Seaweed extracts production and use

Abstract

Disclosed is a seaweed extraction process that produces an unrefined polysaccharide seaweed extract, which has a mixture of unrefined polysaccharides the extract being highly effective for the production of biopolymer films with good properties. The process may be part of a brown seaweed biorefinery that provides a number of new materials and greater flexibility in the use of those materials to maximize the utilization of the seaweed feedstock.

Description

SEAWEED EXTRACTS PRODUCTION AND USEFIELD OF INVENTION

[0001] The present invention relates to a method for processing seaweed, to products provided by such processing, and to the use of such products.BACKGROUND ART

[0002] Conventional plastic materials are primarily derived from petrochemical sources and used for packaging materials and films. However, conventional plastics do not degrade effectively and result in the accumulation of waste in the environment. As well as slow degradation these plastics also degrade to produce or release by-products that can be toxic and can cause damage to the environment. Many conventional plastics are also difficult to effectively recycle, reuse and manage as waste.

[0003] An emerging alternative to conventional plastics are bioplastic materials derived from biological origin. One promising source of such bioplastic materials is seaweed. Of the many types of seaweed available brown seaweeds such as Ascophyllum nodosum and other brown seaweeds are of particular interest as a source of useful materials such as for example alginates. Various methods of processing seaweeds have been developed to extract the various components of seaweed. One active area or interest is to extract film forming polysaccharides from seaweed as alternatives to film forming polymers derived from crude oil and other fossil sources. Commercially available materials of this type are the various alginate extracts of seaweed. Alginates are known to be useful in many industries such as the food and drink industry, the pharmaceutical and medical industry, and the paper and textile industry. Of particular interest is the use of alginates in the manufacture polymer film packaging, barrier coatings for paper-based packaging products, and encapsulation films for liquid products.

[0004] Typically, seaweed is processed to extract, refine and purify individual components of the seaweed so that these relatively pure refined materials may be used in various applications including the manufacture of polymer films. For example, industrialalginate extraction typically consists of a first acid pre-treatment to convert insoluble alginate salts into alginic acid, followed by an alkaline extraction to convert insoluble alginic acid into soluble sodium alginate, which passes from the bulk seaweed into the aqueous phase; further alginate isolation requires solid / liquid separation, precipitation and drying and the production of a seaweed residue. This process produces relatively pure and refined alginate but is complicated and uses unattractive chemicals such as acids. Other seaweed components are similarly individually extracted and refined using complex procedures with unattractive chemicals.

[0005] Whilst progress is being made in the application of current seaweed extraction techniques and in particular for refined alginate production and use in various products there is a need for alternative materials, methods and processes for seaweed extraction. In order for bioplastics to become a viable alternative to conventional plastic materials, bioplastics must show satisfactory comparable physical properties to conventional plastics. Furthermore, refined alginate and other seaweed-based polymer systems tend to have a lack of flexibility and adaptability for film forming formulation and so there is a need for new seaweed derived materials for film forming and other applications.DISCLOSURE OF THE INVENTION

[0006] It has surprisingly been found that if seaweed is processed under specific conditions, then highly versatile and useful polysaccharide extract compositions may be obtained without the need for further refining of the polysaccharide component. These polysaccharide extract compositions, used in the unrefined state, have surprisingly been found to be highly versatile and effective for the forming of polymer films with good properties. In addition, other useful products and compositions may be obtained and prepared through additional processing of the seaweed residue after extraction of this polysaccharide extract composition. In the context of the present invention unrefined means that the polysaccharide containing seaweed extract has not been subjected to further processes to isolate individual seaweed polysaccharide materials from the extract, or to In the context of the present invention unrefined means that the polysaccharide containing seaweed extract has not been subjected to further processes to isolate individual refined seaweed polysaccharide materials from the extract or to eliminate the presence of other materials from the extractother than solid material filtration and / or dilution or dewatering to concentrate the unrefined extract.

[0007] There is provided a seaweed extraction process for producing an unrefined polysaccharide extract composition, the extraction process comprising: a) forming a dispersion by dispersing seaweed in an aqueous basic solution of pH>7 or water, b) stirring the dispersion at a temperature of less than 100°C for at least 15 minutes, and c) filtering the dispersion to separate a solid seaweed residue from an aqueous unrefined polysaccharide extract solution.

[0008] In this process the seaweed preferably has not been acid pre-treated (pH <5) through the addition of added acids to convert the alginate salts within the seaweed into alginic acids before the dispersion of the seaweed in the aqueous basic solution.

[0009] Preferably, the water or aqueous basic solution is heated to a temperature of 100°C or less, more preferably 95°C or less, more preferably 80°C or less, and most preferably 70°C or less and ideally 65°C or less. The temperature of extraction is preferably from 40°C to 90°C, more preferably from 40°C to 80°C, more preferably between 40°C to 65°C, more preferably, 50°C to 65°C and most preferably 60°C to 65°C.

[0010] Preferably, the water or aqueous basic solution of pH>7 is heated to a desired temperature before dispersion of the seaweed into the water or aqueous basic solution of pH> 7. Preferably the aqueous basic solution is pH>7.5 and most preferably is pH>8 ideally pH>8. Heating to desired temperature before dispersion of the seaweed increases the extraction yield for any given extraction period.

[0011] Preferably, the filtration is undertaken using a filter or centrifugation which removes particulate material from the polysaccharide extract solution that is greater thanlOOpm, more preferably greater than 50pm, more preferably greater than 25pm and most preferably greater than 10pm. Preferably, the filtration comprises two or more filtration stages. The first stage preferably removes material of particle size greater thanlOOpm and the second stage removes material of particle size of greater than 10pm. It has been found thatensuring that the polysaccharide rich liquid extract from the process contains particles of less thanlOpm. provides good quality biopolymer films formed from the filtered but unrefined polysaccharide extract solution. Alternatively, or additionally the polysaccharide extract solution may be centrifuged.

[0012] It has been found that once filtered the unrefined polysaccharide extract solution may be used directly in formulations for the preparation of films, preparation of coatings and as an additive for other applications. The unrefined polysaccharide extract solution does not require, other than filtering, and optionally dewatering, any further refinement processing or extraction of any materials contained therein in order for the extract to be usable in formulations for coatings or biopolymer film forming compositions. This is a particular advantage of the simple extraction and stage limited process of the present invention.

[0013] The aqueous basic solution may be prepared from alkali salts or basic salts or mixtures thereof. Examples of such salts include sodium carbonate, sodium bicarbonate, sodium acetate, sodium hydroxide, potassium carbonate, potassium acetate, potassium hydroxide and mixtures of these alkali or basic salts. It is preferred that the aqueous basic solution is prepared from sodium salts or mixtures thereof. The preferred aqueous basic sodium solution is prepared from Na2COs. The aqueous Na2COs solution is preferably 10 % w / v or less Na2COs. more preferably 8 % w / v or less Na2COs. more preferably 6 % w / v or less Na2COs, more preferably 5 % w / v or less Na2COs, more preferably 3 % w / v or less Na2COs, more preferably 2 % w / v or less Na2COs, and most preferably 1 % w / v or less Na2COs.Ideally and preferably the aqueous Na2COs solution is between 0.1 to 3% w / v Na2COs, more preferably 0.1 to 2 % w / v Na2COs, more preferably 0.1 to 1.5 % w / v Na2COs, and most preferably 0.1 to 1 % w / v Na2COs. It is preferred that the process uses aqueous basic solutions and not water.

[0014] The time for the extraction is preferably between 15 to 120 minutes, more preferably between 30 to 120 minutes, more preferably 60 to 120 minutes and most preferably between 70 to 120 minutes. Preferably, the time for extraction is for a minimum of 90 to 120 minutes. It is preferred that the dispersion is stirred throughout the extractionprocess. It is preferred that the means of stirring is isolated from the dispersed seaweed during the extraction process.

[0015] It is preferred that the seaweed used in the basic extraction process has a reduced fucoxanthin level compared to the raw seaweed. In a preferred embodiment the seaweed residue for use in the basic extraction process is the residual seaweed from a pigment extraction process that has removed at least lwt% of the fucoxanthin, more preferably at least 5 wt% and more preferably at least 10 wt%.

