Fruits contain essential vitamins, minerals, bioactive compounds (including phenolics and carotenoids) and fiber, all of which are highly beneficial for health (Chang et al., 2016). However, fruits have a short shelf life and spoil very quickly. Fruit waste accounts for 64% of all food waste, while the FAO estimates that the waste or loss of fruits and vegetables within the food supply chain amounts to 45 to 55% of all fruits and vegetables produced globally (FAO, 2019). Making ‘fruit leather’ from fresh fruits is an effective method of preserving them, as the harvest season for freshest fruits is short and they tend to spoil quickly even when stored in a refrigerator.
       
Fruit leather is a dried, sweet edible product made from fruit, often consumed as a snack or dessert. It is sometimes also referred to as a ‘fruit bar’ or ‘fruit slab’ (Orrego et al., 2014). To make fruit leather, fruit puree is dried and shaped into a sheet that resembles leather in appearance. To remove the moisture from the wet puree, it is spread onto a large, flat tray and allowed to dry until the fruit puree (or fruit juice thickened by cooking with other ingredients) dries into a solid layer that looks like leather (da Silva Simão et al., 2020). Many different types of ‘fruit leather’ products are available in the market, including jackfruit, apricot, grape, berry, kiwi and mango leather. Additionally, fruit leathers made from fruit blends such as guava and papaya fruit leather are also available.
       
Moringa oleifera, commonly known as the “Miracle Tree,” is a renowned medicinal plant belonging to the Moringaceae family of the order Brassicales. It continues to be a focal point of special interest among scientists due to its nutritional benefits and therapeutic properties (Singh et al., 2024). Moringa oleifera leaves are recognized as a highly nutritious food source. On a dry matter basis, 100 g of M. oleifera leaves provides approximately 29±6 g protein, 28±6 mg iron, 1,924±288 mg calcium, 15,620±6,475 IU vitamin A and 773±91 mg vitamin C, highlighting their considerable nutritional value (Ansari et al., 2020). Numerous essential phytochemicals found in the leaves, pods and seeds of the Moringa plant make it extremely nutritious. According to reports, Moringa contains seven times more Vitamin C than oranges, ten times more Vitamin A than carrots, seventeen times more calcium than milk, nine times more protein than yogurt, fifteen times more potassium than bananas and twenty-five times more iron than spinach (Rockwood, 2013). In traditional medicine, malaria, typhoid, fever, parasitic infections, arthritis, inflammation, wounds, skin diseases, genitourinary disorders, high blood pressure and diabetes, all of these are treated using these leaves (Leone et al., 2015).
       
To meet the demand for dietary fiber consumption, the food industry frequently develops high-fiber products-such as those fortified with Fresh Moringa leaf pulp (FMLP). This fiber-rich pulp can improve the functioning of the digestive system; it may possess immune-regulating and anti-tumor properties; these properties can help lower glucose and insulin levels after a meal; it can assist in maintaining or reducing cholesterol and lipid levels; and it may protect against type 2 diabetes and heart disease (Ariani et al., 2023). Keeping the above points in mind, to prepare leather by incorporation of fresh moringa leaf pulp in the concentration of 5-25%, without addition of preservatives and sugars, in order to respond better to the current requirements of consumers. 

Preparation of Fresh moringa leaf pulp
 
The fresh moringa leaf (PKM-1) was collected from the department of horticulture of SHUATS, Prayagraj. To remove impurities, the leaves were washed with tap water, drained out water from the leaves. Fresh leaves were ground in an electric blender and screened through a sieve with 40 mesh size to prepare the fresh moringa leaf pulp.
 
