DESC:FIELD OF THE INVENTION
The present invention discloses a shelf life enhancer composition for preservation of perishable items.

BACKGROUND OF THE INVENTION
Fruits and vegetables need ethylene gas to accelerate ripening. Ethylene is also produced by ripening of fruits. Thus, the fruit ripening process is auto catalytic. More fruits stored in place, help each other to ripen fast. If ethylene is not dissipated fast enough, it leads to rotting of fruits. Nearly 30% of all fruits produced in the world are lost because of over ripening spoilage.

US20100047546 teaches that the cycle of autocatalytic ripening of fruits can be extended by removing the ethylene by incorporating a catalyst that can destroy the ethylene and extend the life of the fruits. It discloses use of silver as a catalyst that is known to oxidize ethylene to ethylene oxide and carbon di oxide. Ethylene oxide is a known biocide that disinfects the atmosphere and helps to further increase life of fruits and vegetables.

However, when a product is made as described by US20100047546, if the fruits are in a sufficiently ripened condition, the ethylene associated with them is quite large and the catalyst is not able to oxidize the ethylene rapidly enough and till the catalytic activity sets in in about 3-4 hours, big damage has already happened to the product. Therefore, there is a need for a solution which is effective under such conditions and acts in synergy with the catalyst.

SUMMARY OF THE INVENTION
The present invention relates to a shelf -life enhancer composition to extend the shelf life of perishable items. The composition comprises of one or more catalyst and one or more adsorbent. The catalyst is selected from a group of elements, which can oxidize light hydrocarbon, preferably ethylene. The adsorbent aids in adsorbing the hydrocarbon.

Also disclosed is a process for preparing a shelf -life enhancer composition, which comprises mixing one or more catalyst and one or more adsorbent.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates the effect of the composition on apples.

Figure 2 illustrates the effect of the compositions on pears.

Figure 3 illustrates the effect of the composition on tomatoes.

Figure 4 illustrates the effect of the composition on lemons.

Figure 5 illustrates the effect of the composition on coriander.

DETAILED DESCRIPTION OF THE INVENTION
Accordingly, the present invention includes a shelf-life enhancer composition the composition comprising:
one or more catalyst to oxidize light hydrocarbon, the light hydrocarbon includes ethylene; and
one or more adsorbent to adsorb ethylene.

The catalysts are elements selected from the group comprising of silver, cobalt, manganese, iron, titanium, vanadium, nickel, copper, palladium, platinum, iridium, osmium, rhodium, antimony, bismuth or combinations thereof.

In preferred embodiment, the catalyst is deposited on a support compound. The support compounds have a high surface area, low density and particle size in the range of 5-50 nm, preferably 5-10 nm. The support compounds can be porous or solid. The support compounds are selected from the group comprising of precipitated calcium carbonate, fumed silica, carbon black, nano titanium dioxide, nano zinc oxide or combinations thereof. In certain embodiments, the support compound is derived from crosslinked polymers particles as taught by WO2000064953, which is incorporated herein by reference. In certain embodiments, catalysts are deposited on the support compound as cations and reduced to elemental form or left as cations. In certain cases, the catalysts can be deposited in their higher oxidation state which makes them anionic. For example, Manganese can be deposited as permanganate and chromium can be deposited as chromate ion. Similarly, compounds releasing active halogen like chlorine, bromine and iodine can also be deposited for instant action.

In preferred embodiments, the catalyst is silver particles and the support compound is precipitated calcium carbonate.

In a preferred embodiment, the size of catalyst ranges from 1-100 nm, preferably 1- 10 nm.

The adsorbents are compound which adsorb ethylene, preferably by chemisorption. These compounds have a high surface area and uniform pore size. These are selected from the group comprising of activated zeolite (sodium alumino silicate), carbon with high surface area and high pore volume (also called carbon molecular sieves), activated clays, activated alumina, silica gel, magnesia or combinations thereof.
In a preferred embodiment, the ratio of the catalyst to the adsorbent is from 95:5 to 30:70.

