EDIBLE FILM MADE USING AMARANTHUS PANICULATUS STARCH- A NON-CONVENTIONAL SOURCE OF STARCH

Abstract

This invention relates to an edible film composition derived from Amaranthus paniculatus starch, along with a method for its preparation. The starch is isolated from Amaranthus paniculatus grains using an alkali steeping method, followed by modification through heat-moisture treatment (HMT) and oxidation processes. The resulting modified starches exhibit enhanced physio-chemical properties, including increased tensile strength and optimized water vapor permeability (WVPR). Specifically, the films made from oxidized starch demonstrate a tensile strength of 1.94 MPa and reduced water solubility of 38.23%, while those from HMT starch show a tensile strength of 2.44 MPa and a WVPR of 7.30 g·mm/m²·day·kPa. These films maintain desirable thickness and transparency, making them suitable for various food applications. The findings highlight the potential of Amaranthus paniculatus as a viable starch reservoir for developing high-performance edible films, contributing to sustainable packaging solutions in the food industry.

Specification

Description:FIELD OF THE INVENTION
This invention relates to Edible film made using Amaranthus paniculatus starch- A non-conventional source of starch.
BACKGROUND OF THE INVENTION
Researchers have focused their efforts on the production of edible films or coatings using biopolymers such as polysaccharides, lipids, and proteins. These biopolymers are preferred due to their environmentally friendly nature and their ability to maintain the quality and safety of food products. Among these biopolymers, starch stands out as the most significant natural polymer, widely utilized as a thickener, emulsifier, and stabilizer in various food applications. The primary focus of the study is on the development of edible films using Amaranth starch. Starch-based edible films offer the advantage of being derived from a renewable and sustainable source, making them environmentally friendly alternatives to traditional packaging materials
EP0547551A1- Compositions useful as edible films comprise, by weight, 5 to 40% modified starch, 5 to 40% gelatin, 10 to 40% plasticizer, 5 to 40% water, and, optionally, 5 to 40% lipid, wherein the compositions have a viscosity of less than about 370,000 cps at 80°C and the edible films are effective to provide water, lipid, solute, gas, physical or microbial barriers in foods. A second set of compositions useful as moisture barrier films comprise, by weight, 8 to 35% modified starch, 10 to 20% gelatin, 15 to 30% lipid, 20 to 60% water, and, optionally, 0 to 15% plasticizer, wherein the compositions have a viscosity of less than about 35,000 cps at 80°C and the edible films are effective to provide a water transmission barrier in foods. The compositions optionally contain mixtures of plasticizer(s), lipid(s), starch(es) or gelatin(s), and optionally contain preservative(s), emulsifier(s), emulsion stabilizer(s), flavor(s), colorant(s), buffer(s), acidulant(s), base(s) or opacifier(s). Fluidity starches and dextrins are preferred.
RESEARCH GAP:
• Amaranthus paniculatus starch was used.
• Glycerol was used as plasticizer
20050233048- The present invention provides an edible film comprising (A) a modified starch mixture of (a) at least one modified starch selected from the group consisting of etherified high amylose starches and esterified high amylose starches, and (b) at least one modified starch selected from the group consisting of etherified starch oxidation products, etherified starch acid decomposition products, etherified starch enzymatic decomposition products, and maltodextrins; (B) at least one gelling agent; and (C) at least one plasticizer.
RESEARCH GAP:
• Amaranthus paniculatus starch was used
• Modification was done using HMT method and Oxidation method.
None of the prior art indicate above either alone or in combination with one another disclose what the present invention has disclosed. This invention relates to Edible film made using Amaranthus paniculatus starch- A non-conventional source of starch.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention.
This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
Modified and native Amaranthus paniculatus starch was used to form edible film. The starch was modified using heat and moisture treatment and oxidation treatment and was compared to the native starch. The edible films prepared with modified starch showed promising results of tensile strength, WVPR, opacity and color.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrated embodiments of the subject matter will be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
FIG 1: (A) FILM FROM NATIVE STARCH, (B) FILM FROM OXIDIZED STARCH, AND (C) FILM FROM HMT STARCH
The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein 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 scope of the present disclosure as defined by the appended claims.
