EDIBLE COATING COMPOSITE, METHOD OF PREPARATION AND ITS APPLICATION THEREOF

Abstract

The present disclosure relates to a edible coating composite comprising: 70 to 90 % v/v of a tamarind extract; 10 to 30 % v/v of a preservative; and 0.1 to 2 % w/v of a thickening agent. The present disclosure also relates to method of preparation of an edible coating composite comprising: a) mixing 10 to 30 % v/v of a preservative in 70 to 90 % v/v of a tamarind extract followed by heating to obtain a mixture; b) adding 0.1 to 2 % w/v of a thickening agent in the mixture of step a) to obtain a gel; and c) processing the gel of step b) by ball-milling under condition to obtain an edible coating composite. The present disclosure also provides method of preparation of a surface coated fruits and vegetables comprising: applying an edible coating composite as claimed in claim 1 to the surface of the fruits and vegetables by dip coating to obtain a surface coated fruits and vegetables, wherein the edible coating composite reduces pesticide residues on fruits and vegetables.

Specification

Description:FIELD OF THE INVENTION
[0001] The present disclosure relates to a field of food and agriculture. Particularly, the present disclosure relates to an edible coating composite. The present disclosure also provides a method of preparation of an edible coating composite. The present disclosure provides a surface coated fruits and vegetables by using the edible coating composite.

BACKGROUND OF THE INVENTION
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] To protect crops from pests, illnesses, and weeds, pesticide use in horticulture has long been a standard practice. Pesticide residues in horticulture products, however, have prompted worries about their safety and potential health implications for users [MCR Alavanja, Rev. Environ. Health, 2009, 24(4), 303-310; PC Abhilash and N Singh, J. Hazard. Mat., 2009, 165, 1-12]. Two typical pesticides used in horticulture to manage pests and insects are chlorpyrifos and lambda cyhalothrin. However, it has been established that ingesting these chemicals through tainted food can have detrimental consequences on human health. An organophosphate pesticide named chlorpyrifos works by preventing the functioning of the enzyme acetylcholinesterase, which overstimulates the nervous system. Developmental delays in children and neurological illnesses like Parkinson's disease have both been linked to prolonged exposure to chlorpyrifos [NK Nandi et al., Pestic. Biochem. Phys., 2022, 185, 105138]. It has been demonstrated that eating produce contaminated with pesticide increases the chance of negative health impacts. For instance, a study carried out in India discovered that numerous commonly consumed vegetables contained high amounts of chlorpyrifos residues, and eating these vegetables was linked to an elevated risk of liver and kidney damage [ET Wan et al. Int. J. Environ. Res. Public Health, 2021, 18 (19)]. The precise processes through which pesticides may cause cancer are not entirely understood, despite some data indicating that prolonged exposure to pesticides may increase the risk of cancer in people. For instance, chlorpyrifos has been labelled as a potential human carcinogen by the US Environmental Protection Agency (EPA) based on animal studies that revealed a higher incidence of lung tumours in rats exposed to high amounts of the chemical [L Ezzi et al., ESPR, 2016, 23(5), 4859-4867; E Wolejko et al., Int. J. Environ. Res. Public Health, 2022, 19(19)]. The data connecting chlorpyrifos to cancer in people, however, is less certain. For instance, a study carried out in Egypt discovered that employees exposed to high doses of chlorpyrifos had a markedly elevated chance of acquiring lung cancer [E Wolejko et al., Int. J. Environ. Res. Public Health, 2022, 19(19)]. There is some evidence to support the idea that exposure to chlorpyrifos can alter hormone levels in both humans and rats as well as the gut microbiome. According to research, disturbances in the gut flora can cause hormonal imbalances and have a significant impact on how the endocrine system functions. It has been demonstrated that exposure to pesticides like chlorpyrifos changes the gut microbiome in both humans and animals. For instance, exposure to chlorpyrifos resulted in an increase in the number of dangerous bacteria and a decrease in the variety of the gut microbiota in a study of rats [C Ventura et al., J. Steriod Bioche. Mol Biol., 2016, 156, 1-9].
[0004] In addition, fruits and vegetables have a limited shelf life due to the development of germs, moisture loss, and enzymatic reactions, which can result in decreased quality and monetary losses. Researchers have been looking into different approaches to decrease pesticide residues and lengthen the shelf life of horticulture products in order to address these issues. Utilizing plant-based edible coatings, which have antibacterial and antioxidant characteristics and can operate as a physical barrier against external elements including moisture, oxygen, and pathogens, is one possible strategy [Saxena et al., Biopolymer-Based Formulations, Elsevier, 2020, 859-880]. The three main categories of edible coatings protein-based coatings, polysaccharide-based coatings, and lipid-based coatings are those that have been created for use in food applications. For meat and poultry products, protein-based coatings including casein, soy protein, and whey protein are frequently employed [Chhikara et al., JPTR, 2022, 6(1), 1-10]. Fruits and vegetables frequently include polysaccharide-based coverings, such as cellulose, chitosan, and starch. Beeswax, shellac, and plant oils are lipid-based coatings that are frequently used on fruits, nuts, and confectionery items. Casein, whey, and soy protein-based coatings, which can act as a barrier against moisture loss and microbial growth, have been employed for meat and poultry products [Gautam et al., Foods. 2023, 12(4)]. Due to their capacity to prolong shelf life by preventing microbiological growth and enzymatic browning, polysaccharide-based coatings, such as chitosan, have been applied on fruits and vegetables. To provide fruits, nuts, and confectionery goods a glossy appearance and moisture barrier, lipid-based coatings such as beeswax and plant oils have been utilized.
[0005] CN201810645369A discloses a kind of concentration fruits and vegetables detergent powder having parts by weight modified activated carbon-polyaluminum ferric chloride composite particles 10-20, alkyl glycosides 30-50, dodecanamide propyl amine oxide 15- 20, guar gum 10-15, sodium chloride 5-10.
[0006] CN201910301536A discloses a kind of preparation methods of environmental and durable food wrapper, include the following steps: (1) pretreatment of raw material (2) slurrying (3) preparation of auxiliary material (4) preparation of mixture (5) preparation of finished product.
[0007] CN201611172888A discloses the fresh-keeping preparation of a kind of fruit, vegetable cold storing, it is characterised in that: It is made up of following mass fraction formula components: citric acid 4-8 parts, food emulsifying agent 1-3 parts, light eleostearic acid 2-4 parts, liquid chlorine dioxide 7-9 parts, ammonium hydroxide 6-8 parts, food paraffin wax 1-2 parts, calcium stearate 3-7 parts, powdered activated carbon 6-10 parts, tween 2-3 parts, guar gum 2-4 parts, semen sojae atricolor separate-25 parts of protein 15, hydrogen peroxide 15-25 parts.
[0008] IN 202311010558A discloses a composite edible film coating composition used as antimicrobial, edible coatings for fruits and vegetables, comprises buckwheat starch, guar gum solutions, essential oil, namely curry leaf oil, and plasticizer such as D-sorbitol, citric acid, glycerol, urea and epichlorohydrin.
[0009] Overall, these studies suggest that chlorpyrifos can have negative effects on the endocrine system, gut microbiota, and reproductive functions. There is a lack of effective, natural methods to remove or degrade pesticides from produce surfaces while also enhancing shelf life. Thus, there is a need to remove or degrade these pesticides from the food before consumption.

