Baobab (Adansonia digitata L.)

Adansonia digitata L., commonly known as the baobab tree, is a highly nutritious plant species widely consumed for its fruits, leaves, and seeds. It is valued for its rich nutrient composition, including macronutrients, vitamins, minerals, phytochemicals, and functional properties. Below is an overview of its chemical composition based on different plant parts. The fruit is rich in carbohydrates (75.60%) and dietary fiber (52.00%), making it a good energy source. Additionally, the fruits are an excellent source of vitamin C (280 mg/100 g), which is essential for immune function. Arowora et al. [51] reported similar high L-ascorbic acid (vitamin C) content in baobab pulp, reinforcing its importance as an antioxidant-rich fruit. Baobab fruit is also rich in calcium (341 mg/100 g), a crucial macronutrient for healthy bones and teeth formation. The flavonoid content (3.59%) is indicative of its strong antioxidant properties, comparable to findings by Zahra’u et al. [16]. The leaves have a high protein content (19.84%), making them a potential protein supplement, particularly in regions with limited protein sources. They are also an excellent source of vitamin A (270 mg/100 g), which supports vision and immune health. The sodium content (1.63 mg/100) may contribute to electrolyte balance, though variations exist between studies due to environmental factors [51]. The leaves also contain lower levels of alkaloids, phenolics, and tannins, which contribute to their medicinal properties. The seeds are notable for their high-fat content (31.42%), making them a viable source for oil extraction. Their exceptionally high vitamin C (522.5 mg/100 g) and vitamin E (429 mg/100 g) content contribute to their potent antioxidant properties. Additionally, seeds have the highest iron (1.83 mg/100 g) and zinc (2.57 mg/100 g) content among the plant parts, essential for cell division and red blood cell formation. The functional properties of baobab seed flour make it suitable for food processing. With a bulk density of 0.72 g/cm³, it can be used as a thickener in food formulations. Its swelling index (3.3 mL) and gelatinization temperature (81°C) indicate potential applications in baking and industrial food processing. Dhlakama et al. [45] reported similar functional properties in baobab seed flour, confirming its suitability for various food applications.

African oak (Afzelia africana)

A. africana, a leguminous plant found in tropical regions, is widely utilized for its seeds, which hold significant nutritional, medicinal, and industrial value. The chemical composition of A. africana seeds reveals their potential as a valuable food source and functional ingredient. The macronutrient profile of A. africana seeds highlights their nutritional significance. They contain 6.68% moisture, 16.10% fat, 13.89% protein, 4.57% fiber, and 59.20% carbohydrates, indicating a high energy content [19]. These values suggest that the seeds could serve as an alternative protein source and an energy-dense food ingredient. A similar study by Ndulaka et al. [82] on indigenous seeds reported comparable macronutrient values, reinforcing their dietary importance. A. africana seeds contain vitamin A (4.56 mg/100 g), vitamin C (138.72 mg/100 g), and vitamin E (0.74 mg/100 g), with no recorded presence of vitamin B or K [66]. This contradicts [82], who reported 0.39 (mg/100 g) of vitamin B₃. The high vitamin C content suggests strong antioxidant properties, aligning with the findings of Okeke et al. [66], who observed similar antioxidant potential in baobab seeds. Mineral analysis shows that A. africana seeds provide essential micronutrients, including iron (1.27 mg/100 g), calcium (0.003 mg/100 g), and magnesium (0.001 mg/100 g) [19]. However, zinc and sodium levels were not reported, but Ndulaka et al. [82] reported 28.88 mg/100 g of sodium level. These values are consistent with Ndulaka et al. [82], who found comparable mineral compositions in indigenous seeds, emphasizing their role in improving dietary micronutrient intake. A. africana seeds contain bioactive compounds that contribute to their medicinal properties. They have tannins (0.025%), alkaloids (0.209%), and flavonoids (8.067%) [19]. These phytochemicals enhance the plant’s antioxidant and antimicrobial activities. The functional attributes of A. africana seeds indicate their potential applications in food processing. They exhibit a water absorption capacity of 5.64 g/g, an oil absorption capacity of 2.89 g/g, a bulk density of 0.68 g/cm³, a swelling index of 1.80 mL, and a gelatinization temperature of 76.00°C [48]. These characteristics suggest that A. africana seed flour could be useful in formulations requiring moisture retention, fat-binding properties, and starch-based thickening. Similar findings by Keskin et al. [80] on leguminous seed flours further validate these functional attributes. A. africana seeds demonstrate significant nutritional, medicinal, and functional potential. Their high carbohydrate and protein content, rich vitamin and mineral profile, and bioactive compounds make them a valuable food and industrial resource. The consistency of these findings with similar studies affirms their importance in dietary applications, food processing, and medicinal research. Future studies could explore potential variations in composition due to environmental or processing factors, further expanding the utilization of A. africana in various industries.