[0016] The seaweed and aqueous basic solution or water are typically combined in proportions to provide at least 1% w / v seaweed (dry mass): to water or aqueous basic solution, preferably at least 2 % w / v seaweed: to water aqueous basic solution: preferably at least 10 % w / v seaweed: to water aqueous basic solution and a preferred maximum of 30% w / v seaweed : water or aqueous basic solution in the dispersion or slurry and preferably within the range of 1 to 30% w / v seaweed: to water aqueous basic solution, preferably within the range of 2 to 20% w / v seaweed: to water aqueous basic solution and most preferably within the range of 2 to 10% w / v seaweed: to water aqueous basic solution. Generally, at levels greater than 10% w / v the dispersion becomes too difficult to process at scale due to the seaweed absorbing fluid and swelling. The ratio may be adjusted to ensure that in the final extract solution the polysaccharides are present at between 1 to 20% w / v DM (dry matter) of the extract solution and more preferably 1 to 10% w / v DM of the extract solution. Ideally the dry matter content of the extract solution is within the range of 0.5 to 16 wt.% of the solution, preferably 2 to 3 wt.% of the solution and ideally at a total dissolved solids of > 5 g.T1and preferably within the range of 5 to 10 g.l'1

[0017] There may be a further step d) where the polysaccharide extract solution is immediately cooled from the elevated temperature of extraction to a temperature of between - 20°C and 20°C, for storage. It is advantageous to keep the extract solution within this temperature range to avoid unwanted early uncontrolled gelation and polymerisation of the dissolved solids in the extract. At low storage temperatures on reheating of the polysaccharide extract solution stirring may be applied to homogenise the polysaccharide extract solution. Preferably, there is no temperature reduction for storage and step d) is maintenance of the extract fluidity through gentle agitation and temperature control to enable effective degassingof the extract whilst preventing gelation prior to use in biopolymer formulations. Preferably, this step occurs after optional dewatering and filtering of the unrefined polysaccharide extract solution.

[0018] The raw seaweed is typically and preferably water washed, dried and or dewatered and then processed into an easily handleable form prior to use in the process. The seaweed may be abraded, cut, shredded or milled to provide a handleable form. The seaweed will preferably be in flake form with thickness from 1 to 10 mm. more preferably 2 to 5 mm and most preferably 1 to 4 mm. A preferred grade of seaweed is 2 mm. If used in the milled form, it is preferred that the seaweed is milled to 500 micron or greater particle size.

[0019] The process of the present invention may be used with any seaweed including Phaeophyta (brown seaweed), Rhodophyta (red seaweed) or Chlorophyta (green seaweed or mixtures thereof to provide unrefined polysaccharide extract solutions for polymer film formation. It is preferred that the seaweeds used in this extraction process to provide unrefined polysaccharides for the biopolymer film are brown seaweeds, which are typically alginate containing seaweeds collectively referred to as algenophytes. Suitable algenophytes may be selected from the orders Laminariales, Fucales or Ectocarpales, Macrocystis, for example M. pyrifera, Lessonia, and Sargassum. The brown seaweed may be selected from one of more of: Laminaria abyssalis, Laminaria agardhii, Laminaria appressirhiza, Laminaria brasiliensis, Laminaria brongardiana, Laminaria bulbosa, Laminaria bullata, Laminaria complanata, Laminaria digitate, Laminaria ephemera, Laminaria farlowii, Laminaria groenlandica, Laminaria hyperborean, Laminaria inclinatorhiza, Laminaria longipes, Laminaria multiplicata, Laminaria nigripes, Laminaria ochroleuca, Laminaria pallida, Laminaria platymeris, Laminaria rodriguezii, Laminaria ruprechtii, Laminaria sachalinensis, Laminaria setchellii, Laminaria sinclairii, Laminaria solidungula, and Laminaria yezoensis The brown seaweed may be from the order Fucales, suitably of the genus Ascophyllum. The seaweed may be selected from S.latissima, L.digitata, A. escuelnte, L. japonica, U. pinnatifida, Sargassum sp., Ascophyllum nodosum, Fucus sp., Fucus spiralis, Fucus vesiculosus, or P. caliculatata. The extraction process is however sufficiently robust to accommodate a mixture of one or more of any of the brown seaweeds listed and may be adapted to maximise the extraction from such mixtures.

[0020] The products of the extraction process are unrefined polysaccharide seaweed extract in aqueous solution and a seaweed residue; both of these resultant products are useful as materials in the manufacture of various products and / or may be useful for further processing into other products. The unrefined polysaccharide seaweed extract being of particular use for biopolymer film production via appropriate formulations comprising the unrefined polysaccharide seaweed extract as a solution or dewatered solid. This unrefined polysaccharide extract solution or solid will typically comprise a mixture of unrefined seaweed polysaccharides and may also include other components of seaweed such as pigments, polyols, glucose, and proteins etc.

[0021] There is further provided an unrefined polysaccharide extract solution or a solid formed after dewatering comprising a mixture of unrefined seaweed polysaccharides.

[0022] Preferably this polysaccharide extract solution is in the form of an aqueous solution and more preferably a basic aqueous solution. This is a complex mixture comprising unrefined polysaccharides and as such is challenging to analyse. The presence or not of polysaccharides in a seaweed or processed seaweed material or such polysaccharide extract solutions may be determined by hydrolyzing the sample and using various techniques, including chromatographic techniques, to detect and quantify the sugar monomer units or derivatized monomer units of the relevant polysaccharide. Alginate, for example, is a complex mixture of oligo-polymers mainly consisting of polymannuronic acid and polyguluronic acid and after processing these provide mannuronic acid and guluronic acid that may easily be detected and quantified. The remaining non-alginate saccharides and sugars produce mannitol, glucose, manatose, galactose, xylose, fucose and other oligomers. Fucose, for example, is a sugar derived from fucoidan another major polysaccharide present in brown seaweed. Preferably the polysaccharide seaweed extract comprises polysaccharides that upon hydrolysis produce one or more of: mannuronic acid, guluronic acid, mannitol, glucan, xylose, fucose, glucose, mannose, and galactose. Preferably the polysaccharide seaweed extract comprises a mixture of unrefined alginate, fucoidan, laminarian and mannitol. The unrefined polysaccharide extract may further comprise unrefined glucose.

[0023] The polysaccharide extract solution typically has a pH >7 and typically comprises 1-20 wt% dry matter, and most preferably between 1 to 10 wt.% dry matter. Thetotal dissolved solids in the aqueous extract are preferablyl.5 to 8.5 g / 1, most preferably 5 to 6 g / 1. Preferably the aqueous unrefined polysaccharide extract has a BRIX @20°C of >1, and most preferably >2. The aqueous polysaccharide extract solution will preferably have a viscosity at @20°C of between 2 and 120 mPas, more preferably 2 to 50 mPas, and most preferably between 2 and 20 mPas.

[0024] When the process utilizes the pigment extraction pretreatment described herein the resultant aqueous polysaccharide extract solution may have a relatively low level of colour due to the low level of extracted pigment, because significant quantities of pigment will have been removed via any pretreatment. Preferably, the normalizing optical density at absorbance 500 nm (OD 500nm / OD 600nm) is less than 4 to help ensure that any film-based products prepared from this extract solution are transparent and exhibiting no more than a light yellow / brown tint.

[0025] The water present in the aqueous polysaccharide extract solution may be removed through any suitable process to provide a substantially water free and solid or semisolid polysaccharide extract.

[0026] Preferably, the extraction residue comprises a reduced level of fucoxanthin compared to the fucoxanthin level in the seaweed source used for the extraction process. In a preferred embodiment the extraction residue has at least lwt% less of the fucoxanthin, more preferably at least 5 wt% less and more preferably at least 10 wt% less of the fucoxanthin of the raw seaweed. It is preferred that the seaweed used in the basic extraction process is seaweed residue from a pigment extraction process as described herein.

[0027] Preferably, the extraction residue comprises significantly reduced levels of unrefined polysaccharides compared to the polysaccharide level in the seaweed source used for the extraction process. Preferably, at least 5wt%, more preferably at least 10 wt%, more preferably at least 15 wt% and most preferably at least 25 wt% of the polysaccharide material of the seaweed introduced to the extraction process is removed from the introduced seaweed during the process.

[0028] There is further provided a packaging material comprising polysaccharide depleted seaweed extraction residue. Typically, in this aspect the seaweed extraction residue is mixed with other materials such as binders, fillers and fibrous materials e.g. cellulose fibre to produce a composite material, which may be formed into a packaging item. In such applications as paper / pulp moulds and fiberboards the seaweed extraction residue may be present at between 5 to 50% by weight of the product.

[0029] There is further provided a process for producing alginate the process comprising steps a) to c) of the process for producing an unrefined polysaccharide extract composition and further comprising. d) carrying out further processing steps on the seaweed residue of step c) to produce alginate.