Preparation of moringa leather
 
Fruit Leather was made following the method of Diamante et al. (2014) with some modifications. Different fruit leather formulations of fresh moringa leaf pulp with Mango Pulp (0, 5, 10, 15, 20 and 25 g/100 g) were developed. T₁ (control); T₂ (Leather consisting 5% (w/v) FMLP); T₃ (Leather consisting 10% (w/v) FMLP); T₄ (Leather consisting 15% (w/v) FMLP); T₅ (Leather consisting 20% (w/v) FMLP); T₆ (Leather consisting 25% (w/v) FMLP). The mango pulp alone was used to formulate leather and taken as a control sample. The ingredients of Leather formulation were Mango pulp (100 gm), sugar (15 gm/100 gm) and citric acid (0.3 gm/100 gm). In the case of mango fruit pulp preparation, mango was washed and peeled and then sliced into small pieces and prepared pulp using a superfine pulper. The mango pulp was then heated for 2-5 minutes at 80°C temperature and sugar, citric acid, different levels of fresh moringa leaf pulp (0%-25%) was added and cooked properly as per required consistency. The flow chart for manufacturing of moringa leather is shown in Fig 1. Coat the polythene paper with grease and spread the pulp on the paper and dry it in the cabinet drier at 40-45°C. Moringa leather was placed on a rack and allowed to cool at room temperature for 15 min to prevent moisture condensation on the leather from the surface and then packed in LDPE bags and kept at ambient temperature. Different combination of moringa leaves leather is shown in Fig 2.




 
Proximate and chemical analysis
 
The physicochemical parameters of moringa leather were analysed following the procedure stated by AOAC (2000) including moisture (method 925.09), total ash (method 923.03) and crude protein (Method 950.48, Nx6.25). Total sugar and reducing sugar were estimated by Fehling’s solution method as per Ranganna, (1986). The estimation of crude fibre was done using the ISO 5498:1981 method. Titratable acidity is measured using titration method and total soluble solids (TSS) using Hand Refractometer (Model RG701, Officine Galileo) following the procedure of Ranganna (1986).
 
Ascorbic acid
 
To determine the ascorbic acid content in leather, a spectrophotometric method utilizing a 2,6-dichloro phenolindophenol indicator solution was employed (Kurubas et al., 2019). A 2 g sample of Moringa leather was extracted for ascorbic acid by homogenizing it in 20 mL of a 6% meta-phosphoric acid solution and the sample was stored overnight at +4°C. The mixture was then centrifuged at 5000×g for 10 min and 2.5 mL of the supernatant was removed and placed in a centrifuge tube and add 2 and 5 ml of acetate buffer (pH 4.0), 1 mL of a freshly prepared 2,6-dichlorophenolindophenol solution (25 ppm) and 5 mL of xylene was added to the tube. Following agitation of the tube, phase separation was achieved via centrifugation (at 6000×g for 2 min). The absorbance of the upper layer was determined at 500 nm with respect to pure xylene. A calibration curve was created from ascorbic acid solutions in meta-phosphoric acid and used to quantify the ascorbic acid content of the samples, which were reported in mg/kg dm.
 
Total phenolic content
 
The determination of total phenolic content was performed in triplicate using the Folin-Ciocalteu method, as described by Wardhani et al., (2018). For the 10,000-ppm extract, the Moringa leather was homogenized in a water-ethanol mixture (1:1) using a Waring blender and soaked for 2 hours. An aliquot of 0.25 mL of the extract was mixed with 1.25 mL of distilled water, 0.25 mL of Folin-Ciocalteu reagent (Merck Supelco, 109,001) and 0.25 mL of ethanol and then incubated for 5 minutes; subsequently, 0.5 mL of Na₂CO₃ (Merck, 106,392) (5% in distilled water) was added and the mixture was incubated in the dark for one hour prior to measurement. A UV-Vis spectrophotometer (Supelco Spectroquant Prove 300, Darmstadt, Germany), operated at 725 nm, was used for the spectrophotometric analysis. Gallic acid (Merck, 842,649) at concentrations of 5, 10, 15, 20, 25, 50 and 100 ppm was used to construct a calibration curve. The unit of measurement for the total phenolics is milligrams of Gallic Acid Equivalent per gram (mg GAE/g).
 
Antioxidant activity
 
The DPPH radical scavenging activity of the samples was evaluated using the technique described by Tontul and Topuz (2017). To do this, 950 µL of a freshly prepared DPPH solution (60 µM in methanol) was mixed with 50 µL of diluted extract. After incubation for 30 min at room temperature, the absorbance of the mixture was measured at 516 nm.
 
