DESCRIPTION
Technical field
The present invention relates to the development of food packaging material from food and agricultural wastes. More specifïcally it deals with the method of preparation of flexible and biodegradable lignocellulosic packaging material from peanut hulls and also the packaging material made thereof.
Background of the invention
The non-biodegradable wastes generated by various kinds of packaging materials has become a major threat to our environment. The need for cost-effective and sustainable variants are appending in the modern era. Further, the demand for food and agricultural waste utilization is'also increasing from nutrition to packaging. The bio-plastics generally derived from renewable sources are finding great applications in the food and pharmaceutical sector as replacements for conventiona! petroleum-based plastics. These plastics or packaging materials are mostly edible or biodegradable and thereby environmental friendly. Minimal processing should be involved in the manufacturing processes to r.educe carbon footprints and reducethe emission of greenhouse gasesn

Peanut/ Groundnut (Arachis hypogaea L.) is one of the most largely produced and used agricultural species in the world. Peanut hulls/shells (the outermost covering of peanuts when harvested) are a major waste material produced in bulk from peanut farms or processing industries. Peanut hulls contribute about 20 % to the weight of dried peanuts. India is the second-largest producer of peanut, the disposal of these wastes is a matter ofcoricern. Peanut hulls are generally burnt by the farmers or arbitrarily dumped, which leads to the pollution of the environment. It is also used as a biofuel or cattle feed in some regions. Peanut huil is a high fiber product with 35-37 % cellulose and 28-30 % lignin content. It has very little oil content contributing tojust 1-2 %of its composition. It is also rich in biologically active compounds showing remarkabte antioxidant activity. Hence, the utilization of peanut hulls for more upgraded and sustainable applications becomes a necessity.
Several works have been performed on the development of packaging materials, bio-plastics or films from renewable sources. Bio-plastics can be made from polymers obtained from microbial sources, polysaccharide, protein or lipid-based polymers. The agro polymers commonly used in the field of packaging are generally derived from:
i) lignocellulosic sources like rice straw, corn cob, wood, etc.
ii) staren sources like potato, wheat or corn.
iii) Other natural sources like fruit and vegetable wastes, gums, etc.
Peanut hulls are lignocellulosic materials, which also have the potential to be developed into agro-polymers.
Prior art
There were several inventions on the preparation of biodegradable or edible films from food and agricultural waste sources. Leaves, husks, hulls, stalks or peels were made use of. The works reported to date involve the extraction of fibers from a nutshell, pulping or using natural fiber sources as reinforcements. However, there are no works reported on the use of whole peanut huil powder as one of the major components in the formation of flexible biodegradable packaging material. The extraction process of antioxidant substances and other functional components from peanut hulls were also patented.
The Korean patent, KR20130072889A deals with the manufacturing of an eco-friendly disposable packaging container from peanut hulls. The steps in preparation involved heating the pulverized
peanut hull at high pressure and bleaching it. The pulp was then mixed with seaweed or starch and

made to dry. This was then converted into a packaging container and coated with a waterproof
layer.
The U.S. patent, US10179856 relates to the development of biodegradable films from biological
components where protein adhesive was the major component foliowed by natural fibers like a
nutshell, hygroscopic minerals, water, and additives.
The Indian patent number 201921014053 developed a fiber-based packaging matërial from corncob which wasclaimed tobeenvironment-friendly, lowcostand reusable. Corncob wasdrilled to make holes and was used to store delicate materials like glasses in it. The residue from dril led corn was used to fill the extra spaces and inner walls of drillings. The packaging matërial was produced just by heating and drilling in this case, thereby reducing the cost of production. The U.S. patent, US6440204 invented packaging and structural matërial from potato peel waste, which can be used as a substitute for binders and adhesives for various food applications. It can also be used for edible and non-edible composite materials.
The U.S. patent, US6083582 relates to the preparation of a biodegradable and edible film from nonwood cellulosic fibers like corn cobs, husks or agricultural wastes like leaves. Highly refined cellulose was prepared and lipids, proteins, plasticizers, and saccharides were added in different concentrations to the mixture while preparing the film.
The Hungarian patent, HN0301667A2 waspatented for the process of preparation of biodegradable packaging matërial and devices from naturally heterogeneous materials like whole grains, oilseeds, food processing, and agricultural wastes. These natural products comprised 70 % of the total mass. The packages were made by subjecting the premix to the dynamic thermal formation. The German patent, DE102005006840B4 involves the preparation of a packaging or composite matërial. The matërial had at least one reservoir for liquid adhesive matërial, which was designed to be in the formation to cure matërial defects. A solid shell, which was designed to exceed a mechanical load limit of the packaging or composite matërial to release the adhesive matërial. The solid matrix was prepared by the nutshell fibers of peanut, hazelnut, brazil nut, macadamia, and pecan to have a cumulative effect of their properties. '•
The German patent, DEI0027906AI (applicable worldwide) patented on a biodegradable molding matërial. It comprises of al iphaticor partially aromatic polyester as the main component and natural fibers including nutshell flour as reinforcements.
The Chinese patent, CN102061322B invented a method for extraction of polysaccharide, flavonoid

