ABSTRACT
Sudan is a rich country in wild plants that play significant roles in securing food and medicine in rural areas, especially. This study explored Sarcocephalus latifolius (African peach) and Vitex doniana (black plum) for their fruits’ proximate composition, minerals, total soluble phenols, phenolic acids, total carotenoids, lutein, β–carotene, α–tocopherol, δ–tocopherol and total antioxidant capacity. African peach fruit and black plum pulp showed total soluble phenols amounting to 16.89 mg gallic acid equivalents (GAE)/g of Dry Weight (DW) and 7.56 mg GAE/g DW, respectively. The paramount phenolic acids were cinnamic acid (895 mg/kg DW) in African peach fruit and protocatechuic acid (1200 mg/kg DW) in black plum pulp. Total antioxidant capacities reached 268 µmoles trolox equivalents (TE)/g DW in African peach and 214 µmoles TE/g DW in black plum, when measured from hydrophilic extracts (HPE) using 2, 2-DiPhenyl-1-PicrylHydrazyl (DPPH) assay. The contents of total carotenoid were 47 mg/kg DW and 22.6 mg/kg DW, lutein reached 18.50 mg/kg DW and 15 mg/kg DW whereas β–carotene showed 0.31 mg/kg DW and 0.23 mg/kg DW in African peach and black plum, respectively. African peach showed α–tocopherol (167 mg/kg DW) whereas black plum showed δ–tocopherol (398 mg/kg DW). From this study, we concluded that African peach fruit and black plum pulp could be good sources of nutrition and antioxidants and have high potential for human health.
Introduction
Arid and semi-arid zones of the world are characterized by soil erosion, frequent fluctuations in rainfall, and periods of food shortage (Verschuur et al., Citation2021). These issues are considered serious challenges facing the rural population, whose livelihood is mainly dependent on agriculture and relevant activities. Traditionally, wild edible plants (WEPs) are considered a momentous coping strategy that secures food and supports the household economy when the production of domestic food is lacking (Koffi et al., Citation2020). The significance of WEPs as a survival strategy is attributed to their accessibility, low cost, close distance, and lack of restrictions to gather fruit. Also, the availability of WEPs, due to their high resistance to severe climatic conditions throughout the year, makes those plants a vital emergency food (Oluoch et al., Citation2022). Furthermore, the high diversity of WEPs is an additional significant factor that contributes to preventing malnutrition and the survival of the local population. In addition, a considerable number of WEPs serve as both nutritional supplements and traditional medicine, especially in remote rural areas where no modern health services exist (Duguma, Citation2020). Despite their numerous significant values, a large number of WEPs are underutilized and have received little research attention in comparison to domesticated edible plants (Cheema et al., Citation2017). This could be due to the limited knowledge of the nutritional and health-related qualities of these plants (Ikram et al., Citation2009).
In Sudan, as well as in other developing countries, lots of WEPs have not yet been explored for their advantageous constituents and potential capacities for human health and nutrition. Sarcocephalus latifolius (J. E. Smith) E.A. Bruce, belongs to the family Rubiaceae, and Vitex doniana Sweet, a member of the family Lamiaceae, are examples of underutilized wild food and medicinal plants indigenous to the Nuba Mountains, Sudan (Salih and Ali, Citation2014). Sarcocephalus latifolius, synonym Nauclea latifolia, commonly known as African peach, Guinea peach, and Sierra Leone peach, has the trade name opepe and is locally named Karmadoda. African peach is popular most for its edible fruit, which is consumed as juice and as a traditional remedy to treat cough and diabetes. Traditional uses, medicinal, and pharmacological properties of African peach were reviewed (Abdel-Rahman, Citation2019; Haudecoeur et al., Citation2018). Vitex doniana is commonly known as vitex or black plum and is locally named Um-tugulgul. Black plum pulp is reported to have high nutritional values and the potential to improve fertility and treat anemia, jaundice, leprosy, and dysentery (Kamal et al., Citation2022; Vunchi et al., Citation2011).