Color parameters
 
Color parameters (L*, a*, b*) were measured using a Hunter Lab Mini Scan XE Plus colorimeter (Model 45/0-L, HAL, USA) equipped with a 25 mm port (Goswami et al., 2015). The instrument was calibrated using standard white and black ceramic tiles. Under D65 illuminant and a 10° viewing angle, L* values represented lightness (0 = black, 100 = white), a* values indicated red/green chromaticity (+a*= red, -a* = green) and b* values indicated yellow/blue chromaticity (+b* = yellow, -b* = blue).
 
Sensory analysis
 
A sensory analysis of moringa leathers was conducted according to Ganga et al., (2019) with slight modifications. Ten semi-trained panelists (25-50 years old) evaluated duplicate samples labeled with random 3-digit codes. Attributes assessed were color, texture, flavor and overall acceptability, rated on a 9-point hedonic scale where 1 represented “dislike extremely” and 9 represented “like extremely”.
 
Data analysis
 
The experiments were performed in triplicate. The data were subjected to analysis of variance and Duncan’s multiple-range test was applied to separate means using IBM SPSS (version 25.0).

Sensory analysis
 
The sensory characteristics of moringa enriched fruit leather varied significantly (p<0.05) as shown in Table 1. Thus, the amount of moringa enrichment has a significant influence on the acceptability of the product. Compared to other treatments, T₃ significantly showed higher color (7.50±0.12), texture (7.40±0.41), flavour (7.40±1.03) and overall acceptability (7.43±1.10). This indicates that moderate levels of FMLP improve sensory quality, perhaps as a result of greater colour uniformity and the emergence of a mild herbal flavour profile. Lower sensory scores for the control sample (T₁) showed that the addition of FMLP at the proper level would enhance the sensory appeal. Fruit leather and other food systems have reported similar improvements at low inclusion levels, where FMLP positively affected the sensory properties up to an optimum inclusion level (Habsari et al., 2026). The increase seen in T₂ and T₃ is similar to previous studies that have shown low to moderate levels of FMLP will improve acceptability without compromising taste and/or texture. A decreasing trend of sensory scores was however observed beyond the optimum level (T₃). The scores for treatments T₄, T₅ and T₆ were significantly lower and lowest for treatment T₆ (4.67±1.03). This reduction is due to the enhanced green colour, fibrous mouthfeel and typical bitter and astringent flavour of FMLP. Previous studies have also found that the optimal moringa powder inclusion was in the range of 2-10%, but that this had a negative effect on the sensory quality of the final product when it exceeded this range (Bourekoua et al., 2018). Such effects have been well reported in moringa-food products, such as bakery products, biscuits and crackers, where an increase in incorporation leads to an adverse sensory perception because of the inherent taste and texture changes (Cervera-Chiner et al., 2024).