OBJECTIVES OF THE INVENTION
[00010] An objective of the present disclosure is to provide an edible coating composite.
[00011] Another objective of the present disclosure is to provide a method of preparation of an edible coating composite.
[00012] Still another objective of the present disclosure is to provide a method of preparation of surface coated fruits and vegetables.
[00013] Yet another objective of the present disclosure is to a plant polysaccharides based sustainable coating for extension of shelf-life and removal of pesticides in horticulture produce.

SUMMARY OF THE INVENTION
[00014] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in Detailed Description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
[00015] An aspect of the present disclosure provides edible coating composite comprising: 70 to 90 % v/v of a tamarind extract; 10 to 30 % v/v of a preservative; and 0.1 to 2 % w/v of a thickening agent.
[00016] Another aspect of the present disclosure provides method of preparation of an edible coating composite comprising: a) mixing 10 to 30 % v/v of a preservative in 70 to 90 % v/v of a tamarind extract followed by heating to obtain a mixture; b) adding 0.1 to 2 % w/v of a thickening agent in the mixture of step a) to obtain a gel; and c) processing the gel of step b) by ball-milling under condition to obtain an edible coating composite.
[00017] Still another aspect of the present disclosure provides a method of preparation of a surface coated fruits and vegetables comprising: applying an edible coating composite as defined above to the surface of the fruits and vegetables by dip coating to obtain a surface coated fruits and vegetables, wherein the edible coating composite reduces pesticide residues on fruits and vegetables.
[00018] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the exemplary embodiments of the invention.

DESCRIPTION OF THE FIGURES
[00019] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[00020] Figure 1 illustrates FTIR spectrum of (a) chlorpyrifos, (b) tamarind pulp extract, (c) chlorpyrifos-vinegar mix, (d) chlorpyrifos treatment with tamarind pulp extract showing, (e) chlorpyrifos treatment with tamarind-vinegar mix.
[00021] Figure 2 illustrates the DPPH assay showing the free radical scavenging activity of (a) vinegar, (b) tamarind, and (c) tamarind-vinegar mixture at different dilution (%).
[00022] Figure 3 illustrates BET analysis for the estimation of pore size of (a) unmilled guar gum (pore size: 0.01 nm), ball milled guar gum (pore size: 10 nm), and (c) guar gum composites (pore size: 21 nm).
[00023] Figure 4 illustrates FE-SEM of (a) unmilled guar gum film at 2µm scale, (b) ball-milled guar gum at 2µm scale, (c) unmilled guar-gum composite 10µm scale, (d) unmilled guar gum composite at 2µm scale, (e) ball milled guar gum composite at 100 µm scale, and (f) ball-milled guar gum composite at 2µm scale.
[00024] Figure 5 illustrates HPLC analysis for (a) tamarind at 2 dilutions, (b) chlorpyrifos at 2 dilutions, (c) tamarind treated chlorpyrifos at 2 different dilutions, (d) the CPF treated leaf having the RT at 8.31 minutes, (e) the peak obtained after washing leaf in water at the same retention time of 8.31 minutes.
[00025] Figure 6 illustrates antibacterial studies for (a) guar gum as a blank against E.coli, (b) unmilled guar-gum composite film (tamarind-vinegar) against E.coli, (c) ball-milled nanocomposite against E.coli, (d) guar gum as a blank against S.aureus, (e) unmilled guar gum composite against S.aureus, (f) ball-milled guar gum composite against S.aureus.
[00026] Figure 7 illustrates contact angle measurement for hydrophobic nature of guar gum film and its composites shown below (a) unmilled guar gum film (22.33°), (b) ball-milled guar gum film (73.71°), (c) unmilled guar gum composite (50.67°), (d) ball-milled guar gum composite (73.57°).
[00027] Figure 8 illustrates morphological studies done of model (a) fruit banana from day 1 to day 14 (showing peeled banana and (b) sapodilla fruits from day 1 to day (Note: C: coated; NC: non-coated).