Little research attention has been paid to Sarcocephalus latifolius and Vitex doniana fruits, despite the traditional vital roles that they play in providing food and medicine in their native habitat, the Nuba Mountains, Sudan. Thus, this study aimed to characterize Sarcocephalus latifolius fruit and Vitex doniana pulp for their nutritional, phytochemical, and antioxidant properties.
Materials and Methods
Plant Materials
Ripe and healthy fruits of uniform size and color were randomly sampled from six trees each of African peach (Sarcocephalus latifolius) and black plum (Vitex doniana) (). Sampling was done during the harvest season of October 2022 in El Rashad district (lat. 11° 40`–11° 55 N` and long. 30° 45`–31° 25` E), Eastern Nuba Mountains, Southern Kordofan State, Sudan. The samples were washed with water and dried at room temperature. Composite samples of each African peach whole fruit and black plum pulp were milled (using M20 universal grinding mill, IKA work) to pass a sieve of 0.2 mm and stored in plastic containers for further analyses.
Figure 1. Sarcocephalus latifolius and vitex doniana fruits.
Proximate Composition
The official method of analysis of AOAC (Citation2000) was applied to measure moisture, ash, crude fat, crude protein, and crude fiber contents. Moisture content was determined using the oven drying method. A muffle furnace controlled to 550°C was used to determine the ash content. A Soxhlet fat extraction unit (B-810 Soxhlet, Büchi Labortechnik AG, Flawil, Switzerland) was used to measure crude fat. For determination of crude protein, first nitrogen was measured according to the Kjeldahl method using a digestion system (Büchi Kjeldahl line K-437) and a distillation unit (Büchi Auto Kjeldahl unit K-370, Büchi Labortechnik AG, Flawil, Switzerland). Crude protein was then calculated by multiplying the corresponding total nitrogen content by a factor of 6.25. To determine the fiber content, the samples were subjected to acid (0.255 N H2SO4) and base (0.313 N NaOH) digestions. A fiber analyzer vessel (ANKOM 200/220 Fiber Analyzer, ANKOM Technology, NY, USA) and a filter bag technique were used. Carbohydrate content was calculated based on differences.
Minerals Content
Minerals were extracted and analyzed as described by Gul and Safdar (Citation2009). The samples were subjected to a cold digestion, for 16 h with concentrated HNO3 (16 N), and a hot digestion, at a temperature of 50°–60°C. The minerals were then measured using an atomic absorption spectrophotometer (AAnalyst 700 atomic absorption spectrometer, Perkin Elmer, Massachusetts, USA).
Total Soluble Phenols (TSP)
The method described by Salih and Yahia (Citation2015) was followed for the extraction and quantification of TSP using the Folin-Ciocalteu reagent assay. The result was expressed as mg gallic acid equivalent (GAE)/g DW.
Phenolic Compounds
For the identification and quantification of phenolic compounds, the method described by Yahia et al. (Citation2011) was applied. High-performance liquid chromatography HPLC (Hewlett – Packard GmbH HP 1100 series, Waldbronn, Germany) equipped with a diode – array detector (DAD) was employed. A 250 × 4.6 mm i.d., 3.5 μm, Symmetry RP18 column (Waters Co., Milford, CT) was used. The mobile phase consisted of formic acid (1%) and acetonitrile in a ratio of 98:2 at a flow rate of 0.5 mL/min. The phenolic compounds were measured at 280 and 320 nm.
Total Carotenoids (TC), β–Carotene, Lutein and Lycopene
The extraction and measurement of TC were done as described in a previous study (Salih and Yahia, Citation2015) using a Beckman DU 65 spectrophotometer (Beckman Instruments, Fullerton, CA) and absorbance was measured at 470 nm.
