Description:FORM 2

The Patents Act 1970
(39 of 1970)
&
The Patent Rules, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

Title: A METHOD FOR PREPARING BIOPOLYMER FILM FOR SHELF-LIFE EXTENSION AND REAL-TIME FOOD SPOILAGE DETECTION

Applicant:
IITM PRAVARTAK TECHNOLOGIES FOUNDATION
B5 - 01, B - Block, 5th Floor, IIT Madras Research Park, Kanagam Road, Taramani, Chennai – 600113, India

The following specification particularly describes the invention and the manner in which it is to be performed.
A METHOD FOR PREPARING BIOPOLYMER FILM FOR SHELF-LIFE EXTENSION AND REAL-TIME FOOD SPOILAGE DETECTION
TECHNICAL FIELD
The present invention relates to the field of food spoilage detection methods and its techniques. More specifically, the present invention related to a method for preparing biopolymer film for shelf life extension and real-time detection of food spoilage. The transparent biopolymer film indicates the freshness of packaged food through visible colour changes.
BACKGROUND
There are many external food quality monitoring devices are available in the market to identify the quality of food material. But, by using the convention methods the user wants to pick and check the fruit/vegetable individually. The aforementioned process consumes more time and energy. On the other hand, the global food industry faces critical challenges related to food spoilage, waste and safety. The significant portion of perishable food products is lost due to microbial contamination and inadequate monitoring systems, resulting in economic losses, environmental burden, and health risks. The current packaging materials primarily focus on physical protection and do not offer real-time information on the freshness or quality of the food. Moreover, the most conventional packaging is derived from non-biodegradable petrochemical-based plastics, contributing to environmental pollution. There are no eco-friendly solutions are available in the market to increase the shelf-life of the fruit/vegetable as well as detect the food spoilage.
Thus, there is a need to introduce a method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection using the extract derived from the red cabbage. The present invention will overcome the aforementioned problems, limitations and disadvantages in an effective manner.
OBJECTIVE OF THE INVENTION
The primary object of the present invention is to provide a method for preparing the biopolymer film for to increase the shelf-life and detect the food spoilage using the extract of red cabbage.
Another object of the present invention is to introduce a biodegradable film for food/vegetable/fruit packaging and quality monitoring.
Another object of the present invention is to provide an eco-friendly method for increasing the shelf-life of the food materials.
Another object of the present invention is to reduce the time consumption, manpower and energy for checking the food materials individually via the user hands.
Another object of the present invention is to provide a transparent material for indicating the food quality using the visual colour changes due to pH levels.
Yet another object of the present invention is to provide a cost effective method for preparing the biodegradable transparent film using the organic materials.
These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
SUMMARY
The various embodiment of the present invention provides a method for preparing biopolymer film for shelf-life extension and real-time food spoilage detection using the extract derived from the red cabbage. The biopolymer film is composed of a blend of poly vinyl alcohol, chitosan, and anthocyanin extracted from red cabbage. The extracted anthocyanin is mixed with the dissolved poly vinyl alcohol and chitosan. The sodium tripolyphosphate is added with the said mixture for acting as the cross linking agent. The pouring of said homogenized mixture in a casting glass plate helps to obtain a transparent biopolymer sheet after the drying process. The transparent biopolymer film can be packed the food material in the form of modified atmosphere packaging method. The biopolymer film detects the food quality using the pH level changes and it is indicated through the colour changes. The biopolymer film reacts with the acids and volatile organic compounds of the ripened or spoiled fruits for identifying the quality of the food material. The integration of QR/RFID tags are helping to monitor the food quality, location and the like from one or more locations.
The method of preparation of biopolymer film comprising:
- collecting and cleaning of 200g of red cabbage;
- crushing and macerating with ethanol and water;
- involving the said mixture (step ii) in magnetic stirrer and adding HCL;
- centrifuging the said mixture (step iii) under 4000 rpm for 20 minutes;
- filtering the supernatant using Whatman paper for obtaining the Anthocyanin extract from the red cabbage;
- dissolving 2-4% of PVA in hot water at 80°C with stirring;
- dissolving 1-2% of Chitosan in 1% of acetic acid;
- blending of dissolved PVA and Chitosan (step vi & vii) with Anthocyanin extract;
- adding 0.1-0.3% of sodium tripolyphosphate in the said mixture (step viii), wherein the STPP is configured for acting as the cross linking agent;
- homogenizing of the said mixture;
- pouring the homogenized mixture on a casting plate and drying at 45-50°C for 24 hours; and,
- peeling of dried film for packaging.