DETAILED DESCRIPTION OF THE INVENTION
[00028] The following is a detailed description of embodiments of the disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[00029] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[00030] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[00031] In some embodiments, numbers have been used for quantifying weights, percentages, ratios, and so forth, to describe and claim certain embodiments of the invention and are to be understood as being modified in some instances by the term "about." Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable.
[00032] The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[00033] Unless the context requires otherwise, throughout the specification which follows, the word "comprise" and variations thereof, such as "comprises" and "comprising" are to be construed in an open, inclusive sense that is as "including, but not limited to."
[00034] As used in the description herein and throughout the claims that follow, the meaning of "a," "an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.
[00035] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. Furthermore, the ranges defined throughout the specification include the end values as well, i.e., a range of 1 to 10 implies that both 1 and 10 are included in the range. For the avoidance of doubt, the applicant shall be entitled to any equivalents according to applicable law.
[00036] All methods described herein can be performed in a suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[00037] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified.
[00038] The description that follows, and the embodiments described therein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles and aspects of the present disclosure. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the disclosure.
[00039] It should also be appreciated that the present disclosure can be implemented in numerous ways, including as a system, a method or a device. In this specification, these implementations, or any other form that the invention may take, may be referred to as processes. In general, the order of the steps of the disclosed processes may be altered within the scope of the invention.
[00040] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
[00041] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
[00042] The term "or", as used herein, is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.
[00043] Various terms are used herein to the extent a term used is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[00044] Concerns arise from pesticide use in horticulture, posing health risks like neurological disorders and respiratory issues. The present disclosure provides an edible coating with tamarind extract, a thickening agent and a preservative, effectively removing pesticides from produce and extending shelf life. Thus, the present disclosure offers a solution for degrading hazardous pesticides named chlorpyrifos from the surface of fruits and also improves the shelf-life of perishable fruits by acting as a shield. The coating is plant based and free from any synthetic chemicals. This natural coating shows promise for widespread use in improving food safety.
[00045] An embodiment of the present disclosure provides an edible coating composite comprising: 70 to 90 % v/v of a tamarind extract; 10 to 30 % v/v of a preservative; and 0.1 to 2 % w/v of a thickening agent.
[00046] In a preferred embodiment, the tamarind extract is added in the range of 71 to 89 %v/v or 72 to 88 %v/v or 73 to 87 %v/v or 74 to 86 %v/v or 75 to 85 %v/v or 76 to 84 %v/v or 77 to 83 %v/v or 78 to 82 %v/v or 79 to 81 %v/v or 80 %v/v.
[00047] In a preferred embodiment, the preservative is added in the range of 11 to 29 % v/v or 12 to 28 % v/v or 13 to 27 % v/v or 14 to 26 % v/v or 15 to 25 % v/v or 16 to 24 % v/v or 17 to 23 % v/v or 18 to 22 % v/v or 19 to 21 % v/v or 20 % v/v.
[00048] In a preferred embodiment, the preservative and tamarind extract are added in a ratio of 1:4.
[00049] In a preferred embodiment, the preservative is added in the range of 0.1 to 1.9 %w/v or 0.2 to 1.8 %w/v or 0.3 to 1.7 %w/v or 0.4 to 1.6 %w/v or 0.5 to 1.5 %w/v or 0.6 to 1.4 %w/v or 0.7 to 1.3 %w/v or 0.8 to 1.2 %w/v or 0.9 to 1.1 %w/v or 1 %w/v.
[00050] In an embodiment, the preservative is selected from a group consisting of vinegar, lemon juice, citric acid, clove oil, thyme oil, honey, ascorbic acid and combination thereof. Preferably, the preservative is vinegar.
[00051] In an embodiment, the thickening agent is selected from a group consisting of guar gum, guar gum, xanthan gum, tragacanth gum, pectin, agar agar, tapioca starch, corn starch, gelatin, methyl cellulose, carrageenan and combination thereof. Preferably, the thickening agent is guar gum, xanthan gum, tragacanth gum, pectin, agar agar, tapioca starch. More preferably, the thickening agent is guar gum.
[00052] Another embodiment of the present disclosure is to provide a method of preparation of an edible coating composite comprising: a) mixing 10 to 30 % v/v of a preservative in 70 to 90 % v/v of a tamarind extract followed by heating to obtain a mixture; b) adding 0.1 to 2 % w/v of a thickening agent in the mixture of step a) to obtain a gel; and c) processing the gel of step b) by ball-milling under condition to obtain an edible coating composite.
[00053] In an embodiment, the edible coating composite is poured into the petri-dish followed by drying at a temperature in the range of 50 to 70 °C for a period in the range of 8 to 12 hrs to obtain an edible coating composite thin film. Preferably, drying is carried out at a temperature in the range of 60 °C for a period in the range of 10 hrs.
[00054] In an embodiment, the heating in step a) is carried out at a temperature in the range of 35 to 55 °C. Preferably, the heating in step a) is carried out at a temperature of 45 °C.
[00055] In an embodiment, the condition in step c) includes speed in the range of 100 to 300 rpm for 20 to 40 cycles for a period in the range of 1 to 10 min. Preferably, the condition in step c) includes speed of 200 rpm for 30 cycle for a period of 5 min.
[00056] In an embodiment, the tamarind extract is prepared by the steps comprising: adding 2 to 5 % w/v of tamarind pulp in the water to form mixture; heating the mixture at a temperature in the range of 50 to 70 °C with stirring in a speed in the range of 400 to 600 rpm till completely dissolve followed by filtration to obtain a clear tamarind aqueous solution; processing the tamarind aqueous solution by centrifugation at a speed in the range of 5000 to 10000 rpm for a period in the range of 10 min to 30 min to obtain tamarind extract.
[00057] In a preferred embodiment, the tamarind pulp is added in the water in the range of 2 to 4 % w/v or 3 to 4% w/v or 4%.
[00058] In a preferred embodiment, the mixture is heated at a temperature of 60 °C with stirring speed of 500 rpm.
[00059] In a preferred embodiment, the centrifugation is carried out at a speed of 8000 rpm for a period of 20 min.
[00060] Another embodiment of the present disclosure is to provide a method of preparation of a surface coated fruits and vegetables comprising: applying an edible coating composite as defined above to the surface of the fruits and vegetables by dip coating to obtain a surface coated fruits and vegetables, wherein the edible coating composite reduces pesticide residues on fruits and vegetables.
[00061] In an embodiment, the edible coating composite forms a protective barrier that effectively removes or degrades pesticide residues while extending the shelf life of the fruits and vegetables.
[00062] Guar gum, a naturally occurring polysaccharide obtained from the seeds of the guar plant, has been demonstrated to have characteristics that help create films and bind water.
[00063] The tropical fruit tree tamarind (Tamarindus indica) is cultivated extensively around the world. Due to its many health benefits, tamarind has been utilised for generations in traditional medicine and food. Some of the tamarind's qualities include anti-inflammatory, antimicrobial etc. Tamarind extract is a great source of antioxidants and has been shown to be effective against fungi and bacteria.
[00064] Vinegar is a weak acid that can lower the pH of produce's surface, which can stop microbial growth and lessen enzymatic activity, vinegar, which is acetic acid in aqueous solution, can be employed as a cross-linker to help guar gum create films. The hydroxyl groups on the molecules of guar gum react with acetic acid to generate ester bonds, which cross-link the polymer chains. The film becomes stronger and more stable. The ability of tamarind to break down these chemicals has been studied in many studies. For instance, one investigation discovered that tamarind extract could breakdown chlorpyrifos in contaminated water with up to 94% effectiveness after 24 hours of treatment [M Nowowi et al., J Environ Chem Ecotoxicol., 2016, 8(7), 69-72]. Compared to conventional procedures, the use of tamarind to remove pesticides has several benefits. These elements are safe to employ in the manufacturing of food because they are natural and non-toxic. They are also a viable option for pesticide removal because they are readily accessible and reasonably priced. The edible coating composite of the present disclosure contains three ingredients i.e. Tamarind, vinegar and guar gum. Tamarind is used for removing or breakdown chlorpyrifos while vinegar is used as a plasticizer to make the guar gum composite film flexible. This composition is better as it serves two purposes (i) to remove chlorpyrifos and (ii) act as coating for enhancing the shelf-life of horticulture produce.
[00065] The edible coating to remove pesticides and enhance shelf life presents substantial market potential due to its scalability across various sectors. With increasing consumer demand for safe and sustainable food products, this solution caters to a wide market of farmers, food processors, retailers, and consumers globally. Its adaptability to different types of fruits and vegetables ensures broad applicability, while its eco-friendly nature aligns with growing trends towards organic and natural food options. As such, the innovation holds promise for large-scale adoption and commercialization in the agricultural and food industries.
[00066] The present disclosure includes the specific combination and proportions of guar gum, tamarind extract, and vinegar, as well as the process for coating fruits and vegetables to effectively remove or degrade pesticides while extending shelf life.
[00067] In accordance with an embodiment, the ingredients of the composite composition of the present disclosure are commercially procured from the following trader:
S. No. INGREDIENTS TRADER
1 Tamarind pulp Brand name: Vedaka Slab; Manufacture- Amazon retail India Pvt Ltd. Purchased from Amazon.com
2 Guar gum Purchased from SRL Chemicals- India
3 Vinegar Brand name: DiSano; Manufacture- Das Foodtech Pvt. Ltd. Purchased from Amazon.com