Desert date (Balanites aegyptiaca)

Balanites aegyptiaca (B. aegyptiaca), commonly known as the desert date, is a drought-resistant tree widely distributed in arid and semi-arid regions. It is valued for its edible fruits, leaves, and seeds, which have significant nutritional, medicinal, and industrial applications. The chemical composition of B. aegyptiaca varies across its different parts, contributing to its diverse uses in food and medicine. The fruit of B. aegyptiaca is rich in carbohydrates (72.61%), making it a valuable energy source [50]. It also contains moderate protein (3.2%) and fiber (16.40%), which support digestive health. The leaves have the highest protein content (22.94%), suggesting their potential as a protein supplement [47]. The seeds have a high-fat content (39.63%), making them valuable for oil extraction. Additionally, their protein content (33.75%) highlights their potential as an alternative protein source [54]. The fruit contains essential vitamins such as vitamin A (0.65 mg/100 g) and vitamin C (1.05 mg/100 g), which contribute to immune function and vision support [47]. The vitamin composition reported by Murthy et al. [47] is comparable to that of Admassu et al. [83], who found vitamin B₁ of 3.35 mg/100 g and vitamin E content of 0.84 mg/100 g in the pulp. Compared to the fruit, the leaves have higher vitamin concentrations, including vitamin B₁/B₆ (0.51 mg/100 g) and vitamin C (2.05 mg/100 g), which play key roles in metabolism and immune function. The presence of vitamin E (0.57 mg/100 g) and vitamin K (1.37 mg/100 g) further enhances the antioxidant and blood-clotting properties of the leaves. The mineral content of B. aegyptiaca varies across its plant parts. The fruit contains significant amounts of zinc (1.69 mg/100 g) and iron (0.69 mg/100 g), both essential for immune function and oxygen transport [84]. The seeds are particularly rich in zinc (2.80 mg/100 g), calcium (48.57 mg/100 g), and magnesium (14.52 mg/100 g), making them beneficial for bone health and enzymatic activities. In contrast, the leaves have lower mineral concentrations, with calcium at 265 mg/100 g and magnesium at 77 mg/100 g [47]. Phytochemicals in B. aegyptiaca enhance its medicinal value. The fruit is rich in tannins (0.007%) and alkaloids (1.51%), which are known for their antimicrobial and anti-inflammatory properties [84]. The seeds also contain tannin (0.0024%), alkaloids (0.00142%), flavonoids 0.001094%), and phenol (0.002%), contributing to their antioxidant and therapeutic properties [84]. Differences in flavonoid and phenolic content have been noted across studies. While Omale et al. [84] reported flavonoid content of 10.94 mg/100 g, Ogori et al. [75] found higher levels (36.60 mg/100 g), which may be due to variations in the extraction methods used during analysis. The functional properties of B. aegyptiaca make it useful for food processing applications. The seeds exhibit a high-water absorption capacity (0.08–0.26 g/mL) and bulk density (60–75 g/mL), which enhances their suitability for food formulation and processing [75]. Additionally, the oil absorption capacity (0.30%) suggests its potential use in fat-based food formulations. Given its rich nutrient profile, B. aegyptiaca has promising applications in food security, pharmaceuticals, and industrial processing.

Sweet detar (Detarium microcarpum)

D. microcarpum, commonly known as sweet detar, is a leguminous tree species widely found in tropical regions. Its fruits and seeds are highly valued for their nutritional, medicinal, and functional properties. The chemical composition of D. microcarpum varies across different parts of the plant, making it a versatile resource for food, pharmaceutical, and industrial applications. The proximate composition of D. microcarpum highlights its rich macronutrient content, making it a valuable food source. The fruit contains 13.86% moisture, 9.40% fat, 21.20% protein, 4.32% fiber, and 47.50% carbohydrates [18]. The high protein and fiber content suggest its potential as a nutritious food source, while its moderate fat content indicates a low lipid profile. The seeds, however, have a significantly higher carbohydrate content (57.00%), making them a potential source of energy. They also contain 12.60% protein, 5.30% fiber, and 16.70% moisture content, making them an excellent source of energy and essential nutrients [55]. D. microcarpum is rich in essential vitamins that support various physiological functions. The fruit contains vitamin A (0.313 mg/100 g), vitamin B₂ (4.20 mg/100 g), vitamin C (55.10 mg/100 g), vitamin E (12.44 mg/100 g), and vitamin K (0.312 mg/100 g) [55, 67]. The high vitamin C content enhances immune function and provides antioxidant protection, while vitamin E contributes to skin health and cellular defense. The vitamin C levels reported by Oibiokpa et al. [67] contradict the findings of Tchatcha et al. [55], who found 4.7 µg/100 g in D. microcarpumfruit pulp. The protein content of D. microcarpumfruit pulp (21.20%) reported by Umar et al. [18] is higher than the 4.68% reported by Oibiokpa et al. [67]. This variation could be attributed to differences in fruit maturity and environmental factors affecting protein accumulation. The mineral composition of D. microcarpum varies significantly between its fruits and seeds, contributing to its health benefits. The fruit is particularly rich in iron (78.71 mg/100 g) and magnesium (113.50 mg/100 g), essential for oxygen transport and acts as a cofactor for enzymatic reactions. It also contains calcium (70.97 mg/100 g), iron (78.71 mg/100 g), and sodium (15.09 mg/100 g) [67]. The seeds contain iron (0.60 mg/100 g), calcium (270.00 mg/100 g), magnesium (70.00 mg/100 g), zinc (0.04 mg/100 g), and sodium (2.82 mg/100 g) [72]. The high calcium content in the seeds suggests their potential role in bone health. Phytochemicals in D. microcarpum contribute to its medicinal and therapeutic properties. The fruit contains tannins (0.17%), known for their antioxidant and antimicrobial effects [8]. The seeds have a more diverse phytochemical profile, including tannins (0.47%), alkaloids (0.37%), flavonoids (2.28%), phenolics (0.35%), and glycosides (0.00005%), which contribute to their bioactive properties, such as anti-inflammatory and antioxidant effects [8, 55]. The tannin content (0.17%) found by Dogara [8] closely matches the 0.00017% reported by Oibiokpa et al. [67], further reinforcing the plant’s antioxidant potential. The functional properties of D. microcarpum influence its application in food processing. It has an oil absorption capacity of 3.12%, which indicates its potential for moisture retention in food formulations. The swelling index is 12.13 mL, suggesting its suitability for improving food structure and texture. Additionally, its high swelling index makes it useful as a thickening and stabilizing agent in food products [80]. D. microcarpum is a nutrient-rich plant with significant potential in nutrition, health, and industrial applications. Its fruits and seeds serve as excellent sources of protein, fiber, essential vitamins, minerals, and bioactive compounds. Given its high phytochemical content and functional properties, it holds promise for applications in food, pharmaceuticals, and industrial product development. Future research could explore optimizing its processing methods and evaluating its potential in functional food formulations and nutraceuticals.

