Title of Invention

"A BIODEGRADABLE FILM FOR EXTENDING SHELF LIFE OF FRUITS AND VEGETABLES AND A PROCESS FOR PREPARATION THEREOF"

Abstract

This invention relates to a biodegradable film for extending shelf life of fruits and vegetables comprising of 4-6% w/v casein, 30-60% v/v of ammonium hydroxide solution, 30-50% w/v green neem leaves, 4-6% w/v turmeric powder, 30-50% v/v of propylene glycol, 20% polyvinyl alcohol solution, 0.8 to 1.2% w/v of ethylene diamine tetra acetic acid. Further this invention relates to a process for the preparation of a biodegradable film for extending shelf life of fruits and vegetables as claimed in claim 1 comprising of the steps of preparing casein solution by dissolving 4-6% wt/v of casein in water by heating 85-95°C for 1-2 hours, with continuous stirring and slowly adding 30-60% v/v ammonium hydroxide solution; preparing the neem and turmeric extract by boiling 30-50% w/v of green neem leaves, 4-6% wt/v of turmeric powder and 30-50% v/v of propylene glycol in water at about 100°C then separating the extract by filtering; blending of casein solution obtained from step a) with an equal volume of polyvinyl alcohol solution, adding 0.8 to 1.2% w/v of a cross linking agent preferably ethylene diamine tetra acetic acid (EDTA) then heating to 85-95°C for 2-4 hrs in an inert atmosphere, then adding the neem and turmeric extract prepared in step b) and further blending for 2 to 3 hrs at 85-95°C; making a film by pouring uniformly 180 ml to 220 ml of the stock solution prepared in step c) on a glass plate of which has been cleaned, dried and then smeared with a thin layer of any vegetable oil, then dried the solution in a dust free chamber at 20-35°C followed by peeling off the dried film and conditioning it at a relative humidity of 60-65%.

