SJA_42_1_339-355

Introduction

Pakistan, a country with multiple agro-climatic environments (tropical to temperate), is an important agricultural hub, producing more than 144 species of fruit plants (Khokhar and Bajwa, 2014, Khan and Shaukat, 2006). Among these delicious fruits, persimmon (Diospyros kaki), a highly appraised fruit crop that is mostly grown in the temperate areas particularly in Swat, Dir, and Shangla districts of Khyber Pakhtunkhwa (KP) province. Where, its production plays a key role in the economy of the region, providing income and employment for small scale farmers in addition to its significant contribution to local fruit industry. The fruit is liked for its vibrant colors (light yellow-orange to dark orange-red), different shapes and varying weights ranging from 30 grams to over 450 grams (Woolf and Ben-Arie, 2011). Persimmon is considered as a nutritional powerhouse, containing glucose, fructose, sucrose, and variety of provitamin A. Furthermore, the fruit also contains a significant portion of vitamin C and different minerals necessary for human nutrition such as calcium, magnesium, potassium, and iron. Moreover, it also contains low levels of fats and proteins (Yaqub et al., 2016; MAPAMA, 2016; Baltacioglu and Artik, 2013). The high phenolic content in persimmon fruit specially tannins are responsible for its antioxidant properties. As a result, it consumption greatly reduce risk of different diseases such as diabetes, cardiovascular diseases, hypertension and different forms of cancer. The fruit also aid in alcohol metabolism and prevention of atherosclerosis (George and Redpath, 2008; Zhang et al., 2016).

The persimmon fruit is produced in abundance in Pakistan, however, the country faces different challenges due to high perishability and limited shelf-life which significantly limit commercial returns for persimmon growers. In Khyber Pakhtunkhwa, Hachiya and Fuyu varieties dominate the markets in the harvesting season. The glut of these persimmon varieties in the market generally leads to losses due to limited processing, inadequate transportation and storage, improper astringency management, short shelflife and preservation knowledge (Ahmad et al., 2021; MNSFR, 2016). Moreover, the temperate to subtropical climate of KP region differs from other major persimmon-growing areas, where humidity, temperature and altitude may uniquely influence fruit ripening, respiration and storage (Bhande et al., 2008). Globally, the production of persimmon has increased from 4.42 million tonnes in 2020 to 5.06 million tonnes in 2023. Asia is on the top, contributing more than 96 % of the share. Pakistan stands in the 10th position in the list of major producers, where, persimmon is grown in an area of 3,147 hectares, yielding more than 26,760 tonnes (FAO, 2024; MNSFR, 2016). Although, the lack of effective and efficient postharvest processing of persimmon, especially for astringent cultivars, hinders proper marketability of the fruit.

The astringency present in persimmon, caused by soluble condensed tannins is the most critical factor that negatively affects commercial acceptability (Das and Eun, 2021). Persimmons are classified into astringent and non-astringent varieties. The astringent persimmons are classified as pollination-constant or pollination-variant varieties, that remain uneatable until the fruit is fully ripened or treated to remove astringency. On the other hand, non-astringent types naturally lose astringency during development (Zhao et al., 2025; Sugiura, 2005). The tannins present in persimmon interact with salivary proteins causing astringency rendering the fruit unpalatable (Jia et al., 2024). This issue makes de-astringency treatment as the critical postharvest treatment to make the fruits palatable. These de-astringency treatments include Carbon dioxide (CO2), modified atmosphere, warm water, ethanol, and nitrogen (N2) treatment (Ding et al., 2025; Han et al., 2022a; Chang et al., 2017; Novillo et al., 2014; Bibi et al., 2007). Among these treatments, CO2 is mostly used for its efficacy and efficiency, however, this treatment induces rapid softening, affecting shelflife and texture. This treatment also increases oxidative stress due to the accumulation of reactive oxygen species (Wang et al., 2021; Chung et al., 2014). Warm water and ethanol treatments are also affective but require prolonged durations and may alter flavor profiles (Ozdemir et al., 2020; Testoni, 2002). As compared to these treatments, nitrogen treatment is more promising and rapidly reduces soluble tannins with no or minimal impact on fruit firmness and sensory characteristics. These benefits of N2 makes it more suitable for fresh as well as dried persimmon products (Ben-Arie and Sonego, 1991).

The current study, therefore, aims to reduce postharvest losses of persimmon by analyzing the efficacy of N2 de-astringency treatment, observing its effects on the physicochemical and organoleptic characteristics of five persimmon cultivars grown in Khyber Pakhtunkhwa, Pakistan. The experimental objectives of this study are: (1) to analyze the efficacy of N2 de-astringency treatment in decreasing soluble tannins in the five selected persimmon cultivars and (2) to evaluate the physicochemical characteristics of N2-treated and untreated persimmons in relation to their organoleptic attributes.

Materials and Methods

Raw materials

Persimmon cultivars namely Fuyu, Hachiya, Great Wall, Maru and Rojo Brillante were harvested before commercial maturity stage (colour-break stage)-fruits showing pale green to yellow color during the months of September, from different farms in district Swat Pakistan. About 70% of the fruit surface had yellow coloration and ripening was initiated. The Fuyu variety belongs to pollination constant, non-astringent group and Maru variety to pollination variant, non-astringent group. Similarly, Rojo brilliante and Hachiya varieties are from pollination constant, astringent group. The Great Wall variety is from pollination variant, astringent group. On the same day the persimmons were transported to the Nuclear Institute for Food and Agriculture Peshawar, where fruits were graded according to size and color. A total of hundred 100 kilograms, from fifteen different trees of each variety was harvested and used for the experiment. External color of the fruit was used as maturity index. Healthy and uniform sized fruits were used for the experiments. In order to reduce the variability of the results, the fruits were selected of same maturity and color for higher homogeneity.

De-astringency treatment

The persimmons were washed with tap water and air-dried. All the fruit varieties were randomly divided into two equal lots. One part of each variety was subjected to a modified atmosphere condition of 99.99 % nitrogen in a specially designed sealed container for 96 hours at 30 oC. Persimmon fruits were placed on single layer trays. First vacuum was created through pressure pump and then vacuum was filled by passing an air stream of 99.99 % nitrogen into the chamber made of stainless steel. The other part of each variety was kept as untreated or control and subjected to above condition without nitrogen. Both of the groups were then stored at 5 oC and 85 % relative humidity for 6 days until analyzed.

Physicochemical analyses

Linear dimensions

The linear dimensions of fresh fruit (length (L)/Y-axis and width (W)/X-axis) were measured according to the method of Neupane et al. (2023). The length and width were measured with a digital Vernier caliper and expressed in millimeter. Readings were taken three times from same position to reduce sampling error

Fruit volume and mass

Liquid displacement method was used for determining volume of the fruit. Persimmons were placed in a beaker containing known volume of toluene. The increase in volume of toluene after adding the fruit was used to determine volume and expressed in cubic centimeter (Desai et al., 2019). Fruits from each sample was taken and mass was measured using digital balance having sensitivity of 0.0001g and expressed in gram (Ahmad et al., 2023).

Fruit density and moisture content

The fruit density was calculated by dividing fruit mass and volume. The moisture content (%) was determined according to the method of Famuyin et al. (2020). The samples were first weighed and the dried at 105 oC in an oven for 12 hours and the final moisture content was calculated using given formula.

Water activity and firmness

Water activity of persimmon samples was determined at 25 oC using a water activity meter (Novasina, swift, Switzerland) following the standard method of Dhake et al. (2023). The meter was calibrated with saline solution before measurement of fruit water activity. The Firmness of samples from each treatment was determined using force measurement IMADA Texture analyzer (FRTs2017O2e) using a 10 mm flat plunger and expressed in Newton. Epicarp (0.6 mm thick) was removed in the equatorial region at two equidistant locations before determination of firmness (Famuyin et al., 2020).

