Preserving Mango Quality: Assessing the Influence of Zinc Oxide Nanocomposite-corn Starch Coating Concentrations on Postharvest Attributes

doi:10.21203/rs.3.rs-4690679/v1

Download PDF

Research Article

Preserving Mango Quality: Assessing the Influence of Zinc Oxide Nanocomposite-corn Starch Coating Concentrations on Postharvest Attributes

https://doi.org/10.21203/rs.3.rs-4690679/v1

This work is licensed under a CC BY 4.0 License

You are reading this latest preprint version

The rise in environmental awareness has led to the development of biopolymers derived from natural sources as a viable alternative to synthetic materials for packaging. Zinc oxide (ZnO) NPs-starch coatings offer an alternative to synthetic materials, but their effectiveness depends on factors like product specifications, environmental implications, and adherence to regulations. The mango industry faces challenges in mitigating and managing diseases that impact mango orchards worldwide. To improve coating properties, zinc oxide (ZnO) and starch are combined to protect mangoes during storage. A study coated mango fruit samples with different concentrations of ZnO solution, and the fruits were stored at ambient temperature for seven days. The ZnO coating significantly preserved mango fruits by delaying fruit senescence, minimising fungal growth, and maintaining sensory quality. Additionally, mangoes coated with 1.5 M ZnO showed reduced weight loss after seven days of storage at room temperature. Field Emission Scanning Electron Microscopy (FESEM) was used to analyze the interaction between ZnO/corn starch coatings and microbes, revealing the physical damages caused by the coating on microbial cells. Thus, ZnO corn starch has improved hydrophobicity and excellent antimicrobial properties in preserving mango quality.

mango

shelf life

nanocoating

zinc oxide (ZnO)

starch

Mango or Mangifera indica is known as the king of fruits in certain countries due to the high consumption and numerous health benefits. Mangoes are delectable, flavourful, fragrant and rich in carbohydrates, proteins, fats, minerals and vitamins, particularly vitamins A, B1, B2 and C [1]. Furthermore, the mango is an excellent source of antioxidants, with anticancer and antiaging properties, improves lung function and reduces diabetes complications [1][2]. However, mangoes are highly perishable and have a short shelf life. Microbial proliferation, encompassing bacteria, yeast, and moulds, stands as a notable determinant of the perishability of fruit [3]. The proliferation of microbes on or within a product can result in spoiling, the development of off-flavors, and potentially even foodborne diseases. The fruit can last approximately 2–4 days at room temperature and 2–3 weeks in cold storage (13 ⁰C), depending on the varieties and storage conditions [1]. Food spoilage is commonly attributed to the presence of bacteria, which can either be naturally occurring in food or introduced by cross-contamination from handlers, transit, or contact surfaces [3]. Coating is a technique used to delay climacteric fruit ripening, improve appearance, inhibit moisture migration and the loss of volatile compounds, and reduce respiration rate in fruits. The use of nanoparticles into edible coatings has yielded several advantages, including enhanced antibacterial efficacy and improved uniformity of coating on the surface of fruits [4]. The use of edible coatings also provides an appealing, safe, and environmentally beneficial solution to fruit preservation. The edible covering functions as a barrier to gas diffusion, slows respiration, slows water loss, preserves sensory properties, slows fruit ripening, and increases storage life [5][6]. Previous reports utilized chitosan-based film to maintain the quality of mangoes by inhibiting respiration rate, maintaining the harness, preventing discoloration, inhibiting Colletotrichum gloeosporides infestation, and reducing the rate of ascorbic acid conversion. Furthermore, the carboxymethyl cellulose (CMC) treatment could be used as a pre-storage treatment to slow postharvest ripening and preserve the eating quality of ambient stored mango fruits [7].

Starch, particularly thermoplastic starch, is widely utilised as a biopolymer within the biodegradable film sector. However, it is important to note that starch exhibits a high degree of sensitivity to moisture and possesses a very low mechanical strength [8][9]. Therefore, researchers have conducted mechanical and thermal modifications on starch molecules, together with the addition of plasticizers, in order to produce gelatinized starch for further processing [8]. Starch-based materials have been utilized in the production of an edible film [10]. The incorporation of nanomaterials has the potential to alter the kinetics of crystallisation, as well as the morphology, shape, and size of starch grains. Several types of nanomaterials have been employed for improved the characteristics of biodegradable materials based on starch. These nanomaterials encompass cellulose nanofibers [11], montmorillonite nanoclay, and bentonite nanoclay [12][13]. For instance, the incorporation of cellulose nanofibers has been observed for enhanced the tensile strength and Young's modulus of nanocomposite films based on starch [13]. Additional nanomaterials can be incorporated into starch-based nanocomposites to enhance various features, such as the inclusion of nano-silver or chitosan-modified bentonite for improved antibacterial characteristics [13][14]. Chitosan, zinc oxide, and silver nanoparticles have been extensively utilized in climacteric fruits, demonstrating favorable outcomes upon application to edible polysaccharide and protein ingredients [4]. An alternative coating material is zinc oxide nanoparticles (ZnO NPs). Zinc (Zn) is an essential micronutrient for humans, and its deficiency leads to serious health repercussions. Furthermore, the FDA approved ZnO NPs as GRAS (Generally Recognised as Safe) substance[15]. This coating material is widely used in the food packaging industry due to its numerous benefits, including wide-spectrum antimicrobial properties[16], ultra-violet (UV) shielding capability [16], non-toxicity, thermal stability[17][18][19] and high specific surface area[20]. Moreover, the ZnO NPs were specially designed to construct a hydrophobic or superhydrophobic surface by deposition on different materials in different fields [21]. The ZnO NPs are believed to be non-toxic, biosafe and biocompatible and have been used in many modern applications, such as product carriers, cosmetics and medical material fillings [1].

The utilization of edible films and coatings may be subject to certain constraints depending on the chosen material. The foundation for their expansion is generated from substances that consist of proteins, polysaccharides and/or lipids [22]. The extensive application of polysaccharides can be attributed to their extraordinary capacity to transform into films, exhibit mechanical strength[23], and exhibit selective permeability in inhibiting the transmission of oxygen [23]. Nevertheless, the functionality of these substances might be influenced by moisture due to their hydrophilic properties[24]. The incorporation of zinc oxide nanoparticles (ZnO NPs) into polysaccharide coatings has been found to improve their barrier properties[25][26], resulting in an extended shelf life and effective prevention of rotting. Additionally, they enhance mechanical strength, hence increasing resistance to physical harm. Zinc oxide nanoparticles (ZnO NPs) have antibacterial properties[25][26], effectively inhibiting the growth of bacteria and fungi on food products that have been coated with them. In addition, they serve as ultraviolet (UV) blockers, so preserving fruit against harmful UV radiation. The combination of these advantages contributes to an elongated lifespan of fruit sustainability, less dependence on chemical preservatives, improved appearance, and adaptive compositions. This approach exhibits considerable potential in enhancing the quality and safety of fruit, as well as prolonging their shelf life. Consequently, both consumers and the food industry stand to benefit from its implementation. Antimicrobial packaging plays a vital role in preventing food spoilage [26]. This active packaging is advantageous for consumers and industrial players; thus, highly in demand to address their environmental concerns. The antimicrobial food packaging consists of organic compounds, inorganic compounds [silver, titanium dioxide (TiO₂)] and natural compounds. Organic and natural compounds are sensitive to the extreme processing conditions in industrial processes to develop microorganism resistance [27]. In contrast, the antibacterial properties of ZnO nanoparticles (NPs) are not reliant on UV irradiation[28], hence eliminating concerns over color fluctuation [29], unlike the existing inorganic antimicrobial compound.