It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a"," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
In addition, the descriptions of "first", "second", "third", and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Modified and native Amaranthus paniculatus starch was used to form edible film. The starch was modified using heat and moisture treatment and oxidation treatment and was compared to the native starch. The edible films prepared with modified starch showed promising results of tensile strength, WVPR, opacity and color.
Amaranthus paniculatus is a pseudo cereal. It is a potential starch reservoir, and the qualities of the eventual product are reliant on the starch. The physical properties of Amaranthus paniculatus grains were studied and found that the grain have a diameter of 0.5 mm, thousand kernel weight was 0.76 g, Angle of repose was 25.65°. The moisture, protein, carbohydrates, fat, fibre and ash content was found to be 11%, 14%, 69%, 8%, 2.9% and 3% respectively. Modification of Amaranthus starch (via oxidation and HMT) was performed followed by the formation of edible films. The films were evaluated for physio-chemical and mechanical properties. The carboxyl content of native and HMT starch was found to be similar whereas it was higher (0.1 COOH/100GU) for oxidized sample. The solubility was found to be higher in modified starch samples (76.44 %) than native (62.58 %) but swelling power was higher for native starch (50.43 g/g) as compared to modified samples. Pasting temperature of native starch, oxidized and heat moisture treated starch was found to be 75.09°C, 76.10°C and 89.36°C respectively. Edible films were prepared and studied for physio-chemical and mechanical. The tensile strength of films was enhanced by both modification procedures, whereas only HMT increased the water vapor permeability, and oxidation had the opposite effect. Modification treatments resulted in the reduction of water solubility of the films. HMT film showed some advantages over the oxidized film and native starch films in terms of mechanical properties.
Physio-chemical properties of Amaranthus paniculatus
The primary constituent of Amaranth is carbohydrates, and starch is the central part, comprised of approximately 40-70 % dry weight. The second most abundantly available are proteins ( 12-18%), followed by lipids(8%) and minerals. The physical attributes of Amaranth paniculatus is given in Table 1. The diameter is found to be 0.5mm because of small size of the grains the thousand kernel weight was found to be 0.76g. Bulk density and true density were found to be 830 kg/m3 and 1396 kg/m3 respectively. Angle of repose was found to be 25.65° this could be because of the small surface area of the grains due to which there will be less surface tension.
Table 1. Physical properties of Amaranthus paniculatus grains
Parameter Result
Diameter (mm) 0.5±0.01
Thousand kernel weight (g) 0.76±0.03
Bulk density (kg/m3) 830±0.05
True density (kg/m3) 1396±0.04
Porosity (%) 40.54%±0.51
Angle of repose (°) 25.65°
The results are reported as mean ± SD of triplicate readings with p= 0.05

The proximate composition of Amaranth paniculatus is given in Table 2.
Table 2. Nutritional composition of Amaranthus paniculatus grains
Composition Content (%)
Moisture 11.39 ± 0.03
Protein 14.24 ± 0.15
Carbohydrates 69.38 ± 0.24
Fat 8.70 ± 0.02
Fibre 2.95 ± 0.01
Ash 3.75 ± 0.04
The results are reported as mean ± SD of triplicate readings with p= 0.05
METHODOLOGY
1. Amaranthus paniculatus grains were procured from NBPGR (National Bureau of Plant Genetic Resources), Shimla, Himachal Pradesh, India
2. Isolation of starch (Alkali steeping method): Amaranth grains were dispersed in 0.3 % NaOH solution overnight at 4ºC with occasional stirring to soften the endosperm and maximized the solubility of protein fractions. The following day, the grains were washed thoroughly with drinking water and ground to make a fine smooth paste. The paste was then passed through a combination of muslin cloth and a 300µm sieve (Jayant Scientific Inc., Mumbai) to maximize starch extraction. The extracted starch was then isolated using a cooling centrifuge (Model C-24 BL, Remi Industries Ltd., Vasai-India), at 3000 rpm for 15 min. The cycle was repeated 3 to 4 times with the scrapping of protein and impurity layers after every cycle, with continuous washing of the starch with distilled water. The sediment was dried overnight in petri plates at 40°C in a hot air oven. The dried starch was kept in airtight amber bottles for further analysis.
