Nutritional and mineral analysis of the ultimate wild food plants of Lotkuh, Chitral, the Eastern Hindukush Pakistan

Abstract

Wild food plants (WFPs) are designated as functional foods owing to their nutritional potential and as a source of bioactive compounds vital for human health. In times of geopolitical upheaval and nutritional imbalance in mountainous areas of the world, the contribution of WFPs is extraordinary. Lotkuh is a remote mountainous region in the Eastern Hindukush that supports distinctive global plant biodiversity. The documentation and nutritional analysis of the wild edible plants have not yet been subjected to scientific investigation, even though WFPs make up a significant component of the inhabitant’s diet. The current study is the first scientific investigation of the nutritional profile of 16 WFPs in the Hindukush region of Pakistan. Plants were collected from different parts of the study area and were subjected to proximate analysis adhering to the standard protocols of AOAC international. Proximate analysis revealed higher moisture in Rheum webbianum (91.5 g/100 g FW) and Oxyria digyna (90.5 g/100 g FW), while Elaeagnus angustifolia had the lowest (25.4 g/100 g FW). Mentha longifolia and Pinus gerardiana had (23.2 g/100 g) and (14.0 g/100 g) protein, whereas Berberis lyceum contained (3.6 g/100 g). Pinus gerardiana had the highest lipid (56.50 g/100 g), followed by Hippophae rhamnoides (45.50 g/100 g), and Berberis lyceum (0.91 g/100 g). Crataegus songarica with high carbohydrate (87.50 g/100 g) was followed by Eremurus stenophyllus (80.83 g/100 g), whereas Berberis lyceum had the least (18.51 g/100 g). High crude fiber (19.33 g/100 g) was found in Ziziphora clinopodiodes followed by Cotoneaster nummularia with (15.50 g/100 g). Pinus gerardiana and Prunus prostrata had low fiber of 1.387 and 1.377 g/100 g. Vitamin C was high in Mentha longifolia (90.63 mg/100 g), Eremurus stenophyllus (86.96 mg/100 g), and Ziziphora clinopodiodes (90.45 mg/100 g). Ca concentration was (948.33 mg/100 g) in Oxyria digyna followed by Cotoneaster nummularia whereas the lowest Ca (20.03 mg/100 g) was recorded in Diospyros lotus. Mg was high in Oxyria digyna (994.00 mg/100 g) and lowest (10.01 mg/100 g) in Diospyros lotus. Berberis lyceum (54.30 mg/100 g), Oxyria digyna (34.33 mg/100 g), and Rheum webbianum (26.04 mg/100 g) had the maximum iron. Mn was high in Berberis lyceum (14.33 mg/100 g), Pinus gerardiana (6.33 mg/100 g), and Elaeagnus angustifolia (4.60 mg/100 g). Prunus prostrata (12.16 mg/100 g), Oxyria digyna (10.30 mg/100 g), and Pinus gerardiana (4.16 mg/100 g) were the leading in Zn concentration whereas Ziziphora clinopodiodes (0.22 mg/100 g). The current study establishes the hitherto unidentified nutritional profile of the WFPs in the area. The prospect of nutritional research on WFPs in the Eastern Hindukush is established by this study.

1. Introduction

The inhabitants of the Hindukush region along the Pakistan-Afghanistan border have a distinctive food system of wild food plants (WFPs), to sustain human life in the rugged terrain of high altitudes. People in this territory collect edible plants from the wild to use them directly as food, sell them in the market, or both. The documentation of the food system, particularly that pertaining to WFPs, is severely lacking. The nutritional status of the wild edible plants in this region is yet to undergo scientific inquiry [1]. The ecosystems in the tribal belt of Hindukush reflect absolute diversity, being composed of alluvial fans, forests, pastures, and graze lands offering diverse wild palatable fruits and vegetables [2]. These WFPs, have significant therapeutic potential in addition to being vital from a caloric and nutritional standpoint [3]. In many parts of the world, WFPs have been investigated for their potential pharmacological benefits and future medicinal perspectives [4,5].

Owing to the nutritional vacuum they can fill; a variety of WFPs have been labeled as “functional food” in recent nutritional studies [6]. These plants not only serve as a healthy diet but also cure ailments [7]. Most WFPs, according to recently conducted studies, provide a sustainable source of biologically active compounds including complex sugars, vitamins, and vital fatty acids, and as a result, significantly contribute to addressing the growing problem of malnutrition [2]. Numerous studies have highlighted their significance in earning revenues, reducing poverty, improving nutritional balance, ensuring food security, and diversifying agriculture [8]. One of the landmark contributions of WFPs is their role in food security by providing a broad spectrum of food diversity and alternative food sources to the local communities [9]. WFPs have played a vital role in ensuring human survival during times of geopolitical instability and famine [10].

Pakistan has a lower-middle economic level and is the sixth most populous country in the world. It has a wide variety of wild resources, particularly wild plants, and experiences all four seasons of the year but ranks as the 11th most food-insecure country in the world [11,12]. About 60% of the population of the country is under the stress of food insecurity. Due to the distance from cities, the semi-arid climate, and border disputes, the food insecurity in the distant Hindukush regions is significantly worse. Due to its geopolitical location, the Pakistan-Afghanistan border in the Hindu Kush Mountain range has historically been a source of conflict. The other main causes of food insecurity and poverty in the tribal belt include man-made disasters, the sharp rise in the human population, restricted access to food, and local livelihood practices. For the local communities of mountainous origin, wild food plants serve as an important natural resource to alleviate hunger and malnutrition if managed on a sustainable basis.