[00068] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
EXAMPLES
[00069] The present invention is further explained in the form of the following examples. However, it is to be understood that the following examples are merely illustrative and are not to be taken as limitations upon the scope of the invention.
Example 1: Preparation of aqueous solution of tamarind extract
[00070] Weigh out 5 g of tamarind pulp to start the process of extracting a transparent tamarind aqueous solution from tamarind pulp. In a glass beaker, add 75 mL of water to the tamarind pulp and bring the mixture to a boil at 60 °C while stirring at 500 rpm to ensure that the pulp extract is completely dissolved. Once the ingredients have been dissolved, turn off the heat and filter the mixture to get rid of any remaining seeds or solids. To obtain a clear tamarind aqueous solution, transfer the strained solution to a centrifuge tube and centrifuge at 8000 rpm for 20 minutes. Lastly, pour the clear solution (approx. volume 50 mL) into an airtight glass bottle and keep the tamarind solution at 4 °C to prevent it from getting spoiled until needed for further experimental use.
Example 2: (A) Preparation of composite solution and thin film of guar-gum
[00071] Take out 40 mL of the tamarind extract solution that has been prepared and refrigerated before beginning to create a composite solution with it. Then, add 10 mL of vinegar to the 40 mL of tamarind solution (Table 1). Heat the mixture by keeping it on a magnetic stirrer at 45°C. Add 0.5 g of guar gum powder while stirring the mixture. The mixture will become viscous once the guar gum powder is added, making it into a gel. All the tamarind's active ingredients will be encapsulated in this gel, and the vinegar will assist the guar gum polymer become crosslinked. After the formation of composite solution of guar-gum, tamarind, and vinegar, it will be ball-milled (@200 rpm for 30 cycles @5minutes milling and 5 minutes pause using tungsten carbide jar and 5mm and 2mm balls) to make tamarind extract uniformly dispersed in guar gum composite, after that the composite solution is poured into the petri-dish of 60 mm and allowed to dry overnight in a hot air oven at 60 °C, next day the thin film was peeled out from the petri-dish for further characterisation and applications.
Table 1: Edible coating composite.
Ingredient Amount (gm/ml) Amount (%)
Tamarind extract 40 mL 80 % v/v
Vinegar 10 mL 20 % v/v
Guar gum 0.5 gm 1 % w/v

