.17 ± 0.51j Seeds 34.19 ± 0.51a 39.04 ± 0.61d 48.09 ± 0.45h 50.03 ± 0.59i 68.29 ± 0.65l 90.03 ± 0.45m Advanced Peel 28.01 ± 0.58a 30.56 ± 0.36b 40.61 ± 0.59f 45.29 ± 0.48i 48.76 ± 0.44k 58.06 ± 0.75o Pulp 35.47 ± 0.71d 39.32 ± 0.76e 41.44 ± 0.98g 46.74 ± 0.64j 50.01 ± 0.34k 55.17 ± 0.51n Seeds 32.28 ± 0.40c 36.11 ± 0.31i 39.88 ± 0.66e 43.21 ± 0.14h 48.68 ± 0.61k 52.24 ± 0.48m Trolox 45.43 ± 0.66a 59.76 ± 0.11b 69.43 ± 0.27c 82.01 ± 0.19d 85.08 ± 0.51e 92.29 ± 0.41f Tests: n=3; means ± standard deviation with different lowercase letters on the same line are significantly different at p<0.0 5 in Duncan's test. Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 207 Table 4 Effet of maturity stage on antioxidant measured by ABTS assays from different parts of C. papaya L. var solo 8 Stages of maturity Evaluate d parts of fruits ABTS C 0.0625 C 0.125 C 0.25 C 0.5 C 1 C 2 Immatur e Peel 44.62 ± 0.58c 49.34 ± 0.38e 56.03 ± 0.92h 61.9 ± 0.74i 64.19 ± 0.94j 70.22 ± 0.46k Pulp 41.24 ± 0.16b 47.01 ± 0.47d 49.36 ± 0.28e 54.29± 0.28g 60.74 ± 0.45i 61.02 ± 0.18i Seeds 40.97 ± 0.29a 44.19 ± 0.98c 46.21 ± 0.11d 51.11 ± 0.24f 57.62 ± 0.49h 60.17 ± 0.90i 1/8 Advance d Peel 47.21 ± 0.80c 49.64 ± 0.51e 54.33 ± 0.92g 59.88 ± 0.17j 63.74 ±0.54m 66.14 ± 0.99o Pulp 45.41 ± 0.91b 49.35 ± 0.77e 51.86 ± 0.26f 56.67 ± 0.42h 61.59 ± 0.80l 64.28 ± 0.23n Seeds 44.82 ± 0.85a 48.23 ± 0.76d 54.18 ± 0.14g 57.71 ± 0.46i 60.07 ± 0.30k 61.47 ± 0.31l 1/4 Advance d Peel 46.90 ± 0.14a 47.67 ± 0.34b 49.53 ± 0.43e 53.92 ± 0.12f 57.09 ± 0.89i 61.78 ± 0.26l Pulp 46.67 ± 0.32a 49.09 ± 0.19c 53.21 ± 0.84f 57.10 ± 0.13i 58.41 ± 0.27j 60.01 ± 0.20k Seeds 47.59 ± 0.56b 48.54 ± 0.42c 54.02 ± 0.24g 55.61 ± 0.42h 57.29 ± 0.15i 58.94 ± 0.13j Advance d Peel 49.75 ± 0.47f 47.19 ± 0.27d 49.21 ± 0.26f 54.39 ± 0.25j 57.43 ± 0.26k 59.07 ± 0.26l Pulp 44.82 ± 0.39b 46.66 ± 0.28c 48.64 ± 0.36e 50.42 ± 0.59g 52.61 ± 0.37i 54.18 ± 0.81j Seeds 43.56 ± 0.50a 46.15 ± 0.20c 48.38 ± 0.27e 50.02 ± 0.11g 51.84 ± 0.29h 52.24 ± 0.27h Trolox 75.15 ± 0.05 a 79.76 ± 0.09b 84.56 ± 0.13c 89.10 ± 0.19d 90.21 ± 0.21e 92.08 ± 0.17e Tests: n=3; means ± standard deviation with different lowercase letters on the same line are significantly different at p<0.05 in Duncan's test. Estimation of ABTS The method described gives a measure of the antioxidant activity of the range of peel, pulp and seeds at different stages of maturity, fruit extract antioxidants, determined by the decolorization of the ABTS, through measuring the reduction of the radical cation as the percentage inhibition of absorbance at 734 nm. The results given in the table 4 remain like DPPH inhibition. Peel had the highest level of ABTS antioxidant (70.22 ± 0.46 %) at immature stage. Infact the used methods have different reaction mechanisms 23. For instance, DPPH and ABTS assays are based on electron and H atom transfer, while the FRAP assay is based on electron transfer reaction 23; 24. However, the three methods clearly indicated that the studied plants possess considerable antioxidant and antiradical activities. Furthermore, well-pronounced correlations were observed between these methods which confirm that the three assays were all suitable and reliable to assess the total antioxidant capacities of plant extracts. Estimation of FRAP As depicted in table 5, immature stage of fruits showed the highest radical TE values. At all extract concentrations, peel