Fruit pH and titratable acidity

The persimmon samples were sliced and blended. The juice was homogenized and then centrifuged. The supernatant was used for the analysis of the pH. Titratable acidity as mg equivalent organic acid per 100 g sample was calculated by the titration method of Zhang et al., (2020).

Total soluble solids and sugar/acid ratio

The total soluble solids were measured using a digital hand refractometer (model PR1, Atago, Tokyo, Japan) with a working range of 0-32 at room temperature (Zhang et al., 2020) and expressed in %, while sugar/acid ratio was calculated using predetermined values of TSS and TA following the given formula.

Reducing and non-reducing sugars

The reducing sugar was determined using 3,5-dinitro salicylic acid (DNSA), in which glucose reduced the DNSA reagent into a reddish color. The color intensity was measured at 540 nm by spectrophotometer (Li and McKee, 2023). The non-reducing sugar was calculated by subtracting the amount of reducing sugar from the amount of total sugar and expressed in %.

Vitamin C and total phenol content

Vitamin C in the persimmon varieties was determined by the dye titration method (AOAC, 2016). Through this method, sample extracts in oxalic acid were titrated against standard 2,6–dichlorophenolindophenol dye to pink color which persisted for 5 to 10 seconds as the end point for measuring the ascorbic acid and expressed in mg per 100 g. The following formula was used for calculation.

Total phenols content of persimmon was determined using the method reported earlier (Ayoub et al., 2022) and a standard curve was prepared using gallic acid (0–200 mg/L) and the results were expressed as mg GAE/100 g fresh weight basis.

Minerals content

The determination of minerals and trace elements Minerals (Na, K, Mg and Ca) and trace elements (Fe, Zn and Mn) was carried out as follows. The samples were lyophilized, then 0.8g of lyophilized samples was mineralized in microwave oven for 15 min with 5ml of concentrated HNO3 according to Jurkiewicz et al. (2004) with slight modifications. The concentrations of all above-mentioned eight elements were estimated by a Perkin-Elmer 5100 ZL atomic absorption spectrometer (Perkin-Elmer Ltd., Beaconsfield, Buckinghamshire, England), using the flame method for Na, K, Mg, Ca, Fe, P, Zn and the flameless method for Mn and reported as mg per 100 g.

Sensory analyses

All samples were evaluated organoleptically for color, texture, flavor, appearance, astringency and overall acceptability by using 9-points Hedonic scale (1 was for extremely dislike, 9 was for extremely like) of Larmond (1977). The sensory test was conducted through a panel of 15 members aged 25-45 years, fully familiar with fruit quality assessment. Samples were presented to the panelists on plates labelled with 2-digit codes at room temperature (30 ± 1 oC) under normal laboratory light conditions. The judges could assess any sample group up to two or three times if needed. The Milk was provided for palate rinsing between samples. The panelists received orientation about the study.

Statistical analyses

The data represented as means of three replicates (n = 3) were analyzed using a completely randomized design (CRD) with least significant difference (LSD) test at P ≤ 0.05.

Results and Discussion

Linear dimensions of persimmon fruit

The final results of the statistical analysis show significant (P < 0.05) varietal dissimilarities in the length and width of the five persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, and Rojo Brillante), while the N2 de-astringency treatment had minor to no effect on these parameters. Hachiya variety showed the highest length at 62.4 mm, followed by Rojo Brillante variety at 56.03 mm, showing a significant difference in length between the two and the other varieties (Fuyu, Great Wall, and Maru,), that ranged from 45.1 to 47.7 mm (Figure 1A). This noticeable variation indicates that genetic factors intrinsic to each variety substantially impact persimmon length, with Hachiya variety being distinctly different in producing longer persimmon fruit. The analogy in length among Fuyu, Hachiya, and Rojo Brillante varieties further endorse the presence of variety specific characteristics that control persimmon morphology, possibly associated with genetic regulation of cell division or elongation during fruit development.

The non-significant alterations were observed in the length of persimmon varieties following N2 de-astringency treatment. Limited increase in the length of Fuyu, Hachiya, Maru, and Rojo Brillante varieties, and a decrease in Great Wall show that N2 de-astringency treatment does not significantly change the genetic tendency of these persimmon varieties for length. This absence of impact may show that the N2 de-astringency treatment, does not interact substantially with the physiological pathways controlling persimmon elongation in the mentioned varieties. Instead, the N2 treatment effect may be trivial to detect under the laboratory conditions. Regarding width, the substantial variation observed between the two groups of persimmon varieties (Fuyu, Hachiya, Rojo Brillante vs. Great Wall, Maru) identifies another dimension of the effect of variety on persimmon morphology. However, the non-significant differences within the mentioned groups shows that fruit width may be invariable within certain varietal groups, possibly as a result of shared and similar genetic or developmental conditions (De Mori and Cipriani, 2023; Okello et al., 2015a). Non-significant changes in width of the persimmon varieties after N2 de-astringency treatment aligns with the results for length, further supporting the conclusion that the N2 treatment has too slight effect on the linear dimensions (Figure 1B).

Overall, these results reinforce the significant role of variety on the linear dimensions, with Hachiya variety as the most elongated persimmon variety. The minimal impact of N2 de-astringency treatment shows that other factors such as genetic makeup and other environmental conditions affect size in the persimmon varieties. Similar differences in persimmon size was observed when 153 cultivars were studied by Maeda et al. (2018). These results also align with the findings of studies conducted on Camellia oleifera fruit, and Mango (Gao et al., 2022; Ahmed and Mohammed, 2015). Furthermore, Combrink et al. (2013) also reported that size of citrus fruits is dependent on genetic makeup of the fruit.

Fruit volume and mass

The findings of current study offer critical insights in to the impacts of N2 de-astringency treatment on the mass and volume of persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, Rojo Brillante), along with the intrinsic differences amongst the persimmon varieties (Figure 1C and 1D). The outcomes of statistical analysis show that N2 de-astringency treatment did not significantly impact either the volume or mass of the persimmon varieties, showing that N2 de-astringency treatment may not have affected biochemical and physiological processes with the potential to change these physical attributes. The absence of substantial effect could be ascribed to different factors such as nature of the N2 de-astringency treatment, duration of application, or the physiological responses of the persimmon varieties to the N2 treatment. Moreover, N2 is a gas and the amount diffused into the persimmon is not sufficient to significantly change the mentioned parameters.

On the other hand, the significant variation noted amongst the persimmon varieties in both volume and mass emphasize the effect of genetic and other varietal characteristics on the persimmon traits. Hachiya variety represented the greatest average volume of 190.65 cm3 (Figure 1C), followed by Rojo Brillante and Fuyu varieties (165.8 and 159.2 cm3 respectively), however, the differences amongst these three persimmon varieties were statistically non-significant. This shows that Hachiya variety produces longer fruits but the magnitude of variation compared to Rojo Brillante and Fuyu is not greater enough for statistical significance. Similarly, Great Wall variety showed the lowest volume of 78.8 cm3, non-significantly lower than Maru variety (85.4 cm3), specifying that these two persimmon varieties might share similar physical attributes compared to the other mentioned varieties. The similar non-significant trend noted in volume and mass further strengthens the fact that these characteristics are closely related and may be affected by common genetic and developmental factors.

The significant difference amongst persimmon varieties might be due to the differences in their genes, that controls persimmon growth patterns and development (De Mori and Cipriani, 2023; Okello et al., 2015a). For instance, Hachiya variety greater volume and mass may arise from more rapid cell division and expansion during development of the fruit. This can be possibly linked to special genetic markers and hormonal regulation (Liu et al., 2020). Previous researches conducted on fruit development have showed that differences in the size and weight of varieties are often linked to differential expression of genes that controls expansion of cell wall and accumulation of sugar (Wai et al., 2017; Houston et al., 2016). Furthermore, treatments of fruits during specific stages of development, may have varying effect on volume and mass (Okello et al., 2015b). The similarity in volume and mass across persimmon varieties further signify the interdependence of the mentioned characteristics and are likely affected by same physiological processes. The non-significant variation observed between certain persimmon varieties show that during development these varieties might have shared same resource allocation and growth patterns (Bennett et al., 2012).