In preferred embodiment, the level of the catalyst is 1 to 100 ppm, preferably 2 to 20 ppm.

According to the present invention, the shelf-life enhancer composition includes transition metal salts. Advantageously, the transition metal salts include oxobio degradable additives.

The invention also discloses a process to prepare the shelf life enhancer composition. The process comprises mixing or blending one or more catalyst and one or more adsorbent.

In a preferred embodiment, a known quantity of silver salt is dissolved into a quantity of chloride-free demineralized water sufficient to soak non-metallic nano or micron-size polymeric or inorganic particles. The particles are dispersed in the solution. The solution is evaporated to produce a thick slurry. In this process, the silver ions are deposited on the surface of the particles. The slurry is further force dried to deposit the residual silver on the particles, preferably using an oven at 50-120°C for 2 hours. A reducing agent is selected from a range of organic or inorganic reducing agents dissolved in water, and is added in commensurate quantity in dilute form to completely cover the surface of the dried particles, then allowed to stand for 2-4 hours and optionally heated to 100-120°C in a closed environment until reduction is complete. Then these reduced particles are slurried in demineralized water, filtered and washed until free of any residual reducing agent and finally dried. The white particles exhibit a light-yellow tinge, which is characteristic of fine silver particles.

The silver salt is selected from nitrate, acetate, or ammonical silver chloride or silver sulfate, which are soluble in water. The particles are the support compounds selected from the group comprising of calcium carbonate, fumed silica, carbon black, nano titanium dioxide, nano zinc oxide or combinations thereof. The reducing agents are solutions of hydrazine, solution of sodium meta- bisulfite or solid meta- bisulfite or sodium sulfite or sodium borohydride, sodium hypophosphate, elemental hydrogen, carbon monoxide or formaldehyde or acetaldehyde or glucose, or other reducing sugars from aldehydes and ketone varieties or their combinations thereof.

An embodiment of the present invention discloses a packaging to store perishable items. The packaging comprises of a base resin and the shelf life enhancer composition. The base resin is preferably plastic.

In a preferred embodiment, shelf-life enhancer composition is further added to a base resin and other typical components required for preparing a packaging to store the perishable items or goods. The base resin is a plastic compound used for domestic products. In preferred embodiment, the plastic compounds are selected from the group comprising of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene, high molecular weight high density polyethylene (HMHDPE), polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 6,10, polyamide 6,12, polyester (polyethylene terephthalate and polybutylene terephthalate), polystyrene, high impact polystyrene, styrene-acrylonitrile resin, polycarbonate, and other engineering plastics. The further processing is carried out by usual methods such as extrusion, blowing, calendaring or injection molded into products.

The packaging is fabricated in various forms, commensurate with the needs of the articles and other supply chains. Apart from films, bags, containers, wraps, foamed plastic wraps, and other shaped articles can be used.

In an alternate embodiment, the shelf-life enhancer composition is added to a second base resin before adding to the first base resin. This is fabricated in appropriate form, preferably extruded in pellets. Alternatively, this is termed as ‘masterbatch’. This masterbatch is then let down in first base resin for fabricated final packaging. In preferred embodiments the first and second resin is the same.

The shelf-life enhancer composition could also be applied as a film on supports such as brown paper, craft paper with a suitable binder selected from co polymer emulsions, solution polymers dissolved in water, organic solvents such as hydrocarbons, esters, ketones, alcohols, or any other aliphatic or aromatic solvents and their combinations. The coated product then can be converted to a suitable container to pack fruits and vegetables. Alternatively, the prepared containers can be coated with the shelf-life enhancer composition.

The composition can be applied to ethylene susceptible and perishable articles including food articles like vegetables and fruits which produce ethylene during ripening. Solution could also be applied to other types of perishable items, such as flowers, to help retain freshness and extend useable life and reduce the degrading effect of the environment.