According to an embodiment, wherein the said Anthocyanin extract can be derived from the fresh or boiled form of red cabbage. The biopolymer film detects the food spoilage using the pH sensitivity by means of incorporated Anthocyanin extract. The usage of sodium tripolyphosphate as the cross linking agent is configured for improving the mechanical strength and film flexibility.
According to an embodiment, wherein the transparent biopolymer film can be packed the food material in the form of modified atmosphere packaging (MAP) method, wherein the MAP method helps to visually monitor the freshness of foods to the user using different colour indications.
According to an embodiment, wherein the QR/RFID tags can be embedded with the biopolymer film while packaging, wherein the tags configured to monitor the food quality, location and the like from one or more locations.
According to an embodiment, wherein the flat levelled glasses are used in the film casting to control the biopolymer film thickness, wherein the said biopolymer film thickness ranges from 50 to 100 microns. The transparent biopolymer film indicates the quality of food by means of pH level indication, wherein the pH level indication ranges from 3 to 9, wherein the bright red indicates pH 3, purple indicates pH 5, blue indicates pH 7 and green indicates pH 9. The biopolymer film reacts with the acids and volatile organic compounds of the ripened or spoiled fruits for identifying the quality of the food material, wherein the said film maintains the sensitivity for the period of 30 days under ambient conditions.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
Fig 1 illustrates the flow chart of method for preparing biopolymer film, according to an embodiment of the present invention.
Fig 2 illustrates the flow chart of preparation method of Anthocyanin extract from red cabbage, according to an embodiment of the present invention.
Fig 3 illustrates the pH analysis of Anthocyanin extract, according to an embodiment of the present invention.
Fig 4 illustrates the confirmatory test on Anthocyanin, according to an embodiment of the present invention.
Fig 5 illustrates the preparation images of the film, according to an embodiment of the present invention.
Fig 6 illustrates the film casting operation and obtained film after drying, according to an embodiment of the present invention.
Fig 7 illustrates the experimental trail of spoilage controlled by film, according to an embodiment of the present invention.
Although the specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
DETAILED DESCRIPTION
The various embodiments and the other advancements and features are illustrated with the reference to the non-limiting details in the following detailed description. Illustration of processing techniques of well-known components are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The various embodiment of the present invention provides a method for preparing biopolymer film for shelf-life extension and real-time food spoilage detection using the extract derived from the red cabbage. The biopolymer film helps to extend the shelf-life of the fruit/vegetable/food materials. The biopolymer film also identifies the food spoilage using the pH level variations and it is indicated through the colour changes. The red cabbage was collected/purchased from the koyambedu market, Chennai, Tamil Nadu, India. The Anthocyanin extract can be derived from fresh or boiled red cabbage.
Fig 1 illustrates the flow chart of method for preparing biopolymer film, according to an embodiment of the present invention. The method for preparing biopolymer film for shelf-life extension and real-time food spoilage detection comprising:
- collecting and cleaning of 200g of red cabbage;
- crushing and macerating with ethanol and water;
- involving the said mixture (step ii) in magnetic stirrer and adding HCL;
- centrifuging the said mixture (step iii) under 4000 rpm for 20 minutes;
- filtering the supernatant using Whatman paper for obtaining the Anthocyanin extract from the red cabbage;
- dissolving 2-4% of PVA in hot water at 80°C with stirring;
- dissolving 1-2% of Chitosan in 1% of acetic acid;
- blending of dissolved PVA and Chitosan (step vi & vii) with Anthocyanin extract;
- adding 0.1-0.3% of sodium tripolyphosphate in the said mixture (step viii), wherein the STPP is configured for acting as the cross linking agent;
- homogenizing of the said mixture;
- pouring the homogenized mixture on a casting plate and drying at 45-50°C for 24 hours; and,
- peeling of dried film for packaging.
According to an embodiment, wherein the said Anthocyanin extract can be derived from the fresh or boiled form of red cabbage.
According to an embodiment, the biopolymer film detects the food spoilage using the pH sensitivity by means of incorporated Anthocyanin extract.
According to an embodiment, the usage of sodium tripolyphosphate as the cross linking agent is configured for improving the mechanical strength and film flexibility.
According to an embodiment, wherein the transparent biopolymer film can be packed the food material in the form of modified atmosphere packaging (MAP) method, wherein the MAP method helps to visually monitor the freshness of foods to the user using different colour indications.