[0030] This process for producing alginate uses conventional processing stages, as the further processing steps, for converting and extracting the insoluble alginate salts. Typically, these will comprise a first acid pre-treatment to convert insoluble alginate salts into alginic acid, followed by an alkaline extraction to convert insoluble alginic acid into soluble sodium alginate, which passes from the bulk seaweed into the aqueous phase; further alginate isolation will typically require solid / liquid separation, precipitation and drying to produce the final product.

[0031] The alginate rich seaweed extraction residue produced from the extraction process for producing an unrefined polysaccharide extract composition may also be exposed to one or more further extraction cycles to produce a liquid product being a further unrefined polysaccharide extract composition that is relatively dilute in polysaccharide seaweed extract. The first and each subsequent unrefined polysaccharide extract composition may be combined to provide a final composition for filtration and use in formulations for various applications especially film forming.

[0032] The unrefined polysaccharide extract solution or solid comprising a mixture of unrefined seaweed polysaccharides may be used in ink or paint compositions as a dispersant solution or additive.

[0033] There is further provided a paint or ink additive comprising an unrefined polysaccharide extract solution or solid comprising a mixture of unrefined seaweed polysaccharides.

[0034] There is further provided an ink or paint composition comprising: a) one or more pigments or dyes, b) one or more binders, c) optionally one or more solvents, and c) an unrefined polysaccharide extract solution or solid comprising a mixture of unrefined seaweed polysaccharides.

[0035] With reference to the basic seaweed extraction process for producing a unrefined polysaccharide extract solution, the process may be undertaken with seaweed that has been washed and processed to produce the required form and particle sizes for the process as outlined above and may optionally but preferably be subjected to an additional pre-treatment stage prior to being used in the unrefined polysaccharide extraction process.

[0036] This pretreatment stage is an extraction process designed to extract a significant proportion of the natural colouring of the seaweed, which in the case of brown seaweed is primarily the xanthophyll pigment fucoxanthin. Fucoxanthin absorbs the bluegreen light to yellow-green light, and the peak value is observed at between 510-525 nm wavelength. Whilst fucoxanthin is the primary target of the pretreatment stage other materials will also be removed in the pretreatment process such as other dyes / pigments, proteins and polysaccharides, oligomers and sugars. The objective is to remove as much dye as possible whilst removing as little polysaccharides, oligomers and sugars as possible. The pigments may be present in the seaweed in their salt form or sugar form therefore a proportion of the overall sugar content of the seaweed will be reduced as some sugars will be extracted with the pigments.

[0037] The pretreatment may use water or a combination of aqueous solutions comprising low levels of solvents and / or hydrogen peroxide and low temperature. Suitable solvents include ethanol, industrial methylated spirits and / or methanol. Mixtures of solventsmay be used in the aqueous solutions and mixtures of one or more solvents with hydrogen peroxide may also be used. The aqueous solutions are preferably free of any added acids or added bases Preferably the solvents and or hydrogen peroxide are present in the aqueous solution at between 2 to 40% v / v solutions in water, more preferably 5 to 30% v / v solutions in water more preferably 5 to 25% v / v solutions in water, more preferably 5 to 20 % v / v solutions in water, more preferably 5 to 15% v / v solutions in water and most preferably 5 to 12% v / v solutions in water. Preferably the aqueous solution is neutral or pH <7., preferably pH is within the range of 5 to 7. In an embodiment the pretreatment aqueous solution is only mildly acidic or non-acidic. In one embodiment the pretreatment solution comprises hydrogen peroxide as a 10% aqueous solution. In one embodiment the pretreatment solution is preferably hydrogen peroxide free. In one embodiment the aqueous pretreatment solution comprises an alcohol, preferably ethanol or industrial methylated spirits.

[0038] The pretreatment is ideally carried out at room temperature or lower. Preferably, the pre-treatment is carried out at < 25°C, more preferably within the range of 15 to 25°C., and most preferably within the range of 20 to 25°C.

[0039] In this pretreatment stage the seaweed is mixed with the aqueous pretreatment solution at an amount of between 5 to 30% (w / v), more preferably 5 to 20% (w / v) and most preferably 5 to 10% (w / v).

[0040] This pretreatment is ideally undertaken with mixing and stirring of the seaweed in the aqueous solvent for a period of between 30 and 120 mins, more preferably 30 and 90 mins and most preferably 60 to 90 mins. After the pretreatment is completed, the seaweed is filtered from the aqueous solvent and may then be used in the unrefined polysaccharide extraction process described in the first aspect.

[0041] The remaining aqueous solvent is a pretreatment extract that contains significant levels of the xanthophyll pigment fucoxanthin and inter alia some sugars. The neutrality or mild acidity of the aqueous solvent under these conditions is sufficient to remove the pigment but not to remove significant quantities of polysaccharides from the seaweed.

[0042] Depending on the starting volumes the pretreatment extract will contain between 1 to 5% by weight of the dry mass of the original seaweed and this will equate to total dissolved solids of <10 g / 1. The remaining seaweed for use in the further stages of the first aspect is between 95 to 99 % by weight of the dry mass of the original seaweed.

[0043] The pretreatment extract is highly coloured due to the high levels of pigment present. This may be assessed by measuring the optical density of the extract by reading the absorbance of the extract at 500 nm and normalizing against an absorbance measurement at 600 nm (OD 500nm / OD 600nm). This normalized optical density can indicate the level of extraction of the pigment and efficiency of the extraction process. Typically, the normalized optical density of this extract is within the range of 1.5 to 4, and preferably less than 4, for each extraction to help ensure that any film-based products prepared from this extract solution are transparent and exhibiting no more than a light yellow / brown tint.

[0044] The pretreatment may be repeated a number of times on the same source of seaweed to ensure maximum pigment extraction. Once the pre-treatment is completed it is preferred that the pre-treated residue is then washed with or soaked in water to remove as much of the absorbed pre-treatment from the pre-treated residue as possible before the pretreated residue is used in the basic extraction process.

[0045] All of the aqueous extraction solutions used may also extract varying minor amounts of oligomers, sugars and polysaccharides from the seaweed, but none extracted any significant amount of polysaccharides. The solutions incorporating hydrogen peroxide for any given species of seaweed resulted in the lowest levels of polysaccharide, oligomer and sugar losses but these solutions were less efficient at pigment removal.

[0046] The unrefined polysaccharide extract composition produced by the seaweed extraction process has surprisingly been found to be highly effective in formulations for use in biopolymer film formation and may be used to produce biopolymer films with good properties.

[0047] Thus, there is further provided a biopolymer film comprising unrefined seaweed polysaccharides and more preferably an extracted mixture of unrefined seaweed polysaccharides.

[0048] The biopolymer film comprises unrefined seaweed extract. This may be unrefined brown seaweed extract, red seaweed extract or green seaweed extract or any combination thereof. Preferably the unrefined seaweed extract is an unrefined brown seaweed extract. The biopolymer film may comprise a mixture of unrefined fucoidan, and unrefined alginate. The biopolymer film may comprise a mixture of unrefined fucoidan and unrefined laminarian. The biopolymer film may comprise a mixture of unrefined alginate and unrefined laminarian. The biopolymer film may comprise any combination of unrefined fucoidan, unrefined alginate or unrefined laminarian with the addition of unrefined mannitol. In a preferred embodiment the biopolymer comprises, unrefined fucoidan, unrefined alginate. These unrefined polysaccharides will be present in any biopolymer film and products manufactured using brown seaweed extract without the use of additional polysaccharide refining steps in the manufacture of the unrefined polysaccharide extract solution used to manufacture the biopolymer film. Preferably the biopolymer film further comprises unrefined extract glucose present in the unrefined extract. In further embodiments the biopolymer comprises unrefined red seaweed extract and such extract may comprise unrefined carrageenan, unrefined agar or unrefined starch and mixtures of two or more of these unrefined polysaccharides. In further embodiments the biopolymer comprises unrefined green seaweed extract and such extract may comprise unrefined s or unrefined ulvan and mixtures of two or more of these unrefined polysaccharides.

[0049] The biopolymer films prepared using the unrefined polysaccharide extract will preferably comprise water and preferably comprise between 4-60 wt.% water, between 4-40 wt.% water and most preferably between 4-30 wt.% water.