In the current global food system, increased food scarcity is accompanied by a lack of nutritious food availability, which leads to a vulnerable human health system. Therefore, in some parts of the world, WFPs can be a crucial part of people’s diets and offer increased dietary diversity to the residents of the mountains. Some species of food plants are consumed for their medicinal benefits, and many others are frequently used in traditional phytotherapy to treat a variety of illnesses [13].

WFPs have historically served as the primary dietary components in rural communities and continue to be an essential component of the world diet today. In addition to being a vital component of the regional cultural heritage, wild plants are frequently used for their socioeconomic viability and environmental sustainability. To put it another way, their consumption and collection can provide cultural ecosystem services [13]. When evaluating the ecosystem services provided by wild food plants in a region, it is essential to understand the nutritional makeup of these plants. Enhanced attention has been paid, in recent decades, concerning the use of wild food plants and their products among rural communities on a sustainable basis. Many floristic inventories and nutritional profiling regarding the use of wild food plants have been produced in Europe, the Americas, Africa, and Asia [14].

A little research work has been conducted on the wild food system of Pakistan and hence the WFPs [15]. It is critical to investigate potential WFPs, the nutrient composition, and primary bioactive compounds of WFPs since they are regarded as a potential source of natural health products [16]. Uncovering the mountain ecosystem services provided by the WFPs of the Eastern Hindukush is one of the objectives of the current research. The well-established knowledge of WFPs has a potential impact on the agricultural system of marginal areas like Lotkuh where it is crucial to enhance food crops tolerant to extreme environmental conditions in the sensitive scenario of climate change. Here, it is noteworthy that the research’s conclusions can be crucial in achieving the 2030 Agenda for Sustainable Development of the United Nations. Understanding how to combine wild foods with other ingredients to improve diet can be achieved by becoming familiar with the nutritional profiles of the species in question. This study will highlight nutrient-dense wild plants that can become the focus of conservation efforts and propagation to satisfy the agenda of sustainable development goals in the escalating situation of food security.

2. Material and method

2.1. Geographical location of the study area

The Lotkuh region, which serves as the research area, occupies the northwest of Pakistan’s Khyber Pakhtunkhwa province. Geographically, the study area is stretched between 35° 47′ 52″ to 36° 29′ 10″ north latitudes and 71° 11′ 52″ to 71° 54′ 42″ east longitudes. The valley has a rugged landscape and is located next to the Wakhan Corridor. The majestic Eastern Hindukush’s vast biodiversity is reflected in the territory. The Terich Mir (7692 m a.s.l.) is the highest peak in the Hindu Kush range, and it is located on the eastern of the research area. Throughout the year, these huge mountain ranges are blanketed in perpetual snow and glaciers. The elevation of the study area ranges from 1600 m to 7000 m. The research area is subdivided into the three sub-valleys viz, Karim Abad, Arkari, and Garam Chashma [17]. The geographic location is further illustrated by Fig. 1.

Fig. 1.

Geographical map of the Lotkuh, Chitral, Khyber Pakhtunkhwa, Pakistan. [Source: Department of Geography, University of Peshawar, Pakistan].

2.2. Plant sample collection and identification

From the beginning of March through the end of December, a field survey was conducted. Various plant specimens were collected in the year 2021. For identification, the collected samples were dried and mounted on herbarium sheets. The specimens were identified by consulting the flora of Pakistan [18] and “the World Flora Online” (http://www.worldfloraonline.org/). The collected plants were assigned voucher specimen numbers and submitted to the Herbarium Department of Botany, University of Peshawar. The voucher specimen numbers provided to the plants are given in Table 1.

Table 1.

Scientific names, parts used, and use method of wild food plants of Lotkuh, Chitral, the Hindukush Pakistan.

Scientific Name	Voucher Specimen Number	Geographic Location	Families	Part Used	Preparation/Use
Berberis lyceum Royle	Ullah Bot. 100 (PUP)	N-35° 59′ 5″ E-71° 48′ 9″	Berberidaceae	Leaf	Eaten Directly
Cotoneaster nummularia Fish.	Ullah Bot. 101 (PUP)	N-35° 58′ 59″ E-71° 48′ 0″	Rosaceae	Fruit	Eaten Directly
Crataegus songarica K. Koch.	Ullah Bot. 102 (PUP)	N-36° 3′ 25″ E-71° 47′ 12″	Rosaceae	Fruit	Eaten Directly
Diospyros lotus L.	Ullah Bot. 103 (PUP)	N-36° 4′ 33″ E-71° 49′ 20″	Ebenaceae	Fruit	Eaten Directly
Elaeagnus angustifolia L.	Ullah Bot. 104 (PUP)	N-36° 5′ 36″ E-71° 50′ 15″	Elaeagnaceae	Fruit	Eaten Directly
Eremurus stenophyllus (Boiss. & Buhse) Baker	Ullah Bot. 105 (PUP)	N-36° 5′ 6″ E-71° 19′ 51″	Asphodelaceae	Leaf	Cooked as recipe
Ferulla narthex L.	Ullah Bot. 106 (PUP)	N-36° 4′ 52″ E-71° 20′ 36″	Apiaceae	Stem	Eaten Directly
Hippophae rhamnoides L.	Ullah Bot. 107 (PUP)	N-36° 5′ 6″ E-71° 19′ 51″	Elaeagnaceae	Fruit	Eaten Directly
Mentha longifolia L.	Ullah Bot. 108 (PUP)	N-35° 58′ 41″ E-71° 47′ 23″	Lamiaceae	Leaf	Cooked as recipe
Oxyria digyna L.	Ullah Bot. 109 (PUP)	N-36° 5′ 37″ E-71° 50′ 14″	Polygonaceae	Leaf	Cooked as recipe
Pinus gerardiana L.	Ullah Bot. 110 (PUP)	N-35° 58′ 41″ E-71° 47′ 23″	Pinaceae	Seed	Eaten Directly
Prunus prostrata Labill.	Ullah Bot. 111 (PUP)	N-35° 58′ 42″ E-71° 47′ 27″	Rosaceae	Fruit	Eaten Directly
Rheum webbianum Royle.	Ullah Bot. 112 (PUP)	N-35° 58′ 48″ E-71° 47′ 46″	Polygonaceae	Leaf	Eaten Directly
Rubus fruticosus L.	Ullah Bot. 113 (PUP)	N-35° 58′ 59″ E-71° 48′ 0″	Rosaceae	Fruit	Eaten Directly
Rumex hestatus L.	Ullah Bot. 114 (PUP)	N-35° 59′ 5″ E-71° 48′ 9″	Polygonaceae	Leaf	Cooked as recipe
Ziziphora clinopodiodes Lam.	Ullah Bot. 115 (PUP)	N-36° 3′ 19″ E-71° 47′ 2″	Lamiaceae	Whole plant	Cooked as recipe