β-carotene, lutein, and lycopene were identified and quantified as described before (Yahia et al., Citation2011). An HPLC (Hewlett-Packard GmbH, HP 1100 series, Waldbronn, Germany) equipped with a DAD was employed. A 150 × 4.6 mm i.d., 3.5 μm, Symmetry C30 column (YMC Inc., Burnt Mill Drive, Wilmington, NC) was used. The mobile phase consisted of methanol and methyl tertiary butyl ether (MTBE). The elution gradient was 100% MTBE in 35 min at a flow rate of 1 mL/min. Peaks were measured at 450 nm and identified based on retention times and UV-Vis spectra of the standards.
Tocopherols
The extraction and measurement of tocopherols were performed as described before (Yahia and Mondragon-Jacobo, Citation2011). Identification and quantification of both α- and δ-tocopherols were done using HPLC, A 150 × 4.6 mm i.d., 3.5 μm, Symmetry C18 column (Waters Co., Milford, CT), and a model FLD G1321A fluorescence detector (Agilent Technologies Corp., Palo Alto, CA). An excitation wavelength of 294 nm and an emission wavelength of 325 nm were applied. The mobile phase used was HPLC-grade methanol (100%) at a flow rate of 0.5 mL/min.
Total Antioxidant Capacity (TAC)
As described earlier (Salih and Yahia, Citation2015), TAC was measured using two extracts; lipophilic extract (LPE) and hydrophilic extract (HPE), and two assays; 2, 2-DiPhenyl-1-PicrylHydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP). A MRX microplate reader (Dynex Technology, Chantilly, VA) at 490 nm for DPPH and 360 nm for FRAP was used to determine TAC, which was expressed as trolox equivalents (TE) in µmoles/g DW.
Statistical Analysis
The statistical analyses of data were performed using the software program StatView 5.0 (SAS Institute Inc, NC, USA). Results were presented as mean of six replicates ± standard deviation.
Results and Discussion
Proximate Composition
shows the proximate composition of the investigated African peach fruit and black plum pulp. African peach fruit showed inferior contents of moisture, protein, ash, and fiber compared to the values reported by Onyekwere and Ernest (Citation2014), and lower moisture content compared to the value reported by Yesufu and Hussaini (Citation2014). This could be attributed to geographical and environmental factors that affect the physiochemical, nutritional, and sensorial characteristics of fruits (Siyuma and Meresa, Citation2021; Wang et al., Citation2024). Lower moisture content, in general, was presumed to reduce the vulnerability of products to microbial and chemical degradation and thereby increase their shelf life (Fellows, Citation2000). In the Nuba Mountains, where African peach samples were collected, a punch of the fruits is usually crushed fresh, made into a disc-shape, and dried in the shade to preserve the fruit for a longer consumption period. The fiber content of our African peach fruit was higher than the value reported for Hyphaene thebaica, which had the highest fiber content in the study of Salih and Yahia (Citation2015). As reviewed by Aleixandre and Miguel (Citation2016), foods rich in fibers are linked to the prevention of a number of diseases, including cholesterol, coronary heart disease, hypertension, and diabetes. The traditional use of African peach fruits to reduce hypertension might be attributed to the high fiber content of the fruit. Black plum pulp showed higher contents of protein, fiber and carbohydrates compared to the values reported by Aiwonegbe et al. (Citation2018) for Nigerian black plum. Charles and Mgina (Citation2023) reported protein content amounting up to 21.73%, fat content reaching 2.40%, and carbohydrate content of 23.98% in Tanzanian V. doniana fruits.
Table 1. Proximate composition (% DW) of sarcocephalus latifolius fruit and vitex doniana pulp.
Mineral Contents
Minerals are crucial nutrients for human health. The mineral contents of our investigated fruits () showed a considerable contribution to the recommended daily intake, which is 1000 mg Ca, 350 mg Mg, and 15 mg Fe per day (FAO, Citation2004). Our African peach fruit showed higher mineral contents, except for the Mg value, compared to those reported by Yesufu and Hussaini (Citation2014). Also, our African peach fruit had much higher contents of potassium (852 mg/100 g) and calcium (488 mg/100 g) compared to domestic fruits, such as guava (417 mg K and 18 mg Ca/100 g DW), orange (200 mg K and 11 mg Ca/100 g DW), banana (358 mg K/100 g DW), and apple (90 mg K/100 g DW), as reported in the study of Sareen et al. (Citation2020). Black plum had mineral contents in agreement with the values reported by Vunchi et al. (Citation2011). In their study of botanical galactagogues, Gbadamosi and Okolosi (Citation2013) reported lower Fe and Mg but higher K concentrations for black plum pulp compared to ours.