Velvet tamarind (Dialium guineense)

D. guineense, commonly known as velvet tamarind, is a tropical leguminous plant valued for its fruits, leaves, and seeds, which have significant nutritional, medicinal, and industrial applications. The chemical composition of its different plant parts influences its functional and health benefits. The proximate composition of D. guineense highlights its nutritional potential. The fruit contains 10.53% moisture, 5.34% fat, 3.94% protein, 1.05% fiber, and 58.65% carbohydrates, making it a good energy source [26]. The leaves exhibit higher protein (18.72%) and fiber (13.34%) contents, alongside (6.48%) carbohydrates [56]. Meanwhile, the seeds contain 10.13% moisture, 35.33% fat, 17.44% protein, 13.52% fiber, and 43.90% carbohydrates, suggesting their potential for oil extraction and dietary applications [26]. In addition to its macronutrient profile, D. guineense is also a significant source of essential vitamins. The fruits contain vitamin A (6.32 mg/100 g), vitamin B₁₂ (2.67 mg/100 g), vitamin C (48.63 mg/100 g), and vitamin E (3.26 mg/100 g), with no recorded vitamin K content [85]. Similar studies by Rahul et al. [15] on other tropical fruits report comparable vitamin C values, reinforcing the antioxidant potential of D. guineense. The mineral composition of D. guineense varies significantly between fruits and seeds. The fruit contains 1.43 mg/100 g iron, 0.035 mg/100 g calcium, 0.04 mg/100 g magnesium, and 0.288 mg/100 g sodium, with no recorded zinc content [26]. The seeds contain 15.28 mg/100 g iron, 0.54 mg/100 g calcium, 268.00 mg/100 g magnesium, and 40.16 mg/100 g sodium [26, 73]. These values are higher compared with findings by Airaodion et al. [86], who observed different mineral distributions in D. guineense fruit pulp, emphasizing their role in human nutrition. Phytochemical analysis of D. guineense reveals its bioactive compound content, which contributes to its medicinal properties. The fruits contain flavonoids (0.04%), phenolics (0.013%), and glycosides (0.022%) [46]. The leaves contain tannins (0.00%), flavonoids (12.44%), phenol (15.44%), and glycosides (0.00%) [49]. Meanwhile, the seeds have tannins (0.023%), flavonoids (0.037%), phenolics (0.013%), and glycosides (0.046%) [49]. These findings contradict research by Adedokun et al. [87], which documented higher phytochemical compositions in different parts of D. guineense, further supporting the therapeutic significance of D. guineense. Beyond its phytochemical components, the functional properties of D. guineense also contribute to its potential applications in food processing. The seeds exhibit a water absorption capacity of 20.00% and an oil absorption capacity of 16.00%, enhancing their potential for moisture retention and fat-binding properties in food formulations [81]. Overall, D. guineense is a nutritionally rich plant with significant potential in food, medicinal, and industrial applications. Its fruits serve as a carbohydrate and vitamin source, while its seeds are valuable for oil extraction and protein supplementation. The presence of essential minerals and bioactive compounds further enhances its health benefits, making it a promising functional food ingredient. Additionally, its nutrient-dense composition suggests its potential role in promoting food security and sustainable agriculture, particularly in regions where access to diverse food sources is limited.

African locust bean (Parkia biglobosa)

P. biglobosa, commonly known as the African locust bean, is a perennial leguminous tree indigenous to Africa (Figure 3). Various parts of the tree, including its seeds and fruit pulp, have been studied for their chemical composition, revealing significant nutritional and phytochemical properties. The fruit’s nutritional profile includes proximate composition, mineral content, vitamin values, and anti-nutritional factors. The seed contains significant levels of moisture, proteins, fats, carbohydrates, and fiber. Specifically, fruit pulp consists of moisture (10.59%), ash (4.18%), crude protein (6.56%), crude fat (1.80%), crude fiber (11.75%), carbohydrates (67.30%) [57]. The fruit is higher in fiber and carbohydrates, making it a better energy source and potentially beneficial for digestive health [70]. African locust bean contains essential minerals necessary for human nutrition, including magnesium (0.16 mg/100 g), calcium (7.10 mg/100 g), sodium (0.14 mg/100 g), potassium (2.15 mg/100 g), iron (1.00 mg/100 g), and zinc (0.25 mg/100 g) [70]. These values are below those reported by Elemo et al. [88], possibly due to variations in environmental conditions or processing methods. The high mineral content suggests African locust bean could be a beneficial dietary supplement. However, quantitative analysis of certain anti-nutritional factors in African locust bean found phytic acid (60.00 mg/100 g), crude saponins (17.80 mg/100 g), tannins (81.00 mg/100 g), total phenols (204.60 mg/100 g), and hydrocyanic acid (17.30 mg/100 g) [57]. Additionally, African locust beanfruit contains minimal anti-nutritional factors, making it suitable for human consumption. Given its health benefits, incorporating African locust bean into diets and promoting its cultivation alongside other legume trees is recommended [70]. The seed, which is mainly used, has a slightly higher moisture content (8.60%) compared to the fruit (10.59%) [58]. Lower moisture content in the fruit suggests better shelf stability, as higher moisture levels can promote microbial growth and spoilage. The seed is significantly richer in fat (16.18%) compared to the fruit (1.80%). This indicates that the seeds may serve as a good source of edible oil, while the fruit is a low-fat food option. The seed has a high protein content (28.33%), making it a valuable plant-based protein source. The fruit has a much lower protein content (6.56%), meaning it contributes less to dietary protein intake. The fruit has a higher fiber content (11.75%) compared to the seed (10.69%). Higher fiber in the fruit suggests benefits for digestion and gut health. The seed of P. biglobosa is nutritionally richer in fat and protein, making it more valuable for protein and oil-based diets [58]. The vitamin values of the seed of African locust bean show its nutritional significance, especially regarding vitamin A and C content [70]. African locust bean is widely used in traditional African diets and is valued for both its nutritional and medicinal benefits. The high vitamin A content makes it an important dietary source to improve vision, while its vitamin C content enhances immune response.