2.3. Sample collection plan for nutritional analysis

Samples were collected according to the following procedure.

2.3.1. Collection sites

Specimens were collected from different regions of the study area. Individuals of a species were gathered from those regions where it was in abundance. Thus, different wild species were obtained from different parts and different locations of the study area. The geographic coordinates are provided for each species in Table 1.

2.3.2. Time of collection

Samples were collected based on the parts utilized. The parts were harvested throughout the year. The parts were collected when they were mature. The plant parts were collected keeping in view that all parts were enough mature to gain maximum nutritional value.

2.3.3. Quantity of collection

Depending on the plant parts used, different amounts were collected for various plants. The crude samples were gathered in textile bags, and it took 6 h for them to go to the dryer. 500 g of fresh biomass was collected for seeds, whereas 1000 g was taken for leaves, stems, and fruits.

2.4. Analytical sample preparation

From healthy individuals of the same species, the edible sections including leaves, stems, fruits, and seeds were collected. The edible parts obtained from the wild plant were dried in an oven (CARBOLITE GERO-301) at 70 °C for 48 h. The dried plant parts were ground using a Silver Crest electric grinder. The resulting powder was weighed for each sample using an analytical balance (ME204E) Mettler Toledo. The powdered material was then subjected to various nutritional analyses.

2.5. Replication of nutritional analysis

From the same homogenized samples, three different samples were obtained, and the process was repeated. Thus, three repeats served as the basis for the statistical analysis.

2.6. Proximate composition analysis

The estimation of proximate composition adhered to Ref. [19] standard protocols. For proximate analysis, the various edible portions of the WFPs were used. The following methods were used to investigate the various biochemical components of the edible parts.

2.6.1. Moisture content

The oven-dry method was used to get dry plant samples. The fresh biomasses of the samples were recorded first. The samples were subsequently dried for 24 h at 70 °C in an ISOTHERM® laboratory oven, and the dry biomass was quantified. The total water content of the material was computed using the equation given.

$$\mathrm{M}\mathrm{o}\mathrm{i}\mathrm{s}\mathrm{t}\mathrm{u}\mathrm{r}\mathrm{e}\%=\frac{\mathrm{F}\mathrm{r}\mathrm{e}\mathrm{s}\mathrm{h}\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{s}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}-\mathrm{D}\mathrm{r}\mathrm{y}\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{s}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}}{\mathrm{F}\mathrm{r}\mathrm{e}\mathrm{s}\mathrm{h}\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{s}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}}\times 100$$ (1)

2.6.2. Crude protein

With the use of Kjeldahl analysis, total nitrogen and hence protein quantity was investigated [19]. The percent nitrogen and crude protein was calculated as follows;

$$\mathrm{N}(\%)=\frac{\left(\mathrm{m}\mathrm{l}\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{a}\mathrm{r}\mathrm{d}\mathrm{a}\mathrm{c}\mathrm{i}\mathrm{d}-\mathrm{m}\mathrm{l}\mathrm{b}\mathrm{l}\mathrm{a}\mathrm{n}\mathrm{k}\right)\times \mathrm{N}\mathrm{o}\mathrm{f}\mathrm{a}\mathrm{c}\mathrm{i}\mathrm{d}\times 1.4007}{\mathrm{W}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{s}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}\mathrm{i}\mathrm{n}\mathrm{g}\mathrm{r}\mathrm{a}\mathrm{m}\mathrm{s}}$$ (2)

2.6.3. Crude lipid

To analyze the percentage of crude fat in the samples Soxtec® 8000 was used. The submersion method also called the gravimetric method was employed for the assessment of ether extract. This method is the most efficient and recommended method for the assessment of crude lipids of animal forage and feed [20]. In this method, the extraction of a non-polar moiety of the fats was carried out in three steps. The steps involved were immersion, washing, and drying [21]. The following formula was used to calculate the percent crude fat (lipid content) of the samples.

$$\mathrm{L}\mathrm{i}\mathrm{p}\mathrm{i}\mathrm{d}\%=\frac{\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{f}\mathrm{l}\mathrm{a}\mathrm{s}\mathrm{k}\mathrm{w}\mathrm{i}\mathrm{t}\mathrm{h}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{f}\mathrm{a}\mathrm{t}-\mathrm{E}\mathrm{m}\mathrm{p}\mathrm{t}\mathrm{y}\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{f}\mathrm{l}\mathrm{a}\mathrm{s}\mathrm{k}}{\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{f}\mathrm{l}\mathrm{a}\mathrm{s}\mathrm{k}\mathrm{w}\mathrm{i}\mathrm{t}\mathrm{h}\mathrm{f}\mathrm{a}\mathrm{t}}\times 100$$ (3)