Therefore, the current study aims to establish a method to improve the hydrophobicity of starch films. Furthermore, this study will determine the concentration of ZnO NPs coat on mango to inhibit fungal growth. In this work, ZnO NPs–corn starch was used to improve the miscibility between the starch and the ZnO NPs and the flexibility of the starch coating layer due to the excellent flexibility and film-forming ability.

ZnO nanopowder < 100 nm was purchased from Sigma-Aldrich Chemicals Pvt. Ltd.(USA) [30]. Corn starch was purchased from the market (Malaysia). The ZnO NP and corn starch (CS) were ball milled using planetary ball mill, model: PM 200 RESTCH.

2.1 ZnO NPs PREPARATION WITH A FILLER

The ZnO NPs were prepared at several concentrations: 0.5 M, 1.0 M, 1.5 M and 2.0 M at a volume of 50 mL. After that, 500 mL of distilled water was added to the corn starch to make a glutinous starch solution. Then, different concentrations of ZnO NPs were mixed with 500 mL of distilled water and stirred until homogeneity was achieved. Finally, the edible coating (ZnO NPs-CS) was weighed and added to the mixture solution with constant stirring at 100 ⁰C for two hours for gelatinization.

2.2 COATING OF MANGO AND MOULD INOCULATION

The mangoes were rinsed with distilled water to remove the dirt and dried at room temperature. After ZnO NPs with starch were gelatinised, each mango was dipped in different concentrations of ZnO NPs-starch mixture for 5 minutes and allowed to dry for 2 hours. One mango was not coated and acted as the control group. Then, the mould was prepared by adding sterile distilled water, and 10µL of mould were inoculated into uniform wounds made on the fruits using sterile needles. The mangoes were placed on a plastic tray and incubated for seven days.

2.3 WEIGHT LOSS AND MOISTURE CONTENT

The mangoes were weighed every two days. The initial weight of the fruit was used as a control sample, and the weight during storage was used as a set of parameters. Next, the weight loss percentage was calculated, and the moisture content % was determined according to the method of AOAC [31]. The mango samples (5 g) were placed in a crucible and oven-dried at 80 ⁰C for 12–18 hours. Then, the crucible was removed and placed in a desiccator, and the weight was recorded. Later, the samples were placed in an oven at 80 ⁰C for two more hours. The moisture content percentage and weight loss percentage were calculated according to the following formula:

Weight Loss = \(\:\left[\right(Initial\:Weight\:\left(g\right)-Final\:Weight\left(g\right))/\:Initial\:Weight]\) X 100% (1)

Moisture Content = \(\:\left[\right(Mi\:-Mf/Mi)\) X 100% (2)

Where Mi is the mass of the mango before oven drying (g) and Mf is the mass of the mango after oven drying (g)

2.4 DISEASE INCIDENCE

The anthracnose infection as explain in detail in previous study [30] was observed every two days, and the percentage of disease incidence was calculated as the following:

Disease incidence= \(\:(Area\:covered\:with\:black\:spot/Area\:of\:whole\:mango)\:\)X 100% (3)

2.5 STORAGE QUALITY EVALUATION (TSS,pH and TA)

After seven days of storage, the total solid soluble (TSS), pH and titratable acidity (TA) of the fruit pulps were analysed. First, the TSS (Brix⁰) was determined with a hand refractometer (Brix 0–32% Atago, Japan) [30]. The refractometer was calibrated with distilled water before reading. A drop of the filtrate was then placed on the prism glass, and a direct reading was recorded as described in AOAC [31].

Next, a sample of mango flesh weighing 10 g was sliced and homogenised with 100 mL of distilled water using a blender. The resulting mixture was then filtered to remove the pulp. Following that, a pH metre was utilised to ascertain the pH value of the juice[30]. The pH meter was calibrated using buffer solutions (pH 4 and 7).

Finally, the titratable acidity (TA) was analysed using the titration method. Fruit juice from five mangoes were homogenised with 400 mL of distilled water and filtered with cotton wool. Then, 100 mL of the filtrate with a few drops of phenolphthalein (1%) as an indicator was titrated using 0.1 M NaOH to an endpoint, marked by the pink colour change (pH 8.2) [30]. The results were expressed as a percentage of citric acid per 100 g fresh weight and calculated according to Eq. 3:

TA(%) = \(\:Acidity\:factor\:x\:titre/\:Sample\) X 100% (4)

where the acidity factor is 0.0064.

2.6 CHARACTERIZATION TECHNIQUES

Field Emission Scaning Electron Microscopy (FESEM)

In this research, the thickness and surface properties of ZnO coating film were measured using a scanning electron microscope (Gemini Model Zeis Supra 40VP (7426)) using a voltage of 10kV. The FESEM instrument can only be used for dried samples either in the form of thin film or powder. In this analysis, the samples were in the form of thin films. The experimental sample consists of dried mango peels acquired from mango fruits. The mango peel is carefully extracted from the fruit, subjected to a controlled drying process until it reaches a predetermined moisture level, and thereafter employed for the purposes of the studies. The process of drying is carried out following standard procedures in order to achieve homogeneity and regularity in the peel samples. In order to determine the impact of varying concentrations of coatings on the postharvest quality of mango peel samples, the preservation of these samples was obtained. This approach ensures that the initial state of the peel, encompassing its moisture content and freshness, is uniform throughout every sample. Since the mango peel is a non-conductive material, a 99.9% gold coat was added as a conductive layer to increase the conductivity of the sample.

X-ray Diffraction (XRD)

The XRD is a versatile and non-destructive technique mainly employed for the purpose of identifying and qualitatively analysing a wide range of crystalline or amorphous substances. In this analysis, the thin film specimen was positioned onto the sample holder prior to its introduction into the instrument. The dried sample exhibited the same features to the FESEM sample.

Fourier Transform Infra-red (FTIR)

FTIR spectroscopy was employed to identify the chemical composition and functional groups present in the sample films, as well as to investigate potential interactions between the various components. The mango films, both coated and uncoated, were subjected to analysis using a Frontier FTIR spectrometer (PerkinElmer, USA). The analysis was conducted within a spectrum range of 4000 to 400 cm^− 1. The dried sample exhibited the same features to the FESEM sample.

Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC)

The quantification of citric acid in mango was conducted using reversed-phase high-performance liquid chromatography (RP-HPLC). The sample was created using freshly extracted mango juice. The prepared sample was introduced into a reversed-phase high-performance liquid chromatography (RP-HPLC) system through injection with a volume of 20 microliters. The RP-HPLC system utilised in this study was outfitted with an analytical column, namely the Synergi 4u Hydro-RP 80A column. Additionally, a diode array detector (DAD) was employed to detect and measure the analytes. The mobile phase employed in this analysis consisted of a phosphate buffer.

The citric acid standard solution was constructed by procuring citric acid from Sigma Aldrich and subsequently dissolving it in a suitable solvent. Various concentrations of citric acid (2000, 1000, 750, and 500 ppm) were generated to establish a standard calibration curve, which exhibited an r-square value of 0.99%. The citric acid content in mango was measured by employing a citric acid standard solution.