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Figure 3. African locust bean tree (Parkia biglobosa). (A). African locust bean leaf with mature pod showing yellow pulp. (B). Dried pods and seeds. (C). Fermented, processed seeds (Dawadawa, iru, soumbala). Taken from [89] without modification. © 2024 The Authors. Licensed under a Creative Commons Attribution license 4.0 (CC BY).

Billygoat weed (Ageratum conyzoides)

The proximate composition analysis of Ageratum conyzoides leaves and roots revealed that the leaf sample contained ash (12.64%), fat (2.27%), fiber (23.50%), moisture (10.02%), protein (14.73%), and carbohydrate (36.84%). In contrast, the roots contained ash (16.95%), fat (2.01%), fiber (26.74%), moisture (13.35%), protein (9.89%), and carbohydrate (31.06%). The relatively high fiber and low fat contents may contribute to some of the medicinal applications of the plant [59]. Agbafor et al. [59] reported higher proximate composition values compared to those of Enerijiofi and Isola [90]. The leaves and roots contain essential minerals such as sodium, potassium, calcium, magnesium, phosphorus, zinc, manganese, and iron, with significantly higher (P < 0.05) concentrations in the roots compared to the leaves. Similarly, the concentrations of phytochemicals in the leaves were significantly higher (P < 0.05) than those in the roots [59]. The medicinal uses of Ageratum conyzoides may be attributed, at least in part, to its identified phytochemical constituents [59]. Enerijiofi and Isola [90] also identified similar phytochemicals in their study. The traditional applications of Ageratum conyzoides vary across regions and cultures, likely due to variations in its phytochemical composition. Notably, differences in the chemical composition of Ageratum conyzoides have been reported in various studies, which may be attributed to variations in collection site and time [77].

Ackee (Blighia sapida)

Blighia sapidais a nutritionally valuable fruit that provides essential macronutrients, minerals, and bioactive compounds [91]. It is particularly noted for its high lipid content and low caloric value [60]. The fruit’s nutritional profile includes proximate composition, mineral content, fatty acid profile, and anti-nutritional factors. The edible portion of ackee, known as the aril, contains significant levels of moisture, proteins, fats, carbohydrates, fiber, and ash. Specifically, ackee apple consists of moisture (73.21%), ash (1.49%), crude protein (9.38%), crude fat (13.98%), crude fiber (2.08%), carbohydrates (0.86%), and vitamin C (4.45%) [60]. Its high lipid content makes ackee distinct among fruits, serving as a valuable dietary fat source [60]. Ackee apple contains essential minerals necessary for human nutrition, including magnesium (49.80 mg/100 g), calcium (47.85 mg/100 g), zinc (0.50 mg/100 g), and iron (1.00 mg/100 g) [53]. These values surpass those reported by Dada et al. [92], possibly due to variations in environmental conditions or processing methods. The high mineral content suggests ackee could be a beneficial dietary supplement. Initial studies identified linoleic acid as the dominant fatty acid in ackee aril. However, subsequent research using improved analytical methods consistently found oleic acid as the primary fatty acid [73, 93, 94]. This highlights the importance of precise analytical techniques in determining fatty acid composition. Ackee seeds contain various essential amino acids, including hydroxy-proline, glutamic acid, serine, glycine, threonine, alanine, histidine, arginine, tyrosine, valine, methionine, isoleucine, phenylalanine, and lysine. This rich amino acid profile suggests that ackee seeds contribute to dietary protein intake. Qualitative screening of anti-nutrients showed the absence of phenols in ackee fruit. However, quantitative analysis of certain anti-nutritional factors in ackee apple found flavonoids (640 mg), phytic acid (340 mg), and oxalates (65 mg) [53]. These levels suggest that while ackee contains some anti-nutritional factors, they are not present in amounts that would significantly hinder nutrient bioavailability. The proximate and mineral composition of ackee apple indicates that it is a nutritious food rich in lipids, proteins, and essential minerals. Its high oleic acid content makes it a valuable dietary fat source, while its amino acid profile enhances its nutritional value. Additionally, ackee fruit contains minimal anti-nutritional factors, making it suitable for human consumption. Given its health benefits, incorporating ackee apple into diets and promoting its cultivation alongside other fruit-bearing trees like oranges, grapes, and lemons is recommended [92].