2.6.4. Total carbohydrates

The methodology adopted by Ref. [22] was followed to calculate total carbohydrates using the given formula;

$$\mathrm{C}\mathrm{a}\mathrm{r}\mathrm{b}\mathrm{o}\mathrm{h}\mathrm{y}\mathrm{d}\mathrm{r}\mathrm{a}\mathrm{t}\mathrm{e}\mathrm{s}(\%)=100-\%\mathrm{A}\mathrm{s}\mathrm{h}+\%\mathrm{C}\mathrm{r}\mathrm{u}\mathrm{d}\mathrm{e}\mathrm{P}\mathrm{r}\mathrm{o}\mathrm{t}\mathrm{e}\mathrm{i}\mathrm{n}+\%\mathrm{E}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{r}\mathrm{E}\mathrm{x}\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{c}\mathrm{t}$$ (4)

2.6.5. Crude fibers

The percentage of crude fiber was determined by the protocol introduced by the [19]. In this method, the sample was digested in sulfuric acid for about 30 min. The sample was then allowed to react with NaOH. The insoluble fraction of the plant material was dried and weighed for further calculations.

$$\mathrm{C}\mathrm{r}\mathrm{u}\mathrm{d}\mathrm{e}\mathrm{F}\mathrm{i}\mathrm{b}\mathrm{e}\mathrm{r}(\%)=\frac{\mathrm{R}\mathrm{e}\mathrm{d}\mathrm{u}\mathrm{c}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{i}\mathrm{n}\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{a}\mathrm{f}\mathrm{t}\mathrm{e}\mathrm{r}\mathrm{i}\mathrm{g}\mathrm{n}\mathrm{i}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}}{\mathrm{W}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{s}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}}\times 100$$ (5)

2.6.6. Vitamin-C

The vitamin-C content of wild edible plants was determined using the HPLC-UV method following sample extraction with 4.5% phosphoric acid, as described by Ref. [23]. A liquid chromatograph (Micron Analytica, Madrid, Spain) with a Sphereclone ODS (2), 5 m Phenomenex column, isocratic pump (model PU-II), an AS-1555 automatic injector (Jasco, Japan), and a UV–visible detector (Thermo Separation Specta Series UV100) operating at 245 nm for AA and 215 nm for organic acids was used. Vitamin C was determined in milligrams per 100 g of dry weight.

2.7. Mineral analysis

The mineral content of the samples was determined using the wet digestion method with per-chloric acid as the solvent. The digested samples were filtered through glass filters and diluted to a final volume of 100 ml with distilled water. The samples were then subjected to Atomic Absorption Spectrometry (AAS) to get the mineral concentration of the samples [24]. The following formula was used to make the calculations.

$$\mathrm{M}\mathrm{i}\mathrm{n}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{l}\left(\frac{\mathrm{m}\mathrm{g}}{100\mathrm{g}}\right)=\frac{\left(\mathrm{A}\mathrm{A}\mathrm{S}\mathrm{r}\mathrm{e}\mathrm{s}\mathrm{u}\mathrm{l}\mathrm{t}\right)\times \mathrm{V}\mathrm{o}\mathrm{l}\mathrm{u}\mathrm{m}\mathrm{e}\mathrm{s}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}\times \mathrm{D}\mathrm{i}\mathrm{l}\mathrm{u}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{f}\mathrm{a}\mathrm{c}\mathrm{t}\mathrm{o}\mathrm{r}}{\mathrm{W}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{S}\mathrm{a}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}}$$ (6)

2.8. Statistical analysis

At the 0.05 level of probability, the statistical analyses were performed using Mstat-C GenStat software for ANOVA and LSD tests [25].

3. Result and discussion

3.1. Wild edible flora

According to the floristic analysis of edible wild plants, a total of 16 wild plants were used as food in the research region. The plants were distributed among 10 families. The families included Rosaceae, Berberidaceae, Elaeagnaceae, Asphodelaceae, Apiaceae, Lamiaceae, Polygonaceae, and Pinaceae as shown in (Table 1).

3.2. Limitations of the study

The investigation was carried out in the isolated, arduous, high-altitude Eastern Hindukush region. It was challenging to reach every portion of the study area due to the topography, which consists of high mountains and cliffs with tiny, tight pathways. Due to the distance of the collecting sites, specimen collection and storage were always difficult tasks that might affect the study. The nutritional status of the samples could slightly alter while they were being stored. Another tough task was maintaining edible plant tissues under specified conditions so that the real nutritional value is retained.

3.3. Proximate analysis

Table 2 shows the proximate composition of the WFPs. The findings on moisture, protein, lipid, carbohydrate, crude fiber, and vitamin C are discussed as under.

Table 2.

Proximate composition analysis of Wild Food Plants of Lotkuh, Chitral, the Hindukush region of Pakistan.

