Solid treatment product for preserving cut flowers

Abstract

The present invention relates to the use of a solid treatment product for preserving cut flowers by introducing the solid treatment product together with water and the stems of cut flowers into a receptacle, wherein the solid treatment product is a shaped dosage unit comprising: • 5 - 50 wt. % of water-insoluble biodegradable thermoplastic polymer; • 40 - 95 wt. % of sugar; and • 0 - 20 wt. % water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit. The treatment product for cut flowers of the present invention is easy to handle, easy to manufacture and effectively increases longevity of cut flowers.

Description

SOLID TREATMENT PRODUCT FOR PRESERVING CUT FLOWERSTECHNICAL FIELD

[0001] The present application relates to a solid treatment product for preserving cut flowers.BACKGROUND OF THE INVENTION

[0002] Cut flowers, once harvested, undergo a series of physiological changes that lead to their wilting.

[0003] Various products have been developed to increase the longevity of cut flowers. These flower preservative products typically contain a mixture of nutrients and preservatives. Most commercially available flower preservative products are provided in the form of concentrated solutions or powders.

[0004] WO 97 / 47180 describes a floral foam for cut flower that has been pre-injected with nutrients and preservatives in an amount of 6-15 g per dm3water to be absorbed by the foam.

[0005] WO 2014 / 115154 discloses a slow-release plant preservation device or use in an aqueous environment in a vessel to increase the vitality of one or more plants placed within said vessel, the device comprising a preservation composition that is slowly released into the aqueous environment in the vessel, wherein said preservation composition comprises at least one preservative and at least one vitalizing agent, wherein said one or more plants comprise any combination of uprooted plants and cut flowers, and wherein the device is adapted for binding said one or more plants together.

[0006] DE1974966U describes a carrier body for active ingredients and nutrients for keeping cut flowers fresh in cups or bowls, characterized in that it has the form of a capsule-shaped hollow body to be attached to the cut flower arrangement - consisting entirely or partially of open-pored plastic - in whose porous wall, as well as in the hollow space enclosed by the wall, there are active ingredients and nutrients necessary for the function of keeping them fresh, which are dissolved or washed out when the carrier body is immersed in water.US 2019 / 263989 describes a floral foam comprising a polylactide polymer in the form of a star polymer having at least three arms. The foam can be rehydrated with the addition of 10ml of water to increase flower longevity. When the stems of cut flowers are inserted into the foam, the flowers do not wilt for at least 132 hours with daily addition of 10 ml of water.JP 2012 241079 describes an floral foam that comprises polylactic acid and a colourant.BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1a shows a rod-shaped dosage unit according to the present invention

[0008] Figure 1b shows a vase containing water and the rod-shaped dosage unit

[0009] Figure 1c shows vase containing water, the rod-shaped dosage unit and cut rosesSUMMARY

[0010] The inventors have devised a solid treatment product for cut flowers that that is easy to handle, easy to manufacture and that effectively increases longevity of cut flowers.

[0011] A first aspect of the invention concerns the use of a solid treatment product for preserving cut flowers by introducing the solid treatment product together with water and the stems of cut flowers into a receptacle, wherein the solid treatment product is a shaped dosage unit comprising:• 5 - 50 wt. % of water-insoluble biodegradable thermoplastic polymer;• 40 - 95 wt. % of sugar; and• 0 - 20 wt. % water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit.

[0012] When the cut flowers have reached the end of their lifetime, the dosage unit and cut flowers can be disposed of together as both the cut flowers and dosage unit are biodegradable.

[0013] According to a second aspect of the present invention, there is provided a receptacle comprising cut flowers and water, the stems of said cut flowers being at least partially immersed in the water, wherein the water further comprises a shaped dosage unit according to the invention.

[0014] A third aspect of the present invention concerns a shaped dosage unit for treating cut flowers, the shaped dosage unit comprising:• 5 - 30 wt.% of water-insoluble biodegradable thermoplastic polymer;• 40 - 95 wt.% of sugar;• 0.5 - 30 wt.% of acid; and• 0 - 20 wt.% water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit and wherein the shaped dosage unit sinks when introduced in demineralised water having a temperature of 20 °C.