Fruit density and moisture content

The density and moisture content of five persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, Rojo Brillante) was analyzed across two groups: untreated and nitrogen treated. After statistical analysis it was observed that variety showed significant effect on density and moisture content while N2 treatment significantly reduced density of Hachiya and increased that of Rojo Brillante variety while it did not show significant effect in case of other varieties. However, N2 de-astringency treatment showed slight and non-significant effect on moisture content of all five persimmon varieties (Figure 2A). The Rojo Brillante variety showed the highest average density of 1.00 g/cm3, followed by Maru and Hachiya while Fuyu showed the lowest density of 0.96 g/cm3. Similarly, Fuyu variety showed the highest average moisture content of 77.13 % followed by Hachiya and Great Wall, while, Rojo Brillante showed minimum moisture content of 72.24 % (Figure 2B).

The findings of this study made it clear that both variety and N2 de-astringency treatment affected density and moisture content of persimmon. The significant difference amongst persimmon varieties specify the key role of genetics in density and moisture content. Previously, a study on persimmon varieties showed significant difference in moisture content ranging from 78 to 83 % among the selected varieties (Baltacioğlu and Artik, 2013). Furthermore, the differences in varieties may arise from differences in structure and composition of the cells (Lara et al., 2019). N2 de-astringency treatment influence on density was specific to each variety. The density of Hachiya variety is significantly reduced, likely due to softening of tissues and enhanced in Rojo Brillante variety, possible due to loss of moisture leading to compaction (Pradhan et al., 2009). The non-significant effect of the N2 de-astringency treatment was observed in Fuyu, Great Wall, and Maru varieties, indicating that response of some varieties may be same but not all varieties respond to the same treatment alike. Similarly, in all persimmon varieties slight but non-significant difference was observed implying minimal impact of N2 de-astringency treatment on water conservation. Previously, Harker et al. (2000) reported in no change in density of strawberry fruit after CO2 gas treatment. Fuyu variety showed the highest moisture while Rojo Brillante showed the lowest, indicating an inverse relationship between moisture content and density of persimmon fruit (Pradhan et al., 2009). Finally, these results and findings signify the critical role of proper variety selection in postharvest treatment programs. Because, the changes occurring in fruit system, after applying postharvest treatments, depend on its intrinsic attributes.

Water activity and firmness

The water activity and firmness of five persimmon varieties were analyzed across two groups: untreated and nitrogen treated. Statistical analyses of the data confirmed that varieties have no effect on average water activity (Figure 2C). However, N2 de-astringency treatment significantly reduced water activity of all five varieties. Average water activity in untreated Fuyu variety was 0.985 that decreased to 0.97 in N2 treated samples. In contrast to the water activity, N2 de-astringency treatment significantly improved firmness of all five varieties. Similarly, the effect of varieties was also significant in the case of firmness (Figure 2D). Maru variety had the highest average firmness of 52.68 N but not significantly different from Great Wall (52.00 N). Fuyu and Hachiya has similar firmness but significantly lower than former discussed varieties. Rojo Brillante showed the lowest firmness amongst all persimmon varieties.

These discussed results show that the persimmon varieties did not substantially impact water activity, however, the effect was significant in the case of firmness. This suggests a more important role of differences among persimmon varieties on textural properties than on moisture conservation (Borrás, 2015). All N2 treated varieties show reduction in water activity indicating efficacy of the treatment in stability of moisture content. This may be due to outflow of moisture and inflow of N2 from surrounding as reported by (Maltini et al., 2003). Similarly, firmness also increased as a result of N2 treatment, indicating the role of treatment in texture of the persimmon fruit. Among the persimmon varieties, Maru and Great Wall showed the highest firmness while Rojo Brillante showed the lowest. The higher firmness in Maru and Great Wall can be attributed to their greater cell wall integrity and lower moisture composition (Su et al., 2022). As de-astringency treatments have been reported to reduce firmness of fruits (Zhao et al., 2025). The closer firmness of Fuyu and Hachiya varieties, yet their difference from Great Wall and Maru, signify varietal-specific responses to N2 de-astringency treatment. The increased in firmness show that N2 treatment maintains structure of the cell wall and delayed enzymatic degradation leading to extended shelf life during storage (Zhao et al., 2019).

Fruit pH and titratable acidity

The findings of the statistical analyses on pH and titratable acidity across untreated and N2 treated five persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, Rojo Brillante) show critical insights in to the biochemical changes in these varieties after N2 de-astringency treatment. The results express distinct patterns in pH and TA of persimmon fruit. Interestingly both variety and N2 treatment, significantly impacted the behavior of Hachiya compared to the other persimmon varieties.

The non-significant influence of both variety and N2 treatment on the pH of Fuyu, Great Wall, Maru, and Rojo Brillante varieties shows that the pH of these persimmon varieties is relatively stable across different varieties and under N2 de-astringency treatment (Figure 3A). The intrinsic buffering capacity in the persimmon varieties keep the pH stable despite N2 treatment. This capacity in persimmon varieties can be attributed to the existence of buffering compounds such as organic acids generally and malic acid particularly (Novillo et al., 2015; Lee et al., 2012). As compared to other varieties, Hachiya showed a notably lower average pH of 5.82, indicating the presence of free hydrogen ions in higher concentration leading to higher acidity. The lower pH of Hachiya could enhance its microbial stability and sensory acceptability. Such variation among cultivars is crucial for selection of proper variety for product development and processing (Vázquez-Gutiérrez et al., 2016). The substantial increase in pH of Hachiya variety from 5.57 to 6.08 shows that N2 de-astringency treatment creates anaerobic condition leading to increase in acetaldehyde for conversion of soluble tannins into insoluble form. The acetaldehyde is a neutral compound and can be the reason for increased pH (Zhao et al., 2025).

Similarly, titratable acidity was significantly affected by both variety and N2 de-astringency treatment. Hachiya variety showed higher titratable acidity of 0.19 % malic acid that perfectly aligns with its lower pH and further strengthens the presence of higher organic acid content (Figure 3B). This attribute of Hachiya makes it more suitable variety for products preparation where high acidity is desired. Conversely, Maru variety has the lowest titratable acidity of 0.10 % malic acid, indicating lower organic acids that possibly affect tartness of the fruit. The significant decrease in titratable acidity after N2 de-astringency treatment in Fuyu, Hachiya, Great Wall, and Rojo Brillante shows that N2 treatment may enhance metabolic processes like conversion and degradation of organic acids (Besada et al., 2013).

Total soluble solids and sugar/acid ratio

The results of this study reveal valuable information concerning the influence of the N₂ de-astringency treatment on total soluble solids (TSS) and sugar/acid ratio in five persimmon varieties. Whereas the N₂ treatment had no significant impact on TSS values, it had a significant effect on the sugar/acid ratio, reflecting the intricate interaction between variety and postharvest treatment.

The noted non-significant decrease in TSS of all the five varieties implies that the N₂ treatment does not significantly influence the overall sugar content or perception of sweetness in persimmons. The decline varied moderately between 0.43 % and 1.02 %, adding credence to the notion that N₂ treatment mostly focuses on eliminating astringency without modifying critical sweetness indicators (Figure 3C). This is consistent with prior research where comparable treatments had little or no effect on TSS, highlighting its stability as a varietal characteristic. Even after treatment, profound varietal variations existed. Rojo Brillante showed the highest TSS (15.23 %), suggesting a potentially better sweetness level, followed by Hachiya, whereas Maru registered the lowest mean TSS of 11.01 %. These inherent discrepancies may be due to genetic variation in sugar metabolism and accumulation patterns in the cultivars.