3.1 DISEASE INCIDENCE

Disease incidence is a crucial parameter in assessing mango postharvest quality, shelf life, coating effectiveness, consumer preference, economic impact, food safety, and research validity. It helps evaluate the effectiveness of coatings in preserving mango postharvest quality, ensuring food safety, and minimizing economic losses associated with fungal contamination. Measuring disease incidence helps determine the effectiveness of coatings and their potential applications in the fruit industry. The implementation of a coating derived from polysaccharides exhibits a distinguishing ability to facilitate the transfer of gases, hence establishing its excellent efficacy as a gas barrier[32]. Although it diminishes the process of gas exchange, it does not entirely halt it. This coating allows for slow aerobic respiration while inhibiting anaerobic respiration from produced unwanted compounds. Slower aerobic respiration also delays senescence, extending the shelf life of fruit [32][33]. Despite the fact that coatings based on polysaccharides offer a commendable level of gas barrier properties, their hydrophilic properties lead to a low performance in terms of moisture barrier properties. Enhancing the water barrier capacity and other properties of polysaccharide-based coatings is necessary in order to improve their effectiveness as food coatings. Numerous studies have attempted to explore approaches focused on enhancing the effectiveness of polysaccharide-based coatings. The utilisation of ZnO nanoparticles has emerged as a viable solution for this purpose. The integration of zinc oxide nanoparticles (ZnO NPs) into polysaccharides leads to the formation of a coating that exhibits exceptional mechanical, structural, and barrier characteristics[34]. Table 1 shows the uncoated mango (control) and mangoes coated with nanocomposite ZnO-corn starch at different concentrations (0.5 M, 1.0 M, 1.5 M and 2.0 M). Fungal growth on control mangoes was detected on day 2 with increasing severity compared to coated mangoes after seven days in storage at room temperature. Meanwhile, no black spots were observed on the coated mangoes throughout the storage. The results show ZnO NPs can retard disease progression on mangoes due to the antimicrobial properties.

Table 1. The condition of mangoes with and without ZnO NPs coating throughout the storage period.

Black spot is a fungal disease affecting mangoes and other tropical fruits, caused by Colletotrichum gloeosporioides[35]. It manifests as dark, sunken spots on the fruits skin, leading to mushy texture, internal damage, and spore production[35]. The disease can cause significant economic losses and spread to healthy fruit. Therefore, nanocomposite coating is effective in inhibiting black spot growth on mangoes. In addition, the ZnO NPs have remarkable antimicrobial properties with high stability, non-toxicity. The inhibitory properties of ZnO nanoparticles have been investigated as it relates to their capacity to prevent the development of several pathogens, hence demonstrating their efficacy in reducing the spread of diseases [36]. Hmmam et al. reported the decay percentage of the control treatment was three to four times higher than that of alginate- and Alg–ZnO NP-coated fruits, respectively. The decrease in decay incidence was probably due to the effect of the coating on delaying senescence, which results in lower pathogenic infections [37]. Additionally, ZnO NPs have antimicrobial effects against several postharvest microbial infections [20][38][39]. The presence of ZnO NPs within the coating solution serves as a physical barrier on the surface of mangoes. This barrier effectively hinders the infiltration of microorganisms, including bacteria and fungi, which have the potential to induce various diseases.

Furthermore, ZnO NPs reduce respiration rate, water loss and oxidation dates, ripening activities and inhibit microbial growth. Meanwhile, corn starch acts as a semipermeable barrier against carbon dioxide, moisture, oxygen and solute movement [40]. This material can also increase the bonding between corn starch and ZnO NPs on the fruit surface. The incorporation of high levels of zinc oxide nanoparticles (ZnO NPs) inside a starch coating might result in several advantageous benefits, including improved barrier qualities, enhanced mechanical strength, prolonged shelf life, antibacterial activity, reduced oxygen permeability, improved color and clarity, and cost considerations [23]. These properties enhance the efficacy of the coating in terms of gas and moisture obstruction, safeguarding the underlying substrate, and prolonging the shelf life. Based on Table 2, there is a noticeable inverse trend between the concentration of ZnO in the polysaccharide coating and the percentage of disease incidence seen in mangoes. This demonstrates the direct relationship between the ZnO concentration in the coating and its effectiveness in reducing disease incidence in mangoes. Corn starch possesses moisture barrier qualities, which result in reduced respiration. Consequently, the reduced respiration inhibits fungal growth on the surface of the fruit peel. Zinc oxide (ZnO) also inhibits the growth of fungi on the surface of the peel. Then, the synergy effect is seen in an effort to reduce black spots.

Table 2

Disease incidence of mangoes.
	Percentage Disease Incidence (%)
0 (Control)	14.05
0.5 M	0.83
1.0 M	0.29
1.5 M	0.29
2.0 M	0

3.2 WEIGHT LOSS

Weight loss is the major factor that affects the shelf life and quality of fresh fruits. During this experiment, weight loss was reduced during storage. The uncoated mango experienced the highest weight loss compared to the coated fruits. In contrast, mangoes coated with different ZnO NPs concentrations (0.5 M-2.0 M) showing 18.63%, 17.67%, 13.53% and 14.25%, respectively (see Fig. 1). The weight loss observed in mangoes with a coating containing ZnO NPs was shown to be considerably lower when compared to mangoes without any treatment. The study findings indicate that the incorporation of ZnO nanoparticles (NPs) in the filler material [41] leads to a reduction in weight loss. The decrease in permeability of oxygen and moisture can be ascribed to the barrier qualities of the filler material [42]. Climacteric mature fruit experiences a sequence of metabolic transformations when detached from the tree, and these metabolic activities ultimately lead to a reduction in fruit weight throughout the postharvest and storage duration [43].

Postharvest water loss can lead to mango shriveling. However, the moisture loss from the coated fruits was slower because the ZnO nano-filler acted as a barrier against moisture diffusion into the stomata of mango skin. Moreover, mangoes coated with 1.5 M ZnO NPs and corn starch showed significantly lower weight loss. The permeability to moisture vapor is an important property of edible coatings since it has a direct impact on the respiration rate and weight loss of fruits during storage [44]. Furthermore, the permeability of moisture vapor in films is also associated with the growth and proliferation of microorganisms [44]. The polysaccharide coating functions as a barrier against moisture [45][46]. The application of a ZnO-starch polysaccharide coating on the mango surface creates a physical barrier that effectively lowers the rate of moisture evaporation from the fruit. The presence of this barrier effect serves to minimise the loss of water vapour, hence facilitating the preservation of the mangos mass. The utilisation of ZnO nanoparticles has been found to possess inhibitory properties against bacteria present on the surface of mangoes, hence reducing the factors that contribute to rotting and decay. The coating assists in preserving the fruits integrity by limiting microbial activity, hence limiting tissue breakdown and moisture loss [46][47]. Earlier, it has been reported that ZnO NPs effectively reduced weight loss in bananas [38], mangoes [48] and strawberries[29] [49]. Additionally, fresh cut kiwi fruit coated with ZnO NPs containing chitosan polymer restricted gas exchange on the fruit surface [50]. The coating material can minimize water loss and reduce these negative consequences; the coating works as a semi-permeable barrier for moisture, oxygen, and carbon dioxide, lowering respiration and water loss and maintaining cell wall turgescence [43] [51]. Wu et al. discovered that adding ZnO NPs to polysaccharide-based biopolymers increased their mechanical characteristics while decreasing water vapor permeability [43][52]. Emamifar and Bavaisi found that ZnO NPs considerably enhanced the moisture barrier of alginate films, minimizing fruit weight loss [43][53]. The findings of the study indicate that edible coatings possess the capability to effectively preserve moisture content [40][54]. This is achieved by the formation of a protective layer that functions as a barrier, impeding the transport of water and thus reducing the rate of transpiration [40][54].