Full Text

FIELD OF INVENTION The present invention relates to a biodegradable film for extending the shelf life of fruits and vegetables and a process for its preparation. PRIOR ART Post harvest fruits and vegetables require extending the shelf life of fruits and vegetables for preservation and export. There are many factors that affect the post harvest shelf life extension of fresh product like the critical composition of O2, CO2 and water vapour (turgor pressure), in and around the fruit and vegetable body. Fruits and vegetables are still alive and therefore respiring when harvested. The rate of respiration of fruits and vegetables is inversely proportional to the shelf life of the product, higher the rate of respiration lower is the shelf life and vice-versa. There are a few modified atmosphere packaging (MAP) methods known in the art for preserving fruits and vegetable. US Patent no. 4531 describes controlling/flushing of CO2 and O2 to maintain optimum concentration i.e. 1 to 2% O2 and 8 to 10% of CO2. Another method is to decrease the respiration rate which can be successfully achieved with a decreased O2 level (1 to 5%) and refrigeration. The main disadvantage of the above known art of using controlled/flushing type of CO2 and O2 is that the equipment used is highly capital intensive. Yet another limitation of the above known art is that it is useful for large consignments only. Still another disadvantage of the above known art is that the equipment used requires regular servicing/maintenance. Another method of MAP (US Patent 9854), is by active packaging in which the packaging material is encapsulated with anti microbial, antioxidant, oxygen scavenger etc. The main disadvantage of using the above known active packaging is that the processing technique is tedious and time consuming. Yet another disadvantage of the above known processing technique is that the synthetic polymer used is not biodegradable and ecofriendly. Still another disadvantage of the above known process is that the encapsulated ingredients loose their properties in the film during processing. There are some other methods known in the art, (US 6579607 & 6579) in which the packaging of fresh fruits and vegetables is done in films, made out of different synthetic polymers that have optimum permeability to oxygen and CO2. The main disadvantage of using the above known permeable films is that they are made of synthetic material which is not biodegradable. Another disadvantage of using the above known permeable films is that they are not ecofriendly and do not confirm to the requirements of Environmental Protection Agency (EPA). Yet another disadvantage of using the above known permeable films is that the process for preparation of these films is very costly. There is a growing concern among consumers and environmentalists about the use of plastic packaging materials, therefore there is a need for newer and ecofriendly material that could extend the shelf life of perishables to certain extent. Due to overall public perception and hesitation about adding more chemicals to fresh agriculture produce, waxing of fruits and edible surface coatings are not commonly used and presently the main issue involves the production of films. Objects of the invention The main object of the present invention is to provide a biodegradable/ breathable film for extending the shelf life of fruits and vegetables and a process for its preparation. Another object of the present invention is to provide a biodegradable/ breathable film for extending the shelf life of fruits and vegetables and a process for its preparation wherein turmeric and neem are used as natural antioxidant and antimicrobial agents. Yet another object of the present invention is to provide a biodegradable/breathable film which is able to maintain critical concentration of O2, CO2 and water vapour for continuous breathing of fruits and vegetables. Still another object of the present invention is to provide a biodegradable/breathable film which has good mechanical properties. Further object of the present invention is to provide a biodegradable/breathable film which extends the shelf life of fruits and vegetable by 10-12 days. Yet further object of the present invention is to provide a biodegradable/breathable film which can be casted with ease on a smooth surface like glass, steel, ceramic etc. Still further object of the present invention is to provide a biodegradable/breathable film whose thickness can be controlled by an applicator. According to this invention there is provided a biodegradable film for extending shelf life of fruits and vegetables comprising of 4-6% w/v casein, 30-60% v/v of ammonium hydroxide solution, 30-50% w/v green neem leaves, 4-6% w/v turmeric powder, 30-50% v/v of propylene glycol, 20% polyvinyl alcohol solution, 0.8 to 1.2% w/v of ethylene diamine tetra acetic acid. Further according to this invention there is provided A process for the preparation of a biodegradable film for extending shelf life of fruits and vegetables as claimed in claim 1 comprising of the steps of: a) preparing casein solution by dissolving 4-6% wt/v of casein in water by heating 85-95°C for 1-2 hours, with continuous stirring and slowly adding 30-60% v/v ammonium hydroxide solution; b) preparing the neem and turmeric extract by boiling 30-50% w/v of green neem leaves, 4-6% wt/v of turmeric powder and 30-50% v/v of propylene glycol in water at about 100°C then separating the extract by filtering; c) blending of casein solution obtained from step a) with an equal volume of polyvinyl alcohol solution, adding 0.8 to 1.2% w/v of a cross linking agent preferably ethylene diamine tetra acetic acid (EDTA) then heating to 85-95°C for 2-4 hrs in an inert atmosphere, then adding the neem and turmeric extract prepared in step b) and further blending for 2 to 3 hrs at 85-95°C; d) making a film by pouring uniformly 180 ml to 220 ml of the stock solution prepared in step c) on a glass plate of which has been cleaned, dried and then smeared with a thin layer of any vegetable oil, then dried the solution in a dust free chamber at 20-35°C followed by peeling off the dried film and conditioning it at a relative humidity of 60-65%. a) Preparing casein solution: 4-6 %wt/v preferably 5 %wt/v of casein is dissolved in water by heating to 85-95°C preferably to about 90°C for 1-2 hours, with continuous stirring by a magnetic stirrer and slowly adding 30-60 %V/V preferably 50 % V/V of 4.96 N ammonium hydroxide solution. b) Preparing the neem and turmeric extract 30-50 % w/v preferably 40 % w/v of green neem leaves, 4-6 % wt/v preferably 5 % w/v of turmeric powder and 30-50 %v/v preferably 40 % v/v of propylene glycol in water, are taken in