(B) Characterization of composite solution and thin film
(i) Fourier transform infrared (FTIR)
[00072] The chemical compositions and potential applications of various substances can be explored by analysing and comparing their recorded FTIR spectra. These substances include guar gum composite, tamarind, chlorpyrifos, chlorpyrifos treated with tamarind/Vinegar and guar gum composite. This analysis aims to elucidate their chemical compositions and explore their potential applications across various fields. Figure 1(a) presenting the FTIR spectrum of CPF demonstrates the presence of distinctive absorption bands at 2986, 1551, 1413, 1272, 1169, 1019, 970, 828, and 674 cm-1. These bands can be attributed to the stretching of C-H bonds, the stretching of C-O bonds, the stretching of C=N bonds, the stretching of pyridine, the vibration of the ring, the breathing of the ring, the presence of P-O-C, the stretching of P =S bonds, and the stretching of C-Cl bonds, respectively. The spectra of tamarind in Figure 1(b) exhibited a prominent band ranging from 3000 to 3700 cm-1, which is associated with the presence of hydrogen bonds and the stretching of the O-H bond in carbohydrates, carboxylic acids, and residual water. The peak observed between 2850 and 3000 cm-1 can be attributed to the stretching of SP3 C-H bonds. Furthermore, the peak observed at 1730-1750 cm-1 is assigned to the stretching of C=O bonds in carboxylic acids and esters. The peaks detected between 1632 and 1695 cm-1 and 1400-1450 cm-1 signify the stretching of C=O bonds in amides and the bending of a-CH2 bonds. Additionally, the peaks appearing around 1308-1212 cm-1 indicate the presence of proanthocyanidins, which are the primary polyphenolic constituents in tamarind pulp. Peaks observed between 1060 and 1150 cm-1 correspond to the stretching of C-O bonds in organic acids and sugars. Peaks ranging from 880 to 995 cm-1 are attributed to the bending of =CH and =CH2 bonds, while peaks at 780-846 cm-1 reflect the bending of CH bonds and ring puckering.
[00073] The treatment of CPF with the tamarind results in the disruption of the bonds as shown in the Figure 1 (d). The characteristic bond disruption in CPF structure occurs at 674 cm-1 (C-Cl), 828 cm-1 (P-O-C), 970 cm-1 (P=S) in the presence of TAM, C=O peak sharpening between 1632-1495 cm-1 in CPF treated TAM which was broad in TAM before the treatment.
[00074] In the presence of vinegar Figure 1(c), the CPF peak from 2966-2924 cm-1 changes to a single sharp peak at 2927 cm-1, a sharp peak observed at 2158 cm-1 in vinegar treated CPF which was not found in CPF band. Similarly, tamarind-vinegar treated CPF also shows major peaks of tamarind which conforms that tamarind have a very good clansisng and degrading properites in Figure 1(e).
ii) DPPH assay
[00075] The DPPH assay is widely used to calculate the antioxidant potential of different substances. In this procedure, a 100µM methanolic solution of DPPH is prepared, 0.5 mL of methanolic solution of DPPH is mixed with 0.1 mL volume of different concentrations of tamarind extract, vinegar, and their composites. After the mixture has been incubated for 20 minutes at 37°C in the dark, 100 µL of each sample is then added to a 96-well plate. The absorbance of each sample is measured at 517 nm using a multiplate reader or UV-vis spectrophotometer. The activity of tamarind, vinegar and its composites to scavenge free radicals is calculated using the following formula.
[00076] Scavenging activity (%) = (AD517-AS517)/AD517 × 100. {A.D. and AS are the absorbance of DPPH solution (without-antioxidants) sample solution (with antioxidants)}, respectively.
[00077] The antioxidant properties of vinegar, tamarind and tamarind-vinegar composite was evaluated at different concentration. The concentration used for assessing the antioxidant properties of vinegar was 100 % pure vinegar solution, 50% diluted and 25% diluted. Tamarind was diluted from a stock of 0.1 g/mL into 3 different dilutions of 100 mg/mL, 50 mg/mL, 25 mg/mL. The tamarind-vinegar composite was created by mixing the 100 mg/mL tamarind stock solution with 100% vinegar in three different ratios: 1:1, 2:1, and 4:1. The free radical scavenging properties of these dilutions were measured using a specified protocol. According to the study's findings, tamarind has a scavenging activity of 41.22% at 25 mg/mL, 44.95% at 50 mg/mL, and 47.81% at 100 mg/mL shown in Figure 2 (b). Vinegar showed scavenging activity of 28.89% at 25% dilution, 40.02% at 50% dilution, and 61.33% in its purest form in Figure 2(a). When tamarind and vinegar were combined in different ratios, the composite showed scavenging activity of 42.20% at a 1:1 ratio, 48.12% at a 2:1 ratio, and 49.9% at a 4:1 ratio in Figure 2(c). The study concludes that vinegar and tamarind both have antioxidant characteristics, and that a composite made of tamarind and vinegar also has considerable scavenging activity. Utilisation of antioxidant capabilities of vinegar and tamarind can help delay oxidation, maintain nutrients, improve food safety, improve texture, and provide an environmentally beneficial method of preserving fruits and vegetables.
iii) Brunauer-Emmett-Teller (BET)
[00078] In the context of pore size analysis utilizing the Brunauer-Emmett-Teller (BET) method, distinct observations were made concerning guar gum films derived from various starting materials as shown in Figure 3. Specifically, the initial guar gum film synthesized from microparticle-sized powder exhibited a nominal pore size of 0.01 nanometers, as determined through BET analysis. Conversely, the pore size of a guar gum film derived from ball-milled guar gum powder was notably larger, measuring at approximately 10 nanometers. This substantial difference in pore size can be attributed to the mechanical forces exerted during the ball-milling process. The process of ball milling serves to diminish the particle dimensions of guar gum powder to the nanoscale. The smaller particles of guar gum have the possesses the property of aggregation which leads to the large interaggregate pores. As an outcome, this phenomenon precipitates an augmentation in porosity and concomitant development of larger pores within the material. Moreover, when a composite film was created by combining ball-milled guar gum with vinegar and tamarind, the resulting pore size distribution exhibited a significant expansion, measuring approximately 21 nanometers. This variation in pore size distribution suggests that the introduction of additional components, such as vinegar and tamarind, had a discernible impact on the porous characteristics of the composite film, likely due to interactions between the constituents. These findings offer valuable insights into the structural modifications and porosity of guar gum films under different processing conditions.
iv) Field emission-Scanning electron microscope
