FIELD OF THE INVENTION

The present invention generally relates to biodegradable plastics derived from green waste. Specifically, the present invention relates to a process for preparing bioplastics from vegetable waste which is easily biodegradable. Moreover, the present invention relates to a process for preparing polylactic acid (PLA), versatile bioplastic by successfully utilizing easily available and economical waste potatoes. PLA based bioplastics are safe and easily biodegradable and reduce the greenhouse gas emissions.

BACKGROUND OF THE INVENTION
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Plastics are organic polymers which can be produced in different ways. Approximately 235 million tons of plastics produced annually and consumption continues to rise from 50 million tons p.a. in 1976 to an estimated 330 million tons in 2015, worldwide. India is the third largest plastic consumer in the world. In terms of numbers, the consumption of plastic in India is around four million tons with a resulting waste production of about two million tons. The environmental implication of the plastic can be viewed from the fact that only less than 4% of all the plastic waste gets recycled worldwide in comparison to more than 30% for paper and 35% for metals. Plastics have detrimental impact on human and aquatic life, environment. These plastics pose several concerns regarding safety and eco-toxicity.
[0004] Bioplastics are plastics that degrade without any processing/facilities and go back into the carbon cycle in the form of basic elements. Bioplastics are derived from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, woodchips, food waste, etc., and are currently used for a wide variety of applications such as food service items, films, bottles, bags, packaging and mulching.
[0005] Thermoplastic, a starch-based bioplastics, represents the most widely used bioplastic, constituting about 50 percent of the bioplastics market. The raw materials used commercially for the manufacture of this bioplastics are mainly starch based polymers obtained from plants such as peas starch, corn starch etc. In this group, polylactic acid (PLA) is today’s most important bioplastic. PLA is based on lactic acid, natural product and is obtained from fermentation of such as corn, sugar cane, sugar beet or tapioca with the help of microorganism. It has been reported that bioplastic reduces carbon dioxide emissions by 42%. Poly Lactic acid is versatile (variety of products can be made like glass, bottle, plate, carry bags, cups) and biodegradable within 6 to 12 months under suitable conditions of organic matter, microbes, and temperature.
[0006] Starch is the major raw material for bioplastic manufacturing and present in potatoes. India ranks third contributing around 8% to the world’s potato production. About 16% goes as waste due to various reasons, besides posing disposal issue. Most of the potato farmers suffer losses due to inadequate storage facilities and uncertainties in weather conditions, therefore, utilization of potatoes for making bioplastics will help in getting some monetary value for their crop. The attempt to utilize the waste potatoes will provide low cost feedstock for bioplastic production without competition with food crops.
[0007] Therefore, there is an urgent need to produce bioplastic by utilizing the waste potatoes which in turn address the problem of potatoes wastes and farmers concern. In addition, the bioplastic made from waste potatoes is easily biodegradable, safe and reduce the greenhouse gases emissions.

OBJECTS OF THE INVENTION
[0008] An object of the present invention is to provide a process for preparation of bioplastic.
[0009] Another object of the present invention is to provide a process for preparation of bioplastic utilizing waste potatoes.
[0010] Another object of the present invention is to provide a process for preparation of bioplastic utilizing waste potatoes which is economic and environmental friendly.
[0011] Another object of the present invention is to provide a process for preparation of bioplastic utilizing waste potatoes which is easily biodegradable, safe and reduce the greenhouse gases emissions.
[0012] The other objects and preferred embodiments and advantages of the present invention will become more apparent from the following description of the present invention when read in conjunction with the accompanying examples and figures, which are not intended to limit scope of the present invention in any manner.