Scientific Name	Moisture	Protein	Lipids	Carbohydrate	Crude Fiber	Vitamin C
	g/100 g (FW)	g/100 g (DW)	g/100 g (DW)	g/100 g (DW)	g/100 g (DW)	mg/100 g (DW)
Berberis lyceum Royle	62.5 ± 0.25i	3.6 ± 0.05h	0.91 ± 0.02i	18.51 ± 0.55j	14.48 ± 0.15c	9.38 ± 0.37f
Cotoneaster nummularia Fish.	56.7 ± 0.55j	12.4 ± 0.01c	17.0 ± 0.01c	65.33 ± 0.35e	15.50 ± 0.02b	8.48 ± 0.21f
Crataegus songarica K.Koch.	87.9 ± 0.11b	13.5 ± 0.25bc	2.16 ± 0.50gh	87.50 ± 0.15a	4.50 ± 0.11h	6.66 ± 0.43g
Diospyros lotus L.	76.0 ± 0.25e	6.2 ± 0.02f	1.05 ± 0.01hi	65.66 ± 0.12de	6.50 ± 0.12f	4.35 ± 0.01h
Elaeagnus angustifolia L.	25.4 ± 0.25l	5.0 ± 0.18g	1.63 ± 0.14ghi	67.33 ± 1.18d	3.86 ± 0.20h	3.56 ± 0.21hi
Eremurus stenophyllus (Boiss. & Buhse) Baker	65.4 ± 0.05h	5.6 ± 0.02fg	2.56 ± 0.28fg	80.83 ± 0.20b	12.83 ± 0.25e	86.96 ± 0.12a
Ferula narthex L.	82.0 ± 0.25d	5.0 ± 0.05g	2.50 ± 0.01fg	70.50 ± 0.05c	5.46 ± 0.25g	5.66 ± 0.05g
Hippophae rhamnoides L.	87.0 ± 0.25bc	10.5 ± 0.02d	45.50 ± 0.01b	36.50 ± 0.02h	6.17 ± 0.25fg	46.66 ± 0.02b
Mentha longifolia L.	78.4 ± 0.37e	23.2 ± 0.05a	2.50 ± 0.01fg	46.16 ± 0.05f	19.50 ± 0.22a	90.63 ± 0.01a
Oxyria digyna L.	90.5 ± 0.95a	7.6 ± 0.82e	4.50 ± 0.75e	45.70 ± 1.05f	13.40 ± 0.20de	27.66 ± 0.15c
Pinus gerardiana Wall.	28.6 ± 0.02k	14.0 ± 0.45b	56.50 ± 0.01a	27.00 ± 0.05i	1.387 ± 0.01j	2.80 ± 0.21i
Prunus prostrata Labill.	81.0 ± 0.01d	2.5 ± 0.01h	1.10 ± 0.01hi	17.38 ± 1.05j	1.377 ± 0.02j	9.33 ± 0.11f
Rheum webbianum Royle.	91.5 ± 0.18a	7.6 ± 0.20e	5.76 ± 0.50c	37.05 ± 0.45h	13.83 ± 0.40cd	14.86 ± 0.12d
Rubus fruticosus L.	88.5 ± 0.01b	5.1 ± 0.01fg	2.38 ± 0.01fg	82.05 ± 0.01b	2.38 ± 0.40i	8.36 ± 0.23f
Rumex hestatus L.	85.5 ± 0.95c	9.7 ± 0.85d	3.50 ± 0.82ef	42.05 ± 1.05f	13.90 ± 0.20cd	12.93 ± 0.45e
Ziziphora clinopodiodes Lam.	70.6 ± 0.35g	12.7 ± 0.05c	2.16 ± 0.01gh	46.00 ± 0.05f	19.33 ± 0.22a	90.45 ± 0.01a
LSD (p ≤ 0.05)	1.54	1.16	1.23	1.72	0.86	1.10

¹Means with different superscript letters are significantly different.

²Part used: 1. Berberis lyceum = Leaf; 2. Cotoneaster nummularia = Fruit; 3. Crataegus songarica = Fruit; 4. Diospyros lotus = Fruit; 5. Elaeagnus angustifolia = Fruit; 6. Eremurus stenophyllus = Leaf; 7. Ferula narthex = Stem; 8. Hippophae rhamnoides = Fruit; 9. Mentha longifolia = Leaf; 10. Oxyria digyna = Leaf; 11. Pinus gerardiana = Seed; 12. Prunus prostrata = Fruit; 13. Rheum webbianum = Leaf; 14. Rubus fruticosus = Fruit; 15. Rumex = Leaf; 16. Ziziphora clinopodiodes = whole plant.

3.3.1. Moisture content

The moisture content was calculated following eq (1) with the results displayed in Table 2. With different plant species, the average moisture content exhibited substantial variation. The moisture level of these plants ranged from 25.4 to 91.5%. The highest moisture content (91.5 g/100 g FW) was found in Rheum webbianum, followed by Oxyria digyna (90.5 g/100 g FW), while Elaeagnus angustifolia contained (25.4 g/100 g FW) moisture. Plant tissue, species, and habitat all affect how moist a plant is. The moisture content of the studied plants is consistent with earlier studies on WFPs [[26], [27], [28], [29]]. The amount of water that plant tissues can hold is determined by their moisture content. Foods with relatively higher water contents are essential for many vital biological processes and keep the body away from dehydration [30]. Some of the WFPs used in this investigation have enough moisture to meet the water requirements of human tissues. On the moisture content of edible wild plants, other researchers' findings are more in line with our results [31]. Leafy cultivated vegetables, on the contrary, have shown slightly higher moisture content than wild allies [32].