3.3 TOTAL SOLUBLE SOLID (TSS), pH AND TITRATABLE ACIDITY

Table 3 shows the ⁰Brix and TSS of coated mango fruits. The changes in TSS observed during storage may be a result of the breakdown of complex carbohydrates by hydrolytic enzymes [43]. TSS should remain consistent with the natural sugar levels, as the coatings primary function is moisture and microbial control. The increment in TSS might be due to the dissociation of some molecules and structural enzymes in soluble compounds. These activities directly influenced the TSS levels in stored fruits due to the increased respiration and metabolic activities[55]. Similarly, an earlier study agreed that higher respiration rates increase due to converting metabolites and carbohydrates into sugar, hence the higher TSS [56]. According to Gol et al., the reason for the low TSS in coated fruits is likely due to the coatings barrier effect against respiration, which slows down the metabolic activities of the fruits [43][57]. The application of an edible coating serves as a protective barrier that effectively mitigates water loss from the mangoes, hence playing a significant role in the preservation of its TSS content.

Table 3

pH, TA, TSS, Ratio of TSS/TA and moisture content of uncoated and coated mangoes during storage.
Sample	pH	TA (%)	Moisture Content (%)	TSS (%)	TSS/TA
Control	6.234	0.51	63.16	2.0	3.92
0.5 M	6.276	0.48	68.18	2.0	4.20
1.0 M	6.312	0.51	53.43	1.5	2.94
1.5 M	6.339	0.50	64.94	1.6	3.20
2.0 M	6.386	0.51	67.17	2.0	3.92

Table 4

Concentration of Citric Acid from mango uncoated and coated with ZnO NPs- CS
	Concentration of Citric Acid (ppm)
Control	109.16
0.5 M	159.10
1.0 M	159.55
1.5 M	161.93
2.0 M	179.23

The TA measures the acid levels present in fruits, and this value increases with higher nanocomposite concentrations. At a lower concentration of ZnO, it is possible that the overall acidity of mangoes might not have significant changes. The features intrinsic to the fruit are the primary factors that impact TA, and these factors tend to remain relatively stable. The low ZnO coating is unlikely to have an effect on TSS. It is crucial to maintain consistency with the inherent sugar levels of mangoes. At the end of the storage period, TA increases in the ZnO NPs-treated commodity (strawberries, tomatoes and peaches). In contrast, TA was slowly reduced in other crops, such as mangoes and longan, associated with the loss of eating quality [58]. According to Buluc and Koyuncu, the presence of O₃ has been found to induce a delay in the respiration rate, hence contributing to the maintenance of TA [59]. Organic acids play a crucial role in the process of respiration by serving as hydrogen ion donors[59]. Coatings can slow down the rate of respiration and metabolic processes, which helps to limit the intake of organic acids during respiration reactions [5][6][43]. The edible coating has been proven to be effective in reducing the rate of fruit respiration and inhibiting the consumption of titratable acids, compared to uncoated fruit samples[60]. Both total soluble solids (TSS) and organic acids have a significant impact on the flavor and ripening process of fruits.

The ratio of total soluble solids to titratable acidity (TSS/TA) was noticeably influenced by the application of coatings during the storage period. The TSS/TA ratio is a well-known indicator of fruit quality, as it reflects the balance between sweetness and acidity. A higher TSS/TA ratio is associated with a sweeter taste, which is the result of increased breakdown of polysaccharides (such as starch), reduced acidity, and accumulation of sugars[61]. This leads to a more favorable sugar/acid ratio, which is a key factor in determining fruit quality[62].

After seven days of storage of mango fruit, there was an increase in pH with increasing concentrations of ZnO NPs (see Table 3). Mango acidity varies depending on ripeness and ripening method. Generally, the mango pH ranges from 5.8 to 6.0. In this study, the pH of the coated samples was comparable with the control sample, indicating that the ripening rate was reduced due to the coating barrier. This characteristic is beneficial in overcoming the limitation of long-distance commercial transport of fruits.

The control sample recorded the lowest pH, while the highest was in mangoes treated with 2.0 M coating. The respiration process may contribute to these observations, where acids are converted into sugars. Organic acids are substrates for enzymatic reactions in respiration; thus, the reduced acidity led to an increase in fruit pH [63]. The organic acid in mangoes is citric acid; the increase in pH during ripening and storage due to the metabolic process of fruit resulted in a decrease in organic acids. Similarly, a study on papaya yielded the same findings [64].

3.4 FESEM AND EDX

Figure 2 shows the FESEM micrograph of dried mango skin coated with different concentrations of ZnO NPs-CS. The strong adhesion of the ZnO nanoparticles (NPs) to the mango skin was seen, likely attributed to the existence of the edible coating composed of corn starch. Furthermore, the FESEM analysis revealed the presence of spherical zinc oxide nanoparticles (ZnO NPs) in the treated samples. The fruit surface was uniformly coated with ZnO nanoparticles (NPs) at a concentration of 1.5 M, which formed agglomerates with corn starch. The phenomenon of agglomeration can be attributed to the interplay of polarity and electrostatic forces among ZnO NPs nanoparticles, which is consistent with the investigations conducted by Fakhari et al. [65] and Umar et al. [66]. In addition, uniform particles of identical size were dispersed across the surface of the mango, which had been coated with ZnO NPs-CS at a concentration of 1.5 M. The mean particle size of the nanocomposites was determined to be 21.59 nm.

EDX analysis could reveal a noticeable increase in the concentration of zinc (Zn) elements in the coating on Fig. 3. The coatings elemental composition may show a more balanced distribution between carbon (C), oxygen (O), and zinc (Zn) elements. Previous studies by Rasha et al. [67], Fakhari et al. [65], and Hasnidawani et al. [68] have also reported similar findings regarding the presence of zinc and oxygen components in EDX analysis [43].

As the concentration of ZnO increases, the FESEM images demonstrate an improved surface roughness and texture, while the EDX analysis may indicate an elevated concentration of zinc (Zn) components within the coating. The utilization of analytical techniques facilitates the evaluation of the coatings structure and content, hence offering valuable insights for quality control purposes and the enhancement of the coatings qualities in related to mango preservation.

3.5 XRD

The XRD patterns of ZnO NPs are shown in Fig. 4. A typical focus diffractometer source Cu target at 30 kV and 15 mA was used with a scan rate of 3˚/min. The X-ray diffraction pattern shows 2θ values at 36.42˚, 42.29˚, 61.36˚ and 77.35˚. All prominent peaks could be indexed as the zinc oxide wurtzite structure (JCPDS Data Card No: 36-1451). The use of X-ray diffraction (XRD) technique in the study of the polysaccharide ZnO-starch coating on mangoes enables the reveal of valuable information related to the crystalline structure and phase composition of the coating. When the concentration of ZnO is low, such as 0.5 M, the XRD an analysis of the coating may exhibit limited or weak diffraction peaks that correspond to the crystalline phases of zinc oxide (ZnO). The observed peaks in the coating suggest the potential existence of ZnO nanoparticles, but at relatively modest levels. With an increase in the concentration of ZnO, X-ray diffraction (XRD) patterns may exhibit enhanced intensity and sharper diffraction peaks, which correspond to the crystalline phases of ZnO. These observations suggest a higher abundance of ZnO nanoparticles and an increased level of crystallinity inside the coating. However, when the sample concentration is increased to 2 M, there is a decrease in peak intensity. This decrease can be attributed to the clumping of particles within the solution.