had the highest TE value where it ranks a percentage inhibition of 87 ± 7.79 %. The lowest value of 28.60 ± 1.60 % was shown by seeds. FRAP assay measures the tendency of an antioxidant which acts as a reducing agent and brings a single electron to the Fe3+ in a redox-linked colorimetric reaction based on the breaking of the free-radical chain in order to stabilize and finish the radical chain reactions 24. This will cause an increase in absorbance; however, it is limited to only hydrophilic antioxidants or water-soluble antioxidants 25. Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XIX, Issue 3 – 2020 Edwige Larissa KOFFI , Thierry Yapo MONNET, Kouassi Hubert KONAN, N’Guessan Jean Parfait Eugène KOUADIO, Impact of maturity stage on antioxidant activity and phytochemical properties of different parts from Pawpaw: Carica Papaya l. Var solo 8, Food and Environment Safety, Volume XIX, Issue 3 – 2020, pag. 199 - 209 208 Table 5 Effet of maturity stage on antioxidant measured by FRAP assays from different parts of C. papaya L. var solo 8 Stages of maturity Evalua ted parts of fruits FRAP C 0.0625 C 0.125 C 0.25 C 0.5 C 1 C 2 Immature Peel 42.00 ± 1.40f 49.00 ± 3.40h 54.20 ± 2.03j 60.80 ± 4.13k 79.60 ± 2.36m 87.00 ± 7.79n Pulp 32.00 ± 0.03b 36.40 ± 2.49c 40.20 ± 1.11e 53.20 ± 5.33i 60.40 ± 3.67k 60.80 ± 6.69k Seeds 28.60 ± 1.60a 33.80 ± 5.07b 36.60 ± 3.55c 48.20 ± 5.18g 60.60 ± 2.43k 64.60 ±1.70l 1/8 Advanced Peel 38.80 ± 0.12c 44.80 ± 3.94e 49.60 ± 2.83g 59.40 ± 4.39h 66.20 ± 2.80i 73.40 ±5.19l Pulp 38.60 ± 2.20c 38.00 ± 2.30c 40.40 ± 3.36d 48.20 ± 5.29f 68.80 ± 5.29j 66.80 ± 3.8i Seeds 34.00 ± 0.13a 35.40 ± 5.60b 36.60 ± 4.01b 40.60 ± 2.10d 69.40 ± 2.50k 74.40 ±4.10m 1/4 Advanced Peel 38.20 ± 2.80d 43.40 ± 4.93g 50.20 ± 6.82j 57.80 ± 2.50l 60.80 ± 3.22m 69.60 ±5.05p Pulp 36.80 ± 4.19b 41.60 ± 3.33f 45.00 ± 5.44h 54.60 ± 4.52k 67.40 ± 7.27o 64.20 ±5.38n Seeds 33.40 ± 5.60a 37.00 ± 3.12c 40.00 ± 3.89e 46.80 ± 6.29i 79.80 ± 9.34q 79.40 ±6.82q Advanced Peel 37.80 ± 3.82c 42.60 ± 3.90e 49.20 ± 7.07g 54.00 ± 5.24h 57.80 ± 8.77i 66.80 ± 6.88l Pulp 35.60 ± 4.10b 39.40 ± 5.26d 46.80 ± 6.35f 49.00 ± 6.42g 63.60 ± 3.55k 62.20 ±7.03j Seeds 32.20 ± 4.99a 35.00 ± 3.94b 38.40 ± 5.07d 41.80 ± 4.71e 64.20 ± 3.40k 51.60 ± 5.12g Trolox 40.21 ± 0.09 a 55.43 ± 0.04b 70.55 ± 0.07c 81.78 ± 0.31d 85.77 ± 0.29e 90.13 ±0.52f 4. Conclusion The results presented in this work clearly demonstrate that the amounts of phenolic compounds and the antioxidant capacities of papaya (Carica papaya L. var solo 8) were affected by maturation stages. It was shown that peel has a notable antioxidant activity at immature stage and it is found to be a good source of antioxidants. These findings confirm the antioxidant potential of papaya (Carica papaya L. var solo 8) and increase focus on the impact on health promoting antioxidative compounds in all parts of the fruit during the four maturation stages. The papaya (Carica papaya L. var solo 8) peel flour could be used as a potential source for functional food ingredients and, in addition, it could be further processed into therapeutic functional food products, at immature stage. However, pulp and seeds are good for consumers from 1/8 to ¼ of advanced maturation. 5. References [1]. PETERSON R.N., CHERRY J.P. SIMMONS J.G., Composition of pawpaw (Asimina triloba) fruit. 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