[0015] A fourth aspect of the invention concerns a process for preparing the aforementioned solid dosage unit, the process comprising the following steps:• introducing water-insoluble biodegradable thermoplastic polymer and sugar into an extruder;• kneading and heating the combination of water-insoluble biodegradable thermoplastic polymer and sugar in the extruder to produce a hot blend; and• expelling the hot blend from the extruder, the hot blend having an exit temperature of at least 40°C.DETAILED DESCRIPTION OF THE INVENTION

[0016] A first aspect of the invention relates to the use of a solid treatment product for preserving cut flowers by introducing the treatment product together with water and the stems of cut flowers into a receptacle, wherein the solid treatment product is a shaped dosage unit comprising:• 5 - 50 wt. % of water-insoluble biodegradable thermoplastic polymer;• 40 - 95 wt. % of sugar; and• 0 - 20 wt. % water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit.

[0017] The term "comprise" and variations thereof, such as "comprises" and "comprising", as used herein, should be construed in an open, inclusive sense, meaning that the embodiment described includes the recited features but that it does not exclude the presence of other features. The same holds for the terms "contain", "contains", and "containing".

[0018] The singular forms "a," "an," and "the" as used herein should be construed to include plural referents unless the content clearly dictates otherwise. It should also be noted that theterm "or" is employed in its broadest sense, that is, as meaning "and / or" unless the content clearly dictates otherwise.

[0019] Numerical ranges expressed in the format "from x to y" are understood to include x and y.

[0020] Whenever components A and B are said to be present in a weight ratio of x:y, what is meant is that the concentration of component A in wt.% divided by the concentration of component B in wt.% equals x:y.

[0021] The ratios mentioned herein are based on weight / weight unless indicated otherwise. Similarly, all percentages are percentages by weight (w / w) unless stated otherwise.

[0022] When multiple preferred ranges are described in the format "from x to y" for a specific feature, it should be understood that all ranges combining the different endpoints are also contemplated.

[0023] If, for a particular component, a range of 0% to y% or less than y% is recited, said component may be absent.

[0024] Additionally, should a particular component be recited as "at least y%", said component may be present in a concentration of y% to 100%.

[0025] The term “water-insoluble biodegradable thermoplastic polymer” as used herein refers to a natural or synthetic thermoplastic polymer that has a solubility in demineralized water at 20°C of less than 1 g / L and that can easily be decomposed by micro-organisms under aerobic and / or anaerobic conditions.

[0026] The shaped dosage unit preferably comprises 8-40 wt.%, more preferably 10-25 wt.% of the water-insoluble biodegradable thermoplastic polymer.

[0027] The thermoplastic polymer preferably is a polyester, more preferably a polyester selected from the group consisting of polycaprolactone, poly lactic acid polybutylene succinate, polyhydroxy alkenoate, poly(butylene adipate-co-terephthalate), polypropylene carbonate, poly(lactic-co-glycolic acid), poly(butylene succinate-co-adipate), poly(ethylene adipate), poly(salicylic glycolide) and poly(salicylic methyl glycolide) and combinations thereof.More preferably, the polyester is selected from polycaprolactone, polybutylene succinate, polyhydroxy alkenoate, poly lactic acid, poly butylene adipate terephthalate and combinations thereof. Examples of polyhydroxy alkenoates that may be employed in accordance with the present invention include poly-(R)-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly(3- hydroxybutyrate-co-3-hydroxyvalerate and combinations thereof. Even more preferably, the polyester is selected from polycaprolactone, polybutylene succinate and combinations thereof. Most preferably, the polyester is polycaprolactone.

[0028] The thermoplastic polymer preferably has a melting point within the range of 30 - 200 °C, more preferably within the range of 40 - 160 °C, most preferably in the range of 45 - 120 °C.

[0029] The term "melting temperature", as used herein, is determined according to ISO 11357-3, preferably on a DSC Q2000 instrument by TA Instruments. In the context of the present invention, the melting temperature refers to the peak of the melting range of a polymer of the second heating when applying the following temperature protocol under a nitrogen atmosphere:• heating from 25 to 200 °C at a rate of 10 °C / min;• maintaining 200 °C for two minutes;• cooling from 200 to -20 °C at a rate of 10 °C / min;• maintaining -20 °C for three minutes;• heating from -20 °C to 200 °C at a rate of 10 °C / min.

[0030] In preferred embodiments, the sugar in the dosage unit is selected from glucose, fructose, sucrose, maltose, lactose, mannose and combinations thereof. More preferably, the sugar is selected from the group consisting of glucose, fructose, sucrose, maltose, lactose and combinations thereof. More preferably, the sugar is selected from glucose, fructose, sucrose and combinations thereof. Even more preferably, the sugar is selected from glucose, sucrose and combinations thereof. Most preferably, the sugar used is glucose.