3.6 FTIR

The FTIR spectra of uncoated and coated samples are shown in Fig. 5. The broad band range (3072.39–3515.18 cm^− 1) was attributed to the hydrogen bonding between different O-H groups in the starch. Meanwhile, the band at 2792.23–2913.39 cm^− 1 represented the C-H stretching. The band from 1421.92–1468.60 cm^− 1 indicated the - COOH stretching, and the 1014.42–1088.27 cm^− 1 was the stretching of the C-N bond, which is in agreement with previous reports [69]. Besides, ZnO NPs bands were not clearly observed because of the low concentration. Nevertheless, some studies reported ZnO stretching at 482, 527, 600, 681 and 1050 cm^− 1 [69]. The chemical interactions among substances are indicated by changes in the peaks of characteristic spectra. Current findings indicated that the spectrum of ZnO NPs coating has a slight shift of the bands corresponding to hydroxyl, amino and amide groups towards lower spectral ranges. At 0.5M, the broad absorption peak was at 3320 cm^− 1 due to the presence of water molecules on the nanoparticles surface. The FTIR spectrum's appearance and strength of ZnO-related peaks are variable on the concentration of ZnO nanoparticles inside the polysaccharide ZnO-starch coating. As the concentration of ZnO increases, the intensity and distinguishability of the Zn-O stretching vibration peaks also increase, providing confirmation of the existence of ZnO within the coating. The FTIR results play a crucial role in evaluating the chemical composition of the coating and gaining information about its qualities related to mango preservation.

3.7 HPLC

The sensitivity of organic acids in mangoes to alteration during processing and storage is relatively low. This characteristic makes them valuable for assessing the authenticity index by means of identification and quantitative analysis. [70]. Citric acid is classified as an organic acid and is naturally occurring in several fruits, such as mangoes. The quantification of citric acid level in mango juice or puree holds significance due to its ability to provide insights into the fruits acidity and offer suggestions regarding mango maturity. RP-HPLC is a widely used analytical technique for determining citric acid levels in food products, demonstrating high efficacy in accurately detecting and quantifying organic acids, particularly citric acid.

Citric acid is the primary organic acid in mango; the HPLC was utilised for acid content analysis after the fruits were treated with ZnO-Corn starch coating. The separation of citric acid was identified and quantified using photodiode array detection (DAD), indicating the retention time (Refer Fig. 6). Furthermore, optimal chromatographic conditions (i.e., flow rate of the mobile phase, wavelength and temperature of column) were obtained from the design separation and peak shape of citric acids. The standard citric acid concentration was also analysed (500, 750, 1000 and 2000 ppm), and the calibration graph was evaluated according to the area of response. Later, the linearity was plotted over the concentration ranges. The correlation coefficient was 0.8267 in 500–3000 mAU per injection. Figure 6 illustrates the chromatographic separation of citric acids in mango juice.

The amounts of citric acid found in uncoated and coated mangoes are shown in Fig. 7. The concentration of citric acid in mangoes coated with 2.0 M ZnO-CS NPs was greater than the uncoated mango. This finding aligned with the TA results where the values were higher in 2.0 M ZnO-CS NPs than in uncoated and other treated fruit samples. The variation in mango quality can be attributed to several factors, including the level of fruit maturity, the specific variety of mango, and environmental conditions such as climate, cultivation practises, and growth environment [71]. The corn starch coating, in combination with ZnO nanocomposite, acts as the matrix on mango skin that helps maintain the fruit citric acid content for a certain period. Similarly, it has been claimed by Liu et al. that the postharvest phase has a negligible impact on the starch content of mangoes, in contrast to sugars and organic acids which are susceptible to degradation [72]. Starch is the main carbohydrate accumulated in pre-climacteric mature mango fruit, which reduces gradually during ripening due to hydrolysis. During the process of fruit ripening, the hydrolysis of complex carbohydrates, such as starch, results in the formation of soluble sugars [73]. These sugars mostly comprise glucose, fructose, and sucrose[73]. The application of a coating on the fruits hinders this physiological process, hence preventing the conversion of complex carbs into simpler forms of sugar[74]. The control treatment exhibited a notable increase in overall sugar content, which can be attributed to the mango fruit's respiratory burst. This phenomenon is characterized by significant changes in the biochemical activity of the fruit, hence facilitating the process of fruit ripening [43]. The application of coatings on fruits serves to decelerate the ripening process and degradation that occurs during storage, hence leading to a notable enhancement in the quality and retention of the bioactive components [46].

In conclusion, our research underscores the promise of the polysaccharide ZnO-corn starch coating as an effective tool for preserving mangoes during post-harvest handling. By carefully adjusting the ZnO concentration within the coating, researchers can tailor their approach to achieve specific preservation and quality objectives. This study contributes to the ongoing efforts to develop sustainable and efficient techniques for prolonging the shelf life of mangoes, reducing food loss, and ensuring a reliable supply of premium produce to consumers. This study demonstrated the effects of different nanocomposite coating concentrations to extend the shelf life of mangoes by maintaining moisture content, TSS, pH and the prevention of black spot growth. We observed a clear correlation between the concentration of ZnO in the coating to quality of mango. In addition, the 1.5 M coating solution was optimal in delaying mango ripening, reducing weight loss and colour changes, and inhibiting the growth of microorganisms compared to uncoated fruits. Further exploration and development of this innovative coating technology are warranted to fully unlock its potential and promote its adoption in the agricultural and food industries.

5. ACKNOWLEDGEMENT

We would like to express our gratitude to the Ministry of Higher Education (MOHE) for funding the research via the FRGS grants (600-IRMI/FRGS 5/3 (415/2019)) and Geran Insentif Penyeliaan (GIP) (600-RMC/GIP 5/3 (037/2018)). We would also like to thank the Research Management Institute, University Teknologi Mara (UiTM), Shah Alam, Selangor, Malaysia for the financial support.

6. FUNDING DECLARATION

The authors declare they have no financial interests.

