DESC:FIELD OF INVENTION
The present invention relates to the field of food industry and preservation, particularly to tender coconuts. More particularly, the present invention relates to a method of processing partially dehusked tender coconut to prolong its shelf life.

BACKGROUND ART
Young fresh tender coconuts are consumed by all age groups regularly in most tropical countries mainly for its medicinal, culinary, and non-culinary uses. The tender coconut is nature’s most nourishing and refreshing drink that not only helps in enhancing the metabolic rate, but also gives instant energy and prevents dehydration. Although the coconut tree yields tender coconut all round the year it is not easily available or reachable beyond tropical countries especially when someone is in need. The problem associated with the export of tender coconut is the physical and chemical changes that take place after harvest, and during the period of transport up to the point of sale. Also, once the upper part is removed and exposed to the environment the coconut water becomes highly perishable. Further, coconut water quickly ferments and therefore there is a need to find a solution to prolong its shelf life.

Normally, vendors keep tender coconuts in stock and offer to consumers by slice opening a tender coconut and serving fresh. However, when the consumer wants to self open the tender coconut, there exist problems for a consumer to cut open a tender coconut because of the tough outer skin the epicarp. Further, it is not easy to carry the tender coconut home due to its shape, size and weight.

There have been attempts to offer tender coconut water in a packaged form. However, the tender coconut water served in a packaged form loses its natural flavour because of the additives included in the drink for preservation.

Also, exists fully or partially dehusked tender coconut, but the discolouration and browning of the mesocarp layer when exposed to air makes it undesirable to consume. Generally, tender coconut loses its colour hours after trimming. The exposed trimmed husk quickly turns brown, reducing the commercial value of the fruit even though the coconut water remains of good quality inside. Numerous attempts have been made to process the young tender coconut and make it available for consumers to drink. One of the methods involves dipping the tender coconut in sodium or potassium metabisulphite and wrapping it in plastic film. Fermentation processes are also encountered but lead to fully different final products which do not resemble natural coconut water.

US20040071846 relates to a method for preserving entire coconut pulp containing water. However, the prior art document uses expensive equipment and complex and a risky process (accidental exposure to UV radiation) to store the tender coconut at -6°C. Moreover, if the husk were to be completely removed and the shell to be exposed, it is highly probable that the outer surface of the tender coconut gets contaminated. Further, the prior art does not disclose about blanching process.

US20150359237 relates to process of dehusking the selected young fresh coconut and then immediately dipping the firm inner nutshell in food-grade water based anti-oxidant solution. Further, the selected young fresh coconut is air-dried by refrigerating the firm inner nutshell at 1.5°- 4.4°C and immediately processing the refrigerated inner nutshell through an automated shrink wrap heat tunnel to seal the coconut in a heat shrinkable plastic film. However, dehusking a tender coconut completely till the hard inner shell is exposed leads to risk of spoilage and accidental breakage of the inner shell leading to a loss and wastage. Further, the prior art does not disclose about blanching process.

US20140272089A1 relates to blast frozen food product comprising young coconut water enclosed in its own young tender coconut meat made by the process of obtaining at least one raw young coconut between within a maturity range of about 9 to about 10 months in age. Blast freezing provides a frozen food product that can be thawed at least one of ambient temperature and refrigerated conditions for consumption. The food product is packaged and sealed while frozen, at a temperature ranging from about -25°Celsius to about -20°Celsius. Here, the entire husk and the shell are removed and inner white coconut meat is exposed, and hence there is risk of spoilage and accidental breakage of this layer leading to a loss and wastage.

Indian Patent Application 2239/CHE/2006 relates to trimming of the outer shell of the endocarp with trimmer knife to make it free from sharp surfaces and removing the husk completely thereby exposing the hard inner shell and makes it resemble a ball. The tender coconut ball is then dipped in solution containing alkali metal salts like Sodium Meta bisulfite or Potassium Meta bisulfite or Calcium Meta bisulfate or combination of all these salts to prevent from fungal attack and to extend the life of endocarp. However, the husk is completely removed and the shell is exposed.

Non-Patent Literature titled coconut water preservation and processing consists of dipping partially husked nuts in a solution of 0.5% citric acid and 0.5% of potassium metabisulphite for 3 min. The final product, wrapped with polypropylene cling film, can be stored for up to 24 days at (5 to 7) °C.

Non-Patent Literature titled application of citric acid, sodium chloride and peroxyacetic acid as alternative chemical treatment for organic trimmed aromatic coconut thereby extending the shelf-life and maintaining quality of trimmed organic coconut up to eight weeks of storage at 2°C.

Accordingly, there exists a need for a method of processing partially dehusked tender coconut to prolong its shelf life and provide tender coconut water to consumers without altering its natural taste.