[0050] This biopolymer film will typically comprise the unrefined polysaccharide extract produced by the seaweed extraction process and in addition various other materials and additives to aid film formation and to provide required final properties in the film. Typically, the unrefined polysaccharide extract and other materials are brought together in aformulation that is in a form suitable for the film forming process to be used such as for example, casting, extrusion, printing or coating. A wide range of formulations are possible.

[0051] Thus, there is further provided a biopolymer film forming composition comprising an extracted mixture of unrefined seaweed polysaccharides.

[0052] The aqueous unrefined polysaccharide extract solution may be used directly from the polysaccharide extraction process and at the extraction temperature or it may be used at its storage temperature of between -21 °C and 20°C. The extract solution may be preconditioned before formulating by raising the temperature of the extract solution to between 50°C and 75°C for a period of 50 to 70 minutes; the extract may be used immediately after this conditioning or may be stored for future use by being cooled to a temperature of between -21 °C and 20°C for long term storage. It is preferred that the unrefined polysaccharide extract solution is used at ambient temperature of between 18°C and 25°C without thermal preconditioning for preparing formulations for coating and biopolymer film formation. Such thermal conditioning may be deferred to the formulation stages.

[0053] The aqueous unrefined polysaccharide extract solution may be dried to a powder (<90% WC) for example using a spray drying process where the inlet temperature is between 160-220 °C, preferably 180-190 °C, and the exhaust temperature is 40-90 °C, preferably 60-70 °C.

[0054] The biopolymer film formulation may also be dried to a powder and / or may be agglomerated with additives. One preferred drying method is spray drying. The biopolymer film formulation may be spray dried with an inlet temperature of 160 to 220 °C, more preferably of 180 to 190 °C, and with an exhaust temperature of 40 to 90 °C and most preferably 60 to 70 °C.

[0055] The aqueous unrefined polysaccharide extract solution or solid may be used in preparing formulations. It is preferred that the formulation is prepared by mixing components together at relatively low temperatures below 50°C, most preferably below 30°C, and most preferably between 19 to 23°C. During this mixing phase the temperature may be increased up to 50°C in stages to ensure complete dissolution of the various components with theunrefined polysaccharide extraction solution. It is preferred that once all of the components of the formulation are combined this mixture then goes through a 30 to 60 minute period of homogenization. It is further preferred that the formulation with or without homogenization is then post-conditioned before use in any coating or film forming process. This formulation post-conditioning requires the temperature of the formulation starting from a temperature of below 50°C, preferably below 30°C, and most preferably between 19 to 23°C and then be raised to a temperature of between 50°C and 95°C, more preferably between 50°C and 85°C, and most preferably between 50°C and 75°C for a period of 50 to 70 minutes. Preferably the post-conditioning temperature is maintained at 72°C±2°C for 60±5 minutes. This postconditioning step may be commenced from the point of dissolution of the formulation components; once dissolution is determined the formulation is not allowed to cool and is raised to the post-conditioning temperature. The biopolymer formulation may have a target viscosity for film formation which depends on the film preparation conditions and this target viscosity may be achieved through adjustment of the conditioning temperature and / or water content of the formulation. On completion of this post formulation conditioning the formulation is ready for use in a film forming operation.

[0056] In preparing the film formulation the aqueous unrefined polysaccharide extract solution may be used as produced from the extraction process or may be diluted to provide the requisite level of unrefined polysaccharide seaweed extract in the final formulation. The extract may be diluted by a factor of 10 or less, preferably 5 or less and still be suitable for biopolymer film production. Alternatively, water may be removed from the unrefined polysaccharide extract solution in order to lower the water level in the formulation and raise viscosity to a level desired for film formation.

[0057] The biopolymer film forming composition may include other materials and additives that either aid in the film forming process and / or provide added benefits and properties to the biopolymer film when formed and during use.

[0058] One such group of materials are polymeric film forming materials or additives that may aid or add to the film forming properties of the biopolymer film. Suitable additional film forming materials may be selected from natural and / or water-soluble polymers. Preferably these are biodegradable polymers and more preferably natural polymers. Onesuitable source are other seaweed sourced biopolymers such as alginates, preferably alginates that have been produced by the alginate process of the present invention as these can easily be processed with the polysaccharide extract solution in a flexible way as part of a seaweed biorefinery to produce a variety of compositions of alginates with polysaccharide extract solutions from the same seaweed source. Other suitable materials include polysaccharides from other seaweeds such as red and green seaweed. From red seaweed these typically include refined seaweed products such as agar, kappa carrageenan, iota carrageenan, lambda carrageenan. For Green seaweed these typically include refined seaweed products such as starch, hemicellulose, cellulose and ulvan.

[0059] Other film forming materials include but are not limited to one or more of modified cellulose derivatives e.g. carboxy methyl cellulose, methyl cellulose, hydroxyl ethyl cellulose, hydroxpropyl celluloses, starches such as natural starch for example potato starch and modified starches, plant and animal proteins, for example milk proteins, gluten, gelatines, zein, potato proteins etc. Gums e.g. gellan gum, locust bean etc, polyvinyl alcohols, and polyvinvyl alcohol polyvinyl amine co-polymers, polylactic acid, PLA, polyhydroxy alkonate PHA, polybutylene adipate terephthalate PBAT, casein, or pectins. The biopolymer film may comprise a seaweed extract-biopolymer system with homopolymer and / or copolymer blends.

[0060] The formulation may incorporate fillers. Suitable fillers can be selected from koalin, bentonites, silicas, TiCh, chalk and these materials can also function as colour modifiers, specifically lighteners and odour control agent. Suitably, a filler may be selected from, colour pigments, carbon black, or other active inorganic materials such as graphene or carbon nanotubes may be included. The formulation may salts and mineral typically at < 2 wt.% and such salts and minerals include NaCl, NaCO3, CaCl, ZnO, or MgO. The formulation may incorporate essential oils or perfumes.

[0061] The formulation may incorporate functional additives and property modifiers such as hydrophobing agents including lipids, resin(s), wax(es), oil(s), shellac or shellac analogues. Suitably, waxes and oils may be selected from paraffin wax, calendula, bees wax, candelilla wax, polyethylene wax, fatty acids. Reactive hydrophobing agent such as Alkyl Ketene Dimers and Alkyl Succinic Anhydrides or Tall Oil Rosins and their functionalised derivatives may also be used. Suitably, a hydrophobing agent that may be provided to theprocessed residual seaweed of the invention may be selected from a lipid, resin(s), wax(ex), oil(s), shellac or shellac analogues. Suitably, waxes and oils may be selected from Alkyl ketene dimers, Alkenyl Succinic Anhydride, Tall Oil Rosin and its derivatives, paraffin wax, calendula, bees wax, candelilla wax, polyethylene wax, fatty acids. The formulation may incorporate other additives such as polyphenols for example tannic acid, carboxylic acids for example citric acid and salts such as calcium and sodium salts for example sodium chloride; minerals for example zinc oxide, some of these may aid crosslinking and film formation during manufacture of the biopolymer film.

[0062] The formulation may incorporate plasticisers. Suitable plasticisers may be selected from glycerol, sorbitol, mannitol, polyethelengyols (PEG), oils for example, mineral oil, vegetable oil, fatty acids, natural and synthetic waxes. Suitable examples are polyols such as glycerol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, sorbitol, mannitol and xylitol, fatty acids, monosaccharides (glucose, fructose and sucrose), ethanolamine, urea, triethanolamine, vegetable oils, lecithin, waxes, amino acids, surfactants may be used. Also, glycerol triacetate mineral oil or vegetable oil, fatty acids, waxes Tall Oil Rosin and its derivative or the like. One suitable plasticiser is a combination of three plasticisers namely a combination of dipropylene glycol as a first plasticizer, a sugar alcohol such as sorbitol as a second plasticizer, and a polyol such as glycerin as a third plasticizer.

[0063] The biopolymer formulations used to manufacture various products may comprise from 10 to 95 wt.% water, preferably from 20 to 95 wt.% water, more preferably from 30 to 95 wt.% water, more preferably from 40 to 95 wt.% water, more preferably from 50 to 95 wt.% water and most preferably from 70 to 95 wt.% water.

[0064] The biopolymer formulations may comprise 100 wt.% of unrefined seaweed extract said extract comprising mainly unrefined polysaccharides as herein indicated and other minor unrefined components of the seaweed, in an aqueous basic environment. The resultant biopolymer films prepared from such biopolymer formulation, if no further materials are added to the formulation, will comprise 100 wt. % of unrefined seaweed extract.

[0065] It is preferred that the biopolymer formulations used comprise other materials in addition to the unrefined polysaccharide extract(s) in order to produce the biopolymer films.