3.3.2. Crude protein

Crude protein content was calculated based on eq (2). Mentha longifolia was discovered to have the highest protein content (23.2 g/100 g) of the WFPs. Pinus gerardiana has the next-highest level of protein (14.0 g/100 g). However, Berberis lyceum possessed the lowest (3.6 g/100 g) total protein. In general, most of the studied plants have a higher level of proteins above (3.6 g/100 g). In general principal plants with higher protein contents are preferred in the edible basket. In this study, Mentha longifolia and Pinus gerardiana were potent sources of protein. The amount of protein can differ depending on the species, the climate, the edaphology, and other environmental conditions. The wild plants in this study have shown more protein content than most of the earlier studies, indicating that wild plants of the Hindukush region are protein-rich [26,29,33]. Our results, however, are closer to the findings of [28,34]. It was discovered that the crude protein level of these wild species is higher than the crude protein content of the most important vegetables, such as lettuce, cabbage, spinach, and pepper.

3.3.3. Crude lipid

The lipid fraction was calculated following eq (3) for the WFPs is presented in Table 2. The highest lipid (56.50 g/100 g) was obtained from Pinus gerardiana followed by Hippophae rhamnoides (45.50 g/100 g) total lipid content. The lipid contents of the 6 plants in the group were significantly different from each other. A minimum lipid content (0.91 g/100 g) was observed in Berberis lyceum. The nuts of Pinus gerardiana are rich in lipid contents and were collected profoundly by the Hindukush inhabitants throughout history. Hippophae rhamnoides berries are a rich source of plant oil and are mostly collected in autumn and early winter. Lipid contents varied with plant and different parts of the plant. In our study 11 plant species had more than 2% of crude lipid with the highest reaching 56.50 g/100 g. In dietary analysis, the content of lipids keeps a pivotal role because lipids are a vital source of energy. Oil contents ranging from 6.12 to 67% have been reported in 32 species of oil-containing wild edible plants of the Himalayan region [35]. Comparably, a lipid content of 44.3% and more have been reported in seed kernels and berries of wild plants [36].

3.3.4. Total carbohydrates

Table 2 depicts the total carbohydrate contents of the WFPs calculated based on eq (4). Analysis of the carbohydrate fraction of the wild edible plants showed significant differences. The highest level of carbohydrate (87.50 g/100 g) was obtained in Crataegus songarica followed by Eremurus stenophyllus carrying (80.83 g/100 g) of total carbohydrate. Both species differ in the parts used. Fruits are the edible parts in the former while leaves are cooked to eat in the latter. The lowest value of carbohydrate (18.51 g/100 g) was detected in Berberis lyceum. The leaves of this plant are edible in all stages of growth. The values obtained suggested that most of the wild plants in this study have a sufficient carbohydrate proportion. Similar results have been shown by other investigators dealing with wild edible plants [37].

3.3.5. Crude fiber

Dietary fiber is a type of non-starch polysaccharide that is a member of the carbohydrate family. It cannot be digested in the small intestine but may be fermented into a form of short-chain fatty acid in the colon [38]. Dietary fibers have more important health implications starting from the usual indigestion issue to more complicated risks of cardiovascular diseases, cancer, and chronic diabetes mellitus [31,39]. Table 2 shows the crude fibers of the wild food plants calculate as per eq (5). A significant difference was seen among plants where the highest level of crude fiber (19.33 g/100 g) was seen in Ziziphora clinopodiodes while Cotoneaster nummularia is the next highest fiber (15.50 g/100 g) containing plant among all. Pinus gerardiana and Prunus prostrata contained (1.387 and 1.377 g/100 g) crude fiber contents respectively. The fiber contents of edible plants vary based on several factors such as type of plant, variety, growth stage, and seasonal and environmental factors [40].

3.3.6. Vitamin-C

The vitamin-C contents of the wild plant showed that Mentha longifolia, Eremurus stenophyllus, and Ziziphora clinopodiodes have the highest level of vitamin C, (90.63 mg/100 g, 86.96 mg/100 g, and 90.45 mg/100 g) respectively. The edible wild plants revealed a relatively higher level of vitamin C and could be used as a vital component of the diet, especially the rural families. According to earlier research, the intake of vitamin C for adults should be 95 mg/day for women and 110 mg/day for men. 150 g of the fresh wild plant can make an adequate contribution to the daily need for the vitamin [41].

The presence of a sufficient quantity of vitamin C in the Hindukush wild plants is quite encouraging that the inhabitants do not face the risk of low vitamin C in their food. It has been observed that l-ascorbic acid increases the uptake of iron in the intestine. The enhanced iron absorption in the intestine because of the ascorbic acid in nutrition resulted in raising the RDA of vitamin C from 45 to 60 mg. Vitamin C is needed for wound repair, the healing process, and collagen synthesis for healthy hair and skin [42].

3.4. Mineral analysis

An analysis of 5 minerals (Ca, Mg, Fe, Mn, Zn) was made for the 16 WFPs wild edible plants expressed as mg/100 g of the dry weight. The quantification of the minerals was made using eq (6) and the result is depicted in Table 2. The ANOVA revealed significant variation among the mineral contents of the plants.

3.4.1. Calcium (Ca)

The analysis showed that calcium was present in all wild edible plants. The maximum value (948.33 mg/100 g) of calcium was recorded in Oxyria digyna. The plant is utilized directly or cooked. The next higher level (878.33 mg/100 g) was seen in Cotoneaster nummularia. The minimum value (20.03 mg/100 g) was recorded in Diospyros lotus. The quantity of calcium ranged from (20.03 mg/100 g–948.33 g/100 g) which manifests that these plants are efficient sources of calcium. Significant variations in the calcium composition of these plants may be due to the differences in genus and species level, geographical variation, growth stage, soil, and weather conditions [43,44]. Previous studies related to wild plants have shown that the calcium content ranges from 27.0 mg to 75 mg/100 g [29,33,45]. The calcium content of wild plants in this study has shown a similar trend as the previous works mentioned above. The role of calcium is pivotal in the coagulation of blood, nerve impulse transmission, cell permeability, and disposal of cellular toxins. A high level of calcium in food is recommended during infancy, pregnancy, and lactation. The DRI (Dietary Reference Intake) value of calcium for adults is 1000 mg/day [46]. The study revealed that wild plants are a better source of calcium than some conventional vegetables.