[00079] Using a Field-Emission Electron Microscope (FE-SEM) (Ultra-Plus Carl Zeiss), the morphology of the guar gum composite thin film was examined. The samples were mounted in FE-SEM at 10.0 kV after being gold-sputtered for 70 s using a Denton gold sputter device.
[00080] The morphological characteristics of thin films derived from unmilled and ball-milled guar gum powders were investigated utilizing field-emission scanning electron microscopy (FE-SEM) as shown in the Figure 4. Additionally, analysis extended to unmilled guar gum composite films-prepared from unmilled guar gum composite solutions-and ball-milled guar gum composite films prepared from ball-milled guar gum composite solutions. The primary objective was to discern particle distribution and arrangement within the films. Results revealed that the ball-milled guar gum composite film exhibited a homogeneous arrangement of tamarind particles, contrasting with the coarse and non-uniform distribution observed in the unmilled guar gum composite film. Moreover, the ball-milled guar gum film displayed a porous structure, whereas the unmilled film lacked discernible pore sizes in the captured images.
v) Sample preparations for estimation of compounds using High-Performance Liquid Chromatography (HPLC)
[00081] In the preparation of samples for High-Performance Liquid Chromatography (HPLC) analysis, meticulous procedures were adhered to for chlorpyrifos, tamarind extract, vinegar, and tamarind-treated chlorpyrifos solutions. The chlorpyrifos solution was formulated by dissolving 500 microliters of chlorpyrifos in 100 mL of HPLC-grade water followed by syringe filtration. Tamarind extract preparation involved dissolving 5 grams of tamarind pulp in 75 mL of HPLC-grade water, subjecting the solution to boiling at 60 °C under magnetic stirring, and subsequent centrifugation and syringe filtration. Two dilutions were derived from both tamarind and chlorpyrifos solutions. For chlorpyrifos, dilutions of 3 µL/mL, and 5 µL/mL were prepared, while tamarind dilutions were obtained from the extracted stock, then further diluted to make 1 mg/mL and 2 mg/mL using HPLC grade water. Regarding the treatment process, a 2 µL/mL and 5 µL/mL chlorpyrifos stock underwent treatment with two different dilutions of tamarind respectively. For further confirmation a plant leaf was dipped in chlorpyrifos solution of concentration 5µL/mL, the same leaf was then washed in running water and then dipped in HPLC grade water for 15 minutes (under magnetic stirrer) to test the chlorpyrifos peak detection in HPLC. The same leaf was then dipped in the tamarind solution of 2mg/mL concentration for treatment for 15 minutes and then leaf treated solution was analysed using HPLC for chlorpyrifos peak detection.
[00082] The HPLC analysis was executed employing an 80% HPLC-grade methanol and 20% HPLC-grade water composition as the mobile phase, maintaining a consistent flow rate of 1.00 mL/hr over a duration of 20 minutes.
[00083] Investigation via High-Performance Liquid Chromatography (HPLC) revealed a notable degradation in the structural integrity of chlorpyrifos upon exposure to tamarind extract. The peaks corresponding to the constituents of the tamarind extract maintained consistent retention times (2.83 min) between the treated and untreated samples Figure 5 (a, c). The characteristic sharp peak representing chlorpyrifos at 270 nm and a retention time of 8.81 minutes in Figure 5(b) was conspicuously absent following treatment with tamarind extract shown in Figure 5(c). The CPF treated leaf have shown the RT at 8.31 minutes shown in Figure 5(d) and peak obtained after washing leaf in water was also at the same retention time shown in figure 5(e), but the treatment of leaf with tamarind disintegrates the CPF characteristic peak and follows the same pattern as was observed in figure 5(c). The subset of multiple peaks is observed in the 5 (d,e) due to the multiple compounds present in leaf.
(vi) Antimicrobial culture
[00084] The antibacterial effectiveness of a guar gum composite thin film composed of guar gum, tamarind extract, and vinegar was tested in this experiment against a control guar gum film using a disc diffusion assay and serial dilution method. The test organisms chosen were E. coli and S. aureus. On Luria Bertani agar and Nutrient agar plates respectively, bacterial cultures were distributed, and discs impregnated with thin films of guar gum and controlled films of guar gum were placed on the plates. The plates were incubated at 37°C for 24 hours, and a ruler was used to measure the zone of inhibition surrounding each disc. While, for serial dilution the combination of tamarind extract (2mg/mL) and vinegar in a ratio of 4:1 was used. The initial load 108 cells/mL, which were serially diluted to 10-1 to 10-5 and 200uL of tamarind-vinegar mixture added to each tube and kept for 24 hours.
[00085] The evaluation of antimicrobial efficacy in guar gum films was conducted through a disk diffusion assay. Notably, unmilled and ball-milled guar gum films exhibited no discernible antibacterial activity. In stark contrast, the unmilled and ball-milled guar gum composite films demonstrated pronounced antibacterial effects against both gram-positive S. aureus and gram-negative E. coli bacteria as shown in Figure 6. This notable antimicrobial activity observed in the guar gum composite films can be attributed to the incorporation of tamarind and vinegar extracts. The presence of these extracts within the composite films appears to confer strong antibacterial properties, contributing to the observed effects against both types of tested bacteria. The similar results were obtained in the serial dilution method confirming that tamarind and vinegar have a very strong anti-microbial properties as shown in Figure 6.
(vii) Contact angle measurement
[00086] The assessment of hydrophobic behaviour in thin films derived from guar gum and its composites was conducted through contact angle measurements as shown in Figure 7 and Table 2. The findings revealed distinct characteristics: unmilled guar gum exhibited a contact angle of 22.33 degrees, indicating pronounced hydrophilicity. Conversely, ball-milled guar gum exhibited a contact angle of 73.71 degrees, representing a moderate level of hydrophilicity. The unmilled guar gum composite displayed a contact angle of 50.67 degrees, indicative of its hydrophilic nature, while the ball-milled guar gum composite exhibited a contact angle of 73.57 degrees, suggesting a moderate hydrophilic attribute. Notably, the ball milling process led to a significant increase in the contact angle, favoring the applicability of the resulting thin films as coatings for perishable fruits. This enhancement in hydrophilicity suggests their potential in extending the shelf-life of such produce.
Table 2: Contact angle measurement of various formulation of guar-gum film.
Type of film Contact angle Nature
Unmilled guar gum 22.33° Hydrophilic
Ball-milled guar gum 73.71° Moderately hydrophilic
Unmilled guar gum composite 50.67° Hydrophilic
Ball-milled guar gum composite 73.57° Moderately hydrophilic