and dietary fiber from peanut shell in a single stretch. It has the advantage of avoiding the loss of

other components from the peanut shells during the individual extraction of each functional ingrediënt mentioned in the process.
The Chinese patent, CN103272568B relates to a method of preparation of a bifunctional amino carboxy modified cellulosic adsorbing agent from peanut shells and the utilization of this sorbent for heavy metals and dyes. Similarly, CN103071463A and CN103071462Adeal with adsorbents for lead and mercury respectively using peanut shells.
The Chinese patent, CN101514302A discloses the extraction of an active ingrediënt from peanut shell to flavor cigarette and utilization of the extraction residue for the preparation of food packaging vessel ortableware.
The Chinese patent, CN1702235A deals with the manufacturing of paper board after blasting pulp production method of oil palm fruit shell.
The Chinese patent, CN104448336A developeda method of extraction of lignin from peanut hulls. The peanut hulls were crushed, dried and made to react with sodium hydroxide, by heating to a temperature of 110 °C. The solution was flltered and the insoluble portion was dried to obtain lignin.
The Indian patent number, 201831009709 relates to the method of extraction of'antioxidant substances like polyphenol concentrates from peanut hulls and the extract obtained thereof. The extract was obtained by maceration using methanol and subsequent evaporation of the solvent.
Summary of the invention
The present invention relates lo the preparation of flexible biodegradable packaging material from peanut huil which is a lignocellulosic material suitable for producing agro-based polymers. The prepared packaging material can be used as an alternative for one-time use plastics. These are safe to use for packing food materials and degrades easily, thereby harmless to the environment. Initially, the peanut hulls were cleaned, dried and powdered. The powder was digested in an acidic solution to remove waxy resins. The digested powder was mixed with binding agents, thickening agents, and plasticizers in water and the film was made. The present invention helps to reduce the burden on the environment by reducing the use of plastic and utilizing peanut hulls which are food processing and agricultural waste.

Objectives
• The first objective of the invention involves the development of packaging material by the utilization of food processing and agricultural byproducts thereby reducing the burden of conventional petroleum-based plastic wastes.
• The second objective is the method of preparing a flexible and biodegradable packaging material with peanut huil powder as a major constituent in a sustainable and economical manner.
Detaüed description
Firstly, the peanut hulls were cleaned, dried (< 5 % M.C) and powdered to a uniform size. The huil powder was then digested in an acidic solution. The main application of digestion is to breakdown the chemical structure of lignin and make the peanut shell powder solubilize in the film making solution. It also aids in the partial removal of hemicellulose and other waxy materials. The film-forming solution was prepared by mixing peanut huil powder with binding agents. Plasticizers and thickening agents were also added to the solution. The bio-plastic film was prepared by the solvent casting method. It was developed in varying proportions of huil powder (30-50 %), binding and thickening agent combinations. The developed biopolymer hadacontinuoussmooth texture. It was flexible and biodegradable.

Brief description of the drawings
Figure 1: Peanut hulls dried and cleaned
Figure 2: Peanut huil powdered and sieved to a particular size
Figure 3: Digestion in acidic solution
Figure 4: Digested peanut huil powder after washing off acid to a pH 6
Figure 5: Preparation of film forming solution by mixing binding agents, thickening agents and
plasticizers
Figure 6: Casting of film forming solution on glass plate
Figure 7: Drying in hot air oven
Figure 8: Flexible packaging material removed from glass plate


CLAIMS We claim:
1. The process of preparing a flexible biodegradable packaging material from peanut hulls.
2. The flexible biodegradable packaging material from claim 1 comprising of i) Peanut huil powder
ii) Thickening agents
iii) Plasticizer
iv) Binders or matrix formers
v) Water
3. The flexible biodegradable packaging material prepared using the ingredients from claim
2, The steps in preparation involve:
I) Collection and cleaning of peanut hulls

ii) Drying of peanut hulls
iii) Milling of peanut hulls
iv) Sieving of peanut huil powder
v) Digesting of peanut huil powder in an acidic solution to remove the waxy resins.
vi) Washing of the digested powder with distilled water to pH 6.
vii) Drying the digested peanut huil powder.
viii) Preparation of film forming solution by mixing binding and thickening agents. These agents can include carboxy methyl cellulose, pectin, corn starch or any natural additives with required properties.
ix) Adding plasticizers like glycerol, sorbitol etc and water repellent or firming agents.
x) Preparation of the packaging material by solvent casting, moulding, extrusion or
any other mode of preparation.