a steel vessel and boiled at about 100°C for about 2 hours. The neem and turmeric extract is filtered in a double fold muslin cloth and the slurry is separated. c) Blending of casein solution The casein solution from step (a) is taken in a three necked flask, fitted with a thermometer, a stirrer with a teflon blade and a nitrogen gas cylinder. An equal volume of a 20 % polyvinyl alcohol solution is added to the reaction flask followed by 0.8 to 1.2 % w/v preferably 1 % w/v of a cross linking agent preferably Ethylene Diamine Terra Acetic Acid (EDTA) and the blending is continued over a heating mantle at 85-95°C for 2-4 hrs in an inert atmosphere. Then the neem and turmeric extract prepared in step (b) is added and the mixture further blended for another 2-3 hrs at 85-95°C. (d) Forming the Film Glass plate of size 10" x 12", bounded on all the sides to a depth of 5 mm is cleaned with detergent and dried. Smear a thin layer of any vegetable oil on the dried surface of the glass plate with the help of a cotton ball. The glass plate is then kept on a leveling table and 180 ml to 220 ml preferably 200 ml of the stock solution prepared in step (c) is poured uniformly. It is allowed to dry for 24 hours in a dust free chamber at 20-35°C. The dried film is peeled off and conditioned at a relative humidity of 60-65%. The thickness of film can be varied by using variable amount of stock solution, but 100 to 200 micron film gives the optimum properties. Fruits/ vegetables to be preserved are washed thoroughly under tap water to remove the surface contamination and surface dried at 20-35°C temperature. They are then placed in wide mouth plastic/ glass containers of 2 litre capacity each and the top is tightly covered with the breathable film. This invention will now be illustrated with a working example, which is intended to be typical example to explain the technique of the present invention and is not intended to be taken restrictively to imply any limitation to the scope of the present invention. Working example 50 gm laboratory grade casein was dissolved in water by heating to 90°C for 2 hrs with continuous stirring by a magnetic stirrer and 50 ml of 4.96 N ammonium hydroxide solution was slowly added. 40 g of green neem leaves, 5 g of turmeric powder was dissolved in 40 ml of propylene glycol with addition of water in a steel vessel and was boiled at 100°C for 2 hrs. It was filtered in a double fold muslin cloth to separate the slurry. Equal volume of polyvinyl alcohol solution was added to the reaction flask. 1 gm of cross linking agent Ethylene Diamine Terra Acetic Acid (EDTA) was then added and the blending was continued over a heating mantle at 90°C for 3 hrs in an inert atmosphere. An equal volume of neem and turmeric slurry was added to the reaction mixture and further blended for another 3 hrs at 90°C. The stock solution is bottled and preserved at ambient temperature. A glass plate of size 10" x 12" was cleaned with detergent and dried, and smeared a thin layer of vegetable oil on the dried surface of the glass plate with the help of a cotton ball. It was bounded on all the sides to a depth of 5 mm. The glass plate was then kept on a leveling table and 200 ml of the stock solution was poured uniformly. It was allowed to dry for 24 hours in a dust free chamber at about 30°C. The dried film was peeled off and conditioned at a relative humidity of 60-65%. 50kg of Alphanso mangoes were washed thoroughly under tap water to remove the surface contamination and surface dried at about 30°C temperature. They were placed in wide mouthed plastic/ glass containers of 2 litre capacity each and the top was tightly covered with the breathable film. Different thicknesses of the films were used and it was found that films having thickness as less than 100 micron gave sporadic black spots on fruits and vegetables, due to CO2 injury and did not extend the shelf life much. However, the films having thickness between 100 - 200 micron gave best results and the shelf life of fruits and vegetables was extended by 10 -15 days. It is to be understood that the process of the present invention is susceptible to modifications, changes, adaptations by those skilled in the art. Such modifications, changes, adaptations are intended to be within the scope of the present invention which is further set forth under the following claims: I CLAIM; 1. A biodegradable film for extending shelf life of fruits and vegetables comprising of 4-6% w/v casein, 30-60% v/v of ammonium hydroxide solution, 30-50% w/v green neem leaves, 4-6% w/v turmeric powder, 30-50% v/v of propylene glycol, 20% polyvinyl alcohol solution, 0.8 to 1.2% w/v of ethylene diamine tetra acetic acid. 2. A process for the preparation of a biodegradable film for extending shelf life of fruits and vegetables as claimed in claim 1 comprising of the steps of: a) preparing casein solution by dissolving 4-6% wt/v of casein in water by heating 85-95°C for 1-2 hours, with continuous stirring and slowly adding 30-60% v/v ammonium hydroxide solution; b) preparing the neem and turmeric extract by boiling 30-50% w/v of green neem leaves, 4-6% wt/v of turmeric powder and 30-50% v/v of propylene glycol in water at about 100°C then separating the extract by filtering; c) blending of casein solution obtained from step a) with an equal volume of polyvinyl alcohol solution, adding 0.8 to 1.2% w/v of a cross linking agent preferably ethylene diamine tetra acetic acid (EDTA) then heating to 85-95°C for 2-4 hrs in an inert atmosphere, then adding the neem and turmeric extract prepared in step b) and further blending for 2 to 3 hrs at 85-95°C; d) making a film by pouring uniformly 180 ml to 220 ml of the stock solution prepared in step c) on a glass plate of which has been cleaned, dried and then smeared with a thin layer of any vegetable oil, then dried the solution in a dust free chamber at 20-35°C followed by peeling off the dried film and conditioning it at a relative humidity of 60-65%. 3. A biodegradable film for extending the shelf life of fruits and vegetables and a process for its preparation substantially as described and exemplified herein.

Documents:

2305-DEL-2004-Abstract-(22-05-2009).pdf

2305-del-2004-abstract.pdf

2305-DEL-2004-Claims-(22-05-2009).pdf

2305-del-2004-claims.pdf

2305-DEL-2004-Correspondence-Others-(11-03-2010).pdf

2305-DEL-2004-Correspondence-Others-(22-05-2009).pdf

2305-del-2004-correspondence-others.pdf

2305-del-2004-correspondence-po.pdf

2305-DEL-2004-Description (Complete)-(22-05-2009).pdf

2305-del-2004-description(complete).pdf

2305-del-2004-form-1.pdf

2305-del-2004-form-18.pdf

2305-del-2004-form-2.pdf

2305-DEL-2004-Form-3-(22-05-2009).pdf

2305-DEL-2004-GPA-(22-05-2009).pdf