In preferred embodiment, the shelf-life enhancer composition comprises silver particles having a size of 1-10 nm as the catalyst and zeolite as an adsorbent.

In an embodiment, the packaging comprises of the shelf-life enhancer composition, wherein the catalyst level in final packaging is in the range of 2 to 20 ppm.

Examples
The following examples illustrate the invention but are not limiting thereof.
Example 1
Step 1: Silver nitrate loading: 100 grams (0.591 gram moles) of silver nitrate was dissolved in demineralized water (1-2 liters) and the silver nitrate solution was subsequently diluted by the addition of 10-12 liters of demineralized water. Nonsurface treated precipitated calcium carbonate (10 kg) was added to the solution with constant stirring to ensure uniform mixing. The mixture was dried in an oven at a temperature below 120° C.

Step 2: 50 g of 85% Hydrazine hydrate (1.325 gram mole) was dissolved in demineralized water (1 liter). This was added to the dried silver nitrate loaded calcium carbonate with constant stirring in a sigma mixer and allowed to react for four hours. The mixture was dried at 100-125°C in an oven. The particles were slurried in demineralized water, filtered and washed till free of any residual reducing agent and nitrates and finally dried.

Step 3: The dried material (catalyst) was then blended with the adsorbent, sodium alumino silicate (zeolite) in 1:2 ratio w/w in dry form.

Example 2
Step 1: Silver nitrate loading: 158.8 grams (0.934 gram moles) of silver nitrate was dissolved in demineralized water (1-2 liters) and subsequently diluted by the addition of 100-120 liters of demineralized water. Fumed silica (10 kg) was added to the solution with constant stirring to ensure uniform mixing.

Step 2: 50 g of 85% Hydrazine hydrate (1.325 gram mole) was dissolved in demineralized water (1 liter). Hydrazine hydrate solution was added with constant stirring to the dispersion of Step 1 and kept for four hours. The mixture was dried at 50°-65°C in an oven to obtain coated silver nano/micro particles with fumed silica core. The particles were slurried in demineralized water, filtered and washed till free of any residual reducing agent and were used either as wet or as a flush in the required medium. The nano silica particles tend to flocculate if completely dried.

Step 3: The dried material (catalyst) was then blended with the adsorbent, sodium alumino silicate (zeolite) in 1:2 ratio w/w in dry form.

Example 3
Step 1: Silver nitrate loading: 100 grams (0.591 gram moles) of silver nitrate was dissolved in demineralized water (1-2 liters) and the silver nitrate solution was subsequently diluted by the addition of 10-12 liters of demineralized water. Nonsurface treated precipitated calcium carbonate (10 kg) was added to the solution with constant stirring to ensure uniform mixing. The mixture was dried in an oven at a temperature below 120° C.

Step 2: 50 g of 85% Hydrazine hydrate (1.325 gram mole) was dissolved in demineralized water (1 liter). This was added to the dried silver nitrate loaded calcium carbonate with constant stirring in a sigma mixer and allowed to react for four hours. The mixture was dried at 100-125°C in an oven. The particles were slurried in demineralized water, filtered and washed till free of any residual reducing agent and nitrates and finally dried.

Step 3: The dried material (catalyst) was then blended with the adsorbent, activated clay in 1:2 ratio w/w in dry form.

Example 4
Step 1: Silver nitrate loading: 100 grams (0.591 gram moles) of silver nitrate was dissolved in demineralized water (1-2 liters) and the silver nitrate solution was subsequently diluted by the addition of 10-12 liters of demineralized water. Nonsurface treated precipitated calcium carbonate (10 kg) was added to the solution with constant stirring to ensure uniform mixing. The mixture was dried in an oven at a temperature below 120° C.