(viii) Dip coating and morphological studies on perishable fruits by time lapse photography
[00087] The investigation involved dip coating bananas with a composite solution derived from guar gum, followed by morphological studies to evaluate the shelf-life extension compared to non-coated bananas. The findings indicated a substantial improvement in the shelf-life of coated bananas, characterized by minimal weight change shown in Figure 8(a). In contrast, non-coated bananas exhibited signs of decay, emitting a foul odour by the 7th day and experiencing significant weight loss. The coated bananas demonstrated a remarkable stability and rigidity for 12 days, while the deterioration of non-coated bananas commenced as early as the 5th day. Another model fruit sapodilla is used for study, sapodilla is very perishable in nature and starts decaying within 2 days at room temperature but after coating the quality and appearance remain in good condition after 5 days of study as shown in Figure 8 (b). This observation suggests that the guar gum composite, comprising guar gum, tamarind, and vinegar, imparts notable antibacterial and antioxidant properties to the solution. Consequently, these properties contribute significantly to preserving the freshness of bananas, offering an enhanced shelf-life compared to their non-coated counterparts. The weight loss% in the coated and non-coated model fruits (banana and sapodilla) were calculated during study (Table 3).
Table 3: Weight loss % of banana (coated and non-coated), and sapodilla (coated and non-coated) fruits.
Fruits name Initial weight Final weight Wt. loss %
Banana (non-coated) 128.26 gm 85.37 gm 33.43
Banana (coated) 137.55 gm 106.51 gm 22.56
Sapodilla (non-coated) 97.34 gm 61.17 gm 37.15
Sapodilla (coated) 99.16 79.82 19.50