According to an embodiment, wherein the QR/RFID tags can be embedded with the biopolymer film while packaging, wherein the tags configured to monitor the food quality, location and the like from one or more locations.
According to an embodiment, wherein the flat levelled glasses are used in the film casting to control the biopolymer film thickness, wherein the said biopolymer film thickness ranges from 50 to 100 microns.
According to an embodiment, the transparent biopolymer film indicates the quality of food by means of pH level indication, wherein the pH level indication ranges from 3 to 9, wherein the bright red indicates pH 3, purple indicates pH 5, blue indicates pH 7 and green indicates pH 9.
According to an embodiment, the biopolymer film reacts with the acids and volatile organic compounds of the ripened or spoiled fruits for identifying the quality of the food material, wherein the said film maintains the sensitivity for the period of 30 days under ambient conditions.
The present invention provides an eco-friendly, biodegradable, and intelligent food packaging film that actively indicates the freshness of packaged food through visible colour change. The film is composed of a novel blend of poly vinyl alcohol (PVA), chitosan (CS), and anthocyanins (ATH) extracted from red cabbage, with sodium tripolyphosphate (STPP) used as a cross-linking agent. This composition enhances the mechanical properties, pH sensitivity, and visual signaling capability of the film. The packaging system is cost-effective, non-toxic, and adaptable for real-time monitoring of spoilage in various food types including meats, vegetables, and seafood. Further, the film is integrated with natural antimicrobial agents and/or digital traceability tools like QR codes, enhancing its functionality and market potential. The QR/RFID tags are helping to share the real-time information to one or more authorized users’ locations.
Fig 2 illustrates the flow chart of preparation method of Anthocyanin extract from red cabbage, according to an embodiment of the present invention. The 200g of red cabbage was collected from the koyambedu market, Chennai, Tamil Nadu. After several processing, the extract will be filtered by the Whatman paper.
Fig 3 illustrates the pH analysis of Anthocyanin extract; the samples were tested in the laboratory for analysing the pH levels.
Fig 4 illustrates the confirmatory test were conducted on Anthocyanin presence in the said extract.
Fig 5 illustrates the preparation images of the film for initiating the film casting process.
Fig 6 illustrates the film casting operation, and obtained film after drying.
Fig 7 illustrates the experimental trail of spoilage controlled by film.
In an embodiment, QR or RFID tags can be operated by the battery power source. The users may see the colour changes at any time by means of visual inspection due to pH level changes. The power source integration allows the users to check the location, date of packaging, colour changes and the like from one or more locations.
The synergistic composition of PVA/CS/ATH matrix with STPP as a cross-linker to enhance both structural and functional attributes of the film. The present invention proposes multi-colour spoilage detection, enhanced durability, and compatibility with MAP systems and digital traceability. The method also utilizes Nano-encapsulation of anthocyanins for stability.
The smart packaging film is fabricated by blending at least 1% w/v PVA and 1% w/v CS in specific ratios. The Anthocyanins extracted from red cabbage are incorporated as pH-sensitive indicators. The sodium tripolyphosphate acts as a cross-linking agent to enhance film durability. The film optionally includse nano-encapsulated indicators or antimicrobial agents, and can be customized in thickness and transparency based on food type.
The preparation of method of biopolymer film uses the STPP as a cross-linker improves mechanical strength and film flexibility. The combination of nano-encapsulation for anthocyanin and multi-dye integration allows multi-color indication. The integration with MAP and QR technology enhances practical and commercial applicability. The biodegradable, edible, and scalable casting technique suited for mass production.
According to an embodiment, the anthocyanin extract will be collected from the red cabbage. The PVA (2–4%) is dissolved in hot water at ~80°C with stirring. The Chitosan (1–2%) is dissolved in 1% acetic acid. The both solutions are blended with anthocyanin extract. The STPP (0.1–0.3%) is added for cross-linking. The mixture will be homogenized. The mixture will be poured on a casting plate and dried at 45–50°C for 24 hours. Finally, the dried film will be peeled and used for packaging.
According to an embodiment, the QR/RFID tags can be embedded in or attached to the packaging. These tags provide details on production date, origin, test results, and storage conditions. The consumers can scan the code for real-time freshness updates linked to film’s colour change. By using the tags, the supply chain transparency is enhanced, reducing food waste and ensuring safety.
