DESC:FIELD OF THE INVENTION

The present invention discloses a bio-waste based biodegradable packaging materials. The said bio-waste based flexible packaging material has been prepared from peels of onion and other bio-waste foods which is a waste generated by food industry. The present invention also provides a process for preparation of bio-waste based biodegradable packaging materials. Moreover, the said packaging material is disposable, ecofriendly and can be packed in any semipermeable containers such as containers and bags thereby making it easy to use also.

PRIOR ART DISCUSSION
Food waste is a serious problem for food processing industries. Therefore, there should be always necessity for development of products for minimizing waste by conversion of food waste into useful products.
In this regards, the onion is one of the food that become waste if not stored properly due to short shelf life of onion. Even crop growing farmers has to throw bad quality onion and have to face cash loss. Over the past 20 years, world production of onion has raised at least by 25%, becoming the second most important horticultural crop. Increased market of processed onion has also led to a higher waste accumulation. India produces around 2.5 lakh MT of onion every year. Most of the onions get wasted every year due to inadequate storage facilities in the country. Therefore, to face the high production of onion waste, there is the need to find sustainable process and eco-friendly product and develop sustainable solutions for recovering key natural products in an usable form.

Some of the efforts taken in prior arts, as disclosed in paper title: Onion Peel: Turning a Food Waste into a Resource. This documents discloses that the onion peel rich in bioactive phenolic compounds having antioxidant and anti-diabetic properties. Therefore the said bioactive are extracted from onion peels using solvent extracted.
The above technologies discuss on onion waste valorisation focus on the extraction of active ingredients/flavonoids from onion. While these components have high value, they have a very low yield and the problem of disposal of onion waste is not addressed.

A wide variety of base materials such as plastic films, metal foils, and papers are used to prepare a packaging material. These material have some problems like non-biodegradation, environmentally unsafe, costly materials.
Therefore, there is also need of new packaging materials which plays a vital role in reduction of environmental problems related to the use of synthetic plastics and paper packaging material to save tree cutting.

The inventors of present invention have developed a new process and packaging product obtained from the entire onion waste. More particularly, the novel packaging product obtained from the densification process of waste onion bulb.

Therefore, the present technology developed by inventors uses the entire onion along with the moisture such that there are no residues left behind for development of biodegradable packaging products. Thereby, the invention addresses the challenge of making biodegradable packaging materials while also valorizing the waste.

SUMMARY OF THE INVENTION
The present invention discloses a bio-waste based biodegradable packaging composite materials having high compressibility strength between 50 to 150 Megapascal (MPa) and composite comprising of:
-50 to 94% w/w of powder of Onion waste pulp(on dried basis),
-1 to 20% w/w of Synthetic polymer,
-0.1 to 5% w/w of catalyst agent,
-5 to 20% w/w of oxidising agent.

In accordance to present invention the Synthetic polymer selected from Poly Methyl Methacrylate, Poly Acrylonitrile and catalyst agent selected from ((2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl).
Further, the oxidizing agent selected from Sodium hypochlorite and sodium chlorite.
In second embodiment, the present invention also provides a process for preparation of bio-waste based biodegradable packaging materials and process steps comprising of:
Step 1: Reacting oxidizing agent, catalyst agent with powder of onion waste pulp in water under stirring for 15 min to 2 Hr,
Step 2:Addition of Synthetic polymer solution in step 1 mixture under stirring and continue reaction for 15 min to 2 Hr,
Step 3:Casting the reaction mass in moulds at temperature between 40 to 100 °C for 2 to 10 Hrs.

In accordance to process of present invention, the solvent in step 2) selected from toluene, water and combination thereof and the Synthetic polymer selected from Poly Methyl Methacrylate, Poly Acrylonitrile.
Further, the catalyst agent for above said process was selected from ((2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl).
In further embodiment, the oxidizing agent as per present invention selected from Sodium hypochlorite and sodium chlorite.
Therefore, the inventors of present invention have developed a new process and packaging product obtained from the entire onion waste. More particularly, the novel and inventive packaging product obtained from the densification process of waste onion bulb which provides a ecofriendly products and environment safe packaging product.

DESCRIPTION OF THE DRAWING
For a more detailed understanding of the present invention, reference is made to the following description taken in conjunction with the accompanying drawing. It is to be understood; however, each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
Figure No. 1: Illustrates the image of packaging composite prepared in example no. as per comparative example.
Figure No. 2: Illustrates the image of packaging composite prepared in example no. as per comparative example.
Figure No. 3: Illustrates the image of packaging composite prepared in example no. as per present invention.
Figure No. 4: Illustrates the image of packaging composite prepared in example no. as per present invention.