SUMMARY OF THE INVENTION
[0013] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in Detailed Description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
[0014] The present invention generally relates to biodegradable plastics derived from green waste. Specifically, the present invention relates to a process for preparing bioplastics from vegetable waste. Moreover, the present invention relates to a process for preparing versatile bioplastics by successfully utilizing easily available and economical waste potatoes.
[0015] In one aspect, the present invention relates to a process for preparing a bioplastic from waste potatoes comprising the steps of:
(a) extracting starch from the waste potatoes;
(b) saccharificating the starch to obtain a sugar;
(c) fermenting the sugar obtained in step (b) using microorganism to form a lactic acid;
(d) polymerizing the lactic acid obtained in step (c) to obtain the bioplastic, polylactic acid (PLA); and
(e) optionally subjecting the bioplastic to extrusion to form different products.
[0016] In another aspect, the present invention relates to a process for preparing a bioplastic products from waste potatoes comprising the steps of:
(a) extracting starch from the waste potatoes;
(b) saccharificating the starch to obtain a sugar;
(c) fermenting the sugar obtained in step (b) using microorganism to form a lactic acid;
(d) polymerizing the lactic acid obtained in step (c) to obtain the polylactic acid (PLA); and
(e) subjecting the polylactic acid obtained in step (d) to extrusion methods to form the bioplastic products.
[0017] In another aspect, the extraction of starch from the waste potatoes comprises coarse cleaning of potatoes, rasping, sieving (centrifugation), hydro-separation, and filtration.

[0018] In another aspect, the saccharification of starch of the present invention is enzymatic saccharification.
[0019] In another aspect, the fermentation of sugar to lactic acid is carried out in a bioreactor under controlled temperature in the range of 38°C to 42°C and at pH in the range of 5 to 7.
[0020] In another aspect, the polymerization of lactic acid to polylactic acid is carried out using catalytic reaction.
[0021] Other aspects of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learnt by the practice of the invention.