Bush mango (Irvingia wombulu)

The proximate composition of Irvingia wombulu (I. wombulu) (bush mango) reveals significant variations across different plant parts, influencing their nutritional and industrial applications. Moisture content was highest in seed coats (9.80%) and lowest in seeds (6.50%), with high moisture levels in peels and seed coats making them more susceptible to microbial spoilage. Seeds had the highest ash content (6.30%), indicating a rich mineral composition, while peels had the lowest (0.75%). The lipid content was highest in seeds (37.9%), making them valuable for oil extraction and energy provision, whereas other parts contained minimal lipids. Crude fiber was most abundant in peels (22.50%), followed by seeds (20%) and seed coats (2.20%), suggesting their potential in digestive health and functional foods. The crude protein content in seed coat (9.45%) appears high, while seeds (8.40%), leaves (7.70%), and peels (6.30%) contained moderate levels [61]. These findings suggest that I. wombulu seeds are the most valuable for energy and mineral content, while peels and seed coats offer high fiber. The variations in composition indicate potential uses in food processing, oil extraction, and dietary supplementation, enhancing their economic and nutritional significance. The mineral composition of I. wombulu varies across its parts [61]. The highest iron concentration was found in seed coats (0.0565 mg/100 g), while seeds contained 0.304 mg/100 g, making fruits more preferred for consumption. Sodium levels varied, with seed containing the highest amount, followed by peels, leaves, and seed coat. Calcium was most concentrated in seed coats (0.3772 mg/100 g) compared to seeds (0.064 mg/100 g) [61]. The proximate composition showed the presence of carbohydrates, proteins, fibers, lipids, and moisture in varying amounts, making I. wombulu a valuable food source. Essential minerals such as magnesium, sodium, calcium, and zinc were detected, while iron had the lowest concentration. Leaves contained the highest overall mineral content. Phytochemical analysis confirmed the presence of alkaloids, flavonoids, tannins, glycosides, terpenoids, saponins, and steroids, reinforcing I. wombulu’s nutritional and medicinal significance [61].

Bush mango (Irvingia gabonensis)

The moisture content of I. gabonensis was recorded as follows: 1.4% in seeds, 22.2% in leaves, 38.7% in peels, and 57.6% in seed coats. The ash content in the peels and seed coats of I. gabonensis was 0.75% and 6.8%, respectively. The leaves and seed coats had identical ash content values of 2.4%. The ash content was higher than that reported by Adeyeye [95], where values ranged from 2.4% and 2.5%,. Additionally, the results are comparable to those reported by Efosa et al. [96]. Notably, the seed coats of I. gabonensis exhibited a high ash content, indicating a significant mineral composition. For dietary recommendations, it is advised that daily calorie intake from I. gabonensis should not exceed 30 calories to prevent obesity, diabetes, and heart disease. Crude fiber in the plant consists of indigestible cellulose, which aids in water absorption, provides roughage, and enhances the functioning of the digestive system. Protein content contributes to the synthesis of essential biomolecules required for tissue repair, maintenance, and hormone production [61]. The carbohydrate content was highest in the seeds of I. gabonensis, making them a valuable energy source. Regarding mineral composition, the highest iron (Fe) concentration was recorded in the seed coats (0.395 mg/kg), while the lowest was found in the seeds (0.040 ± 0.00 mg/kg). Due to its high iron content, the seed is recommended for consumption. Similarly, calcium levels were highest in the seed coats (4.912 mg/kg) and lowest in the seeds (3.278 mg/kg). These mineral concentrations were lower than those reported by Adeyeye [95]. Phytochemical analysis revealed the presence of alkaloids, flavonoids, tannins, glycosides, terpenoids, saponins, and steroids. The presence of these phytochemicals, along with essential minerals and other nutrients, underscores the nutritional value of Irvingia species. Therefore, the consumption of I. gabonensis is highly recommended for its health benefits and nutrient content [97]. Additionally, various parts of the plant, especially the leaves and peels, hold significant nutritional and medicinal potential and should be further explored for their applications [61].

African star apple (Chrysophyllum albidum)

The nutritional composition of Chrysophyllum albidum varies across its juice, pulp, and peel. The juice has the highest moisture content (69.9%), making it highly perishable, while the peel (57.2%) is more stable. The pulp is the most nutrient-dense, containing the highest protein (8.2%), fat (14.3%), and carbohydrate (68.2%) [58]. However, these findings differ from those reported by Musa et al. [62]. The peel has the highest fiber (14.2%) and ash content (5.1%), indicating a rich mineral profile. The juice is an excellent source of vitamin C (49.4 mg/100 mL) and reducing sugar (1.34%), with a pH of 3.3 aiding preservation [98]. A similar result was reported by Musa et al. [62]. The fruit contains vitamins K, B-complex, C, and D in small amounts. The juice is rich in sodium, potassium, calcium, and phosphorus, while the peel contains the highest iron (131 mg/100 g), copper (100 mg/100 g), and magnesium (251.7 mg/100 g). A similar result was reported by Ibrahim et al. [99]. Phytochemicals such as tannins (62.94 mg/100 g), flavonoids (18.69 mg/100 g), and phenols (45.85 mg/100 g) contribute to the fruit’s antioxidant and anti-inflammatory properties, potentially aiding in disease prevention [100].