A. Eshetu, A. M. Ibrahim, S. F. Forsido, and C. G. Kuyu, ‘E ff ect of beeswax and chitosan treatments on quality and shelf life of selected mango ( Mangifera indica L .) cultivars’, ELSEVIER, vol. Heliyon 5, no. December 2018, pp. 1–22, 2019, doi: 10.1016/j.heliyon.2018.e01116.
V. Tirado-Kulieva, S. Atoche-Dioses, and E. Hernández-Martínez, ‘Phenolic compounds of mango (Mangifera indica) by-products: Antioxidant and antimicrobial potential, use in disease prevention and food industry, methods of extraction and microencapsulation’, Sci. Agropecu., vol. 12, no. 2, pp. 283–293, 2021, doi: 10.17268/SCI.AGROPECU.2021.031.
J. Domingues, M. Goulão, M. Coelho, J. Gonçalves, and C. S. Pintado, ‘Different postharvest storage conditions of Arbutus unedo L. fruits, and their physicochemical and microbiological characterisation’, Int. Food Res. J., vol. 29, no. 1, pp. 32–41, 2022, doi: 10.47836/ifrj.29.1.04.
T. Odetayo, S. Tesfay, and N. Z. Ngobese, ‘Nanotechnology-enhanced edible coating application on climacteric fruits’, Food Sci. Nutr., vol. 10, no. 7, pp. 2149–2167, 2022, doi: 10.1002/fsn3.2557.
S. Panahirad, R. Naghshiband-Hassani, B. Ghanbarzadeh, F. Zaare-Nahandi, and N. Mahna, ‘Shelf life quality of plum fruits (Prunus domestica L.) improves with carboxymethylcellulose-based edible coating’, HortScience, vol. 54, no. 3, pp. 505–510, 2019.
S. Shah and M. S. Hashmi, ‘Chitosan–aloe vera gel coating delays postharvest decay of mango fruit’, Hortic. Environ. Biotechnol., vol. 61, pp. 279–289, 2020.
S. Ali et al., ‘Carboxymethyl cellulose coating delays ripening of harvested mango fruits by regulating softening enzymes activities.’, Food Chem., vol. 380, p. 131804, Jun. 2022, doi: 10.1016/j.foodchem.2021.131804.
K. Babaremu, O. P. Oladijo, and E. Akinlabi, ‘Biopolymers: A suitable replacement for plastics in product packaging’, Adv. Ind. Eng. Polym. Res., no. xxxx, 2023, doi: 10.1016/j.aiepr.2023.01.001.
S. Sid, R. S. Mor, A. Kishore, and V. S. Sharanagat, ‘Bio-sourced polymers as alternatives to conventional food packaging materials: A review’, Trends Food Sci. Technol., vol. 115, pp. 87–104, 2021, doi: https://doi.org/10.1016/j.tifs.2021.06.026.
J. Sadeghizadeh-Yazdi, M. Habibi, A. A. Kamali, and M. Banaei, ‘Application of edible and biodegradable starch-based films in food packaging: A systematic review and meta-analysis’, Curr. Res. Nutr. Food Sci., vol. 7, no. 3, pp. 624–637, 2019, doi: 10.12944/CRNFSJ.7.3.03.
Y. Fourati, A. Magnin, J.-L. Putaux, and S. Boufi, ‘One-step processing of plasticized starch/cellulose nanofibrils nanocomposites via twin-screw extrusion of starch and cellulose fibers’, Carbohydr. Polym., vol. 229, p. 115554, 2020, doi: https://doi.org/10.1016/j.carbpol.2019.115554.
D. Merino, A. Y. Mansilla, C. A. Casalongué, and V. A. Alvarez, ‘Effect of Nanoclay Addition on the Biodegradability and Performance of Starch-Based Nanocomposites as Mulch Films’, J. Polym. Environ., vol. 27, no. 9, pp. 1959–1970, 2019, doi: 10.1007/s10924-019-01483-2.
H. Cheng et al., ‘Starch-based biodegradable packaging materials : A review of their preparation , characterization and diverse applications in the food industry’, Trends Food Sci. Technol., vol. 114, no. February, pp. 70–82, 2021, doi: 10.1016/j.tifs.2021.05.017.
S. Batool, Z. Hussain, M. B. K. Niazi, U. Liaqat, and M. Afzal, ‘Biogenic synthesis of silver nanoparticles and evaluation of physical and antimicrobial properties of Ag/PVA/starch nanocomposites hydrogel membranes for wound dressing application’, J. Drug Deliv. Sci. Technol., vol. 52, pp. 403–414, 2019, doi: https://doi.org/10.1016/j.jddst.2019.05.016.
B. Naiel, M. Fawzy, M. W. A. Halmy, and A. E. D. Mahmoud, ‘Green synthesis of zinc oxide nanoparticles using Sea Lavender (Limonium pruinosum L. Chaz.) extract: characterization, evaluation of anti-skin cancer, antimicrobial and antioxidant potentials’, Sci. Rep., vol. 12, no. 1, pp. 1–12, 2022, doi: 10.1038/s41598-022-24805-2.
P. Chaudhary, F. Fatima, and A. Kumar, ‘Relevance of Nanomaterials in Food Packaging and its Advanced Future Prospects’, J. Inorg. Organomet. Polym. Mater., vol. 30, no. 12, pp. 5180–5192, 2020, doi: 10.1007/s10904-020-01674-8.
A. Ashfaq, N. Khursheed, S. Fatima, Z. Anjum, and K. Younis, ‘Application of nanotechnology in food packaging: Pros and Cons’, J. Agric. Food Res., vol. 7, no. September 2021, p. 100270, 2022, doi: 10.1016/j.jafr.2022.100270.
C. Dularia, A. Sinhmar, R. Thory, A. K. Pathera, and V. Nain, ‘Development of starch nanoparticles based composite films from non-conventional source - Water chestnut (Trapa bispinosa)’, Int. J. Biol. Macromol., vol. 136, pp. 1161–1168, 2019, doi: https://doi.org/10.1016/j.ijbiomac.2019.06.169.
P. H. Campelo, A. S. Sant’Ana, and M. T. Pedrosa Silva Clerici, ‘Starch nanoparticles: production methods, structure, and properties for food applications’, Curr. Opin. Food Sci., vol. 33, pp. 136–140, 2020, doi: https://doi.org/10.1016/j.cofs.2020.04.007.
I. Kim, K. Viswanathan, G. Kasi, S. Thanakkasaranee, K. Sadeghi, and J. Seo, ‘ZnO Nanostructures in Active Antibacterial Food Packaging: Preparation Methods, Antimicrobial Mechanisms, Safety Issues, Future Prospects, and Challenges’, Food Rev. Int., vol. 38, no. 4, pp. 537–565, 2022, doi: 10.1080/87559129.2020.1737709.
S. Arulkumar, S. Parthiban, A. Goswami, R. S. Varma, M. Naushad, and M. B. Gawande, ‘Fabrication and Characterization of Superhydrophobicity ZnO nanoparticles with two morphologies by using stearic acid’, Mater. Today Proc., vol. 27, no. xxxx, pp. 1–21, 2019, [Online]. Available: https://doi.org/10.1016/j.matpr.2019.12.188%0Ahttps://doi.org/10.1016/j.matpr.2019.09.090%0Ahttps://doi.org/10.1080/14484846.2018.1432089
A. Matloob et al., ‘A Review on Edible Coatings and Films: Advances, Composition, Production Methods, and Safety Concerns’, ACS Omega, vol. 8, pp. 28932–28944, 2023, doi: 10.1021/acsomega.3c03459.
R. Bhaskar, S. M. Zo, K. B. Narayanan, S. D. Purohit, M. K. Gupta, and S. S. Han, ‘Recent development of protein-based biopolymers in food packaging applications: A review’, Polym. Test., vol. 124, no. May, p. 108097, 2023, doi: 10.1016/j.polymertesting.2023.108097.
D. A. da S. Rios, M. M. Nakamoto, A. R. C. Braga, and E. M. C. da Silva, ‘Food coating using vegetable sources: importance and industrial potential, gaps of knowledge, current application, and future trends’, Appl. Food Res., vol. 2, no. 1, p. 100073, 2022, doi: 10.1016/j.afres.2022.100073.
R. H. Kadi, ‘ Development of zinc oxide nanoparticles as safe coating for the shelf life extension of grapes (Vitisvinifera L., Red Globe) fruits ’, Mater. Express, vol. 13, no. 1, pp. 182–188, 2023, doi: 10.1166/mex.2023.2334.
N. Kamarudin,Ainnur Syamira; Asli, Noor Asnida; Hajar, ‘Edible Nanocoating: The Effect of Different Concentrations of Metal Nanoparticles Incorporated with Pollysaccharides-Based Material on Antimicrobial and Antifungal Activity’, Symp. Res. Innov. Food 2021, no. 2016, pp. 2016–2019, 2021.
M. Mizielińska and A. Bartkowiak, ‘Overview of Food Antimicrobial Packaging’, J. S. Tumuluru, Ed. Rijeka: IntechOpen, 2022, p. Ch. 10. doi: 10.5772/intechopen.108666.
E. A. S. Dimapilis, C. S. Hsu, R. M. O. Mendoza, and M. C. Lu, ‘Zinc oxide nanoparticles for water disinfection’, Sustain. Environ. Res., vol. 28, no. 2, pp. 47–56, 2018, doi: 10.1016/j.serj.2017.10.001.
Y. Gao, D. Xu, D. Ren, K. Zeng, and X. Wu, ‘Green synthesis of zinc oxide nanoparticles using Citrus sinensis peel extract and application to strawberry preservation: A comparison study’, LWT, vol. 126, p. 109297, Mar. 2020, doi: 10.1016/j.lwt.2020.109297.
N. F. Rosman et al., ‘Fungal Growth Physicochemical Properties Inhibition by Novel Zinc Oxide/ Glutinous Tapioca Starch Composite’, J. Adv. Res. Appl. Sci. Eng. Technol., vol. 29, no. 1, pp. 76–89, 2022, doi: 10.37934/araset.29.1.7689.
AOAC, ‘Official Methods of Analysis’, 16th ed. Assoc. Off. Anal. Chem., 1994.
A. R. A. Hammam, ‘Technological, applications, and characteristics of edible films and coatings: a review’, SN Appl. Sci., vol. 1, no. 6, pp. 1–11, 2019, doi: 10.1007/s42452-019-0660-8.
B. Yousuf, O. S. Qadri, and A. K. Srivastava, ‘Recent developments in shelf-life extension of fresh-cut fruits and vegetables by application of different edible coatings: A review’, LWT, vol. 89, pp. 198–209, 2018, doi: https://doi.org/10.1016/j.lwt.2017.10.051.
A. H. D. Abdullah et al., ‘Harnessing the Excellent Mechanical, Barrier and Antimicrobial Properties of Zinc Oxide (ZnO) to Improve the Performance of Starch-based Bioplastic’, Polym. Technol. Mater., vol. 59, no. 12, pp. 1259–1267, 2020, doi: 10.1080/25740881.2020.1738466.
A. Sharma, I. M. Sharma, M. Sharma, K. Sharma, and A. Sharma, ‘Effectiveness of fungal, bacterial and yeast antagonists for management of mango anthracnose (Colletotrichum gloeosporioides)’, Egypt. J. Biol. Pest Control, vol. 31, no. 1, 2021, doi: 10.1186/s41938-021-00480-9.
S. Gharpure, R. Yadwade, and B. Ankamwar, ‘Non-antimicrobial and Non-anticancer Properties of ZnO Nanoparticles Biosynthesized Using Different Plant Parts of Bixa orellana’, ACS Omega, vol. 7, no. 2, pp. 1914–1933, Jan. 2022, doi: 10.1021/acsomega.1c05324.