[0066] The total unrefined polysaccharide extract present in the biopolymer formulations is preferably from 1 to 70 wt.%, more preferably from 1 to 50 wt.%, more preferably, 1 to 40 wt.%, more preferably 1 to 30 wt.%, more preferably 2 to 20 wt.%, and most preferably 2 to 16 wt.%. The exact wt.% of unrefined polysaccharide extract used will depend in part on the solids concentration of the unrefined polysaccharide extract, which can be variable depending on the seaweed used or even the batch of seaweed used to prepare the unrefined seaweed extract. The exact percentage of unrefined seaweed extract used will be selected to take into account the solids content of the extract and the desired level of unrefined polysaccharide in the biopolymer films prepared from the extract.

[0067] The biopolymer formulations preferably comprise one or more further refined polysaccharides and / or other film forming polymeric materials. Refined polysaccharides are typically substantially pure polysaccharide materials obtained from a natural source such as seaweed and other biomass. As an example, refined carrageenan is typically obtained through an extraction and refining process from red seaweed. Preferably the formulation comprises between 1 to 70 wt% of formulation DM or refined polysaccharide more preferably between 20 to 70 wt.% and most preferably between 30 to 60 wt.%. Preferred additional refined additives comprise starch or carrageenan and mixtures thereof, the most preferred is a mixture of unrefined polysaccharide extract with added refined starch and added refined carrageenan.

[0068] The plasticisers may be present in the formulation within the range of 1-80 wt.% of formulation DM.

[0069] Functional additives: may be present in the range of 0-10 wt.% of formulation DM.

[0070] Fillers may be present in the formulation in the range of 0 - 5 wt.% of formulation DM.

[0071] These unrefined polysaccharide formulations may then be used to make biopolymer films. These biopolymer films may comprise a mixture of components.Typically, water may be present within the range of 9 to 40 wt.%, preferably, 9 to 30 wt. % and most preferably 10 to 25 wt.% of film mass. The biopolymer film may comprise additional polysaccharide / film forming components e.g. starch and / or carrageenan at between 10 to 80 wt.%, more preferably 20 to 70 wt.%, and most preferably 30 to 60 wt.% of the film. The biopolymer film may comprise plasticisers at between 10 to 60 wt.%, more preferably 10 to 50 wt.%, and most preferably 20 to 40 wt.% of the film. Functional additives may be present within the range of 0 to 20 wt.% of the film. Fillers may be present within the range of 0 to 10 wt.% of the film.

[0072] The various components and wt.% of the components in the biopolymer formulation and resultant films are selected in order that the total additive wt.% of all components is 100 wt.%. Where the additive wt. % is less than 100 wt.% the balance to 100 wt.% for the formulation is preferably made up of water.

[0073] Most preferred composition ranges for the formulations and resultant films are as follows:

[0074] The formulation may incorporate natural fibre material in order to form a composite film of fibre within a biopolymer binder.

[0075] The formulations may be processed to form various products by a number of methods. The formulations may be used to form blow moulded parts comprising the unrefined polysaccharide extract. It is envisaged that the unrefined polysaccharide extracts may be used to provide parts produced by other plastic processing technologies e.g. blown film, vacuum formed and extruded profiles may be provided comprising the s unrefined polysaccharide extract. It is also envisaged that the unrefined polysaccharide extracts may be used to provide biopolymer coatings, paints and inks comprising the unrefined polysaccharide extract. Any ink, paint or coating formulation comprising the unrefined polysaccharide seaweed extract, may be applied to a surface of a base material to provide a protective or decorative layer to that material or to provide barrier properties to that material such as for example to reduce oxygen transport through the material or to provide chemical resistance to the material. Coating compositions based on the unrefined polysaccharide extract may be suitable to provide a decorative or oxygen and oil barrier coating to a substrate, for example paper or textiles on which it is applied.

[0076] An ink, paint or coating process using formulations comprising the unrefined polysaccharide extract may be used in any suitable coating process such as an emersion coating, spray coating, screen printing and / or other printing or coating methods as would be known in the art e.g. blade or slot die.

[0077] The formulations comprising the unrefined polysaccharide seaweed extract may be processed in extrusion or injection moulding equipment to make pellets and or to make 2D films or 3D injection moulded parts.

[0078] In a further and preferred aspect there is provided a casting method for manufacturing a biopolymer film, which method comprises preparing an aqueous formulation comprising a unrefined polysaccharide extract, casting the formulation onto a material surface to provide a cast biopolymer film and drying the cast biopolymer film at elevated temperature to remove water to form the biopolymer film. The cast biopolymer film may be left attached to the material surface and used in applications that would require such a castbiopolymer film laminate e.g. food packaging. In a further aspect the cast biopolymer film is delaminated from the surface of the material substrate, which is typically reusable, and is used as a freestanding biopolymer film in various applications.

[0079] Products derived from the unrefined polysaccharide extract are composable and biodegradable. Certain products may be dissolved and dispersed in water or aqueous environments, especially at room temperature or above.

[0080] There is further provided a biodegradable compostable packaging material having a coating comprising an extracted mixture of unrefined seaweed unrefined polysaccharides on a compostable or biodegradable substrate.

[0081] A contemplated class of embodiments is characterized by good thermoformability of the water-soluble film made as described herein. The biopolymer film may be thermoformable. Athermoformable film is one that can be shaped through the application of heat and a force. Thermoforming can be performed by any one or more of the following processes, for example: the manual draping of a thermally softened film over a mold, or the pressure induced shaping of a softened film to a mold (e.g., vacuum forming), or the automatic high-speed indexing of a freshly extruded sheet having an accurately known temperature into a forming and trimming station, or the automatic placement, plug and / or pneumatic stretching and pre-pressuring forming of a film. The extent of the film stretch is defined by the areal draw ratio which is the pocket (or cavity) surface area divided by the film surface area before thermoforming. The areal draw ratio (also called areal depth of draw) can be calculated according to the method described in Technology of Thermoforming, James L. Throne, Hanser publisher, (1996) Chapter 7.4, pg 488-494 (ISBN 3-446-17812-0). Herein for thermoformed films, the areal draw ratio can be in a range of 1.05 to 2.7; or in a range of 1.2 to 2.3; or in a range of 1.3 to 2.0.

[0082] The film comprising extracted mixture of unrefined seaweed polysaccharides may be vacuum formed without the application of heat. The film may be wetted and once a film has been wetted, it may be drawn into an appropriate mold, preferably using a vacuum.

[0083] The biopolymer films of the present invention will have a range of properties making them suitable for packaging, polymer film, polymer coating and other applications. For film applications various physical parameters are desirable and are typically measured. A water-soluble biopolymer film is typically characterized by or to be tested for tensile strain according to the Tensile Strain (TS) Test and e-modulus (elongation modulus or tensile stress). The procedures typically include the determination of tensile strain and the determination of e-modulus according to ASTM D 882 (“Standard Test Method for Tensile Properties of Thin Plastic Sheeting”). Water soluble films are typically pre-conditioned to the testing environmental conditions for a minimum of 48 h. Tests are typically conducted in the standard laboratory atmosphere of 23±2.0° C. and 35±5% relative humidity. For tensile strain or modulus determination, l"-wide (2.54 cm) samples of a single film sheet having a thickness of 3.0±0.15 mil (or 76.2±3.8 pm) are typically prepared. For e-modulus testing virgin films are usually tested. For tensile strain testing test films are typically first preimmersed in a testing detergent.

[0084] A further test important for characterizing water-soluble films is the Monosol Dissolution and Disintegration Test (MSTM 205), which is classed as an industry standard. A film can be characterized by or tested for Dissolution Time and Disintegration Time according to the MonoSol Test Method 205 (MSTM 205), a method known in the art and discussed in US20160024446. Another test is the test methods described in OECD guidelines 120 and 105.

[0085] Embodiments of the invention will now be described by way of example only with reference to the accompanying figures in which:

[0086] Figure 1 illustrates a schematic of a biorefinery for the production of biopolymer films from unrefined polysaccharide extract,

[0087] Figure 2 illustrates analytical compositional data for various samples of Example 2,

[0088] Figure 3 illustrates analytical compositional data for various samples of Example 2, and

[0089] Figure 4 illustrates analytical compositional data for various samples ofExample 2

[0090] With reference to Figure 1, there is shown a preferred biorefinery, which utilizes the key processes described herein to produce inter alia the unrefined polysaccharide extracts and biopolymer film.