Thorn apple (Datura stramonium)

The proximate composition of Datura stramonium (thorn apple) varies across the seed coat, seeds, and whole seed. The seed coat has the highest ash (15.7%) and protein (20%) content, indicating a rich mineral and nitrogen source. Seeds contain the highest carbohydrate (29.8%) and fat (19.9%), making them energy-dense. The whole seed composition shows balanced fiber (23.7%), fat (16.6%), and protein (16.2%) levels. Moisture content is highest in the seed coat (8.65%), suggesting lower stability. The high fiber content, particularly in seeds (25.1%), suggests potential dietary benefits but may require further evaluation for safety [63]. A similar result was reported by Sharma et al. [101]. The mineral composition of Datura stramonium (thorn apple) varies across the seed coat, seeds, and whole seeds. The seed coat contains the highest magnesium (399.2 mg/g) and zinc (8.25 mg/g), while seeds are richest in calcium (426.5 mg/g) and phosphorus (275 mg/g), essential for bone health. Whole seeds have high manganese (8.49 mg/g) and chromium (2.85 mg/g). Iron levels are relatively stable across all parts. Lead presence (0.95 mg/g in whole seeds) raises safety concerns. The potassium and sodium content is low, indicating minimal electrolyte contribution [63]. These variations highlight the nutritional and potential toxicological aspects of the plant. Similar result was reported by Batool et al. [102]. The antinutrient composition of Datura stramonium (thorn apple) varies across different seed components. Seeds have the highest phytic acid content (29.19 mg/g), which can reduce mineral bioavailability, while whole seeds contain the least (16.75 mg/g). Tannin levels increase from seed coat (4.00 µg/g) to whole seeds (8.00 µg/g), potentially affecting protein digestibility. Oxalate, which can contribute to kidney stone formation, is highest in whole seeds (7.77 mg/g) and lowest in the seed coat (3.75 mg/g). These findings suggest that while thorn apple contains beneficial nutrients, its antinutrients may limit its nutritional value and require processing to reduce toxicity [63]. The functional properties of Datura stramonium (thorn apple) seeds vary significantly. The seed coat has the highest water absorption capacity (87.67%), while whole seeds have the highest oil absorption (57.1%) and emulsion capacity (55.10%). Bulk density increases from the seed coat (0.30 g/cm³) to whole seeds (0.42 g/cm³) [63, 102].

Woodland waterberry (Syzygium guineense)

Syzygium guineense (S. guineense), a widely consumed indigenous fruit, has a high water content (81.5%), making it an excellent hydrating fruit, particularly in hot climates. It provides 1.6 g of protein per 100 g, contributing a small but beneficial amount of protein to the diet. The fruit is naturally low in fat (0.7 g/100 g), making it a suitable option for individuals on low-fat diets while still delivering essential nutrients. With 13.5 g of carbohydrates per 100 g, S. guineense serves as a moderate energy source. Additionally, its 1.8 g fiber content promotes digestive health by supporting bowel regularity and aiding in blood sugar regulation. The ash content (1.0 g/100 g) indicates the presence of important minerals such as calcium, phosphorus, potassium, magnesium, iron, and zinc, which play key roles in bone health, metabolic processes, and overall physiological functions. Furthermore, the fruit contains 11.9 mg of vitamin C per 100 g, contributing to immune function, antioxidant defense, and collagen synthesis [64]. Beyond its nutritional profile, S. guineense is rich in bioactive compounds, including polyphenols, flavonoids, flavanones, tannins, saponins, and alkaloids, which have potential health benefits. The bark and leaves are widely used in traditional medicine to treat ailments such as malaria, diarrhea, epilepsy, asthma, cough, and wound healing [103]. Additionally, the plant is utilized for food and construction purposes. Given its rich composition and health-promoting properties, S. guineense plays a crucial role in food security and nutrition, particularly in regions where indigenous fruits are vital dietary components.

Monkey orange (Strychnos spinosa)

The proximate composition of Strychnos spinosa (S. spinosa) highlights its nutritional significance. The fruit has a moisture content of 40.80%, indicating a relatively high water content, which contributes to its juiciness and perishability. The ash content (16.50%) reflects the presence of essential minerals, which may include calcium, magnesium, phosphorus, and potassium. This suggests that S. spinosa is a good source of micronutrients necessary for various physiological functions, including bone health and enzyme activity. With a crude protein content of 5.70% and crude lipid content (19.80%), the fruit provides a moderate amount of protein, which contributes to dietary protein intake, particularly in regions where alternative protein sources may be limited. S. spinosa may serve as a good source of dietary fats. The crude fiber content (4.17%) supports digestive health by promoting bowel movement and reducing the risk of constipation. The carbohydrate content (11.80%) provides an energy source, although it is lower compared to many other fruits [74]. A similar result was reported by Tittikpina et al. [37]. The fruit contains significant amounts of potassium (0.407 mg/100 g), manganese (0.380 mg/100 g), phosphorus (0.390 mg/100 g), calcium (0.335 mg/100 g), magnesium (0.257 mg/100 g), and sodium (0.316 mg/100 g) [74]. Calcium and magnesium contribute to bone development, muscle contraction, and enzymatic activities. Magnesium also plays a key role in energy metabolism and nerve function. Sodium, though present in moderate amounts, helps maintain fluid balance and supports nerve and muscle function. However, excessive sodium intake can lead to high blood pressure, making S. spinosa a preferable fruit for balanced mineral intake. The presence of manganese indicates potential antioxidant benefits, as manganese plays a crucial role in enzymatic reactions and the prevention of oxidative stress [37, 74]. The total phenolic content (TPC) is 0.356 mg GAE/g, indicating the presence of phenolic compounds known for their antioxidant and anti-inflammatory properties. These compounds play a role in reducing oxidative stress and may help in disease prevention. Similarly, the total flavonoid content (TFC) is 0.031 mg CE/g, suggesting a lower flavonoid concentration [104]. The fruit is exceptionally rich in ascorbic acid (73.00 mg/g), making it a potent source of vitamin C. The DPPH radical scavenging activity (50.32%) suggests moderate antioxidant potential, indicating the fruit’s ability to neutralize free radicals and reduce cellular damage. Additionally, the ferric reducing antioxidant power (FRAP) is 1.40 mg GAE/g, further confirming the fruit’s antioxidant capacity by demonstrating its ability to reduce oxidative stress [104].