DETAILED DESCRIPTION OF THE INVENTION
The present invention primary relates to a development of biodegradable packaging material from onion waste and process of preparation thereof. More preferably, the present invention is providing an economic, environment safe and biodegradable packaging material from waste food. Wherein treated onion waste densified and shaped into a suitable flexible moisture resistant and biodegradable packaging material. As inventor have identified that the waste onion bulb consists of sugars, sucrose and fibers that are essential for formation of densified material.

The present invention provides an onion based densified composition, is used a flexible packaging material, the onion based densified composition comprises ; part of cross-linked onion sugars (glucose and fructose), sucrose and fibers; using oxidant and an additional cross-linking agent.

In accordance to embodiment, the present invention provides a high compressibility strength biodegradable packaging composite comprising:
-50 to 94% w/w of powder of Onion waste pulp,
-1 to 20% w/w of Synthetic polymer,
-0.1 to 5% w/w of catalyst agent,
-5 to 20% w/w of oxidising agent;
Characterized in that the compressibility strength is achieved between 50 to 150 Megapascal (MPa).

Further, the present invention provides a process, wherein the sugars and fibers are taking part into a chemical decomposition and crosslinking reaction to for said densified material. The resulting product is a strong packaging material. The flexibility of the packaging material can be tuned by changing the moisture content and thickness of casted sheets.

Therefore, the present invention provides a process for preparation of a high compressibility strength biodegradable packaging composite and process steps comprising of:
Step 1: Reacting oxidizing agent, catalyst agent with powder of onion waste pulp in water under stirring for 15 min to 2 Hr,
Step 2:Addition of Synthetic polymer solution in step 1 mixture under stirring and continue reaction for 15 min to 2 Hr,
Step 3:Casting the reaction mass in moulds at temperature between 40 to 100 °C for 2 to 10 Hrs.

The following examples briefly discloses the present inventions:
Example 1: Preparation of onion powder:
265g of waste onion was collected from market and sliced into small pieces including onion peals, roots, some growing leaves. After fine chopping is done, it is taken to tray dryer to dry at a temperature between 40 to 100? for 5 minute to 10 hours to let it dry (moisture less than 0.1 % or less than 0.001 %). After oven drying, it is taken out and let it for solar drying to ensure the material is crisp and well dried before taking to grind. The well dried the material was grinded using food grade grinder and powder onion sample is made for further proceedings. Therefore, the non-limiting examples of drying technology may selected from oven drying, solar drying, thermal drying or freeze drying etc and combination thereof.

Example 2: Preparation of Semi-solid mass before casting:
50 to 95 % w/w of onion powder prepared in example 1 was weighed and transferred to a beaker. 5 to 20 % w/w of Sodium hypochlorite (8-10% Cl content) was added drop wise followed by stirring in a glass rod. Stirring continued till the formation of a dough.
The alternative agent for Sodium hypochlorite is solution sodium chlorite (10% w/w).

Example 3: Casting and Drying of packaging material:
Once dough was formed in example 2, it was casted in a silicon oil greased watch glass and taken to vacuum oven for drying. Vacuum oven temperature was set between 40 to 100 ?, more preferably between 60 to 70 ? and had an internal pressure of 410mmHg.
In that condition, sample was dried for time between 5 minutes to 10 hours and then flipped to other side for drying of another drying cycle. A solid onion disk was formed having a descent amount of strength and taken for characterization and analysis.

Example 4: Addition of Polyacrylonitrile(PAN) as additive :
During the dough preparation process as in example 2, 1 to 20 % w/w of PAN was added and mixed well before casting. The well-mixed dough was then cast and dried within the condition of Vacuum oven drying where the temperature was set between 40 to 100 ?, more preferably between 60 to 70 ?, and had an internal pressure of 410mmHg. After drying, a solid disk was recovered and analyzed further.

Example 5: Addition of Poly Methyl Methacrylate(PMMA) as additive:
During the dough preparation process as in example 2, 1 to 20 % w/w/ of PMMA was dissolved in 10 ml of toluene and 6 ml of it was added to the dough before mixing. Then a well-mixed dough was formed, casted, and dried within the condition of Vacuum oven drying where the temperature was set between 40 to 100 ?, more preferably between 60 to 70 ?, and had an internal pressure of 410mmHg. After drying, a solid disk was recovered and analyzed further.