[0091] In a first stage (Pigment Extraction) raw seaweed, typically 2-4 mm flake / powder is introduced to an extraction vessel at 2-10% w / v of the vessel and extraction solution typically a 10% hydrogen peroxide solution and / or ethanol in water is added (typically 10-30% v / v) are mixed at a low temperature. After a period of time (typically 1 hour) the mixture is filtered to provide two products; (1) a liquid pigment rich by-product (1- 10 wt% DM) and a wet seaweed solid residue (90-99 wt% DM). The liquid by-product (1) contains high levels of fucoxanthin, other pigment related extracts and relatively low levels of sugars and polysaccharides. The wet solid (retaining low levels of water and solvent from the first stage) may then be passed to a washing stage where it is washed with water and agitation and then passed to a solid de-watering stage to provide a washed seaweed solid residue and a further dilute pigment solution (l)b. The washed seaweed solid residue comprises from 90 to 99 wt% DM and is then passed to a polymer extraction (unrefined polysaccharide extraction) stage.

[0092] In the polymer extraction stage, the wet solid from the dewatering stage is combined with a basic aqueous solution with mixing at moderate temperatures for typically 15 to 120 minutes. The seaweed is present in the vessel at typically 2-10 w / v to the extraction solution. The extraction is preferably carried out at between 40 to 65 ° C, with a 1% NaCO3 (pH 10-12) extraction solution for 30-90 minutes. The mixture is then passed to a further dewatering stage using a press or a centrifuge tor provide a wet solid (2) that may be recycled to the polymer extraction vessel for further base extractions. The liquid phase obtained from the second dewatering stage is an aqueous solution comprising a mixture of unrefined polysaccharides and other components of the seaweed. This liquid extract is then filtered to provide a final unrefined polysaccharide extract (3). Filtering is typically with a filter mesh of 100pm or less and preferably 10pm or less.

[0093] The unrefined polysaccharide extract (3) may then be used directly as the extract in a formulation stage with inter alia plant based plasticizers and other materials to provide a biopolymer formulation to prepare formulations for final products comprising the unrefined polysaccharide extract. Such formulations are then subjected to a thermal condition stage before use. Alternatively, the extract (3) may be further dewatered to a dry powder or flake and then formulated for desirable products. After thermal conditioning if the formulation is for a biopolymer film it may be cast to form a roll of biopolymer film (4), which may then be fed into a vacuum forming process to produce water-soluble capsules comprising for example laundry detergent.

[0094] The invention will now be further illustrated by means of the following nonlimiting examples.

[0095] Example 1 - Pre-treatment for pigment extraction

[0096] A raw brown seaweed Ascophyllum nodosum (1-4 mm flakes or milled powder -500 micron) was sourced and treated either with a solvent (Industrial Methylated Spirit, Ethanol or Methanol) or with a weak oxidizing agent hydrogen peroxide to facilitate a preliminary pigment extraction.

[0097] Various aqueous solutions were prepared at 10% (v / v) IMS, Methanol or H2O2 in water. 0. IKg of raw seaweed provided as a water washed and particulate form (1-4 mm flakes) was added to IL of an aqueous solution to provide a 10% (w / v) seaweed: water solution mixture. Each solution containing the raw seaweed was stirred and mixed at room temperature for at least Ih. Optical density (OD) was measured by reading absorbance at 500nm, the peak wavelength value for the most abundant pigment, the xanthophyll pigment fucoxanthin. The OD was measured by normalization to the 600nm absorbance, considered as a blank value using the following equation:OD = A (500nm) / A (600nm)

[0098] The results are shown in Table 1.

[0099] The results show that both EtOH and MeOH extractions provide comparable and higher pigment extraction compared to H2O2. However, the pre-treatment with H2O2, an oxidising agent, showed lower pigment extraction efficiency yet effectively decolouring the pre-treated seaweed solids. It is important to say that when extracting pigment, either via alcohol or oxidizing agent, with a 10% v / v water solution, the main polar solvent is the water - water will naturally extract polar pigments. The 10% v / v Ethanol or Methanol water extraction can extract pigments, both hydrophilic and hydrophobic molecules, preserving their quality and resulting with pure pigments with minimal structural alteration. In contrast, the 10% v / v H2O2 water solution can extract mainly polar pigments yet leading to oxidation of these and therefore altering their structure, therefore resulting in lower yield when compared to alcohol: water solutions.

[0100] A further set of extractions were undertaken to compare extraction time and concentration of the extraction solution. This series of extraction re-treatments were conducted with IMS or desaturated Ethanol at three different concentration levels (10%, 20% and 40% v / v). The results are shown in Table 2. These results confirmed that a Ih extraction pre-treatment at 10% v / v IMS: water solution is sufficient to extract enough pigment, presenting a similar OD500 / OD600 ratio to Ethanol (3.24 vs. 3.27), to allow decolouring of wet solid seaweed prior to any alkaline extraction. IMS is a good solvent for pigment extraction and analyses, providing comparable efficacy to ethanol, potentially preserving chemical structure of pigments (the pigment containing extract may be used for further processing in other industries).

[0101] In general, the higher the absorbance in optical density at 500nm or OD(500), the higher is the pigment density in the pre-treatment extract, indicating a higher pigment extraction yield and in turn a higher pigmen extraction efficiency. Hence the OD can be used as proxy to determine pigment extraction efficiency.

[0102] A further set of extractions were evaluated to determine the impact of multiple extractions on the same seaweed sample for a given solvent or H2O2.

[0103] A further series of extractions were undertaken by first extracting the dry seaweed, followed by two further extractions on the wet solid mass with a fresh 10% (v / v) solution for each extraction. The resulting 10% (w / v) seaweed pigment extracts were rich dark green-brown solutions with high concentration of seaweed-derived pigments. The results are provided in Table 3.

[0104] The extracts for each solvent and H2O2 were combined, and the combination measured for OD. The results are shown in Table 4.

[0105] The H2O2 oxidizing agent acts as a decoloring agent oxidizing the pigments present in the extract. The resulting combined extract from the H2O2 solution, presents a lower normalized OD of 2.3, compared to the ethanol and methanol extracts with OD of 4.6 and 4.4, respectively.

[0106] These results suggest that ethanol and methanol are stronger pigment extractors with higher extraction efficiency than H2O2, although the 10% v / v solutions used for pre-treating the raw seaweed is a very low concentration. Even though the H2O2 pretreatment appears to show a low extraction efficiency the later produced unrefined polysaccharide extract solution showed lower OD values compared to the ethanol and methanol equivalents, resulting in a much lighter coloured unrefined polysaccharide extract.

[0107] Example 2 - Pre-extraction I Extraction Residue and Unrefined Polysaccharide Sugar

[0108] Analysis Method

[0109] 2.1 Gas Chromatography - Mass spectrometry (GC-MS) testing

[0110] Samples were frozen at -20°C. 1 ml of each of the extraction liquid fractions were dried down in a speed- vacuum concentrator (SpeedVac, Eppendorf Concentrator Plus) to obtain about 20 mg of dried material.

[0111] Samples were hydrolysed in 4 ml of 4 M HC1 at 80 °C for 10 h. After samples had cooled to room temperature 20 pl of the hydrolysate was dried in the SpeedVac. A set of standards containing alginic acid and fucoidan was prepared, dried and derivatised as for the liquid extraction samples to enable calibration.

[0112] Hydrolysed samples and standards were derivatized by adding 20 pl of methoxylation solution (20mg / ml methoxyamine hydrochloride, (Fluka®), in dry pyridine, (Fluka®). After shaking at 30 °C for 90 min (BenchMark Multi Therm) 40 pl of MSTFA (Macherey -Nagel) was added to complete derivatization in the thermomixer at 37 °C for 30 min. Derivatised samples were immediately transferred into 200 pl glass micro-vials, crimp capped and analysed using GC-MS.

[0113] 1 pl of each sample and standard was injected onto a 30 m DB5-MS column at a split-ratio of 2: 1 (Trace-GC, Thermo Scientific®) coupled to an ISQ7000 mass spectrometer (Thermo Scientific®). Mass spectra were collected in the m / z range 54-500 at ion source and transfer-line temperatures of 230 °C and 250 °C, respectively. Helium carrier gas flow was ramped from 2.2 ml min-1 for 10 min up to 2.6 ml min-1 in one minute and held for further 2 min. The temperature programme started at 80 °C, held for 1 min, ramped at 10 °C min-1 to 90 °C; then 30 °C °C min-1 till 330 °C and held for 3 min before cooling. Fucose, mannuronic acid, glucose and mannitol were quantified using five calibration standards in the range of between 0.5 mg / ml and 1 pg / ml with these used to determine sample concentrations.