OBJECTS OF INVENTION
One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention.

It is the primary object of the present invention to provide a method of processing partially dehusked tender coconut to prolong its shelf life.

It is another object of the present invention to provide a method of processing partially dehusked tender coconut to prolong its shelf life and provide tender coconut water to consumers without altering its natural taste.

It is another object of the present invention to provide a method of processing partially dehusked tender coconut while retaining its nutrients.

It is another object of the present invention, wherein the processing of tender coconut involves heat treatment process that includes chemical treatment process, followed by immediate cooling it in water.

It is another object of the present invention, wherein the process prevents enzymatic browning and growth of microbial activity on the tender coconut.

It is another object of the present invention, wherein the processing of tender coconut increases the shelf life for up to 7 days and retains the appearance of the tender coconut.

SUMMARY OF INVENTION
Thus, according to the basic aspect of the present invention, there is provided a method of processing partially dehusked tender coconut, comprising the steps of:
obtaining a young tender coconut;
peeling outer green epicarp layer of the young tender coconut and partially dehusking the peeled tender coconut without exposing hard inner shell of the tender coconut;
blanching the partially dehusked tender coconut in hot water containing antioxidant solution which is a mixture of citric acid and sodium chloride;
performing immediate cooling of the blanched tender coconut by dipping in cold water to form processed tender coconut;
drying the cooled processed tender coconut; and
applying protective coating around the dried tender coconut.

It is another aspect of the present invention, wherein the antioxidant solution is a mixture consisting of 20% citric acid and 15% sodium chloride.

It is another aspect of the present invention, wherein the partially dehusked tender coconut is blanched in hot water containing antioxidant solution at a temperature of 65° - 95°C for 5 - 10 minutes.

It is another aspect of the present invention, wherein the partially dehusked tender coconut is blanched in hot water containing antioxidant solution to prevent enzymatic browning and growth of microbial activity on the tender coconut and hence thereby increases the shelf life of the tender coconut to seven days.

It is another aspect of the present invention, wherein the protective coating around the dried tender coconut is a plastic film or wax.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1: illustrates a known tender coconut and its constituent parts.
Figure 2: illustrates partially dehusked processed tender coconut according to present invention.
Figure 3: illustrates blanching process of the partially dehusked processed tender coconut according to present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING FIGURES
The present invention as herein described relates to a simple, cost effective method of processing partially dehusked tender coconut to prolong its shelf life. The processing of tender coconut involves blanching process also known as heat treatment process that includes chemical treatment process, followed by immediate cooling it in water. The blanching process prevents enzymatic browning and growth of microbial activity on the tender coconut which thereby increases the shelf life of the tender coconut.

Referring to Figure 1, the tender coconut comprises an outer epicarp [1], a mesocarp [2], and an inner endocarp [3]. The epicarp [1] is the green colour outer skin of the coconut, and the mesocarp [2] is white in colour and fibrous. The endocarp [3] is the hard inner shell that houses the tender coconut meat or otherwise known as endosperm [4] and a sweet liquid called coconut water. Coconut trees produce inflorescences every month and tender coconuts are best harvested when they are seven to eight month old.

In an aspect of the present invention, the harvested tender coconuts are cleaned and partially dehusked either manually using a sickle or using motorized equipment fitted with a cutting edge. Referring to Figure 2, the husk is partially removed and the mesocarp [2] is brought to a geometrical shape [5] gradually by partial removal of the husk, said geometrical shape is preferably cylindrical shape. The bottom of the tender coconut is sliced to provide a flat bottom [5a]. The top portion of the coconut is tapered to provide a conical shape [5b] with a flat top [5c].

In yet another aspect of the present invention, a method of processing the partially dehusked tender coconut, comprising the steps of obtaining a young tender coconut; peeling outer green epicarp layer of the young tender coconut and partially dehusking the peeled tender coconut without exposing hard inner shell of the tender coconut; blanching the partially dehusked tender coconut in hot water containing antioxidant solution; performing immediate cooling of the blanched tender coconut by dipping in cold water; drying the cooled tender coconut; and applying protective coating around the dried tender coconut. Referring to Figure 3, the partially husked tender coconut is immersed in blanching water which is heated up to a temperature of 65° - 95°C for 5 - 10 minutes. The tender coconut is then removed from the hot water tank and cooled immediately by immersing in cold water and allowing it to cool down to room temperature. The antioxidant solution includes a mixture of citric acid and sodium chloride. In one aspect, the antioxidant solution used is 50L solution of 20% citric acid and 15% sodium chloride. The blanching process sanitizes the tender coconut, prevents enzymatic browning and growth of microbial activity on the tender coconut. The white husk of the tender coconut does not tend to develop the browning effect due to restriction of enzymatic activity due to blanching process and hence the shelf life of the tender coconut is significantly increased to seven days. The application of protective coating around the processed tender coconut could either be a plastic film or wax. Said wax includes Paraffin wax or Carnauba wax or its derivatives. The application of protective coating around the processed tender coconut prevents contamination while handling of the product during transportation and ensures that the outer layer retains the white colour and protects it from contamination. The processed tender coconut stays fresh and is fit for consumption even after three weeks when stored under normal refrigerated condition and does not require a blast storage or static freezer unit.