Table 2. Mineral concentrations (mg/100 g DW) in sarcocephalus latifolius fruit and vitex doniana pulp.
Total Soluble Phenols (TSP)
Total soluble phenols contents were 16.89 mg GAE/g DW in African peach fruit and 7.56 mg GAE/g DW in black plum pulp (). These values were lower than those reported for four commonly consumed edible wild fruits in Sudan (Salih and Yahia, Citation2015), in the range reported for several domestic fruits including apples, plum, apricot, and berries (Sultana et al., Citation2012), comparable to most of the values reported for Burkina Faso’s wild fruits (Lamien-Meda et al., Citation2008), and superior to Indian dry fruits (Reddy et al., Citation2010). The black plum fruit of Côte d’Ivoire was reported to have total phenols contents ranging from 2.02–2.60 mg GAE/g DW for pulp and 2.25–4.63 mg GAE/g DW for peel (Traore et al., Citation2021). The intake of fruits and vegetables is recommended to reduce the risk of cardiovascular and chronic diseases (Aune et al., Citation2017), due to the high content of total phenols and their associated bioactive potentials (Yu et al., Citation2021).
Table 3. Total soluble phenols (TSP) and phenolic compounds in sarcocephalus latifolius fruit and vitex doniana pulp.
Phenolic Compounds
The potential of phenolic acids as antioxidant, antifungal, antimicrobial, and anticancer agents was reported (De et al., Citation2011). In this study, the most dominant phenolic compounds () were cinnamic acid (894.60 mg/kg DW), chlorogenic acid (142.40 mg/kg DW), and quercetin acid (153.70 mg/kg DW) in African peach fruit. Black plum pulp showed protocatechuic acid (1200.00 mg/kg DW), cinnamic acid (193.70 mg/kg DW), and catechin acid (181.90 mg/kg DW). Caffeic acid and ferulic acid measured in African peach showed amounts superior to those reported earlier for domestic fruits (Sultana et al., Citation2012). The amount of caffeic acid in African peach was much lower compared to Sudanese Hyphaene thebaica and Ziziphus spina-christi fruits (Salih and Yahia, Citation2015). Traore et al. (Citation2021) identified a number of phenolic compounds in the pulp and peel of V. doniana samples collected from three sites in Côte d’Ivoire; however, only protocatechuic acid, cinnamic acid, and chlorogenic acid were common in all the investigated sites. The variations in composition and profile of phenolic compounds between ours and the Côte d’Ivoire V. doniana samples could be attributed to environmental and soil factors. The antioxidant effect of protocatechuic acid, which was the dominant phenolic acid in our black plum pulp, was reported to be ten times stronger than that of α-tocopherols (Ueda et al., Citation1996).
Total Carotenoids (TC), β–Carotene, Lutein and Lycopene
Bioactive constituents, such as carotenoids, in edible fruits and vegetables were found to play crucial roles in reducing the risk of chronic diseases (Bohn, Citation2018). The importance of carotenoids is attributed to their content of antioxidants and provitamin A. The provitamin A carotenoid, β-carotene, is a significant source of vitamin A in the diet. A high correlation between β-carotene and TC was reported (Corral–Aguayo et al., Citation2008). In this study, the amount of TC in African peach fruit reached 47.00 mg/kg DW, whereas black plum pulp showed 22.60 mg/kg DW (). These values were higher than the TC amounts measured in four wild edible fruits in Sudan (Salih and Yahia, Citation2015).