Example 6: The Composite of Onion powder with sodium hypochlorite[sample C1]:
5gm of powder onion was taken and reacted with 3.846ml sodium hypochlorite (NaClO) where NaClO was added dropwise followed by stirring for respective time (here 30 minutes). Once reaction is completed, the dough was cast in the form of chips and subjected for drying for 4 hours under the temperature of 60–70-°C. Figure no. 1 provides an image of packaging composite.
Determination of the compressibility strength For C1:
Diameter= 2.4cm
Radius= 1.2 cm
Area of cross-section (A=pr^2) = 4.523cm2
Load on sample 1= 47KN
Load on sample 2= 45 KN
Average load= 46KN
Compressibility strength= Average Load/Area of cross-section
Here, Compressibility strength = 46/4.523= 10.17 KN/cm2
Or 10170N/cm2 or 101.7 MPa

Example 7: Effect of TEMPO Catalysed oxidation of Onion Pulp on compression strength:
After getting results from the above, a new reaction condition was designed. 38.46g of onion pulp was collected. To this onion pulp, 7.692Mg of Homogeneous TEMPO ((2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl) dissolved in 3.846 ml of water was added. After that, 3.846ml of Sodium hypochlorite and 3.845mg of water-solubilized NaBr were added dropwise. The reaction continued for 1 to 10 hours. Once the reaction is complete, it was filtered and processed as same as disclosed in example 3.

Observation:
Surprisingly the sheet formed out of it has higher strength than previous example no. 6. It has higher flexibility than the initial one and therefore It seems the catalyst has worked efficiently.

Example 8: Packaging composite of onion powder with H2O2: [Sample C2]
As reported earlier, the oxidizing agent is playing a great role in cross-linking.
Weight of onion powder taken= 5 gram
As per the defined ratio, 3.846 ml of H2O2 is taken and added dropwise followed by stirring for 1 hour.
Observation: No exothermic reaction is observed, seems H2O2 is not oxidizing the onion powder It seems the dough is not forming but getting coagulated due to H2O2.
After getting a dough-like form, casted it and put it in a precession oven for drying for about 4 hours. The dough formed but not of higher strength. Then we subjected it to compression testing. Figure no. 2 provides an image of packaging composite. Determination of the compressibility strength For C2:
Diameter= 2.4cm
Radius= 1.2 cm
Area of cross-section (A=pr^2) = 4.523cm2
Load on sample 1= 35KN
Load on sample 2= 37 KN
Average load= 36KN
Compressibility strength= Average Load/Area of cross-section
Here, Compressibility strength = 36/4.523= 7.959 KN/cm2
Or 7959N/cm2 or 79.59 MPa


Example 9: Effect of addition of additives during the rection with onion powder: Addition of Poly Acrylonitrile (PAN) [Sample C3]

Weight of dry onion powder taken= 5gm
Amount of Sodium Hypochlorite used= 3.846ml
Amount of PAN Used (10% w/w) = 0.561g
Procedure:
5 gm of dry onion powder derived from waste onion as described by chopping and drying was transferred into a tray for solar drying.
Once the powder is out of moisture, it was transferred into a beaker.
As per the predefined ratio, 3.846 ml of NaClO was taken in a test tube for reaction.
Now NaClO was added dropwise followed by mechanical stirring for the proper mixing of the reagent and stirring continued for desired time (Here, 30 minutes) This process was as similar to before.
Once the reaction is complete, 0.561g of PAN was weighed and added slowly in the stirring condition and the process continued until it forms a dough. In between the process, 500-700microliter was added from time to time for the proper mixing of PAN.
When the mixing was completed, the casing and drying process started as mentioned before.
Drying Condition:
Temperature= 90 °C
Duration= 3+2 Hours
Observation: Figure no. 3 provides an image of packaging composite.
After drying, we get a solid, rigid onion chip of higher strength.
Then it was subjected to compressibility testing.
Determination of the compressibility strength For C3:
Diameter= 2.4cm
Radius= 1.2 cm
Area of cross-section (A=pr^2) = 4.523cm2
Load on sample 1= 57KN
Load on sample 2= 60 KN
Average load= 58.5KN
Compressibility strength= Average Load/Area of cross-section
Here, Compressibility strength = 58.5/4.523= 12.933 KN/cm2
Or 12933N/cm2 or 129.33 MPa