 
Proximate and chemical analysis
 
The physicochemical properties of fruit leather in all the treatments (T₁ to T₆) were significantly (p≤0.05) affected by the incorporation of FMLP as shown in Table 2. As the FMLP increased, there was a progressive increase in moisture content, ranging from 17.72% to 20.10%. This trend is due to the presence of dietary fibre in FMLP, which has a high-water binding capacity, thus retaining the moisture in the product matrix (Alam et al., 2024). T₃ was found to have moderate moisture (18.93%) which is desirable for the flexibility and chewiness of a good shelf stable product. The ash content showed a significant rise from 0.31% (T₁) to 2.90% (T₆), which suggested that the mineral enrichment was increased after the incorporation of FMLP. Moringa leaves have been documented to be rich in essential minerals which can help to improve the ash content of fortified products. The same trend of increasing ash content as the addition of FMLP has been reported in fruit leather studies (Thiruvengadam et al., 2020). The minerals composition of T₃ was balanced with a smaller amount of ash (1.54%) than in the others, indicating good mineral composition but not much fortification. The protein content also showed a significant increase with increasing moringa concentration (0.76-4.23%), which was a prime reason for its consideration as protein rich functional ingredient. According to Zaku et al. (2015), moringa leaves are abundant in Protein, calcium, potassium and vitamin C are abundant. In reality, moringa contain 10 times the vitamin A present in carrots, 17 times the calcium available in milk, 9 times the protein found in yogurt, 15 times the potassium present in bananas and 25 times the iron contained in spinach (Rockwood, 2013). However, high incorporation (T₅-T₆) could have adverse effects on sensory characteristics despite high nutritional values. The protein content in T₃ was moderate (2.92%), which was the optimal level of nutritional enhancement in accordance to product acceptability. On the other hand, the total sugars and reducing sugars showed a significant decrease as the FMLP increased. The drop could be attributed to the dilution effect of the introduction of moringa fibre and protein that is non-sugar. The key role of sugar content in producing fruit leather is evident in its impact on taste, texture and consumer acceptance, as it directly relates to sweetness and mouthfeel (de Menezes Rodrigues et al., 2023). T₃ had higher sugar levels which resulted in maintaining the desirable sweetness and palatability. The incorporation of moringa did significantly increase the crude fibre content, ranging from 0.83 to 4.29%, thus confirming its functional food potential. However, higher levels of fibre can have a negative impact on the texture of the product, creating a dense or coarse texture, while providing the nutritional benefits. Also observed in recent studies, fibre content was increased in moringa fortified products (Oyeyinka and Oyeyinka, 2018). The fibre content in T₃ was moderate (1.89 %), which will be beneficial for health, but won’t have adverse effects on the texture. As the FMLP increased, the acidity showed decreasing trend which may be because of the dilution of organic acids in the fruit pulp. The results of T₃ showed that it had a balanced acidity of 2.63%, which is essential to ensure the stability of the flavor, safety from the microorganisms and acceptability. As a result of the increasing moringa concentration there was a significant decrease in total soluble solids (TSS) which indicated the reduction of sugar concentration and soluble constituents. T₃ had moderate TSS (72.61°Brix), which is desirable in terms of concentration and palatability.


 
Ascorbic acid, Total phenolic content and Antioxidant activity
 
The ascorbic acid, total phenolic content and antioxidant activity were increased significantly (p≤0.05) from T₁ to T₆ as shown in Table 3. Ascorbic acid increased from 21.91 to 63.39 mg/100 g, while phenolic content rose from 7.63 to 36.70 mg/100 g. Similarly, the antioxidant activity was increased from 132.16 μmol TE/g to 416.96 μmol TE/g showing a significant positive correlation between bioactive compounds and antioxidant activity. The higher values of T₆ are indicative of the significant improvement in functional quality of the product with an increase in fortification level. The increase of antioxidant activity may be due to synergistic action of phenolic compounds and ascorbic acid as free radical scavengers. The same has been reported for those other cases in which incorporation of plant-based ingredients has significantly increased the phenolic content and antioxidant potential (Singleton et al., 1999; Prior et al., 2005). In addition, ascorbic acid content is directly related to the oxidative stability and nutritional value (Davey et al., 2000).


 
Color parameters
 
The Color parameters of moringa enriched fruit leather varied significantly (p<0.05) as shown in Table 4. The L* value was found to diminish significantly (p≤0.05) from T₁ to T₆, this value is a measure of lightness and the value decreased from 34.71 to 5.41, where a* (redness) and b* (yellowness) values also decreased significantly from T₁ to T₆, these values are a measure of the color parameters. This decrease could be due to chlorophyll pigments and non-enzymatic browning reactions during processing. Darker color at higher treatment levels is in line with the results obtained by Pathare et al. (2013) which indicated that plant pulp rich in pigments had significant brightness and chromaticity reduction. Furthermore, reactions of oxidation and polymerization can be responsible for color loss of phenolic compounds (Maskan, 2001).

The present study revealed that mango leather incorporated with fresh moringa leaf pulp (FMLP) showed significant improvement in the nutritional and functional quality of mango leather. The findings of progressive rise of all the parameters, such as protein, ash, fibre, ascorbic acid, total phenolics and antioxidant activity substantiated the potential of FMLP as a valuable nutraceutical ingredient. But increased levels of incorporation had a negative impact on sensory qualities and color parameters because of the increased green pigmentation, fibrous texture and characteristic bitterness effect. Treatments, T₃ (10% FMLP) was found to be the best, having the least objectionable sensory characteristics and the highest nutritional enhancement. It gave better bioactive properties, while preserving the quality of the product. Thus, the moringa enriched fruit leather could be formulated as a functional food having a higher nutritional value and reasonable amount of moringa is suggested for commercial production of this product.

None.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.