Table 4. Contents (mg/kg DW) of total carotenoids (TC), lutein, β–carotene, α- and δ-tocopherol in sarcocephalus latifolius fruit and vitex doniana pulp.
Amounts of lutein reached 18.50 mg/kg DW in African peach and 15.00 mg/kg DW in black plum. β-carotene contents were 0.31 mg/kg DW in African peach and 0.23 mg/kg DW in black plum, whereas no lycopene was detected in any of the analyzed fruits. Most of the 26 Indian types of vegetables, tubers, and fruits investigated by Pritwani and Mathur (Citation2017) showed higher β-carotene contents compared to our African peach and black plum fruits.
Tocopherols
As presented in , African peach fruit showed α–tocopherol (167.00 mg/kg DW), while black plum pulp showed δ-tocopherol (398.00 mg/kg DW). Alpha-tocopherol is the most available bioactive form of vitamin E in nature (Bjorneboe et al., Citation1990; Pahrudin Arrozi et al., Citation2020). Ching and Mohamed (Citation2001) screened 62 edible tropical plants for their α-tocopherol contents and reported values ranging from 13.4 to 796.5 mg/kg DW in leaves, 31.9 to 250.3 mg/kg DW in shoots, 12.7 to 290.7 mg/kg DW in fruits, and <90 mg/kg DW in beans, edible roots, and flowers. According to the recommended daily intake of vitamin E (mostly α-tocopherol) for adults (FAO, Citation2004; IOM, Citation2000), African peach fruit contributes a considerable amount.
Total Antioxidant Capacity (TAC)
TAC showed different values when measured using DPPH and FRAP assays. Also, there were differences in TAC values between HPEs and LPEs (). In both fruits, the highest TAC values were measured from HPEs using DPPH assay; the results showed 268.41 µmoles TE/g DW in African peach and 214.62 µmoles TE/g DW in black plum. This study agreed with the work of Corral–Aguayo et al. (Citation2008), which reported higher TAC in HPEs compared to LPEs, when measured for eight horticultural crops using six different assays. Additionally, a high correlation between TAC, measured from HPE using DPPH assay, and TSP was reported (Corral–Aguayo et al., Citation2008; Salih and Yahia, Citation2015), indicating that TAC in HPE is mainly due to TSP. Corral–Aguayo et al. (Citation2008) reported no correlation between TAC, measured from LPE, and vitamin E, β-carotene, or TC. On the other hand, Condelli et al. (Citation2015) stated that the dissimilarity in antioxidant capacity could be explained by differences in the composition and profile of phenolic compounds rather than their total phenolic contents.
Figure 2. Total antioxidant capacity (TAC) of hydrophilic (HPE) and lipophilic (LPE) extracts measured by DPPH and FRAP assays for sarcocephalus latifolius fruit and vitex doniana pulp.
This study agreed with Salih and Yahia (Citation2015), who reported higher TAC values when measured using DPPH compared to FRAP in four commonly consumed wild edible fruits in Sudan. As stated by Yahia et al. (Citation2011), DPPH and FRAP could be limited in their abilities to detect the antioxidant activity of lipophilic compounds, such as carotenoids. Also, an underestimation of TAC might happen as the fruit extract is a complex mixture that allows interaction with other phenolic compounds. For the accuracy of estimating TAC, it is recommended to adopt different assays that might vary in their capability of detecting the antioxidant activity of different compounds existing in samples (Yahia et al., Citation2011).
Conclusion
The wild fruits investigated in this study possess considerable amounts of macro- and micro-nutrients, which have a high potential for fighting hidden hunger. The bioactive potentials of those wild fruits for human health and nutrition need to be explored through biological studies. Processing wild fruits into different value-added food products, such as juice and jams, could contribute additionally to improving the household’s economy and alleviating poverty. Knowledge regarding the various values of those fruits would encourage business enterprises and lead to conservation and domestication.
Acknowledgments
We would like to acknowledge the staff of Phytochemical and Nutrition, Animal Nutrition, and Human Nutrition Laboratories, UAQ, Mexico, for their kind support and help.