Example 10: Effect of addition of additives during the rection with onion powder: Addition of Poly Methyl Methacrylate (PMMA): [Sample C4]
Weight of dry onion powder taken= 5gm
Amount of Sodium Hypochlorite used= 3.846ml
Amount of PMMA Used (10% w/w) = 0.561g
Preparation of PMMA:
PMMA used here was initially in crystal form.
We dissolved it with toluene (it acts as a solvent only).
0.5g of PMMA crystals were dissolved in 10ml of toluene
During the dissolution, the temperature was 55-60 °C followed by continuous stirring
Procedure:
5 gm of dry onion powder derived from waste onion as described by chopping and drying was transferred into a tray for solar drying.
Once the powder is out of moisture, it was transferred into a beaker.
As per the predefined ratio, 3.846 ml of NaClO was taken in a test tube for reaction.
Now NaClO was added dropwise followed by mechanical stirring for the proper mixing of the reagent and stirring continued for desired time (Here, 30 minutes) This process was as similar to before.
After the reaction, PMMA solution (4 to 6ml) was added (and stirring continued for well mixing of it. It was a fast process as after cooling PMMA start producing threading.
Casting process started and was taken into a precession oven.
Drying Condition:
Temperature= 80 °C
Drying time= 4 hours
Figure no. 4 provides an image of packaging composite. Once dried, it was taken for compression testing.
For C4:
Diameter= 2.4cm
Radius= 1.2 cm
Area of cross section (A=pr^2) = 4.523cm2
Load on sample 1= 30KN
Load on sample 2= 33 KN
Average load= 31.5KN
Compressibility strength= Average Load/Area of cross section
Here, Compressibility strength = 31.5/4.523= 6.964 KN/cm2
Or 6964N/cm2 or 69.64 MPa.

Example 10: Compression Testing of various samples:

List of Sample Area of Cross section Test 1 Test 2 Average Load Compressive strength in MPa
C1 4.523 47 45 46 101.7
C2 4.523 35 37 36 79.59
C3 4.523 57 60 58.5 129.33
C4 4.523 30 33 31.5 69.64
Table No. 1
,CLAIMS:We claim,
1. A high compressibility strength biodegradable packaging composite comprising:
-50 to 94% w/w of powder of Onion waste pulp,
-1 to 20% w/w of Synthetic polymer,
-0.1 to 5% w/w of catalyst agent,
-5 to 20% w/w of oxidising agent;
Characterized in that the compressibility strength is achieved between 50 to 150 Megapascal (MPa).

2. The high compressibility strength biodegradable packaging composite as claimed in claim 1, wherein Synthetic polymer selected from Poly Methyl Methacrylate, Poly Acrylonitrile.
3. The high compressibility strength biodegradable packaging composite as claimed in claim 1, wherein catalyst agent selected from ((2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl).
4. The high compressibility strength biodegradable packaging composite as claimed in claim 1, wherein oxidizing agent selected from Sodium hypochlorite and sodium chlorite.
5. A process for preparation of a high compressibility strength biodegradable packaging composite as claimed in claim 1, steps comprising of:
Step 1: Reacting oxidizing agent, catalyst agent with powder of onion waste pulp in water under stirring for 15 min to 2 Hr,
Step 2:Addition of Synthetic polymer solution in step 1 mixture under stirring and continue reaction for 15 min to 2 Hr,
Step 3:Casting the reaction mass in moulds at temperature between 40 to 100 °C for 2 to 10 Hrs.

6. The process for preparation of a high compressibility strength biodegradable packaging composite as claimed in claim 5, wherein solvent in step 2) selected from toluene, water and combination thereof.
7. The process for preparation of a high compressibility strength biodegradable packaging composite as claimed in claim 5, wherein Synthetic polymer selected from Poly Methyl Methacrylate, Poly Acrylonitrile.
8. The process for preparation of a high compressibility strength biodegradable packaging composite as claimed in claim 5, wherein catalyst agent selected from ((2,2,6,6-Tetramethylpiperidinyloxy or 2,2,6,6-Tetramethylpiperidine 1-oxyl).
9. The process for preparation of a high compressibility strength biodegradable packaging composite as claimed in claim 5, wherein oxidizing agent selected from Sodium hypochlorite and sodium chlorite.