In comparison to TSS, however, the sugar/acid ratio was greatly influenced by N₂ treatment and variety, showing its susceptibility to postharvest modification as well as varietal nature (Figure 3D). Maru variety, with the lowest TSS, contained the highest sugar/acid ratio (125.45). This indicates a reduced acidity level, which leads to increased sweetness in taste perception, and thus would contribute to an increase in consumer preference for this variety (Chen et al., 2016). In contrast, Hachiya had the lowest sugar/acid ratio of 78.4, which may be because it has greater acidity, and this could also lead to a balanced taste. These major differences within varieties emphasize the need to take into account both the sugar and acid content while assessing fruit quality. Interestingly, treatment with N₂ led to a uniform and significant increase in the sugar/acid ratio of all varieties, with gains between 27.86 and 33.93. This may be the result of selective titratable acidity reduction, a well-documented outcome of de-astringency treatments (Zhao et al., 2025). The improvement in sugar/acid ratio, while TSS remains constant, implies an overall enhancement in the sweetness and taste balance, which could translate into favorable marketability and consumer acceptance outcomes.

Reducing and non-reducing sugars

The reducing and non-reducing sugars of five persimmon varieties was analyzed across two groups: untreated and nitrogen treated. After statistical analysis it was observed that N2 de-astringency treatment significantly increase reducing sugars of Fuyu and Maru variety. N2 treatment slightly and non-significantly increase reducing sugar of Hachiya, Great Wall and Rojo Brillante varieties (Figure 4A). In contrast to reducing sugar, N2 treatment significantly reduced non-reducing sugar in three varieties (Fuyu, Maru, and Rojo Brillante), while slight and non-significant reduction was observed in Hachiya and Great Wall varieties. A significant variation in both reducing sugar and non-reducing sugar was observed among all five varieties. The highest average reducing sugar of 11.85 % was observed in Hachiya followed by Rojo Brillante while, the lowest reducing sugar of 8.63 % was observed in Maru variety. Similarly, the highest average non-reducing sugar of 2.43 % was observed in Rojo Brillante followed by Great Wall, while, the lowest average non-reducing sugar of 1.52 % was observed in Maru variety (Figure 4B).

The increase in reducing sugars after N₂ de-astringency treatment, as noted in the Fuyu and Maru varieties, indicates that N2 is involved in encouraging sugar metabolism or mobilization in some persimmon genotypes. Such a notable response could be due to increased activity of enzymes such as invertase or amylase, which helps to decompose complex carbohydrates into reducing sugars during the process of de-astringency (Zhao et al., 2025). The minor, non-significant increases in reducing sugars in Hachiya, Great Wall, and Rojo Brillante could reflect a varietal variation in metabolic responsiveness as reported in previous studies on fruit varieties (Rosend et al., 2019; Monti et al., 2016).

Conversely, the dramatic decline in non-reducing sugars in Fuyu, Maru, and Rojo Brillante under N2 treatment suggests their reduction to reducing forms (Gurbanova et al., 2018), supporting the premise of increased carbohydrate hydrolysis (Tilahun et al., 2017). Minimal variations in Hachiya and Great Wall indicate potential stability or resistance to metabolic changes caused by N2 in these varieties. Such differential response substantiates the belief in varietal-specific pathways of sugar metabolism (Rosend et al., 2019; Monti et al., 2016).

In addition, the large difference in sugar level between varieties is an indicator of carbohydrate composition and genetic diversity of response to postharvest treatment. The maximum reducing sugar level in Hachiya and Rojo Brillante signifies a sweet nature by the virtue of natural profile, whereas low reducing and non-reducing sugars in Maru signify comparatively lower capacity for sugar accumulation. In all, these results underscore the need for variety-specific postharvest treatment strategy and the potential of N2 to regulate persimmon sugar profiles.

Vitamin C and total phenol content

The vitamin C and phenol content of five persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, Rojo Brillante) was analyzed across two groups: untreated and nitrogen treated. After statistical analysis it was observed that both variety and N2 treatment have significant effect on the two nutritionally critical parameters. The Great Wall variety showed vitamin C content of 37.17 mg/100 g, non-significantly different from 37.15 mg/100 g of Rojo Brillante but significant higher from other varieties (Figure 4C). The lowest vitamin C content was observed in Hachiya variety as 24.39 mg/100 g. Similarly, a significant variation in phenol content was observed in all five varieties. The Great Wall variety showed average phenol content of 1747.80 mg GAE/100 g FW followed by Hachiya variety (Figure 4D). The lowest average phenol content of 487.5 mg GAE/100 g FW was observed in Maru variety. N2 de-astringency treatment showed decreasing effect on vitamin C and phenol content of all five varieties. The greatest decrease of 15.33 mg/100 g in vitamin C was observed in Fuyu variety followed by Rojo Brillante. Interestingly, a non-significant decrease of 1.78 mg/100 g was observed in Maru variety after N2 treatment. Similarly, the greatest decrease of 1909 mg/100 g was observed in Great Wall followed by Hachiya variety. While, the lowest decrease of 232 mg/100 g was observed in N2 treated Fuyu variety.

The investigation emphasizes notable varietal variations and the effect of N2 de-astringency treatment on persimmon vitamin C and phenol levels. Great Wall variety recorded the maximum content of vitamin C, statistically equivalent to that of Rojo Brillante but significantly greater than other varieties, whereas Hachiya registered the minimum. Likewise, Great Wall recorded the maximum phenols content followed by Hachiya, while Maru recorded the minimum. These results indicate that genetic components significantly affect the nutritional content of persimmons, where Great Wall appears to be a good cultivar for high phenolic and vitamin C content (Borrás, 2015).

De-astringency treatment with N2 consistently lowered the levels of vitamin C and phenol in all varieties, most probably due to oxidative enzyme activity of polyphenol oxidase and ascorbate oxidase leading to degradation of ascorbate and phenolics. Additionally, de-astringency treatment converts soluble tannins into insoluble forms, where phenolics serve as a substrate (Han et al., 2021). Furthermore, anaerobic condition due to higher concentration of N2 affect availability of NADPH leading to degradation of vitamin C (Bibi et al., 2007). The highest reduction in vitamin C was seen in Fuyu, whereas Maru displayed minimal loss, suggesting varietal resistance to N2-induced nutrient loss (Gurbanova et al., 2018). Likewise, the significant loss in phenols in Great Wall and Hachiya implies that these varieties are more susceptible to N2 treatment, while Fuyu indicated relative stability. The decrease in phenolic compounds after N2 treatment may have resulted from oxidation of soluble tannins in to insoluble forms (Han et al., 2022a). This led to lower antioxidant and lowered nutritional value, but it improved organoleptic quality by reducing bitterness and astringency leading to improved consumer acceptance. This requires optimization of de-astringency treatment conditions to balance nutritional profile and sensory characteristics. The lack of significant vitamin C decline in Maru suggests possible tolerance and thus requires further investigation into its biochemical resilience.