Disclosure Statement
No potential conflict of interest was reported by the author(s).
Data Availability Statement
All the datasets regarding this study are presented.
References
- Abdel-Rahman, N.A. 2019. Nauclea latifolia (Karmadoda): Distribution, composition and utilization, p. 435–445. In: A. Mariod (ed.). Wild fruits: Composition, nutritional value and products. Springer, Cham. doi: 10.1007/978-3-030-31885-7_33.
- Aiwonegbe, A.E., J.U. Iyasele, and N.O. Izevbuwa. 2018. Proximate composition, phytochemical and antimicrobial screening of the methanol and acetone extracts of vitex doniana fruit pulp. Ife J. Sci. 20(2):317. doi: 10.4314/ijs.v20i2.12.
- Aleixandre, A., and M. Miguel. 2016. Dietary fiber and blood pressure control. Food Funct. 7(4):1864–1871. doi: 10.1039/C5FO00950B.
- AOAC. 2000. Official methods of analysis of the Association of Official Analytical Chemists International. 17th ed. AOAC, Rockville, Maryland.
- Aune, D., E. Giovannucci, P. Boffetta, L.T. Fadnes, N. Keum, T. Norat, D.C. Greenwood, E. Riboli, L.J. Vatten, and S. Tonstad. 2017. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality: A systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiol. 46(3):1029–1056. PMID: 28338764; PMCID: PMC5837313. doi: 10.1093/ije/dyw319.
- Bjorneboe, A., G. Bjorneboe, and C. Drevon. 1990. Absorption, transport and distribution of vitamin E. J Nutr. 120(3):233–242. doi: 10.1093/jn/120.3.233.
- Bohn, T. 2018. Carotenoids, chronic disease prevention and dietary recommendations. Int J Vitam Nutr Res. 87(3–4):121–130. doi: 10.1024/0300-9831/a000525.
- Charles, D., and C. Mgina. 2023. Proximate composition of vitex doniana and Saba comorensis fruits. Sci. Rep. 13:20553. doi: 10.1038/s41598-023-46874-7.
- Cheema, J., K. Yadav, N. Sharma, I. Saini, and A. Aggarwal. 2017. Nutritional quality characteristics of different wild and underutilized fruits of Terai region, Uttarakhand (India). Int. J. Fruit. Sci. 17(1):72–81. doi: 10.1080/15538362.2016.1160271.
- Ching, L.S., and S. Mohamed. 2001. Alpha-tocopherol content in 62 edible tropical plants. J. Agric. Food. Chem. 49(6):3101–3105. doi: 10.1021/jf000891u.
- Condelli, N., M.C. Caruso, F. Galgano, D. Russo, L. Milella, and F. Favati. 2015. Prediction of the antioxidant activity of extra virgin olive oils produced in the Mediterranean area. Food Chem. 177:233–239. doi: 10.1016/j.foodchem.2015.01.001.
- Corral–Aguayo, R.D., E.M. Yahia, A. Carrillo-Lopez, and G. Gonzalez-Aguilar. 2008. Correlation between some nutritional components and the total antioxidant capacity measured with six different assays in eight horticultural crops. J. Agric. Food. Chem. 56(22):10498–10504. doi: 10.1021/jf801983r.
- De, P., M. Baltas, and F. Bedos-Belval. 2011. Cinnamic acid derivatives as anticancer agents-a review. Curr. Med. Chem. 18(11):1672–1703. doi: 10.2174/092986711795471347.
- Duguma, H.T. 2020. Wild edible plant nutritional contribution and consumer perception in Ethiopia. Int. J. Food Sci. 2020:1–16. doi: 10.1155/2020/2958623.
- FAO. 2004. Human vitamin and mineral requirements. Report of a joint FAO/WHO expert consultation, Bangkok, Thailand and Rome, Italy.
- Fellows, P.J. 2000. Food processing technology, principles and practice. Wood Head Publishing, Cambridge.