3.4.2. Magnesium (Mg)

Based on species, it was observed that magnesium varied considerably. The contents of Mg for different plants are depicted in Table 2. The highest magnesium content was determined to be (994.00 mg/100 g) in Oxyria digyna, whereas the lowest potassium content was found to be (10.01 mg/100 g) in Diospyros lotus. The WFPs like Cotoneaster nummularia Mentha longifolia Oxyria digyna Prunus prostrata Ziziphora clinopodides carry Mg content of more than 200 mg/100 g which indicates that they have as much magnesium as or more than most typical commercial vegetables [32].

Magnesium is a part of multiple metabolic reactions in the body and is crucial in cardiovascular and nerve activities. Cellular metabolism like protein synthesis and other vital activities also needs the presence of an adequate quantity of magnesium. The DRI value recommended for magnesium is 310–420 mg/day for the adult group [33]. It is thus evident that most of the plants analyzed are promising to fulfill the daily requirement of magnesium for the boy.

3.4.3. Iron (Fe)

Berberis lyceum, Oxyria digyna, and Rheum webbianum had the highest iron concentration of all the plants studied, with (54.30 mg/100 g, 34.33 mg/100 g, and 26.04 mg/100 g), respectively. The iron content varied largely among the plants and a significant difference was observed (P ≤ 0.05). Six plants in the group showed relatively higher contents of iron, more than 10 mg/100 g. The iron fraction of the investigated plants was higher than most of the commercially grown vegetables [47]. A bunch of previous workers has shown iron contents of wild edible plants in the range of 4.3–119.1 mg/100 g [45], 0.17–4.88 mg/100 g [33], 18.33–48.86 mg/100 g [48], 2.51–55.62 mg/100 g [27].

Iron is a trace element and an essential part of hemoglobin to transport oxygen for the oxidation of carbohydrates, proteins, and fats. Millions of people in the world face the problem of anemia and other blood-related disorders because of a deficiency of iron [49]. The presence of an adequate amount of iron in the diet of nursing mothers is essential to fulfilling the iron needs of the feeding baby. The DRI (Dietary Reference Intake) value for females is 18 mg for women, 8 mg for men, and 27 mg for pregnant and nursing women [50]. From the study of these wild plants, it becomes evident that the inhabitants of Hindukush using these plants may not encounter iron deficiency in their food. The plants can thus be used to reduce the iron deficiency of most of the population in the countryside.

3.4.4. Manganese (Mn)

A large variation in the manganese content of different plants was seen. The sample contained Mn contents ranging from 0.23 mg/100 g-14.33 mg/100 g (Table 3). The highest Mn content was possessed by Berberis lyceum (14.33 mg/100 g) followed by Pinus gerardiana, and Elaeagnus angustifolia with Mn contents of 6.33 mg/100 g and 4.60 mg/100 g respectively. The plants showed a significant difference in the contents of Mn. A similar result in wild plants was obtained by Refs. [27,29,51]. However, the values of manganese obtained in this study are appreciably higher than that of some cultivated vegetables and wild edible plants (0.04–1.27 mg/100 g) reported by Ref. [33].

Table 3.

Mineral analysis of wild food plants of Lotkuh, Chitral, the Hindukush region of Pakistan.

Scientific Name	Mineral Composition (mg/100 g) Dry Weight
	Ca	Mg	Fe	Mn	Zn
Berberis lyceum Royle	192.47 ± 5.02g	12.40 ± 1.06°	54.30 ± 4.05a	14.33 ± 1.00a	3.53 ± 0.01d
Cotoneaster nummularia Fish.	878.33 ± 5.54b	373.67 ± 3.87b	16.40 ± 1.11e	3.53 ± 0.07d	1.02 ± 0.01f
Crataegus songarica K.Koch.	304.40 ± 10.01d	150.3 ± 2.25f	3.33 ± 0.51j	2.03 ± 0.05e	3.46 ± 0.07d
Diospyros lotus L.	20.03 ± 1.37m	10.01 ± 1.23p	2.33 ± 0.05k	0.63 ± 0.01fg	0.43 ± 0.01gh
Elaeagnus angustifolia L.	41.66 ± 0.15l	20.16 ± 1.05n	7.66 ± 0.01g	4.60 ± 0.03c	0.46 ± 0.01gh
Eremurus stenophyllus (Boiss. & Buhse) Baker	40.01 ± 0.37l	38.33 ± 0.01m	10.03 ± 1.27f	0.32 ± 0.02g	0.51 ± 0.03gh
Ferula narthex L.	72.42 ± 2.32k	54.67 ± 1.21l	4.06 ± 1.45i	0.51 ± 0.01fg	0.53 ± 0.02gh
Hippophae rhamnoides L.	81.33 ± 1.38j	62.03 ± 2.10k	6.03 ± 1.22h	0.91 ± 0.04f	0.66 ± 1.12fg
Mentha longifolia L.	257.33 ± 3.5e	240.33 ± 1.15e	2.22 ± 0.12k	0.41 ± 0.04g	0.51 ± 0.06gh
Oxyria digyna L.	948.33 ± 2.12a	994.00 ± 1.45a	34.33 ± 1.55b	3.26 ± 2.25d	10.30 ± 1.15b
Pinus gerardiana Wall.	18.03 ± 0.45m	130.55 ± 3.15h	4.34 ± 0.05i	6.33 ± 1.11b	4.16 ± 0.01c
Prunus prostrata Labill.	648.33 ± 2.15c	270.33 ± 1.15c	22.33 ± 1.05d	3.63 ± 0.15d	12.16 ± 1.35a
Rheum webbianum Royle.	119.33 ± 3.14i	98.45 ± 1.35j	26.04 ± 1.67c	0.30 ± 0.001g	3.70 ± 1.15b
Rubus fruticosus L.	180.50 ± 3.35g	144.00 ± 1.45g	6.03 ± 1.12h	0.23 ± 0.008g	2.00 ± 0.01e
Rumex hestatus L.	144.67 ± 1.75h	120.33 ± 2.02i	3.03 ± 1.10j	1.00 ± 0.12f	0.81 ± 0.05fg
Ziziphora clinopodiodes Lam.	241.33 ± 1.33f	250.33 ± 1.45d	3.06 ± 0.51j	0.72 ± 0.01fg	0.22 ± 0.01h
LSD (p ≤ 0.05)	1.72	1.21	0.50	0.49	0.41