3. Modification of starch by HMT and oxidation: A calculated amount of distilled water was added to adjust the moisture level to 20%. The samples were stirred and kept overnight in glass jars at 4º C for moisture equilibration. The sealed jars were kept in a hot air oven at 80º C for 4 h followed by drying with open lids till the moisture content was reduced to 10%.
For oxidation 100 g of starch was dispersed in 500 mL of distilled water. 2M NaOH was used to adjust the pH to 9. With constant stirring and preserving the pH, 25 mL of sodium hypochlorite with 4% active chlorine was slowly added to the starch slurry. After 10 min, the pH was adjusted to 7 with 1M H2SO4 and centrifuged for 15 min at 5000 rpm. The pellet was dried at 40° C in a hot air oven. The dried oxidized starch was sieved at 100 microns, packaged in amber vials, and stored in a cool, dry location for subsequent examination.
4. Formation of edible film: Films from native and modified starches (Oxidized and HMT Modification) was formed. 5 g of starch was dispersed in 100 mL of distilled water with constant stirring on magnetic stirrer (Remi 10 MLH plus) at 75°C for 15 min using glycerol as plasticizer (0.5 g/g of starch) to make the filmogenic solutions. Casting technique was used to pour the solution onto polypropylene trays and dried at 45°C for 20 h.
RESULTS: Effect of Oxidation and HMT treatment on Amaranth starch and its application in Edible film
Carboxyl content
The carboxyl content (Table 3) of oxidized starch (0.10) was found to be higher as compared to native (0.057) and HMT starch (0.057). No difference was found in the carboxyl content of native and HMT modified starch. The carboxyl groups were formed due to oxidation process which causes depolymerisation of starch molecules by breaking glycosidic linkages which explains the high carboxyl content in oxidized starch.
Amylose content
Table 3 depicts the amylose content of native and modified starches. The amylose content was found to be higher in HMT modified starch (5.86%) this is due to the interaction of amylose and amylopectin in the amorphous region and the degradation of amylopectin during heat moisture treatment. The amylose content of oxidized starch was found to be less as compared to native and HMT modifies starch this is due to the oxidation of starch which resulted in the leaching of the amylose.
Swelling power and solubility
Swelling power is defined as the capacity of a material to absorb water at a particular temperature. It was found that in comparison to native starch, the swelling power of oxidized and HMT starch was decreased by 73.93% and 49.17%, respectively, this may be due to the amylose and amylopectin starch present in starch which undergo breakage cause deconstruction of crystalline sites when heated with excess amount of water.
Table 3. Carboxyl content, solubility, and swelling power of native and modified starches

Starch Carboxyl content
(COOH/100GU) Solubility (%)
Swelling power (g/g)
Amylose content (%)
Native 0.057± 0.10b 62.58 ± 0.39c 50.43 ± 0.46a 3.91 ± 0.16b
Oxidized 0.10 ± 0.00a 71.98 ± 0.52b 13.13 ± 0.09c 3.74 ± 0.03c
HMT 0.057 ± 0.00b 76.44 ± 0.12a 25.63 ± 0.41b 5.86 ± 1.04a
The results are reported as mean ± SD of triplicate readings with p= 0.05
Pasting properties
Pasting properties are depicted in Table 4. There was no significant difference in the pasting temperature of native and oxidized starch; however, the HMT sample had a higher (89.36 ºC) pasting temperature. It was found that the oxidation and HMT modifications reduced the peak viscosity as compared to the native sample. The holding viscosity of HMT starch was found to be slightly higher than the native sample which is inconsistent with the literature values; however, the holding viscosity of oxidized sample was significantly lower than the native sample. The breakdown viscosity of the HMT sample was significantly lower than the native and oxidized sample. Low values indicate the stability of starch granules during heating and shearing. The final viscosity of HMT sample was significantly lower than the native and oxidized starch.