- Gbadamosi, I.T., and O. Okolosi. 2013. Botanical galactogogues: Nutritional values and therapeutic potentials. J. Appl. Biosci. 61:4460–4469. doi: 10.4314/jab.v61i0.85594.
- Gul, S., and M. Safdar. 2009. Proximate composition and mineral analysis of cinnamon. Pak. J. Nutr. 8(9):1456–1460. doi: 10.3923/pjn.2009.1456.1460.
- Haudecoeur, R., M. Peuchmaur, B. Pérès, M. Rome, G.S. Taïwe, A. Boumendjel, and B. Boucherle. 2018. Traditional uses, phytochemistry and pharmacological properties of African nauclea species: A review. J. Ethnopharmacol. 212: 106–136. Epub 2017 Oct 16. PMID: 29045823. doi: 10.1016/j.jep.2017.10.011.
- Ikram, E.H.K., H.E. Khoo, M.J.A. Maleyki, I. Amin, I. Salma, A. Azrina, M.N.H. Saadiah, M.D.N. Akmar, and M.M.R. Azli. 2009. Antioxidant capacity and total phenolic content of Malaysian underutilized fruits. J. Food Composit. Anal. 22(5):388–393. doi: 10.1016/j.jfca.2009.04.001.
- IOM (Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds). 2000. Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoidsDietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. National Academy Press, Washington DC, USA.
- Kamal, N., N.S. Mio Asni, I.N.A. Rozlan, M.A.H. Mohd Azmi, N.W. Mazlan, A. Mediani, S.N. Baharum, J. Latip, S. Assaw, and R.A. Edrada-Ebel. 2022. Traditional medicinal uses, phytochemistry, biological properties, and health applications of vitex sp. Plants. 11(15):1944. doi: 10.3390/plants11151944.
- Koffi, C.K., A. Lourme-Ruiz, H. Djoidi, E. Bququet, S. Dury, and D. Gautier. 2020. The contributions of wild tree resources to food and nutrition security in sub-Saharan African dry lands: A review of the pathways and beneficiaries. Int. For. Rev. 22(1):64–82. doi: 10.1505/146554820828671490.
- Lamien-Meda, A., C.E. Lamien, M.M.Y. Compaoré, R.T.N. Meda, M. Kiendrebeogo, B. Zeba, J.F. Millogo, and O.G. Nacoulma. 2008. Polyphenol content and antioxidant activity of fourteen wild edible fruits from Burkina Faso. Molecules. 13(3):581–594. doi: 10.3390/molecules13030581.
- Oluoch, W.A., C.W. Whitney, C. Termote, C. Borgemeister, and C.B. Schmitt. 2022. Integrated participatory approach reveals perceived local availability of wild edible plants in Northwestern Kenya. Hum. Eco. 51(1):59–74. doi: 10.1007/s10745-022-00370-0.
- Onyekwere, E.S., and O. Ernest. 2014. Phytochemical and nutrient evaluation of the leaves and fruits of Nauclea Latifolia (uvuru-ilu). Comm. Appl. Sci. 2(1):8–24. doi: 10.1155/2014/437081.
- Pahrudin Arrozi, A., S.N.S. Shukri, W.Z. Wan Ngah. 2020. Comparative effects of alpha- and gamma-tocopherol on mitochondrial functions in alzheimer’s disease in vitro model. Sci. Rep. 10(1):8962. doi: 10.1038/s41598-020-65570-4.
- Pritwani, R., and P. Mathur. 2017. β-carotene content of some commonly consumed vegetables and fruits available in Delhi, India. J Nutr Food Sci. 7(5):625. doi: 10.4172/2155-9600.1000625.
- Reddy, C.V.K., D. Sreeramulu, and M. Raghunath. 2010. Antioxidant activity of fresh and dry fruits commonly consumed in India. Food Res. Int. 43(1):285–288. doi: 10.1016/j.foodres.2009.10.006.
- Salih, N.K.M., and A.H. Ali. 2014. Wild food trees in Eastern Nuba Mountains, Sudan: Use, diversity, and threatening factors. J. Agric. Rural Develop. Tropics Subtropics. 115(1):1–7.