EXPERIMENTAL STUDY:
MATERIALS:
6 tender coconuts, chemicals used: 50L solution of 20% citric acid and 15% sodium chloride (food grade salts used), tissue papers for cleaning. Three batches of the solution were prepared each corresponding to a specific temperature. The first batch was kept at room temperature to serve as control while the remaining batches were heated to 65? and 90? respectively.

PROCEDURE:
Each of the tender coconuts was partially dehusked manually, removing the epicarp layer. The samples were then immediately dipped in the antioxidant solution. Depending on the temperature, the samples were dipped for a set time of 15 minutes at room temperature, 10 minutes at 65? and 5 minutes at 90?. The time of exposure was reduced with increasing temperature to ensure that the samples were not exposed to too much heat which can reduce the quality of the water. The samples were then removed and dipped in water at room temperature which not only washes the chemicals but also cools the coconuts. The processed partially dehusked tender coconuts were dried to remove moisture from the surface that can lead to microbial growth. The blanching process makes it easy to store and preserve the tender coconut for a long period of time without losing any of the freshness of the tender coconut water.

RESULTS:
The microbial growth obtained from total plate count was tabulated for each of the conditions for both the outer shell and the liquid endosperm and are shown in Table 1.
Table 1: Total Plate Count for samples at different temperatures on day 0 and day 7
TPC (cfu/g)
Room Temp 65? 90?
Day 0 Outer shell 1450 845 655
Coconut water 191 145 127
Day 7 Outer shell NA 868 659
Coconut water NA 159 186

Similarly, the microbial growth obtained from total plate count was tabulated for each of the conditions for both the outer shell and the liquid endosperm and are shown below.
Day-wise comparison of the TPC of samples at different temperatures

FINDINGS:
From the above tests, it was observed that the amount of microbial growth had reduced with the introduction of the sample in an antioxidant solution. The samples exposed to the solution at temperature of 95? showed minimum microbial growth with 655 cfu/g and 127 cfu/g on the shell and in the water respectively. The samples at 65? showed significant decrease in growth as well with 845 cfu/g and 145 cfu/g. After a period of 7 days of storage at room temperature, it was observed that the total microbial growth in the blanched samples did not change notably while the control that was not blanched started browning on the first day and had to be discarded. These results conclude that the introduction of blanching to the process of preservation of the partially dehusked tender coconuts can improve their storage at room temperature for up to 7 days.

Thus, the results clearly show that by blanching the partially dehusked tender coconut in an antioxidant solution heated to temperatures 65? and 90? exhibited a significant reduction in the amount of microbial growth on the outer shell and in the water and has shelf life of seven days. Further, the blanched tender coconuts did not require additional facilities for storage such as refrigerators and could therefore be stored at room temperature.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
,CLAIMS:1. A method of processing partially dehusked tender coconut, comprising the steps of:
obtaining a young tender coconut;
peeling outer green epicarp layer of the young tender coconut and partially dehusking the peeled tender coconut without exposing hard inner shell of the tender coconut;
blanching the partially dehusked tender coconut in hot water containing antioxidant solution which is a mixture of citric acid and sodium chloride;
performing immediate cooling of the blanched tender coconut by dipping in cold water to form processed tender coconut;
drying the cooled processed tender coconut; and
applying protective coating around the dried tender coconut.

2. The method of processing partially dehusked tender coconut as claimed in claim 1, wherein the antioxidant solution is a mixture consisting of 20% citric acid and 15% sodium chloride.

3. The method of processing partially dehusked tender coconut as claimed in claim 1, wherein the partially dehusked tender coconut is blanched in hot water containing antioxidant solution at a temperature of 65° - 95°C for 5 - 10 minutes.

4. The method of processing partially dehusked tender coconut as claimed in claim 3, wherein the partially dehusked tender coconut is blanched in hot water containing antioxidant solution to prevent enzymatic browning and growth of microbial activity on the tender coconut and hence thereby increases the shelf life of the tender coconut to seven days.
5. The method of processing partially dehusked tender coconut as claimed in claim 1, wherein the protective coating around the dried tender coconut is a plastic film or wax.