The oxidation and HMT modification reduced the peak viscosity, holding viscosity (for oxidized sample), breakdown viscosity (for HMT sample), final viscosity and setback viscosity. The higher value of breakdown viscosity observed for oxidized starch sample can be explained by the alkaline conditions in the initial phase of experiment. It has been theorized that ionized carboxyl groups are not as effective as the protonated carboxyl groups in maintaining the starch integrity, due to their negative charge repulsion. The low values of peak, breakdown, final and setback viscosity for HMT sample indicates partial gelatinization of starch. The amorphous regions of the starch granules are reoriented and become crystalline due to the hydrothermal treatment. This decreases the leaching of free amylose from the granules thereby promoting the amylose-amylose/ amylose-amylopectin linkages (forming retrograded starch), presenting itself as lower setback viscosity.
Table 4: Pasting properties of native and modified starches
Starch Native Oxidized HMT
PT (°C) 75.09±0.08c 76.10±0.15b 89.36±0.25a
PV (cP) 1212.06±0.84a 1102.09±0.84b 986.79 ± 0.31c
HV (cP) 851.19±5.27a 491.84±0.79b 986.79 ± 0.31c
BD (cP) 371.02 ± 0.60b 401.40 ± 0.39a 146.51 ± 0.58c
FV (cP) 1033.77±2.02a 976.68±1.58b 525.97±1.55c
SB (cP) 186.57±0.53a 162.00±0.75b 150.86±0.68c
The results are reported as mean ± SD of triplicate readings with p= 0.05
Pasting temperature, peak viscosity, hold viscosity, breakdown viscosity, final viscosity, and setback viscosity are denoted as PT, PV, HV, BD, FV, SB, respectively
Thickness, color and opacity of starch films
The thickness of the prepared films was found to be constant at 0.16 mm. the films were transparent, continuous, and easy to peel (Fig. 1). There was no significant difference of the films since the starch concentration was kept constant. The prerequisite for a consistent mechanical strength is the consistency in the film thickness. No difference was found in the thickness of native and modified starches as concentration of starch was kept constant while forming films.
The key factor influencing the appearance is the color (Table 5). No symbolic difference was seen in the L*, a*, b* and opacity % value of the native and modified starches. L* value showed no significance differnce. However, there was a slight difference in the a* value of the oxidized sample. The a* value is an indication of redness or greenness in the sample. The a* value of HMT sample and native sample was similar but the oxidized sample had a higher value indicating less redness than the other two samples. The redness is usually a characteristic of maillard and/or caramelization reactions. The b* value indicates blueness or yellowness of a sample. The oxidized sample had a slightly lower b* value in comparison to other two samples but the difference is not very significant. The total color difference (?E*) value is an indication of differences between L*, a* and b* values. The ?E* values for all oxidized and native sample were found to be similar whereas it was slightly lower for the HMT sample. Opacity value is essential for food surface coating because low value of opacity implies transparency.
Table 5: Thickness, color and opacity of native and modified starch films
Starch Native Oxidized HMT
Thickness (mm) 0.16 ± 0.01a 0.16 ± 0.00a 0.16 ± 0.01a
L* 88.47 ± 0.47a 87.94 ± 0.51b 87.18 ± 0.53b
a* -0.27 ± 0.01a -0.40 ± 0.03c -0.23 ± 0.37b
b* 3.12 ± 0.14a 2.58 ± 0.19b 3.58 ± 0.34a
Color difference 1.32 ± 0.36a 1.22 ± 0.22a 0.69 ± 0.10b
Opacity (%) 11.22 ± 0.57a 11.70 ± 0.28a 12.15 ± 0.0a
The results are reported as mean ± SD of triplicate readings (p =0.05).
Water solubility of films
The water solubility of films is a key factor in determining the applicability of the film as lower solubility could result in lower degradability, whereas the higher value of solubility will collapse the film in short time. The values for water solubility of the films were found to be the highest (48%) for native starch and (32%) for HMT starch (Table 6). The reduced water solubility of oxidized starch and HMT might be due to the increased interaction between amylopectin- amylose chains.