DETAILED DESCRIPTION
[0022] The following is a detailed description of embodiments of the disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0023] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0024] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0025] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0026] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0027] Unless the context requires otherwise, throughout the specification which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.”
[0028] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0029] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
[0030] The description that follows, and the embodiments described therein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles and aspects of the present disclosure. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the disclosure.
[0031] It should also be appreciated that the present disclosure can be implemented in numerous ways, including as a system, a method or a device. In this specification, these implementations, or any other form that the invention may take, may be referred to as processes. In general, the order of the steps of the disclosed processes may be altered within the scope of the invention.
[0032] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
[0033] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
[0034] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0035] In a general embodiment, the present invention relates to a process for preparing bioplastic. Specifically, the present invention relates to a process for preparing bioplastics from vegetable waste. Moreover, the present invention relates to a process for preparing versatile bioplastics by successfully utilizing easily available and economical waste potatoes.
[0036] In an embodiment, the present invention relates to a process for preparing biodegradable plastics comprising the steps of:
Step 1: Collection of Waste Potatoes
The waste potatoes are collected from local mandis, nearby potato storage go-downs and potato peels from potato processing units.
Step 2: Extraction of starch from the waste potatoes
The extraction of starch involves coarse cleaning of potatoes, rasping, sieving, hydro-separation, and filtration. The starch obtained in this step is used further for preparing lactic acid.
Step 3: Saccharification of starch to sugars
Methodology: Selected microbes (Lactobacillus bulgaricus, Lactobacillus amylophilli) were utilized for saccharification of starch to sugar. The sugars obtained from the fermentation of starch, include but not limited to, monosaccharides such as glucose, fructose, galactose, and disaccharides include sucrose and lactose.
Step 4: Fermentation of sugar to lactic acid
Fermentation of sugar is carried out in reactors, under controlled temperature in the range of 38°C to 42°C and at pH in the range of 5-7 to obtain lactic acid.
Step 5: Polymerization of Lactic acid to obtain bioplastic (PLA)
Methodology: Polymerization of lactic acid is carried out using suitable catalyst such as diphenyl ester.
Step 6: Extrusion
The polylactic acid obtained was subjected to extrusion methodology such as heated screw to form different bioplastic products.
[0037] In another embodiment, the present invention relates to a process for preparing a bioplastic from waste potatoes comprising the steps of:
(a) extracting starch from the waste potatoes;
(b) saccharificating the starch to obtain a sugar;
(c) fermenting the sugar obtained in step (b) using microorganism to form a lactic acid;
(d) polymerizing the lactic acid obtained in step (c) to obtain the bioplastic, polylactic acid (PLA) and
(e) optionally subjecting the bioplastic to extrusion to form different products.
[0038] In yet another embodiment, the present invention relates to a process for preparing a bioplastic products from waste potatoes comprising the steps of:
(a) extracting starch from the waste potatoes;
(b) saccharificating the starch to obtain a sugar;
(c) fermenting the sugar obtained in step (b) using microorganism to form a 20 lactic acid;
(d) polymerizing the lactic acid obtained in step (c) to obtain the polylactic acid (PLA) and
(e) subjecting the polylactic acid obtained in step (d) to extrusion methods to form the bioplastic products.
[0039] In yet another embodiment of the present invention, saccharification of starch is carried out enzymatically, but the other methods such as acid hydrolysis can also be performed. Saccharification can occur either in special reactors or be partially or fully performed in fermentation tanks.
[0040] In yet another embodiment of the present invention, the enzymes used in the saccharification of starch includes but not limited to, Lactobacillus bulgaricus, Lactobacillus amylophilli, alpha-Amylase, beta-Amylase, Glucoamylase and Pullulanase.
[0041] In yet another embodiment of the present invention, the sugars obtained from the fermentation of starch include but not limited to monosaccharides such as glucose, fructose, galactose, and disaccharides include sucrose, maltose, and lactose.
[0042] In yet another embodiment, the fermentation of sugar may be a batch process or fed batch process to obtain the lactic acid. The fermentation was carried out in a bioreactor by following the sterilization procedure, maintaining the temperature and pH to obtain high pure and good concentration of lactic acid. Lactic acid is now manufactured by one of several synthetic and fermentative methods, for the reason that sources of sugars for mono- and disaccharides, are not only less costly to purchase but also are renewable. Further the processing costs for fermentation processes are lower than those for synthetic processes, particularly those based on petroleum-based raw materials.
[0043] In yet another embodiment, the lactic acid is produced in a fermentation broth containing fermentable sugars. The lactic acid is produced in a concentration in the range from 5%-25% by weight with the control of pH of the fermentation broth. pH of the fermentation broth is ideally kept at pH 6 to retain the activity of base sensitive enzymes used in the fermentation process.
[0044] In yet another embodiment, the polylactic acid is obtained by the polymerization of lactic acid. The purity of lactic acid plays the important role in preparing the polylactic acid. The polymerization of the lactic acid is carried out using a catalytic reaction. Lactic acid cannot be polymerized directly as the water produced prevents the polymerization process. The acid is therefore first dimerized by heating and afterwards dimer undergoes ring opening polymerization a catalyst. This method avoids the formation of water during polymerization.
[0045] In an embodiment, the evaluation of techno-commercial viability of the bioplastic shall be done via several qualitative tests including flammability, moldability, flexibility, resistance to tearing, and susceptibility to microbial decomposition.
[0046] According to another embodiment of the present invention, the polylactic acid produced is a100% compostable having properties similar to that of polyethylene and polypropylene. It is a low molecular weight polymer that can be converted into high molecular weight polymer by adding chains. L-Polylactic acid is a semi-crystalline polymer with a high melting point of 180-degree Celcius, which results in a better quality finished product.
[0047] In yet another embodiment, the bioplastic products of the present invention are selected from water bottles, compostable bags, catering-serviceware, packaging boxes for fruits, vegetable and foods, foams, insulators, crockery, containers, packaging for FMCG products etc.
[0048] In yet another aspect, the bioplastic products of the present invention are easily biodegradable, safe and reduce the greenhouse gases emissions.
[0049] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
[0050] The present invention is further explained in the form of following examples. However, it is to be understood that the following examples are merely illustrative and are not to be taken as limitations upon the scope of the invention.
[0051] Example 1: General Procedure
[0052] The starch was extracted from the potato using centrifugation. Bacillus species like Bacillus Stearothermophilus were used to convert potato starch into lactic acid under anaerobic conditions. The fermentation was carried out at a temperature above 50 ?C to avoid any kind of contamination. A pH around 6 was maintained for the optimal growth of bacteria. The amylase activity of the bacillus species makes it suitable for the production of lactic acid directly from potato starch. Corn steep liquor and nutrient broth were used to carry out the process that would support the growth and activity of bacteria. Batch fermentation was carried out with the help of impellers, the initial starch concentration was maintained at 50g/L. The process was conducted under non-sterile conditions i.e. the feeding of reactor and sampling from rector took place at regular intervals by opening it to the non-sterile atmosphere. It was found that L-Lactic Acid has better mechanical properties than D-Lactic Acid hence L-Lactic Acid concentration was maximized during the fermentation process.
[0053] HPLC analysis along with other analytical methods like enzyme assay were used to measure the concentration of lactic acid formed and also to measure how much starch is converted into lactic acid after the process is completed.
[0054] The foregoing examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention.