According to an embodiment, the homogenized solution is cast on a flat, levelled glass or Petri dish. The controlled volume ensures uniform thickness (50–100 microns). Finally, it is dried in hot air oven at 45–50°C for 24 hours to prevent bubble formation. This step resulting that film is flexible, transparent, and mechanically stable.
Mechanical Testing of the film: Tensile Strength = 28–35 MPa; Elongation = 15–25%
Barrier Testing: Water Vapor Transmission Rate (WVTR) = 180–210 g/m²/day
Optical Clarity, Thickness (via micrometer), Biodegradability in soil (7–10 days)
The pH Sensitivity: Film changes color visibly across pH range 3 to 9:
- pH 3: Bright Red
- pH 5: Purple
- pH 7: Blue
- pH 9: Green
Shelf Life: Maintained sensitivity for up to 30 days under ambient conditions.
According to an embodiment, the method of pH level detection using the film comprises: as fruit ripens or spoils, it emits acids and volatile organic compounds (VOCs); these alter the surface pH near the packaging film; and, Anthocyanins in the film undergo color changes in response to these pH changes.
The transparent biopolymer film can be packed by wrapping individual fruits using film sheets; and, lining the interior of fruit pouches or containers. The QR/RFID tags can be inserted while the packaging at the inside or alongside or edge area, for enabling virtual interaction with one or more users. The virtual interaction helps to monitor the location, quality, time line and the like.
The present invention increases the shelf-life of the food products by means of the biopolymer film. The present invention reduces the manual testing and time delay. The present invention identifies the food spoilage using the pH level variation. The present invention indicates different colour to the user based on the quality of the food material. The present invention provides the virtual interaction for monitoring the one or more parameters digitally. The transparent film is biodegradable.
It is noted that the above-described examples of the present invention is for the purpose of illustration only. Although the present invention has been described in conjunction with a specific example thereof, numerous modifications may be possible without materially departing from the teachings and advantages of the subject matter described herein. Other substitutions, modifications and changes may be made without departing from the spirit of the present solution. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications.
, Claims:CLAIMS
We claim,
1. A method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection, comprising:
i. collecting and cleaning of 200g of red cabbage;
ii. crushing and macerating with ethanol and water;
iii. involving the said mixture (step ii) in magnetic stirrer and adding HCL;
iv. centrifuging the said mixture (step iii) under 4000 rpm for 20 minutes;
v. filtering the supernatant using Whatman paper for obtaining the Anthocyanin extract from the red cabbage;
vi. dissolving 2-4% of PVA in hot water at 80°C with stirring;
vii. dissolving 1-2% of Chitosan in 1% of acetic acid;
viii. blending of dissolved PVA and Chitosan (step vi & vii) with Anthocyanin extract;
ix. adding 0.1-0.3% of sodium tripolyphosphate in the said mixture (step viii), wherein the STPP is configured for acting as the cross linking agent;
x. homogenizing of the said mixture;
xi. pouring the homogenized mixture on a casting plate and drying at 45-50°C for 24 hours; and,
xii. peeling of dried film for packaging.
2. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the said Anthocyanin extract can be derived from the fresh or boiled form of red cabbage.
3. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the biopolymer film detects the food spoilage using the pH sensitivity by means of incorporated Anthocyanin extract.
4. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the usage of sodium tripolyphosphate as the cross linking agent is configured for improving the mechanical strength and film flexibility.
5. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the transparent biopolymer film can be packed the food material in the form of modified atmosphere packaging (MAP) method, wherein the MAP method helps to visually monitor the freshness of foods to the user using different colour indications.
6. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the QR/RFID tags can be embedded with the biopolymer film while packaging, wherein the tags configured to monitor the food quality, location and the like from one or more locations.
7. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the flat levelled glasses are used in the film casting to control the biopolymer film thickness, wherein the said biopolymer film thickness ranges from 50 to 100 microns.
8. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the transparent biopolymer film indicates the quality of food by means of pH level indication, wherein the pH level indication ranges from 3 to 9, wherein the bright red indicates pH 3, purple indicates pH 5, blue indicates pH 7 and green indicates pH 9.
9. The method for preparing biopolymer films for shelf-life extension and real-time food spoilage detection as claimed in claim 1, wherein the biopolymer film reacts with the acids and volatile organic compounds of the ripened or spoiled fruits for identifying the quality of the food material, wherein the said film maintains the sensitivity for the period of 30 days under ambient conditions.