[00088] In comparison to these other coating kinds, the coating made of guar gum, tamarind, and vinegar has several benefits. Compared to coatings created from synthetic materials or animal proteins, this coating is made from plants, making it more environmentally friendly, cost-effective and sustainable. The cost of 100 ml of edible coating composite is around Rs. 1.5 only which is much cheaper than the commercially available products such as Nim wash (Rs.226/L), Veg Fru Wash (1098/L) and Mommypure (638/L). It is a safer alternative for consumers as it has been demonstrated to efficiently remove dangerous pesticides from fruits and vegetables. By acting as a barrier against moisture loss and microbiological growth, it also lengthens the shelf life of fruits and vegetables. Finally, compared to some of the other coatings on the market, it is a more affordable option. Overall, the coating made of guar gum, tamarind, and vinegar is a promising advancement in the field of food coatings, providing several advantages to both manufacturers and consumers.
[00089] The foregoing examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention.

ADVANTAGES OF THE PRESENT INVENTION
[00090] The edible coating solution offers significant environmental benefits by reducing reliance on chemical pesticides and promoting sustainable agriculture practices. Its natural composition, derived from guar gum, tamarind extract, and vinegar, minimizes environmental pollution and ecological harm associated with conventional pesticide use. It is also cost-effective. Furthermore, by extending the shelf life of fruits and vegetables, it helps reduce food waste, contributing to overall environmental conservation efforts. Overall, the present disclosure aligns with global efforts towards environmentally sustainable food production and consumption, making it a valuable asset for both ecological preservation and human well-being.

, Claims:1. An edible coating composite comprising:
70 to 90 % v/v of a tamarind extract;
10 to 30 % v/v of a preservative; and
0.1 to 2 % w/v of a thickening agent.
2. The composition as claimed in claim 1, wherein the preservative is selected from a group consisting of vinegar, lemon juice, citric acid, clove oil, thyme oil, honey, ascorbic acid and combination thereof.
3. The composition as claimed in claim 1, wherein the thickening agent is selected from a group consisting of guar gum, xanthan gum, tragacanth gum, pectin, agar agar, tapioca starch, corn starch, gelatin, methyl cellulose, carrageenan and combination thereof.
4. A method of preparation of an edible coating composite comprising:
a) mixing 10 to 30 % v/v of a preservative in 70 to 90 % v/v of a tamarind extract followed by heating to obtain a mixture;
b) adding 0.1 to 2 % w/v of a thickening agent in the mixture of step a) to obtain a gel; and
c) processing the gel of step b) by ball-milling under condition to obtain an edible coating composite.
5. The method as claimed in claim 4, wherein the edible coating composite is poured into the petri-dish followed by drying at a temperature in the range of 50 to 70 °C for a period in the range of 8 to 12 hrs to obtain an edible coating composite thin film.
6. The method as claimed in claim 4, wherein the heating in step a) is carried out at a temperature in the range of 35 to 55 °C.
7. The method as claimed in claim 4, wherein the condition in step c) includes speed in the range of 100 to 300 rpm for 20 to 40 cycle for a period in the range of 1 to 10 min.
8. The method as claimed in claim 4, wherein the tamarind extract is prepared by the steps comprising:
adding 2 to 5 % w/v of tamarind pulp in the water to form mixture;
heating the mixture at a temperature in the range of 50 to 70 °C with stirring in a speed in the range of 400 to 600 rpm till completely dissolve followed by filtration to obtain a clear tamarind aqueous solution;
processing the tamarind aqueous solution by centrifugation at a speed in the range of 5000 to 10000 rpm for a period in the range of 10 min to 30 min to obtain tamarind extract.
9. A method of preparation of a surface coated fruits and vegetables comprising:
applying an edible coating composite as claimed in claim 1 to the surface of the fruits and vegetables by dip coating to obtain a surface coated fruits and vegetables, wherein the edible coating composite reduces pesticide residues on fruits and vegetables.
10. The method as claimed in claim 9, wherein the edible coating composite forms a protective barrier that effectively removes or degrades pesticide residues while extending the shelf life of the fruits and vegetables.

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