Minerals content

The mineral content of five persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, Rojo Brillante) was analyzed across two groups: untreated and nitrogen treated. After statistical analysis it was observed that N2 treatment has non-significant effect on potassium (K), sodium (Na), and phosphorus (P) content of the persimmon varieties while it significantly increased zinc (Zn) content and decreased calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) content of all five varieties. N2 treatment slightly and non-significantly increased K content of Fuyu, Hachiya, and Rojo Brillante from 3.34 to 10 mg/100 g, while decreased K content of Great Wall and Maru variety from 6.67 to 9.67 mg/100 g (Figure 5A). Similar increasing and decreasing trends were also observed in Na and P content of the persimmon varieties (Figure 5B and 5C). A significant decrease occurred in Ca content of Fuyu, Great Wall, Maru, and Rojo Brillante ranging from 1.73 to 10.33 mg/100 g while no changes was observed in Ca content of Hachiya after N2 treatment (Figure 5D). There was significant decrease in Mg, Fe, and Mn of all five varieties ranging from 0.7 to 1.6 mg/100 g, 0.07 to 0.14 mg/100 g, and 0.02 to 0.17 mg/100 g respectively (Figure 6A, 6B and 6D). In contrast to this, significant increase occurred in Zn content of all varieties ranging from 0.03 to 0.11 mg/100 g (Figure 6C). Significant difference in mineral content was observed among persimmon varieties. Average P and Na content was found significantly higher in Maru variety followed by Rojo Brillante while the lowest was observed in Fuyu variety. Average P content was significantly higher in Rojo Brillante followed by Great Wall and Fuyu while the lowest P content was noted in Hachiya variety. Average Ca content was significantly greater in Maru followed by Fuyu, while the lowest was observed in Great Wall. Average Mg content was significantly higher in Great Wall, Fe content in Fuyu, Zn in Great Wall, and Mn in Fuyu variety.

The present research emphasizes the impact of N2 de-astringency treatment on the mineral composition of five persimmon varieties. Generally, the treatment had a selective impact on the levels of minerals, where a statistically significant decreasing trend in the levels of Ca, Mg, Fe, and Mn in all varieties was observed. Despite these dramatic shifts, levels of K, Na, and P were statistically unaffected by N2 treatment, with some slight varietal fluctuation detected. Mg being part of chlorophyll play role in photosynthesis and activation of enzymes. N2 treatment effect metabolites such as tannins that are not directly associated with Mg related processes (Tian et al., 2021). Similarly, K and P are not affected by N2 de-astringency treatment as they remain stable under anaerobic conditions and modification in tannins. Fe is often occurred in bounded form with compounds like tannins (Nakajima and Sakaguchi, 2000). After N2 treatment, tannins are polymerized and degraded leading to release of Fe (Zhou et al., 2022). The increase in acidity and anaerobic conditions further speed up precipitation of Fe as oxides and hydroxides (Kaksonen et al., 2014). Ca, Mg and Mn in persimmon fruit decreased after N2 treatment due to changes in membrane activity leading to cation leakage and polymerization of tannins that chelate these ions. Furthermore, anaerobic condition hinders ion transport and decreased vacuolar pH precipitate these ions, thereby decreasing their measurable levels (Li et al., 2025; Celus et al., 2018). Lastly, Zn occur as a part of enzyme systems involved in metabolic processes and stress response (Hassan et al., 2020). To slow down ripening and senescence through tolerating shift in metabolic patterns, activity of essential mineral such as Zn-dependent reactions are increased (Deng et al., 2020).

Sensory characteristics of persimmons

The sensory characteristics such as appearance, taste, aroma, texture, and overall acceptability of five persimmon varieties (Fuyu, Hachiya, Great Wall, Maru, Rojo Brillante) was analyzed across two groups: untreated and nitrogen treated. After statistical analysis it was noted that non-significant effect of N2 de-astringency treatment was observed on appearance and texture, while a significant effect was observed on taste, aroma, astringency, and overall acceptability of the persimmon fruit. However, the difference due to variety was significant in case of all sensory parameters except texture. Among the varieties, Fuyu obtained the highest acceptability score of 8.01, while Great Wall obtained the lowest score of 6.12 for appearance (Figure 7A). Maru obtained the highest acceptability score of 6.93 and 6.68, while Great Wall and Fuyu obtained the lowest score of 5.92 and 5.46 for taste and astringency respectively (Figure 7B and 7C). Rojo Brillante obtained the highest acceptability score of 7.16, while Great Wall obtained the lowest score of 6.43 for aroma (Figure 7D). The highest acceptability score of 7.56 was obtained by Fuyu while the lowest of 6.60 was obtained by Maru, however, the difference was not statistically significant. N2 treatment resulted in an increase of appearance score in all varieties, ranging from 0.027 to 0.26 except Hachiya, that showed 0.12 decrease in appearance score. The treatment also significantly increased taste score in all varieties ranging from 0.37 to 2.04. Similarly, N2 treatment significantly reduced astringency in all varieties but the treatment effect varied with variety. The increase in astringency acceptability score was the highest for Hachiya (4.91) followed by Rojo Brillante while, the lowest increase in acceptability score was observed for Maru variety (0.73). Just like other sensory characteristics, improvement in aroma, texture, and overall acceptability score was observed in all varieties (Figure 8A). Maru variety showed the highest increase in acceptability score for aroma and texture (1.06 and 0.28 respectively). Lastly, the highest increase in overall acceptability score was observed in Hachiya variety that increased from 5.91 (untreated) to 7.30 after N2 de-astringency treatment (Figure 8B).

Organoleptic analyses of five persimmon varieties indicated that N2 de-astringency treatment had substantial effect on taste, aroma, astringency, and overall acceptability, whereas its effect on appearance and texture was non-significant. This indicates that the treatment by N2 strengthens the chemical and volatile compounds responsible for flavor and aroma and tannin reduction, respectively, without exerting a pronounced effect on visual and structural characteristics. Previously, N2 treatment has been reported for improving sensory characteristics of persimmon fruit (Bibi et al., 2007). The varietal differences had significant impact on all sensory parameters except texture, indicating inherent genetic differences affect sensory characteristics of persimmon varieties (Han et al., 2022b). The high appearance and overall acceptability scores of Fuyu indicate its market acceptability that can be attributed to its higher moisture content, balanced TA and TSS content, whereas Great Wall was the lowest scorer in most of the parameters, indicating varietal shortcomings in sensory quality. The possible reason for its inferior sensory acceptability could be possibly attributed to lower moisture content, TSS, sugar/acid ratio and higher firmness. The response of different varieties to N2 treatment showed clear variation in terms of astringency reduction. Among the control group, Maru showed the lowest astringency while Hachiya showed the highest. Upon N2 treatment, all varieties showed reduction in astringency. Hachiya and Rojo Brillante responded most strongly to the N2 treatment while Maru weakly responded to the treatment. This showed magnitude of response is dependent on variety, making it clear that inherent physiological variations affect efficacy of de-astringency treatment. The sharp reduction in astringency, especially in Hachiya variety indicates the effectiveness of the N2 treatment in offsetting tannin-related bitterness, with differential success among varieties (Bibi et al., 2007). The significant increase in Hachiya overall acceptability further suggests the possibility of the treatment to increase consumer preference, especially for astringent varieties. Moreover, Hachiya showed moderate moisture content, firmness and composition. These attributes optimize the release of aromatic compounds and N2 treatment enhances sugar accumulation and synthesis of volatile compounds improving the sugar/acid ratio. These effects noticeably improved overall acceptability of Hachiya variety. The significant increase in aroma and texture scores for Maru suggests variety-specific response to N2 treatment, perhaps because of its varietal distinctions in volatile compound formation and cell wall composition (Amorim et al., 2020; Besada et al., 2013). These results align with previous researches on de-astringency treatments, indicating that N2 application is a potential solution to improve sensory quality, especially for taste and astringency (Bibi et al., 2007), although its effectiveness is variety-specific, requiring variety-specific strategies in postharvest processing to maximize consumer acceptability.