Step 2: 50 g of 85% Hydrazine hydrate (1.325 gram mole) was dissolved in demineralized water (1 liter). This was added to the dried silver nitrate loaded calcium carbonate with constant stirring in a sigma mixer and allowed to react for four hours. The mixture was dried at 100-125°C in an oven. The particles were slurried in demineralized water, filtered and washed till free of any residual reducing agent and nitrates and finally dried.

Step 3: The dried material (catalyst) was then blended with the adsorbent, activated alumina in 1:2 ratio w/w in dry form.

Test Data

A. Efficacy of anti-ripening trays on Apples

Test Samples:
a. Anti-Ripening Trays: A composition comprising 20 mg of silver per Kg of dry tray weight and 3000 mg of zeolite per Kg of dry tray weight was coated on the trays by spray method.

b. Control Trays

Test Conditions: At room temperature

Test Parameters:
a. Refer to Figure 1.
b. Physiological Loss in Weight (PLW): The results are summarized below.
Table 1
Sample Day 0
(PLW %) Day 5
(PLW %) Day 7
(PLW %) Day 9
(PLW %) Day 14
(PLW %) Day 18
(PLW %)
Control Tray 0.00 1.25 1.36 1.41 2.04 7.88
Anti-Ripening Tray 0.00 0.45 0.54 0.65 1.15 6.53

After 18 days of observations, it was concluded that the Anti Ripening trays performed better than the Control trays, this is evident from the above results and Figure 1. On day 18, the physiological loss in weight of apples kept in Anti-ripening trays is lesser than the Control tray, which did not contain the composition. This demonstrates that the anti-ripening composition is effective in extending the shelf -life of the apples.

B. Efficacy of anti-ripening trays on Pears

Test Samples :-
a. Anti-Ripening Trays: A composition comprising 20 mg of silver per Kg of dry tray weight and 3000 mg of zeolite per Kg of dry tray weight was coated on the trays by spray method.

b. Control Trays
Test Conditions : At room temperature

Test Parameters:
a. Refer to Figure 2.
b. Physiological Loss in Weight (PLW): The results are summarized below.

Table 2
Sample Day 0
(PLW %) Day 5
(PLW %) Day 7
(PLW %) Day 9
(PLW %) Day 14
(PLW %) Day 18
(PLW %)
Control Tray 0.00 1.32 1.63 1.89 2.60 3.85
Anti-Ripening Tray 0.00 0.56 0.79 1.04 1.73 3.45

After 18 days of observations, it was concluded that Anti Ripening trays performed better than Control trays, this is evident from the above results and Figure 2. On day 18, the physiological loss in weight of pears kept in Anti-ripening trays is lesser than the Control tray, which did not contain the composition. This demonstrates that the anti-ripening composition is effective in extending the shelf -life of the pears.

C. Efficacy of anti-ripening bags on Tomatoes
Test Samples :-
a. Anti-Ripening Bags: Ripening-002 bags (40 micron) having 1% of the composition film. 1% of the film contains 20 mg of silver and 3000 mg of Zeolite per kg of the film.

b. Control Bag (40 microns)

Test Conditions : At room temperature/ All bags are with perforation.

Test Parameters:
a. Refer to Figure 3
b. Physiological Loss in Weight (PLW): The results are summarized below.
Table 3
Sample Day 0
(PLW %) Day 2
(PLW %) Day 3
(PLW %) Day 5
(PLW %) Day 7
(PLW %)
Control 0.00 0.928 1.48 37.06 55.60
Anti-Ripening Bags 0.00 0.754 1.14 2.24 24.68

As can be seen from the above data, on day 7 and Figure 3, the physiological loss in weight of tomatoes kept in Anti-ripening bags is much less than the Control bags, which did not contain the composition. This demonstrates that the anti-ripening composition is effective in extending the shelf -life of the tomatoes.