- Salih, N.K.-E.M., and E.M. Yahia. 2015. Nutritional value and antioxidant properties of four wild fruits commonly consumed in Sudan. Int. Food. Res. J. 22(6):2389–2395.
- Sareen, A., R. Chand Gupta, G. Bansal, and V. Singh. 2020. Comparison of key mineral elements in wild edible fruits of Ziziphus mauritiana and Z. nummularia using atomic absorption spectrophotometer (AAS) and flame photometer. Int. J. Fruit. Sci. 20(sup2):S987–S994. doi: 10.1080/15538362.2020.1774468.
- Siyuma, Z.H., and T.A. Meresa. 2021. Physicochemical properties and nutritional values of Carissa spinarum L./”AGAM” fruit. Int. J. Fruit Sci. 21(1):826–834. doi: 10.1080/15538362.2021.1936348.
- Sultana, B., F. Anwar, M. Ashraf, and N. Saari. 2012. Effect of drying techniques on the total phenolic contents and antioxidant activity of selected fruits. J. Med. Plants Res. 6(1):161–167. doi: 10.5897/JMPR11.916.
- Traore, K.F., K.Y. Kone, A.P. Ahi, D. Soro, N.E. Assidjo, M.L. Fauconnier, and M. Sindic. 2021. Phenolic compounds characterization and antioxidant activity of black plum (Vitex doniana) fruit pulp and peel from Côte d’Ivoire. J. Food Meas. Charact. 15(2):1281–1293. doi: 10.1007/s11694-020-00719-3.
- Ueda, J., N. Saito, Y. Shimazu, and T. Ozawa. 1996. A comparison of scavenging abilities of antioxidants against hydroxyl radicals. Arch. Biochem. Biophys. 333(2):377–384. doi: 10.1006/abbi.1996.0404.
- Verschuur, J., S. Li, P. Wolski. 2021. Climate change as a driver of food insecurity in the 2007 Lesotho-South Africa drought. Sci. Rep. 11(1):3852. https://doi.org/10.17632/ntjtg6wd5g.1.
- Vunchi, M.A., A.N. Umar, M.A. King, A.A. Liman, G. Jeremiah, and C.O. Aigbe. 2011. Proximate, vitamins and mineral composition of Vitex doniana (black plum) fruit pulp. Niger. J. Basic Appl. Sci. 19(1):97–101. doi: 10.4314/njbas.v19i1.69352.
- Wang, C., X. Chen, Y. Ren, X. Xuan, T. Pervaiz, L. Shangguan, and J. Fang. 2024. Geographical location influence ‘cabernet franc’ fruit quality in Shandong province. Sci. Rep. 14(1):2382. doi: 10.1038/s41598-023-50140-1.
- Yahia, E.M., F. Gutiérrez-Orozco, and C. Arvizu-de Leon. 2011. Phytochemical and antioxidant characterization of mamey (Pouteria sapota jacq. H.E. Moore & Stearn) fruit. Food Res. Int. 44(7):2175–2181. doi: 10.1016/j.foodres.2010.11.029.
- Yahia, E.M., and C. Mondragon-Jacobo. 2011. Nutritional components and anti-oxidant capacity of ten cultivars and lines of cactus pear fruit (opuntia spp.). Food Res. Int. 44(7):2311–2318. doi: 10.1016/j.foodres.2011.02.042.
- Yesufu, H.B., and I.M. Hussaini. 2014. Studies on dietary mineral composition of the fruit of sarcocephalus latifolius (Smith) Bruce (Rubiaceae). J Nutr Food Sci. S8:006. doi: 10.4172/2155-9600.S8-006.
- Yu, M., I. Gouvinhas, J. Rocha. 2021. Phytochemical and antioxidant analysis of medicinal and food plants towards bioactive food and pharmaceutical resources. Sci. Rep. 11(1):10041. doi: 10.1038/s41598-021-89437-4.