Conclusions and Recommendatoins

Overall it can be summarized that a substantial effect of varieties was observed on both physicochemical and organoleptic characteristics. The fruit of Hachiya variety was the longest with greatest volume while Maru and Great Wall were shorter. Non-significant effect of N2 treatment was observed on these physical characteristics. However, density of Hachiya was reduced while that of Rojo Brillante was increased. Moreover, N2 treatment resulted in reduction of sugars, ascorbic acid, total phenol content and some minerals. While other biochemical parameters were not notably affected. Organoleptic analyses showed improving effect of N2 treatment on sensory characteristics except appearance and texture of all varieties. Hachiya variety showed the greatest reduction in astringency while Maru and Fuyu excelled in taste and appearance respectively. Finally, using these findings, it can be concluded that N2 treatment is effective in reducing astringency in persimmon varieties without significantly affecting physicochemical attributes. These findings provide unique insight into the varietal differences and varying response to N2 de-astringency treatment. Further researches should explore molecular and genetic level basis to clearly understand the way changes occur in varieties after N2 treatment.

Acknowledgements

This work has been done as a part of the PhD study of the first author. No external funding was received for this study.

Novelty Statement

This research work provides first comprehensive and comparative evaluation of 99.99 % nitrogen de-astringency treatment on the physico-chemical and organoleptic characteristics of different persimmon cultivars grown in KPK, Pakistan. Unlike previous researches that mainly focus on single variety or limited quality indicators, the present research combines varietal morphology, sugar-acid balance, phenolic content, mineral content, and consumers-relevant organoleptic traits to explain cultivar-specific responses to N₂ treatment. The identification of some varieties as superior in post-treatment quality and acceptability emphasizes the potential for cultivar-targeted postharvest management strategies to lower down losses and improve marketability. Moreover, these findings provide new insights into differential varietal behavior under N₂ atmospheres, providing a basis for future molecular and biochemical investigations into de-astringency mechanisms in persimmon.

Author’s Contribution

Shah Alam: Designed, conducted lab work and data analyses, prepared and formatted the manuscript.

Muhammad Ayub: Supervised the study, proofread and finalized the manuscript.

Generative AI or AI assisted technology statement

The authors declare that no genrative AI was used in the creation of this manuscript.

Conflict of interests

The authors declare no conflict of interests.

References

Ahmad, A., M.S. Hashmi, Y. Durrani, N.A. Khan, M.R. Khan, M.Z., Siddiqi, A. Riaz, M. Alam and W.U. Rahman. 2023.Synergy of 1-MCP and hypobaric treatments prevent fermented flavour and improve consumers’ acceptability of ‘Shughri’ pear. J. Food Sci. Technol., 60(1): 200-210. https://doi.org/10.1007/s13197-022-05605-y

Ahmad, K., M. Afridi, N.A. Khan and A. Sarwar. 2021. Quality deterioration of postharvest fruits and vegetables in developing country Pakistan: A mini overview. Asian J. Agric. Food Sci., 9(2): 83-90. https://doi.org/10.24203/ajafs.v9i2.6615

Ahmed, T.H.M. and Z.M.A. Mohamed. 2015. Diversity of Mango (Mangifera indica L.) cultivars in Shendi area: morphological fruit characterization. Int. J. Res. Agric. Sci., 2(4): 2348-3997.

Amorim, C., E.G. Alves Filho, T.H.S. Rodrigues, R.J. Bender, K.M. Canuto, D.S. Garruti and L.R. Antoniolli. 2020. Volatile compounds associated to the loss of astringency in ‘Rama Forte’ persimmon fruit. Food Res. Int., 136: 109570. https://doi.org/10.1016/j.foodres.2020.109570

AOAC. 2016. Official Methods of Analysis of AOAC International (20th ed., Method 967.21). AOAC International, Gaithersburg, MD, USA.

Ayoub, A., J. Singh and S. Sharma. 2022. Physico-chemical analysis of fresh persimmon (Diospyros kaki L) fruit pulp from Jammu Region India. Int. J. Plant Soil Sci., 34(22): 1028-1034. https://doi.org/10.9734/ijpss/2022/v34i2231464

Baltacioğlu, H. and N. Artik. 2013. Study of postharvest changes in the chemical composition of persimmon by HPLC. Turk. J. Agric., 37(5): 568-574. https://doi.org/10.3906/tar-1210-21

Ben-Arie, R, Y. Zutkhi, L. Sonego and J. Klein. 1991. Modified atmosphere packaging for long-term storage of astringent persimmons. Postharvest Biol. Technol., 1: 169-179. https://doi.org/10.1016/0925-5214(91)90009-Z

Bennett, E., J.A. Roberts and C. Wagstaff. 2012. Manipulating resource allocation in plants. J. Exp. Bot., 63(9): 3391-3400. https://doi.org/10.1093/jxb/err442

Besada, C., G. Sanchez, A. Salvador and A. Granell. 2013. Volatile compounds associated to the loss of astringency in persimmon fruit revealed by untargeted GC–MS analysis. Metabolom., 9(1): 157-172. https://doi.org/10.1007/s11306-012-0436-2

Bhande, S.D., M.R. Ravindra and T.K. Goswami. 2008. Respiration rate of banana fruit under aerobic conditions at different storage temperatures. J. Food Eng., 87(1): 116-123. https://doi.org/10.1016/j.jfoodeng.2007.11.019

Bibi, N., A.B. Khattak and Z. Mehmood. 2007. Quality improvement and shelf life extension of persimmon fruit (Diospyros kaki). J. Food Eng., 79(4): 1359-1363. https://doi.org/10.1016/j.jfoodeng.2006.04.016

Borrás, P.N. 2015. Harvest and Postharvest Quality of Persimmon Fruit: Physicochemical and Nutritional Aspects (Doctoral dissertation, Ph. D. Thesis, Food Technology Department, Nstituto Valenciano de Investigaciones Agrarias (IVIA), Universitat Politecnica De Valencia, ALÈNCIA, Spain).

Celus, M., C. Kyomugasho, A.M. Van Loey, T. Grauwet and M.E. Hendrickx. 2018. Influence of pectin structural properties on interactions with divalent cations and its associated functionalities. Compr. Rev. Food Sci. Food Saf., 17(6): 1576-1594. https://doi.org/10.1111/1541-4337.12394

Chang, K.H., J.M. Lee and S.S. Hur. 2017. Physical characteristics of deastringent Persimmons during modified atmosphere storage as affected by packaging materials. J. Korean Appl. Sci. Technol., 34(3): 478-486.

Chen. J., J, Du, Z.Z. Ge, W. Zhu, R. Nie and C.M. Li. 2016. Comparison of sensory and compositions of five selected persimmon cultivars (Diospyros kaki L.) and correlations between chemical components and processing characteristics. J. Food Sci. Tech., 53(3): 1597–1607 https://doi.org/10.1007/s13197-015-2102-y

Chung, H.S., H.S. Kim, Y.G. Lee and J.H. Seong. 2014. Effect of deastringency treatment of intact persimmon fruits on the quality of fresh-cut persimmons. Food Chem., 166: 192–197. https://doi.org/10.1016/j.foodchem.2014.06.015

Combrink, N.K., M.T. Labuschagne and Z. Bijzet. 2013. Variation of fruit size and shape in Kiyomi tangor families. Sci. Hortic., 162: 357-364. https://doi.org/10.1016/j.scienta.2013.08.010

Das, P.R. and J.B. Eun. 2021. Removal of astringency in persimmon fruits (Diospyros kaki) subjected to different freezing temperature treatments. J. Food Sci. Technol., 58: 3154-3163. https://doi.org/10.1007/s13197-020-04818-3

De Mori, G. and G. Cipriani. 2023. Marker-assisted selection in breeding for fruit trait improvement: A review. Int. J. Mol. Sci., 24(10): 8984. https://doi.org/10.3390/ijms24108984

Deng, B., H. Shi, H. Liu, S. Li, S. Tian and X. Zhao. 2020. Soaking with an essential mineral (Fe, Zn, Cu, Mn and Se) mixture delays senescence and improves nutrient accumulation in postharvest fruit of Ziziphus jujuba. Postharvest Biol. Technol., 166: 111186. https://doi.org/10.1016/j.postharvbio.2020.111186