ADVANTAGES OF THE PRESENT INVENTION
[0055] The present invention provides a process for preparation of bioplastic.
[0056] The present invention provides a process for preparation of bioplastic utilizing waste potatoes.
[0057] The present invention provides a process for preparation of bioplastic utilizing waste potatoes which is economic and environmental friendly.
[0058] The present invention provides a process for preparation of bioplastic utilizing waste potatoes, which is easily biodegradable, safe and reduce the greenhouse gases emissions.

We Claim:

1. A process for preparing bioplastics from waste potatoes comprising the steps of:
(a) extracting starch from the waste potatoes;
(b) saccharificating the starch to obtain a sugar;
(c) fermenting the sugar obtained in step (b) using microorganism to form a lactic acid;
(d) polymerizing the lactic acid obtained in step (c) to obtain the bioplastic, polylactic acid (PLA); and
(e) optionally subjecting the bioplastic to extrusion to form different products.
2. A process for preparing a bioplastic products from waste potatoes comprising the steps of:
(a) extracting starch from the waste potatoes;
(b) saccharificating the starch to obtain a sugar;
(c) fermenting the sugar obtained in step (b) using microorganism to form a lactic acid;
(d) polymerizing the lactic acid obtained in step (c) to obtain the polylactic acid (PLA); and
(e) subjecting the polylactic acid obtained in step (d) to extrusion methods to form the bioplastic products.
3. The process as claimed in claims 1 and 2, wherein extraction of starch involves coarse cleaning of potatoes, rasping, sieving, hydro-separation, and filtration.
4. The process as claimed in claims 1 and 2, wherein saccharification of starch is carried out enzymatically in special reactors or fully performed in fermentation tanks.
5. The process as claimed in claims 1 and 2, wherein the enzymes used in the saccharification of starch are selected from Lactobacillus bulgaricus, Lactobacillus amylophilli, alpha-Amylase, beta-Amylase, Glucoamylase and Pullulanase.
6. The process as claimed in claims 1 and 2, wherein fermentation of sugar is carried out in reactors, under controlled temperature in the range of 38°C to 42°C and at pH in the range of 5-7 to obtain lactic acid.
7. The process as claimed in claims 1 and 2, wherein the sugars obtained from the fermentation of starch are monosaccharides selected from glucose, fructose, galactose, and disaccharides selected from sucrose, maltose, and lactose.
8. The process as claimed in claims 1 and 2, wherein lactic acid is produced in a concentration in the range from 5%-25% by weight.
9. The process as claimed in claims 1 and 2, wherein the bioplastic, polylactic acid is obtained by the polymerization of lactic acid, in the presence of catalyst diphenyl ester.
10. The process as claimed in claims 1 and 2, wherein heated screw extrusion methodology is used to form different bioplastic products.
11. The process as claimed in claims 1 and 2, wherein the bioplastic products are selected from water bottles, compostable bags, catering serviceware, packaging boxes for fruits, vegetable and foods, foams, insulators, crockery, containers or packaging for FMCG products.