[0114] A further set of analyses were undertaken using IMS (Industrial Methylated Spirit) in the pre-treatment extraction process. Raw Asco seaweed (washed and processed to 1-4 mm particle size) was pre-treated with 10% v / v, 20% v / v and 40% v / v industrial methylated spirit in water. The extracts were analysed on a dry matter basis (mg / g DW) after acid hydrolysis, and the results are provided in Table 6 and Figure 2. The is date shows that both mannuronic acid and guluronic acid (both markers for alginate) and fucose (marker for fucoidan) were detected at relatively low levels, whereas mannitol and glucose (probably derived from laminarin and other polysaccharides) were much higher. At these levels the pigment extract solution is substantially free of fucoidan and alginate, whilst having much higher levels of mannitol and glucose. This would suggest that the amount of fucoidan andalginate polysaccharide extraction is minimal with this extraction stage, but that other sugars and polysaccharides may be extracted at higher levels. This means that the mixture of polysaccharides sugars in the residual seaweed will be different in proportion compared to the untreated seaweed. The residual seaweed will have proportionally higher levels of fucoidan and alginate and proportionately less mannitol and glucose producing polysaccharides compared to the untreated seaweed, which is beneficial for the following basic extraction stage. It is preferred that the pigment extract provides on hydrolysis less than 0.3 mg.g’1DW of each of mannuronic acid, guluronic acid and fucose and most preferably less than 0.25 mg.g’1DW of each of these. It is preferred that the pigment extract provides on hydrolysis greater than 2 mg.g’1DW of glucose, preferably greater than 2.4 mg.g’1DW of glucose. It is preferred that the pigment extract provides on hydrolysis greater than 3 mg.g’1DW of mannitol, preferably greater than 4 mg.g’1DW of mannitol and most preferably greater than 4.5 mg.g’1DW of mannitol. The residual solid seaweed material for each of the samples extracted for 90 minutes were analysed for their composition before base extraction and the results are provided in Figure 3 and |Table 7 as SI 0, S20, S40. It can be seen for each of these samples that the level of fucose is 14 mg.g’1DW or higher and significantly higher than the level of mannuronic acid between 5.24 and 8.25 mg.g’1DW, glucose and mannitol are at comparable or slightly lower levels than the mannuronic acid. This would suggest that the pre-treatment solid has high levels of fucoidan compared to the other polysaccharides.

[0115] A sample of brown seaweed was pre-treated using 10% v / v industrial methylated spirits in water to provide a pre-treated residual solid seaweed broadly corresponding to S10 Solid in Table 7. This pre-treated solid was divided into three parts, and each part was base extracted with a 1% Na2COs aqueous solution at room temperature, 50°C and 60°C for 90 mins. Samples for analysis were taken at 30, 60 and 90 mins. The results of the testing of the solid reside samples after extraction are shown in Table 7 and Figure 3. It can be seen that the room temperature residual solid after extraction still retains relatively high levels of fucose and mannuronic acid in its hydrolysate with relatively low levels of glucose and mannitol. This is in contrast with the extractions at 50°C and 60°C where it can be seen that there is a significant drop in fucose and mannuronic acid as the temperature increases with the lowest levels being with the 60°C extraction. The analysis of the hydrolysed liquid samples corresponding to the desirable aqueous unrefined polysaccharide extract solutions are shown in Table 8 and Figure 4. It can be seen that as the extraction temperature increases and the time of extraction increases the levels of fucose and mannuronic acid increase in the liquid extract. Glucose and mannitol are also extracted. Theresultant aqueous unrefined polysaccharide extract solutions contain a mixture of fucoidan, alginate, mannitol and glucose. Although not directly detected the high levels of glucose in both the pre-extract and unrefined polysaccharide extract imply the presence of laminarian in both the pre-extract and the unrefined polysaccharide extract as laminarian is hydrolysed in the test to produce glucose. The exact level of laminarian in both extracts may be determined by known analysis techniques.

[0116] Example 3 - Alkaline extracts of various seaweed species and their blend

[0117] Wet solid seaweed, after been extracted in cold (15-18 C) with either ethanol or H2O2, were extracted at 65°C for 90min. The pH and the total dissolved solids (TDS, mg / 1) were measured once the extract was completed and filtered. The filtered liquid extracts were analyzed for sugar content, oligomer content and BRIX. The results are shown in Table 9.

[0118] Extracts of different species pretreated with different solvents, ethanol and H2O2, respectively, performed at the same extraction conditions, showed comparable total dissolved solutes (TDS). Only Fucus spiralis extracted after H2O2 pretreated, showed higher TDS than the ethanol extracts, overall, the blends showed comparable TDS levels.

[0119] Overall total oligomer content of the extracts showed higher values in H2O2 pretreated seaweed species as well as in their blend, when compared with those seaweeds pretreated with ethanol (610.6 vs. 206.4, respectively). Similarly, the species, Ascophyllum nodosum and Fucus vesiculosus showed the higher total sugar content and oligomer content that other species especially with the H2O2 pretreated samples.

[0120] Example 4 - Biopolymer film manufacture.

[0121] The liquid extracts of Example 3 were employed in biopolymer film production.

[0122] To each of the extracts of Example 3 when below 50°C, was added 2.00 wt.% starch, 0.50 wt.% carrageenan, 1.20 wt.% glycerol, 0.60wt% sorbitol and 0.00124 wt.% Bittrex (based on a solution with a 94-96% water content). After mixing and conditioning these formulations were used to slip cast biopolymer films. Typical properties of thebiopolymer films made were measured, including tensile strength data, water content, area density and thickness. The results are shown in Table 10. These results show that all of the biopolymer films, which contained the unrefined mixed polysaccharide extracts exhibited acceptable physical and mechanical properties with low water content.

[0123] Example 5 - Extraction time v Temperature

[0124] A series of pre-extracted seaweed samples were subjected to basic extraction with 1,0 wt% Na2CO3 solution. The pre-extracted seaweed samples are shown in Table 11.

[0125] Three basic extraction times were tested (30min, 60min, 90min) over three temperatures (40degrees, 50degrees, 60degrees). A sample of wet pre-treated seaweed was heated at either 40, 50, 60 degrees for either 30min, 60min or 90min. Following extraction, the solid was filtered and the basic liquid extract was collected, and TDS, DM, pH, and Brix were recorded. The results are shown in Table 12.

[0126] Example 6- Biopolymer Film Formation

[0127] Various film formulations were prepared using various unrefined polysaccharide extract solutions from the basic extraction process as described in preceding examples and with various pre-extraction processes. The concentration of material in the unrefined polysaccharide extract will vary. Typically, the raw extract will be diluted at a 5X dilution with water, and this may provide anywhere between 0.1 and 0.8 wt.% DM (dry mass)._Formulated solutions may be cast at a water content of 50-96 wt.% to make biopolymer films.Typical formulation ranges showing the lower and upper values (DM= Dry Mass) are as illustrated in Table 13 for the unrefined polysaccharide based formulations and the resultant films. The films have been case to a water content of 20 wt.%.Atypical formulation comprising unrefined polysaccharide extract (PS Extract) used for casting and evaluation is as follows.Typical variants of this formulation suitable for and evaluated for biopolymer film forming are as follows and % are wt.% DM with the balance being water:

[0128] PS.1~ a film formulation comprising unrefined seaweed-derived extract (0.1- 0.8%) and organic plasticizers including potato starch (0.5- 2%), carrageenan (0.25-0.75%) and glycerol (1.2 - 3%).

[0129] PS 2- a film formulation comprising unrefined seaweed-derived extract (0.1- 0.8% DM%) and organic plasticizers including potato starch (0.5-2%), carrageenan (0.25- 0.75%) and sorbitol (1.2 - 3%)

[0130] PS3 - a film formulation comprising unrefined seaweed-derived extract (0.1- 0.8%) and organic plasticizers including potato starch (0.5-2%), carrageenan (0.25-0.75%) and Propanediol (1-1.8%)

[0131] PS5- a film formulation comprising unrefined seaweed-derived extract (0.1- 0.8%) and organic plasticizers including potato starch (0.5-2%), carrageenan (0.25-0.75%), glycerol (0.8 - 1.4%) and sorbitol (0.4-1%)

[0132] PS.Flexi. series - a film formulation comprising unrefined seaweed-derived extract and organic plasticizers including potato starch (0.5%), carrageenan (0.5-1.5%), glycerol (1.8%)

[0133] The properties of various films were measured and are provided in Table 14. Pretreatment method is described as either ethanol or H2O2. Both pre-treatments were undertaken at 10% concentration applied to 10% w / v seaweed.