Desai, N.N., V.M. Modi, G.K. Saxena, R.H. Chaudhari, M.K. Jaipal, K.H. Gohil and A. Gora. 2019. Physical properties of dates fruits. Int. J. Curr. Microbiol. Appl. Sci., 8(4): 1243-1249. https://doi.org/10.20546/ijcmas.2019.804.143

Dhake, K., S.K. Jain, S. Jagtap and P.B. Pathare. 2023. Effect of pretreatment and temperature on drying characteristics and quality of green banana peel. Agric. Eng., 5(4): 2064-2078. https://doi.org/10.3390/agriengineering5040127

Ding, Y., X. Shen, Y. Ding, P. Zhang, Q. Zhu, Y. Wang, Q. Zhang, Z. Luo, Y. Yang, X. Du and C. Guan. 2025. A comprehensive transcriptomic and metabolomic map reveals the molecular mechanism of persimmon fruit deastringency upon 40 °C warm water treatment. Postharvest Biol. Technol., 220: 113313. https://doi.org/10.1016/j.postharvbio.2024.113313

Famuyini, J., O.A. Patrick and A. Sedara. 2020. Effect of maturity stage on quality and shelf life of tomato (Lycopersicon esculentum Mill) using refrigerator storage system. Eurasian J. Agric. Res., 4(1): 23-44.

FAO statistics. 2024. https://www.fao.org/faostat/en/#data/QCL/visualize?item=587&area=5000&startYear=2020&endYear=2023&aggregate=average

Gao, S., B. Wang, F. Liu, J. Zhao, J. Yuan, S. Xiao, J. Masabni, F. Zou and D. Yuan. 2022. Variation in fruit morphology and seed oil fatty acid composition of Camellia oleifera collected from diverse regions in southern China. Hortic., 8(9): 818. https://doi.org/10.3390/horticulturae8090818

George, A.P. and S. Redpath. 2008. Health and medicinal benefits of persimmon fruit: a review. Adv. Hortic. Sci., 22(4): 244-249.

Gurbanova, S.O., A.A. Gasimova, U.A. Babayeva, I.Y. Khusayinova, A.A. Nabiyev, and I.H. Kazimova. 2018. The study of biochemical indices of persimmon fruit under various storage conditions. Polsha. Sylwan., 162(4): 175-187.

Han, W.J., K. Cao, Y.J. Suo, S.F. Diao, P. Sun, H.W. Li and J.M. Fu. 2021. Effect of deastringency treatment with CO2 on physiological quality of ‘Hiratanenashi’ persimmon fruit. Food Sci., 42(17): 43-53.

Han, W., K. Cao, S. Diao, P. Sun, H. Li, Y. Mai, Y. Suo and J. Fu. 2022a. Characterization of browning during CO2 deastringency treatment in astringent persimmon fruit. J. Food Meas, Charact., 16(3): 2273-2281. https://doi.org/10.1007/s11694-022-01298-1

Han, W., Q. Zhang, T. Pu, Y. Wang, H. Li, Y. Luo, T. Li and J. Fu. 2022b. Diversity of Fruit Quality in Astringent and Non− Astringent Persimmon Fruit Germplasm. Hortic., 9(1): 24. https://doi.org/10.3390/horticulturae9010024

Harker, F.R., H.J. Elgar, C.B. Watkins, P.J. Jackson and I.C. Hallett. 2000. Physical and mechanical changes in strawberry fruit after high carbon dioxide treatments. Postharvest Biol. Technol., 19(2): 139-146. https://doi.org/10.1016/S0925-5214(00)00090-9

Hassan, M.U., M. Aamer, M.U. Chattha, T. Haiying, B. Shahzad, L Barbanti, M. Nawaz, A. Rasheed, A. Afzal, Y. Liu and H. Guoqin. 2020. The critical role of zinc in plants facing the drought stress. Agric., 10(9): 396. https://doi.org/10.3390/agriculture10090396

Houston, K., M.R. Tucker, J. Chowdhury, N. Shirley and A. Little. 2016. The plant cell wall: a complex and dynamic structure as revealed by the responses of genes under stress conditions. Front. Plant Sci., 7: 984. https://doi.org/10.3389/fpls.2016.00984

Jia, Y., Z. Wang, X. Liang, C. Tu, I. Khalifa, C. Wang, Y. Zhu, H. Chen, L. Hu and C. Li. 2024. Unlocking the potential of persimmons: A comprehensive review on emerging technologies for post-harvest challenges, processing innovations, and prospective applications. Food Chem., 459: 140344. https://doi.org/10.1016/j.foodchem.2024.140344

Jurkiewicz, A., D. Wiechula, R. Nowak, T. Gazdzik K. Loska. 2004. Metal content in femoral head spongious bone of people living in regions of different degrees of environmental pollution in Southern and Middle Poland. Ecotoxicol. Environmen. Safety., 59: 95–101. https://doi.org/10.1016/j.ecoenv.2004.01.002

Kaksonen, A.H., C. Morris, S. Rea, J. Li, J. Wylie, K.M. Usher, M.P. Ginige, K.Y. Cheng, F. Hilario and C.A. du Plessis. 2014. Biohydrometallurgical iron oxidation and precipitation: part I—effect of pH on process performance. Hydromet., 14: 255-263. https://doi.org/10.1016/j.hydromet.2014.04.016

Khan, D. and S.S. Shaukat. 2006. The fruits of Pakistan: Diversity, distribution, trends of production and use. Int. J. Biol. Biotechnol., 3(3): 463-499.

Khokhar I. and R. Bajwa. 2014. Prevalence of post-harvest rot of fruits and vegetables by Penicillium species. Int. J. Adv. Res. Biol. Sci., 1(9): 14–19.

Lara, I., A. Heredia and E. Domínguez. 2019. Shelf life potential and the fruit cuticle: the unexpected player. Front. Plant Sci., 10: 770. https://doi.org/10.3389/fpls.2019.00770

Larmond, E. 1977. Laboratory methods for sensory evaluation of food (Vol. 1284). Agriculture Canada.

Lee, J.H., Y.B. Lee, W.D. Seo, S.T. Kang, J.W. Lim and K.M. Cho. 2012. Comparative studies of antioxidant activities and nutritional constituents of persimmon juice (Diospyros kaki L. cv. Gapjubaekmok). Prev. Nutr. Food Sci., 17(2): 141. https://doi.org/10.3746/pnf.2012.17.2.141

Li, H. and L. McKee. 2023. Measuring enzyme kinetics of glycoside hydrolases using the 3,5-dinitrosalicylic acid assay. In Carbohydrate-Protein Interactions: Methods and Protocols (pp. 15-25). New York, NY: Springer US. https://doi.org/10.1007/978-1-0716-3151-5_2

Li, M., H. Jafari, O.V. Okoro, L. Nie and A. Shavandi. 2025. Optimization of peroxidase-like activity of manganese-tannic acid complexes. Colloids and Surfaces A: Physicochem. Engineer. Aspec., 710: 136109. https://doi.org/10.1016/j.colsurfa.2025.136109

Liu, X., Y. Pan, C. Liu, Y. Ding, X. Wang, Z. Cheng and H. Meng. 2020. Cucumber fruit size and shape variations explored from the aspects of morphology, histology, and endogenous hormones. Plant., 9(6): 772. https://doi.org/10.3390/plants9060772

Maeda, H., T. Akagi and R. Tao. 2018. Quantitative characterization of fruit shape and its differentiation pattern in diverse persimmon (Diospyros kaki) cultivars. Sci. Hortic., 228: 41-48. https://doi.org/10.1016/j.scienta.2017.10.006

Maltini, E., D. Torreggiani, E. Venir and G. Bertolo. 2003. Water activity and the preservation of plant foods. Food Chem., 82(1): 79-86. https://doi.org/10.1016/S0308-8146(02)00581-2

MAPAMA. 2016. Spanish Ministry of Agriculture, Fisheries, Nutrition and Environment. Available at: http://www.mapama.gob.es/

Ministry of National Food Security and Research, Economic Wing, Islamabad. 2016. Fruit, vegetables and condiments statistics of Pakistan 2014-15.