F. S. Daraghmah and T. Qubbaj, ‘Impact of gum arabic and cactus mucilage as potential coating substances combined with calcium chloride treatment on tomato (Solanum lycopersicum L.) fruit quality attributes under ambient storage conditions’, Can. J. Plant Sci., vol. 102, no. 2, pp. 375–384, 2022, doi: 10.1139/cjps-2021-0164.
D. D. La et al., ‘Effects of antibacterial ZnO nanoparticles on the performance of a chitosan/gum arabic edible coating for post-harvest banana preservation’, Prog. Org. Coatings, vol. 151, p. 106057, 2021, doi: https://doi.org/10.1016/j.porgcoat.2020.106057.
M. Sobhy et al., ‘Exploring the potential of zinc oxide nanoparticles against pathogenic multi-drug resistance Staphylococcus aureus from ready-to-eat meat and its proposed mechanism’, Food Control, vol. 156, p. 110117, 2024, doi: https://doi.org/10.1016/j.foodcont.2023.110117.
A. Yadav, N. Kumar, A. Upadhyay, S. Sethi, and A. Singh, ‘Edible coating as postharvest management strategy for shelf-life extension of fresh tomato (Solanum lycopersicum L.): An overview’, J. Food Sci., vol. 87, no. 6, pp. 2256–2290, 2022, doi: 10.1111/1750-3841.16145.
D. Praseptiangga, N. Mufida, C. Panatarani, and I. M. Joni, ‘Enhanced multi functionality of semi-refined iota carrageenan as food packaging material by incorporating SiO2 and ZnO nanoparticles’, Heliyon, vol. 7, no. 5, p. e06963, 2021, doi: https://doi.org/10.1016/j.heliyon.2021.e06963.
H. Babapour, H. Jalali, and A. Mohammadi Nafchi, ‘The synergistic effects of zinc oxide nanoparticles and fennel essential oil on physicochemical, mechanical, and antibacterial properties of potato starch films’, Food Sci. Nutr., vol. 9, no. 7, pp. 3893–3905, 2021, doi: 10.1002/fsn3.2371.
I. Hmmam, M. A.-S. Ali, and A. Abdellatif, ‘Alginate-Based Zinc Oxide Nanoparticles Coating Extends’, Coatings, vol. 13, p. 362, 2023.
N. P. Minh, ‘Synergistic Effect of Methyl Cellulose and Carvacrol Coating on Physicochemical and Microbial Attributes of Mango (Mangifera indica) Fruit in Postharvest storage’, J. Pure Appl. Microbiol., vol. 15, no. 4, pp. 2280–2287, 2021, doi: 10.22207/JPAM.15.4.50.
E. Díaz-Montes and R. Castro-Muñoz, ‘Edible Films and Coatings as Food-Quality Preservers: An Overview’, Foods, vol. 10, no. 2. 2021. doi: 10.3390/foods10020249.
T. T. Pham, L. L. Nguyen, M. S. Dam, and L. Baranyai, ‘Application of Edible Coating in Extension of Fruit Shelf Life: Review’, AgriEngineering, vol. 5, no. 1. pp. 520–536, 2023. doi: 10.3390/agriengineering5010034.
P. Bernabé-Galloway, M. Ángel Ramírez-Arrebato, and Y. Mederos-Torres, ‘Polysaccharide-based films as biodegradable coatings in fruits postharvest’, Cultiv. Trop., vol. 41, no. 3, p. 9, 2020, [Online]. Available: http://ediciones.inca.edu.cu
F. S. Kittur, ‘Polysaccharide-based composite coating formulations for shelf-life extension of fresh banana and mango’, no. October 2001, 2016, doi: 10.1007/s002170100363.
B. Abu Salha and A. Gedanken, ‘Extending the Shelf Life of Strawberries by the Sonochemical Coating of their Surface with Nanoparticles of an Edible Anti-Bacterial Compound’, Appl. Nano, vol. 2, no. 1, pp. 14–24, 2021, doi: 10.3390/applnano2010002.
X. Meng, M. Zhang, and B. Adhikari, ‘The Effects of Ultrasound Treatment and Nano-zinc Oxide Coating on the Physiological Activities of Fresh-Cut Kiwifruit’, Food Bioprocess Technol., vol. 7, no. 1, pp. 126–132, 2014, doi: 10.1007/s11947-013-1081-0.
A. Nawab, F. Alam, and A. Hasnain, ‘Mango kernel starch as a novel edible coating for enhancing shelf- life of tomato (Solanum lycopersicum) fruit’, Int. J. Biol. Macromol., vol. 103, pp. 581–586, 2017, doi: https://doi.org/10.1016/j.ijbiomac.2017.05.057.
J. Wu, Q. Sun, H. Huang, Y. Duan, G. Xiao, and T. Le, ‘Enhanced physico-mechanical, barrier and antifungal properties of soy protein isolate film by incorporating both plant-sourced cinnamaldehyde and facile synthesized zinc oxide nanosheets’, Colloids Surfaces B Biointerfaces, vol. 180, pp. 31–38, 2019.
A. Emamifar and S. Bavaisi, ‘Nanocomposite coating based on sodium alginate and nano-ZnO for extending the storage life of fresh strawberries (Fragaria× ananassa Duch.)’, J. Food Meas. Charact., vol. 14, no. 2, pp. 1012–1024, 2020.
Y. Peralta-Ruiz, C. D. Tovar, A. Sinning-Mangonez, E. A. Coronell, M. F. Marino, and C. Chaves-Lopez, ‘Reduction of Postharvest Quality Loss and Microbiological Decay of Tomato “Chonto” (Solanum lycopersicum L.) Using Chitosan-E Essential Oil-Based Edible Coatings under Low-Temperature Storage’, Polymers, vol. 12, no. 8. 2020. doi: 10.3390/polym12081822.
M. Al-Dairi, P. B. Pathare, and R. Al-Yahyai, ‘Chemical and nutritional quality changes of tomato during postharvest transportation and storage’, J. Saudi Soc. Agric. Sci., vol. 20, no. 6, pp. 401–408, 2021, doi: 10.1016/j.jssas.2021.05.001.
A. Ali, M. Tengku, M. Muhammad, K. Sijam, and Y. Siddiqui, ‘Effect of chitosan coatings on the physicochemical characteristics of Eksotika II papaya ( Carica papaya L .) fruit during cold storage’, Food Chem., vol. 124, no. 2, pp. 620–626, 2011, doi: 10.1016/j.foodchem.2010.06.085.
N. B. Gol, M. L. Chaudhari, and T. V. R. Rao, ‘Effect of edible coatings on quality and shelf life of carambola (Averrhoa carambola L.) fruit during storage’, J. Food Sci. Technol., vol. 52, pp. 78–91, 2015.
M. Vargas, A. Albors, A. Chiralt, and C. González-Martínez, ‘Quality of cold-stored strawberries as affected by chitosan-oleic acid edible coatings’, Postharvest Biol. Technol., vol. 41, no. 2, pp. 164–171, 2006, doi: 10.1016/j.postharvbio.2006.03.016.
N. L. Bambalele, A. Mditshwa, L. S. Magwaza, and S. Z. Tesfay, ‘Postharvest effect of gaseous ozone on physicochemical quality, carotenoid content and shelf-life of mango fruit’, Cogent Food Agric., vol. 9, no. 1, 2023, doi: 10.1080/23311932.2023.2247678.
I. M. Taha et al., ‘Impact of Starch Coating Embedded with Silver Nanoparticles on Strawberry Storage Time’, Polymers (Basel)., vol. 14, no. 7, 2022, doi: 10.3390/polym14071439.
H. Li et al., ‘Smartphone-Based Image Analysis for Rapid Evaluation of Kiwifruit Quality during Cold Storage.’, Foods (Basel, Switzerland), vol. 11, no. 14, Jul. 2022, doi: 10.3390/foods11142113.
Y. Wang, H. Yang, S. Zhong, X. Liu, T. Li, and C. Zong, ‘Variations in sugar and organic acid content of fruit harvested from different Vaccinium uliginosum populations in the Changbai mountains of China’, J. Am. Soc. Hortic. Sci., vol. 144, no. 6, pp. 420–428, 2019, doi: 10.21273/JASHS04740-19.
S. L. Marpudi, P. Ramachandran, and N. Srividya, ‘Aloe vera gel coating for post harvest quality maintenance of fresh fig fruits Research Journal of Pharmaceutical , Biological and Chemical Sciences Aloe vera Gel Coating For Post Harvest Quality Maintenance of Fresh Fig Fruits January-March’, no. January 2013, 2016.
A. Eryani-raqeeb, S. Omar, and M. Zaki, ‘Effects of Different Concentrations and Applications of Calcium on Storage Life and Physicochemical Characteristics of Papaya ( Carica Papaya L .) Al Eryani , Abdul-Rahman Department of Crop Science , Department of Land Management , Faculty of Agriculture’, vol. 3, no. 3, pp. 526–533, 2008.
S. Fakhari, M. Jamzad, and H. Kabiri Fard, ‘Green synthesis of zinc oxide nanoparticles: a comparison’, Green Chem. Lett. Rev., vol. 12, no. 1, pp. 19–24, 2019.
H. Umar, D. Kavaz, and N. Rizaner, ‘Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines’, Int. J. Nanomedicine, vol. 14, pp. 87–100, 2020.
E. Rasha, A. Monerah, A. Manal, A. Rehab, D. Mohammed, and E. Doaa, ‘Biosynthesis of zinc oxide nanoparticles from Acacia nilotica (L.) extract to overcome carbapenem-resistant Klebsiella pneumoniae’, Molecules, vol. 26, no. 7, p. 1919, 2021.
J. N. Hasnidawani, H. N. Azlina, H. Norita, N. N. Bonnia, S. Ratim, and E. S. Ali, ‘Synthesis of ZnO nanostructures using sol-gel method’, Procedia Chem., vol. 19, pp. 211–216, 2016.
S. Wardana, A.A., Suyatma, N.E., Muchtadi, T.R., Yuliani, ‘Influence of ZnO nanoparticles and stearic acid on physical , mechanical and structural properties of cassava starch-based bionanocomposite edible films Influence of ZnO nanoparticles and stearic acid on physical , mechanical and structural properties of ’, Int. Food Res. J, vol. 25, no. 5, pp. 1837–1844, 2018.
V. Nour, I. Trandafir, and M. E. Ionica, ‘HPLC Organic Acid Analysis in Different Citrus Juices under Reversed Phase Conditions’, vol. 38, no. 1, pp. 44–48, 2010.
H. L. Cavalcante, ‘Mango flowering : factors involved in the natural environment and associated management techniques for commercial crops’, pp. 1–43, 2022.
B. Liu et al., ‘Research Progress on Mango Post-Harvest Ripening Physiology and the Regulatory Technologies’, Foods, vol. 12, no. 1, 2023, doi: 10.3390/foods12010173.
S. Durán-Soria, D. M. Pott, S. Osorio, and J. G. Vallarino, ‘Sugar Signaling During Fruit Ripening.’, Front. Plant Sci., vol. 11, p. 564917, 2020, doi: 10.3389/fpls.2020.564917.
E. M. Yahia, A. Carrillo-López, and L. A. Bello-Perez, ‘Chapter 9 - Carbohydrates’, E. M. B. T.-P. P. and B. of F. and V. Yahia, Ed. Woodhead Publishing, 2019, pp. 175–205. doi: https://doi.org/10.1016/B978-0-12-813278-4.00009-9.