*Means with different superscript letters are significantly different.

*Part used: 1. Berberis lyceum = Leaf; 2. Cotoneaster nummularia = Fruit; 3. Crataegus songarica = Fruit; 4. Diospyros lotus = Fruit; 5. Elaeagnus angustifolia = Fruit; 6. Eremurus stenophyllus = Leaf; 7. Ferula narthex = Stem; 8. Hippophae rhamnoides = Fruit; 9. Mentha longifolia = Leaf; 10. Oxyria digyna = Leaf; 11. Pinus gerardiana = Seed; 12. Prunus prostrata = Fruit; 13. Rheum webbianum = Leaf; 14. Rubus fruticosus = Fruit; 15. Rumex hestatus = Leaf; 16. Ziziphora clinopodiodes = whole plant.

Manganese is one of the microelements crucial for human health. It acts as the activator of many of the enzymes and performs a pivotal role in the production of energy and protection of the body by supporting the immune system. It also helps in blood clotting and blood sugar regulation [52,53]. Manganese DRI for adults is 2.3 mg for men and 1.8 mg for females. All these wild plants are good suppliers of this trace mineral.

3.4.5. Zinc (Zn)

The zinc contents of the wild plants are illustrated in Table 3. The three highest Zn-containing plants in the group are Prunus prostrata (12.16 mg/100 g), Oxyria digyna (10.30 mg/100 g), and Pinus gerardiana (4.16 mg/100 g) respectively. The lowest zinc content (0.22 mg/100 g) was recorded in Ziziphora clinopodiodes. The range of zinc contents for the wild group of plants in this experiment ranged between 0.22 and 12.16 mg/100 g. Zinc values in several wild edible plants ranged from 0.1 to 9.7 mg/100 g in earlier investigations [27,33,45] and 0.08–0.9 mg/100 g in some commercial vegetables [29].

Zinc is required for the synthesis of protein, genomic DNA metabolism, glucose metabolism, immune system function, disease recovery, and normal growth and development [54]. Growth failure, malnutrition, diarrhea, pneumonia, immunological impairment, increased child mortality, disrupted neurophysiological performance, and prenatal development anomalies are among the symptoms of its insufficiency [55]. Zinc insufficiency affects up to one-third of the world’s population. Zinc’s DRI value for adults is 11 mg for men and 8 mg for females [46]. Regular and enough consumption of these plants in the diet may help to prevent the negative effects of zinc deficiency, such as anemia.

4. Conclusions and recommendations

The effort necessary for a comprehensive analysis of a specific food plant is entirely justifiable. Researchers must have access to reliable empiric data for their examination if wild food plants are to be used to diversify diets during times of hunger and food insecurity. With the rising worldwide population, people are becoming more interested in adding wild plants to their meals, and the importance of dietary minerals in disease prevention is clear. When compared to most commercial veggies, most of the wild plants in this study were comparable and some of them were more nutrient-dense. Mentha longifolia, Pinus gerardiana followed by Hippophae rhamnoides had higher protein and lipid content. Crataegus songarica and Eremurus stenophyllus are rich in carbohydrates. Ziziphora clinopodiodes and Cotoneaster nummularia make the high crude fiber group. Mentha longifolia, Eremurus stenophyllus, and Ziziphora clinopodiodes have the highest level of vitamin C. Oxyria digyna and Cotoneaster nummularia can contribute to the supply of calcium while Oxyria digyna the potassium. Berberis lyceum, Oxyria digyna, and Rheum webbianum had the highest iron concentration. The highest Mn content was possessed by Berberis lyceum and Pinus gerardiana. Prunus prostrata, Oxyria digyna, and Pinus gerardiana are valuable sources of zinc. The WFPs studied in the current study have sufficient mineral nutrition to be included in the human diet. They are inexpensive and can be harvested seasonally. Finally, it is recommended to conserve, propagate, and sustainably use these plants. Future research should focus on the medicinal and pharmacological effects of these plants.

Declarations

Author contribution statement

HAFIZ ULLAH: Performed the experiments; Contributed reagents, materials, analysis tools or data; Wrote the paper.

Lal Badshah: Conceived and designed the experiments; Analyzed and interpreted the data.

Funding statement

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability statement

Data will be made available on request.

Declaration of interest’s statement

The authors declare no conflict of interest.