Monti, L.L., C.A. Bustamante, S. Osorio, J. Gabilondo, J. Borsani, M.A. Lauxmann, E. Maulión, G. Valentini, C.O. Budde, A.R. Fernie and M.F. Drincovich. 2016. Metabolic profiling of a range of peach fruit varieties reveals high metabolic diversity and commonalities and differences during ripening. Food Chem., 190: 879-888. https://doi.org/10.1016/j.foodchem.2015.06.043

Nakajima, A., and T. Sakaguchi. 2000. Uptake and removal of iron by immobilised persimmon tannin. J. Chem. Technol. Biotechnol., 75(11): 977-982. https://doi.org/10.1002/1097-4660(200011)75:11<977::AID-JCTB305>3.0.CO;2-J

Neupane, C., M. Pereira, A. Koirala and K.B. Walsh. 2023. Fruit sizing in orchard: A review from caliper to machine vision with deep learning. Sens., 23(8): 3868. https://doi.org/10.3390/s23083868

Novillo, P., C. Besada, L. Tian, A. Bermejo and A. Salvador. 2015. Nutritional composition of ten persimmon cultivars in the “ready-to-eat crisp” stage. Effect of deastringency treatment. Food Nutr. Sci., 6(14): 1296-1296. https://doi.org/10.4236/fns.2015.614135

Novillo, P., R. Gil, C. Besada and A. Salvador. 2014. Astringency removal of ‘Rojo Brillante’ persimmon by combining CO2 and ethanol application. InV Int. Conf. Posthar. Unlim., 1079: 599-604. https://doi.org/10.17660/ActaHortic.2015.1079.81

Okello, R.C., E.P. Heuvelink, P.H. de Visser, P.C. Struik and L.F. Marcelis. 2015a. What drives fruit growth?. Funct. Plant Biol., 42(9): 817-827. https://doi.org/10.1071/FP15060

Okello, R.C., P.H. de Visser, E. Heuvelink, M. Lammers, R.A. de Maagd, P.C. Struik and L.F. Marcelis. 2015b. A multilevel analysis of fruit growth of two tomato cultivars in response to fruit temperature. Physiol. Plant., 153(3): 403-418. https://doi.org/10.1111/ppl.12247

Ozdemir, A.E., E. Candir, C.E.L.İ.L. Toplu and E.R.C.A.N. Yildiz. 2020. Effect of hot water treatment on astringency removal in persimmon cultivars. International J. Fruit Sci., 20: S557-S569. https://doi.org/10.1080/15538362.2020.1746729

Pradhan, R.C., S.N. Naik, N. Bhatnagar and V.K. Vijay. 2009. Moisture-dependent physical properties of jatropha fruit. Ind. Crops Prod., 29(2-3): 341-347. https://doi.org/10.1016/j.indcrop.2008.07.002

Rosend, J., R. Kuldjärv, S. Rosenvald and T. Paalme. 2019. The effects of apple variety, ripening stage, and yeast strain on the volatile composition of apple cider. Heliyon., 5(6): e01953. https://doi.org/10.1016/j.heliyon.2019.e01953

Su, Q., X. Li, L. Wang, B. Wang, Y. Feng, H. Yang and Z. Zhao. 2022. Variation in cell wall metabolism and flesh firmness of four apple cultivars during fruit development. Food., 11(21): 3518. https://doi.org/10.3390/foods11213518

Sugiura, A. 2005. Retrospect and prospects on persimmon research. Acta Hortic., 685: 177-187. https://doi.org/10.17660/ActaHortic.2005.685.20

Testoni, A. 2002. Post-harvest and processing of persimmon fruit. In E. Bellini, & E. Giordani (Eds.). First Mediterranean symposium on persimmon. Option. Mediterraneennes. Ser., A. 51: 53−70.

Tian, X.Y., D.D. He, S. Bai, W.Z. Zeng, Z. Wang, M. Wang, L.Q. Wu and Z.C. Chen. 2021. Physiological and molecular advances in magnesium nutrition of plants. Plant Soil., 468(1): 1-17. https://doi.org/10.1007/s11104-021-05139-w

Tilahun, S., J.Y. Heo and C.S. Jeong. 2017. Quality and expression of ethylene response genes of ‘Daebong’persimmon fruit during ripening at different temperatures. Posthar. Biol. Technol., 133: 57-63. https://doi.org/10.1016/j.postharvbio.2017.06.011

Vázquez-Gutiérrez, J.L., A. Quiles, E. Vonasek, J.A. Jernstedt, I. Hernando, N. Nitin and D.M. Barrett. 2016. High hydrostatic pressure as a method to preserve fresh-cut Hachiya persimmons: A structural approach. Food Sci. Technol. Int., 22(8): 688-698. https://doi.org/10.1177/1082013216642049

Wai, C.M., J. Zhang, T.C. Jones, C. Nagai and R. Ming. 2017. Cell wall metabolism and hexose allocation contribute to biomass accumulation in high yielding extreme segregants of a Saccharum interspecific F2 population. BMC Genom., 18(1): 773. https://doi.org/10.1186/s12864-017-4158-8

Wang, D., W. Li, D. Li, L. Li and Z. Luo. 2021. Effect of high carbon dioxide treatment on reactive oxygen species accumulation and antioxidant capacity in fresh-cut pear fruit during storage. Sci. Hortic., 281: 109925. https://doi.org/10.1016/j.scienta.2021.109925

Woolf, A. and R. Ben-Arie. 2011. Postharvest Biology and Technology of Tropical and subtropical fruit. UK: Woodhead Publishing. 166-194. https://doi.org/10.1533/9780857092618.166

Yaqub, S., U. Farooq, A. Shafi, K. Akram, M.A. Murtaza, T. Kausar and F. Siddique. 2016. Chemistry and functionality of bioactive compounds present in persimmon. J. Chem., 2016(1): 3424025. https://doi.org/10.1155/2016/3424025

Zhang, J., L.I. Jing, H. Zhang, L.I. Ye, S. Farooq, S.A.S. Bacha and W.A.N.G. Jie. 2020. Evaluation of sugar and organic acid composition and their levels in highbush blueberries from two regions of China. J. Integr. Agric., 19(9): 2352-2361. https://doi.org/10.1016/S2095-3119(20)63236-1

Zhang, K., Y. Zhang, M. Zhang, L. Gu, Z. Liu, J. Jia and X. Chen. 2016. Effects of phospholipid complexes of total flavonoids from Persimmon (Diospyros kaki L.) leaves on experimental atherosclerosis rats. J. Ethnopharmacol., 191:245-253. https://doi.org/10.1016/j.jep.2016.06.043

Zhao, W., M. Zheng, X. Li, K. Song and D. Shi. 2025. Fruit Astringency: Mechanisms, Technologies, and Future Directions. Hortic., 11(6): 699. https://doi.org/10.3390/horticulturae11060699

Zhao, Y., X. Zhu, Y. Hou, X. Wang and X. Li. 2019. Effects of nitric oxide fumigation treatment on retarding cell wall degradation and delaying softening of winter jujube (Ziziphus jujuba Mill. cv. Dongzao) fruit during storage. Postharvest Biol. Technol., 156: 110954. https://doi.org/10.1016/j.postharvbio.2019.110954

Zhou, M., J. Chen, J. Bi, X. Li and G. Xin. 2022. The roles of soluble poly and insoluble tannin in the enzymatic browning during storage of dried persimmon. Food Chem., 366: 130632. https://doi.org/10.1016/j.foodchem.2021.130632