Bungo fruit (Saba Comorensis)

Saba comorensis (S. comorensis) is a nutritionally valuable fruit that provides essential macronutrients, minerals, and bioactive compounds. The fruit contains 74.08 g/100 g moisture, 1.93 g/100 g total ash, 4.83 g/100 g crude protein, 7.97 g/100 g dietary fiber, 0.00 g/100 g crude fat, 19.16 g/100 g total carbohydrates, 1.27 mg/100 g beta-carotene, and an energy content of 97.78 kcal [96]. A similar result was reported by Charles and Mgina [105]. Notably, it has a high concentration of vitamin C (430.50 mg/100 g), making it a potent antioxidant source that supports immune function, collagen synthesis, and skin health. The absence of fat suggests that the fruit is a healthy option for individuals looking to minimize fat intake [106]. Additionally, the significant dietary fiber content is beneficial for digestion, gut health, and glucose metabolism, making it suitable for individuals seeking high-fiber diets. In terms of mineral composition, S. comorensis provides essential minerals crucial for maintaining various physiological functions. The fruit contains 79.0 mg/100 g sodium, 1,493.75 mg/100 g potassium, 209.0 mg/100 g calcium, 3.40 mg/100 g iron, 0.19 mg/100 g copper, 1.80 mg/100 g zinc, and 894.9 mg/100 g magnesium [65]. These minerals contribute to electrolyte balance, bone health, enzymatic activities, and overall metabolic function [105]. Regarding antioxidant activity, studies have shown that S. comorensis exhibits considerable free radical scavenging capacity. At a concentration of 1,000 μg/mL, the antioxidant activity ranged between 56.26% and 56.30% for fruit samples, indicating the fruit’s potential as a natural antioxidant source [105].

Challenges

Nigeria boasts a rich diversity of EWPs, integral to various ethnic groups’ diets and cultural practices. However, their sustainable utilization faces numerous challenges and threats that demand urgent attention and strategic interventions [6, 22, 129–134].

• 1.

  Insufficient baseline information on nutritional properties: Currently, there is a lack of organized baseline data regarding the nutritional qualities of native plants, hindering informed decision-making on their cultivation and consumption [22]. Comprehensive research efforts are imperative to fill this knowledge gap and promote the nutritional value of EWPs across diverse geographic locations [22].

• 2.

  Indiscriminate and illegal logging: Rampant tree felling, driven by factors like youth unemployment and food insecurity, poses a grave threat to native fruit trees and their habitats [132]. Efforts to curb illegal logging and promote sustainable forestry practices are essential to safeguard EWP populations.

• 3.

  Limited acceptability and accessibility: EWPs face challenges in gaining acceptance and accessibility due to a general lack of interest and investment in their cultivation [129]. Addressing barriers to production and distribution, including inadequate funding and infrastructure, is crucial to enhancing their availability and utilization [133].

• 4.

  Population growth and biodiversity loss: Nigeria’s rapid population growth exacerbates pressure on natural resources, leading to biodiversity loss and habitat destruction [131]. Sustainable population management strategies and conservation initiatives are needed to mitigate these adverse impacts on EWP ecosystems [6].

• 5.

  Poverty and biodiversity degradation: Poverty perpetuates biodiversity degradation as marginalized communities resort to unsustainable practices for meager financial gains [6]. Empowering rural populations through education, alternative livelihoods, and sustainable resource management can alleviate poverty-driven threats to EWPs.

• 6.

  Inadequate policy support: The absence of focused policies and research support hampers conservation efforts and undermines the protection of EWP species. Strengthening regulatory frameworks and investing in scientific research are essential to promote the sustainable management of EWPs [134].

• 7.

  Lack of standardization and documentation: Insufficient documentation of EWP knowledge contributes to their underrepresentation and potential extinction [130]. Standardizing data collection and documentation procedures can enhance our understanding of EWP diversity and support conservation efforts.

Integrated conservation and sustainability strategies

To address the threats to edible wild plants and realize their long-term utilization, a set of comprehensive conservation and management strategies are proposed as follows [22, 52, 135–146].

• 1.