[0134] These biopolymer films exhibited good properties and could be easily vacuum formed without applied heat.

[0135] Example 7 - Film Solution Composition Processing and Rheology

[0136] Film composition rheology was evaluated. A film formulation PS.06-03 was prepared by adding the plasticizers to the clarified unrefined polysaccharide seaweed extractwhile mixing at room temperature and then heated up to 60C for enhancing homogeneity of final solution. The solution turned into a gel after cooling down to below 50C.

[0137] The viscosity (MPas) was measured every hour while mixing at constant temperature for 7 hours. The data is provided in Table 15. As shown in the table, a significant change of viscosity occurred when the solution was heated up at temperature of 70 or above. Continuous stirring at 80C led to a decline in viscosity compared to when the same solution was mixed at 70C - this may indicate that 70 is the maximum / optimal temperature to stir the solution over time.

[0138] The overall increase of viscosity of the solution may be related to increases of polymerization or increases of intermolecular forces regulated by the time of stirring at constant temperature. The decline observed at higher temperatures could indicate a reversal of these reactions, a break-down, or transformation.

[0139] The same solution prepared at 60C and heated at 50C was cooled down into a gel form and re-heated to 60C and 70C. Similarly, the same solution prepared at 60C and heated at 70C was cooled into a gel form and re-heated to 60C and 70C. The results are shown in Table 16. The heat and re-heat processes are also referred to first and second heating cycle, respectively. For example, a solution prepared at 60C is heated at 50C, cooled to room temperature and re-heated at 70C (also referred to 60C / 50C / 70C.TABLE 16

[0140] Results showed significant increase of viscosity after a second heating cycle at 60C with viscosity values higher than those recorded at first heating cycle at 50C. Similarly, after a second heating cycle at 70C. Likewise, a further increase in viscosity was recorded on a solution subjected to a first heating cycle at 70C and reheated at 50C and 70C. Results maysuggest the role of temperature over time and how a further heating cycles within 50C and 70C may increase the viscosity.

[0141] While exemplary embodiments incorporating the principles of the present disclosure have been described herein, the present disclosure is not limited to such embodiments. Instead, this application is intended to cover any combinations of the individual features of the exemplary embodiments described herein and the principles described herein and to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains. It is also to be understood that any aspects described as such and their features are not mutually exclusive from any other aspect and its features in this disclosure and this disclosure should not be interpreted as such. Any individual features of any two or more aspects may be combined with each other.

Claims

1. CLAIMS1. A seaweed extraction process for producing an unrefined polysaccharide extract composition, the extraction process comprising: a) forming a dispersion by dispersing seaweed in water or an aqueous basic solution of pH >7, b) stirring the dispersion at a temperature of less than 100°C for at least 15 minutes, and c) filtering the dispersion to separate a solid seaweed residue from an aqueous unrefined polysaccharide extract solution2. A seaweed extraction process as claimed in claim 1, wherein the water or an aqueous basic solution of pH>8 is heated to a maximum temperature of 100°C before addition of the seaweed.

3. A seaweed extraction process as claimed in claim 1, having a further step d), wherein the aqueous unrefined polysaccharide extract solution is cooled from the elevated temperature of extraction to a temperature of between -21 °C and 40°C.

4. A seaweed extraction process as claimed in claim 1, wherein the dispersion is formed by dispersing seaweed in an aqueous basic solution of pH >8.

5. A process as claimed in claim 1 to 4, wherein the aqueous basic solution is a sodium carbonate solution.

6. A process as claimed in any one of the preceding claims in which the seaweed comprises one or more brown, red or green seaweeds or mixtures thereof.

7. A process as claimed in any one of claims 1 to 5, wherein the seaweed is brown seaweed.

8. A process for producing alginate the process comprising: performing steps a) to c) of claim 1 and carrying out further processing steps on the basic seaweed extraction residue to produce alginate.

9. A process as claimed in claims 1 or 8, wherein an aqueous pre-treatment of the seaweed is carried out prior to step a).

10. A process as claimed in claim 9, wherein the aqueous pre-treatment uses and aqueous solvent.

11. A process as claimed in claim 9, wherein the aqueous pre-treatment uses an aqueous hydrogen peroxide solution.

12. A process as claimed in claim 10, wherein the aqueous solvent comprises and alcohol or mixture of alcohols.

13. A process as claimed in claim 12, wherein the alcohol is ethanol or industrial methylated spirits.

14. A process as claimed in any one of claims 9 to 13, wherein the process is carried out a temperature from 10 to 30°C.

15. A polysaccharide extract solution or solid comprising a mixture of unrefined seaweed polysaccharides.

16. A polysaccharide extract solution or solid as claimed in claim 15, wherein the mixture of unrefined polysaccharides comprises fucoidan, alginate, laminarin and mannitol.

17. A polysaccharide extract solution or solid as claimed in claim 15 comprising unrefined glucose.

18. A biopolymer film forming composition comprising a polysaccharide extract solution or solid as claimed in any one of claims 15 to 17.

19. A biopolymer film forming composition according to claim 18, comprising further materials and additives to provide a formulation and the formulation having been homogenized.

20. A biopolymer film forming composition according to claim 18, wherein the unrefined polysaccharide extract solution has been pre-conditioned before addition to the composition.

21. A biopolymer film forming composition according to claim 18, in which the unrefined polysaccharide extract solution is pre-conditioned during or after the formulation homogenization process.

22. A biopolymer film forming composition according to claim 18, in which the unrefined polysaccharide extract solution is pre-conditioned in a further process step after the formulation homogenization process.

23. A biopolymer film comprising a mixture of unrefined seaweed polysaccharides.

24. A biopolymer film according to claim 23, wherein the mixture of unrefined polysaccharides comprises fucoidan, alginate, laminarin and mannitol.

25. A biopolymer film according to claim 23, further comprising plant-based plasticisers.

26. A biopolymer film according to claim 23, which is compostable.

27. A biopolymer film according to claim 23, which is soluble in water at ambient or elevated temperatures.

28. An encapsulated product comprising a biopolymer film according to claim 23.

29. A packaging material comprising an unrefined polysaccharide extract solution or solid according to claim 15.

30. A packaging material having a coating comprising a biopolymer film according to claim 23.

31. A paint or ink additive comprising an unrefined polysaccharide extract solution or solid according to claim 15.

32. A method for forming a biopolymer film in which method a composition comprising an unrefined polysaccharide extract solution or solid according to claim 15 is deposited in a suitable form and cured to form a biopolymer film.

33. A method as claimed in claim 32, in which the composition is coated onto a moving substrate and cured before delaminating from that substrate to form a free-standing biopolymer film.

34. A method as claimed in claim 32, in which the composition is coated onto a shaped mould and cured before delaminating from the mould to provide a free-standing moulded biopolymer film.

35. A method as claimed in claim 32, in which the composition is extruded using a film extruder and cured during extrusion to form an extruded free-standing biopolymer film.

36. A method as claimed in claim 32, in which the composition is spray coated onto a substrate and cured to bond to the surface of that substrate to provide a biopolymer film coated substrate.

37. A method according to any one of claims 32 to 36, in which the curing process comprises drying the mixture, for example heating and / or passing an air flow over the mixture to evaporate solvent.

38. A method of forming an extruded biopolymer object, in which method a composition comprising an unrefined polysaccharide extract solution or solid as claimed in claim 15, is extruded using an extruder and cured during extrusion to form an extruded biopolymer object.

39. A method of forming a moulded biopolymer object, in which method a composition comprising an unrefined polysaccharide extract solution or solid as claimed in claim 15, ismoulded using an injection moudling machine and cured to form a moulded biopolymer object.

40. A biopolymer film forming composition according to claim 18 further comprising alginate as obtained by the process of claim 8.

41. A biopolymer film according to claim 23 further comprising alginate as obtained by the process of claim 8.

42. A seaweed biorefinery for processing brown seaweed, which comprises a combination of the processes of claims 1 and 14 and any additional processes for the utilization of the products of these processes.

43. A biopolymer film according to claim 25, wherein the plasticizer is selected from the group consisting of glycerine, trimethylol propane, sorbitol, and combinations thereof.

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