No competing interests reported.

GraphicalAbstract.pdf

Download PDF

Editorial decision: Revision requested
19 Jul, 2024
Reviews received at journal
18 Jul, 2024
Reviews received at journal
16 Jul, 2024
Reviewers agreed at journal
11 Jul, 2024
Reviewers agreed at journal
11 Jul, 2024
Reviewers invited by journal
11 Jul, 2024
Editor assigned by journal
10 Jul, 2024
Submission checks completed at journal
10 Jul, 2024
First submitted to journal
05 Jul, 2024

You are reading this latest preprint version

Preserving Mango Quality: Assessing the Influence of Zinc Oxide Nanocomposite-corn Starch Coating Concentrations on Postharvest Attributes

Status:

Version 1

Abstract

Figures

1. INTRODUCTION

2. METHODOLOGY

2.1 ZnO NPs PREPARATION WITH A FILLER

2.2 COATING OF MANGO AND MOULD INOCULATION

2.3 WEIGHT LOSS AND MOISTURE CONTENT

2.4 DISEASE INCIDENCE

2.5 STORAGE QUALITY EVALUATION (TSS,pH and TA)

2.6 CHARACTERIZATION TECHNIQUES

3. DISCUSSION

3.1 DISEASE INCIDENCE

3.2 WEIGHT LOSS

3.3 TOTAL SOLUBLE SOLID (TSS), pH AND TITRATABLE ACIDITY

3.4 FESEM AND EDX

3.5 XRD

3.6 FTIR

3.7 HPLC

4. CONCLUSION

Declarations

References

Additional Declarations

Supplementary Files

Status:

Version 1