  Collaborative identification and prioritization: Collaborative identification and prioritization of EWPs through active engagement with indigenous communities are essential for effective conservation and sustainable utilization [135, 136]. Sustainable use of EWPs emphasizes selective and seasonal harvesting of usable plant parts, such as fruits, leaves, and seeds, while avoiding destructive practices (e.g., uprooting whole plants) that hinder natural regeneration and long-term population stability. Integrating EWPs into managed systems, including agroforestry and home gardens through domestication, enrichment planting, and nursery propagation, can reduce pressure on wild populations [135]. Agroforestry systems offer significant potential for biodiversity conservation when local communities are motivated to integrate indigenous forest species, particularly those with edible value, into farming landscapes [136]. However, the successful integration of EWPs into agroforestry systems depends not only on their nutritional and socio-economic benefits but also on their allelopathic potential. Allelopathy plays a critical role in determining species compatibility within agroforestry systems, as allelochemicals released by plants can exert inhibitory or stimulatory effects on neighboring crops and associated species [139]. These biochemical interactions influence ecosystem dynamics and regulate plant-plant, plant-insect, and plant-herbivore relationships, thereby shaping productivity and stability in agricultural and natural ecosystems [140]. Crop performance may be enhanced or suppressed through synergistic or antagonistic interactions, including weed suppression or growth inhibition of companion or subsequent crops [139, 141]. Empirical evidence indicates that several agroforestry tree species exhibit notable allelopathic effects on crop growth. Aleem et al. [142] reported that Neem (Azadirachta indica), locust bean (P. biglobosa), and shea butter (Vitellaria paradoxa) significantly inhibited the germination and growth of cowpea, with possible implications for other arable crops. Consequently, farmers are advised to adopt adequate spacing, thinning, or selective retention of such trees, particularly where volunteer species occur in dense clusters, to minimize negative crop-tree interactions. Similarly, Suleimana et al. [143] demonstrated that extracts from Adansonia digitata inhibited seed germination and seedling growth of Lactuca sativa, Hibiscus sabdariffa, and Sorghum bicolor, with lettuce and sorghum being more sensitive. Root growth was more adversely affected than shoot growth, suggesting the presence of root-derived allelochemicals responsible for the restricted growth of neighboring plants near baobab trees. From a practical agroforestry perspective, understanding the allelopathic behavior of EWPs is essential for species selection, spatial arrangement, and system design. Integrating EWPs with neutral or beneficial allelopathic interactions can enhance crop productivity and ecosystem services, whereas species with strong inhibitory effects require strategic placement, wider spacing, or controlled integration. One practical approach involves raising promising EWPs in nurseries before field establishment, allowing for compatibility assessments prior to large-scale planting. Community engagement remains critical throughout this process to ensure transparency, shared decision-making, and local acceptance of agroforestry interventions, thereby enhancing the long-term sustainability and effectiveness of EWP-based agroforestry systems.

• 2.

  Reviewing Endangered Species Acts: Strengthening endangered species legislation through regular review and enforcement of Endangered Species Acts is essential for the long-term conservation of threatened plant species and their habitats [137, 138]. Effective legal protection should be complemented by methodologically sound supplementary regeneration strategies, particularly where natural regeneration is insufficient. As emphasized by Nguru [138], the combined application of in situ and ex situ conservation approaches provides a robust framework for preserving plant biodiversity. Supplementary regeneration can be achieved through several established techniques, including grafting, budding, cuttings, and the propagation of nursery-grown seedlings. Grafting and budding are particularly valuable for conserving rare genotypes and enhancing survival rates of endangered woody species, while cuttings offer a cost-effective means of clonal propagation. Nursery-based propagation allows for controlled growth conditions, improving seedling vigor prior to field establishment and increasing the likelihood of successful reintroduction [146]. However, the reintroduction of nursery-grown or vegetatively propagated plants into natural habitats requires careful consideration of ecological and genetic compatibility. Potential risks include poor adaptation to local environmental conditions, disruption of existing plant communities, and reduced genetic diversity if propagation materials are sourced from limited populations. Therefore, regeneration efforts should prioritize the use of locally adapted plant material, gradual acclimatization, and post-introduction monitoring to ensure successful establishment and ecosystem integration [144]. Overall, integrating strengthened legal protection with scientifically guided regeneration methods enhances the effectiveness and applicability of conservation strategies for endangered plant species, ensuring both ecological integrity and long-term sustainability.

• 3.

  Promoting nutritional awareness: Raising public awareness about the nutritional value and cultural significance of EWPs can foster appreciation and conservation efforts [145]. Seasonal food availability booklets and calendars, and simple, locally appropriate picture posters can serve the dual purpose of revitalizing the use of EWPs and imparting basic nutrition information derived from national nutrition guidelines [145]. The institute’s future plans include establishing an herb garden on the school premises where EWPs will be grown and harvested for use in cooking courses. School gardens serve as an effective means to stimulate interest in biodiversity and can play a vital role in enhancing the nutrition, well-being, and education of students and their families. Furthermore, these gardens act as conservation networks for tree genetic resources and help revive traditional food systems and cultural practices [146].

• 4.

  Domestication programs and sustainable collection guidelines: Depending on the conservation status and utilization level of wild food plants (WFPs), domestication programs may be necessary to encourage the cultivation of these wild species, alleviate pressure on their natural populations, and revitalize lost genetic diversity. Turkey offers a successful model in its efforts to mitigate the overexploitation of golden thistle (Scolymus hispanicus L.). This flowering plant holds significant cultural and economic value in Turkey, where its roots and immature leaves are traditionally harvested from the wild and sold in local markets [52]. Similarly, Omotayo et al. [22] advocate for the domestication of indigenous fruit trees as a means to support land management systems, offering a viable approach for climate change adaptation and mitigation strategies. By promoting domestication initiatives, countries can foster sustainable practices while safeguarding the genetic diversity and ecological balance of their natural habitats.

Addressing the multifaceted challenges facing Nigerian EWPs requires a concerted effort from policymakers, researchers, and local communities. By implementing integrated conservation strategies and promoting sustainable practices, we can safeguard Nigeria’s rich botanical heritage for future generations.