D. Efficacy of anti-ripening bags on Lemons
Test Samples :-
a. GF-006 bags (30-40 Micron) having 1.0% of the composition film. 1% film contains 20 mg of silver and 3000 mg of Zeolite per kg of the film.

b. GF-006 bags (30-40 Micron) having 1.5% of the composition film. 1.5% film contains 30 mg of silver and 4500 mg of Zeolite per kg of the film.

c. Control bag (30-40 micron)

Test Conditions : At room temperature/ All bags are with perforation.

Test Parameters:
a. Refer to Figure 4
b. Physiological Loss in Weight (PLW): The results are summarized below.

Table 4
Sample Day 0
(PLW %) Day 3
(PLW %) Day 6
(PLW %) Day 8
(PLW %) Day 10
(PLW %)
Control 0.00 4.32 8.44 10.80 13.04
GF -006-1% Film 0.00 3.32 7.28 9.10 11.15
GF -006- 1.5% Film 0.00 2.92 5.95 7.71 9.34

As can be seen from the above data and Figure 4, on day 10, the physiological loss in weight of lemons kept in Anti-ripening bags is less than the Control bags, which did not contain the composition. This demonstrates that the anti-ripening composition is effective in extending the shelf -life of the tomatoes.

D. Efficacy of anti-ripening composition on Coriander
Test Samples :-
a. Anti Ripening-002 bags (40 micron) having 1% of the composition film. 1% film contains 20 mg of silver and 3000 mg of Zeolite per kg of the film.

b. Control bag (40 micron)

Test Conditions: At room temperature/ All bags are with perforation.

Test Parameters:
a. Refer to Figure 5.
b. Physiological Loss in Weight (PLW): The results are summarized below.
Table 5
Sample Day 0
(PLW %) Day 1
(PLW %) Day 2
(PLW %) Day 3
(PLW %) Day 4
(PLW %)
Control Bag 0.00 7.28 15.69 28.79 41.45
Anti-Ripening Bag 0.00 6.64 10.59 16.34 34.15

As can be seen from the above data and Figure 5, on day 4, the physiological loss in weight of coriander kept in Anti-ripening bags is less than the Control sample, which did not contain the composition. This demonstrates that the anti-ripening composition is effective in extending the shelf -life of coriander.

Further, the composition comprising both the catalyst and adsorbent is more effective in increasing the shelf -life of the perishable items in comparison to the catalyst or adsorbent, when present alone.

The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the disclosure.
,CLAIMS:
1. A shelf-life enhancer composition, the composition comprising:
one or more catalyst to oxidize light hydrocarbon; the light hydrocarbon preferably includes ethylene; and
one or more adsorbent to adsorb ethylene.

2. The shelf-life enhancer composition as claimed in claim 1, wherein the catalyst is selected from the group comprising of silver, cobalt, manganese, iron, titanium, vanadium, nickel, copper, palladium, platinum, iridium, osmium, rhodium, antimony, bismuth or combinations thereof.

3. The shelf-life enhancer composition as claimed in claim 1, wherein the adsorbent is selected from the group comprising of activated zeolite, carbon with high surface area and high pore volume, activated clays, activated alumina, silica gel, magnesia or combinations thereof.

4. The shelf-life enhancer composition as claimed in claim 2, wherein the size of the catalyst is in the range of 1-100 nm.

5. The shelf-life enhancer composition as claimed in claim 2, wherein the catalyst is deposited on a support compound selected from the group comprising of calcium carbonate, fumed silica, carbon black, nano titanium dioxide, nano zinc oxide or combinations thereof.

6. The shelf-life enhancer composition as claimed in claim 1, wherein the ratio of the catalyst to the adsorbent is from 95:5 to 30:70.

7. The shelf-life enhancer composition as claimed in claim 1 comprising transition metal salts.

8. A process to prepare a shelf life enhancer composition, the process comprising mixing one or more catalyst and one or more adsorbent.

9. A packaging to store perishable items, the packaging comprising a base resin and the shelf life enhancer composition as claimed in claim 1.

10. The packaging as claimed in claim 9, wherein the base resin is plastic.