Tensile strength of films
The force obtained at the sample break point is defined as tensile strength. The tensile strength of modified starch films was found to be higher as compared to native starch (Table 6). This can be due to carboxyl group which may form hydrogen bridges with OH- of amylopectin and amylose which in turn provides more structural integrity hence, increasing the tensile strength. HMT promotes a stronger crystalline structure and increases the cohesion force in starch thereby enhancing the tensile strength. Tensile strength also depends on the others factors such as quantity and type of plasticizer used, thickness of the film, relative humidity in the environment as well.
Water vapor permeability of films
Water vapor permeability is defined as the ability of material to allow water vapour to pass through it. It is an essential function of films and it is desirable for the film to have a low water permeability. A significant difference was observed in the WVPR of native and modified starches films. The values (Table 6) indicate that the oxidized starch film showed a 14 % decrease in WVP as compared to native starch. During HMT, retrogradation takes place in starch gel due to which crystalline domains are formed, which explains the higher value of WVPR of HMT modified starch film which may result in micro cracks and pores on the surface of films resulting in increased WVPR.
Table 6: water solubility, tensile strength and WVPR of native and modified starch films
Starch Water solubility
(%) Tensile strength
(MPa) WVPR
(g.mm/m2.day.kPa)
Native 48.54 ± 0.45a 1.21 ± 0.24c 6.76 ± 0.25b
Oxidized 38.23 ± 0.11b 1.94 ± 0.06b 5.75 ± 0.08c
HMT 32.59 ± 0.42c 2.44 ± 0.96a 7.30 ± 0.13a
The results are reported as mean ± SD of triplicate readings (p= 0.05)
RECOMMENDATION:
The edible films prepared with modified Amaranthus paniculatus starch samples showed promising results of tensile strength, WVPR, opacity and color, which can be used for the formation of edible film.
ADVANTAGES OF THE INVENTION
• Amaranthus paniculatus is a non-conventional source of starch.
• Sustainable and biodegradable edible film
, Claims:1. A composition for an edible film made from Amaranthus paniculatus starch, wherein the composition comprises:
o Native starch in a proportion of 100 g,
o Oxidized starch in a proportion of 100 g with a carboxyl content of 0.10 COOH/100 g of starch,
o Heat-moisture treated (HMT) starch in a proportion of 100 g, exhibiting a pasting temperature of 89.36°C, and
o A glycerol plasticizer at a ratio of 0.5 g per g of starch, wherein the edible film demonstrates a tensile strength of at least 1.21 MPa and a water vapor permeability rate (WVPR) of 6.76 g·mm/m²·day·kPa.
2. The composition as claimed in claim 1, wherein the native starch exhibits a swelling power of 50.43 g/g and a solubility of 62.58% in water.
3. The composition as claimed in claim 1, wherein the edible film formed from oxidized starch has a water solubility of 38.23% and a tensile strength of 1.94 MPa.
4. The composition as claimed in claim 1, wherein the edible film formed from HMT starch demonstrates a tensile strength of 2.44 MPa and a WVPR of 7.30 g·mm/m²·day·kPa.
5. A method for preparing an edible film from Amaranthus paniculatus starch, comprising the steps of:
o Isolating starch from Amaranthus paniculatus grains through an alkali steeping method,
o Modifying the starch by heat-moisture treatment (HMT) or oxidation treatment to create modified starches,
o Mixing 5 g of the native or modified starch with 100 mL of distilled water and 0.5 g of glycerol plasticizer per gram of starch,
o Heating the mixture at 75°C for 15 minutes to form a filmogenic solution,
o Casting the solution onto trays and drying at 45°C for 20 hours to obtain the edible film.
6. The method as claimed in claim 5, wherein the oxidation treatment involves adjusting the pH to 9 using 2M NaOH and adding sodium hypochlorite, followed by drying at 40°C.
7. The method as claimed in claim 5, wherein the heat-moisture treatment includes equilibrating the starch with water at 20% moisture content before heating at 80°C for 4 hours.
8. The method as claimed in claim 5, wherein the edible films are evaluated for physio-chemical properties including tensile strength, water vapor permeability, and color analysis post-preparation.

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