[0031] The shaped dosage unit employed in accordance with the use of the present invention preferably comprises 50 - 94 wt.% sugar, more preferably 60 - 92 wt.% sugar; most preferably, 70 - 90 wt.% sugar.

[0032] It is particularly preferred that the combination of water-insoluble biodegradable thermoplastic polymer and sugar constitutes at least 80 wt.% of the dry matter that is contained in the shaped dosage unit. More preferably, the combination of water-insoluble biodegradablethermoplastic polymer and sugar constitutes at least 85 wt.%, most preferably at least 90 wt.% of the dry matter contained in the shaped dosage unit.

[0033] The water content of the dosage unit preferably is in the range of 0-12 wt.%, most preferably in the range of 0-8 wt.%.

[0034] In particular embodiments of the invention, the shaped dosage unit further comprises an acid. Release of acid from the dosage unit into the water lowers the pH, thereby enhancing nutrient uptake and inhibiting the growth of bacteria and fungi. Examples of cut flowers that benefit from a more acidic pH include roses, carnations, lilies and tulips.

[0035] Preferably, the acid is selected from the group consisting of citric acid, acetic acid, lactic acid, gluconic acid, glucono-deltalactone, tartaric acid, propionic acid, glycolic acid, fumaric acid, sorbic acid, malic acid, ascorbic acid, phosphoric acid, boric acid and combinations thereof. More preferably, the acid is selected from the group consisting of citric acid, lactic acid, ascorbic acid, boric acid, acetic acid, malic acid, tartaric acid, phosphoric acid, sorbic acid and combinations thereof. Still more preferably, the acid is selected from the group consisting of citric acid, lactic acid, acetic acid, ascorbic acid, boric acid and combinations thereof. Most preferably, the acid is citric acid.

[0036] The introduction of the treatment product in accordance with the present use preferably reduces pH of the water in the receptacle to within the range of 3 - 6.5, preferably within the range of 3.2 - 6, most preferably within the range of 3.5 - 5.Preferably, the shaped dosage unit comprises 0.5-30 wt.% of acid, more preferably 1-25 wt.%, most preferably, the shaped dosage unit comprises 1.5-22 wt.% of acid.

[0037] In a preferred embodiment, in addition to acid, an effervescent carbonate is employed in the preparation of the shaped dosage unit. During preparation of the shaped dosage unit, carbon dioxide is generated by a reaction between the carbonate effervescent and the acid. The released carbon dioxide acts a blowing agent and forms small bubbles within the dosage unit. Thus, the use of a combination of acid and effervescent carbonate enables the preparation of a porous dosage unit. The inventors have found that dosage units that are porous are particularly effective in increasing longevity of cut flowers.

[0038] The effervescent carbonate preferably is a carbonate or bicarbonate salt. Examples of suitable effervescent carbonates include sodium carbonate, sodium bicarbonate, potassiumcarbonate, potassium bicarbonate, ammonium bicarbonate, calcium carbonate, magnesium carbonate and zinc carbonate.

[0039] In a further preferred embodiment of the invention, the shaped dosage unit further comprises a preservative. Here the term “preservative” does not encompass acids.

[0040] Preferably, the preservative is selected from the group consisting of aluminium sulphate, sodium hypochlorite, silver nitrate, silver thiosulfate, calcium nitrate, chlorine dioxide quaternary ammonium compounds containing at least one C6-C24 hydrocarbon residue, guanidine compounds containing at least one C6-C24 hydrocarbon residue, bromo-nitrogen derivates, isothiazolinones, hydroxyquinolines, 1 ,3-dihalo-5,5-dimethylhydantoins, chloramphenicol, spectinomycin, alkyl parabens, salicylic acids and salts thereof, benzoic acids and salts thereof, sorbates, thiabendazole1 ,3-dichloro-5,5-dimethylhydantoin, N- chlorosulfonamides, isocyanurates, lysozymes and combinations thereof. Most preferably, the preservative is selected from the group consisting of bromo-nitrogen derivates, isothiazolinones, quaternary ammonium compounds containing at least one C6-C24 hydrocarbon residue, guanidine compounds containing at least one C6-C24 hydrocarbon residue and combinations thereof.

[0041] The shaped dosage unit according to the invention preferably comprises 0.01 - 5 wt.% of preservative, more preferably 0.1 - 3.5 wt.% of preservative, most preferably 0.2 - 2.0 wt.% of preservative.

[0042] To ensure that the nutrients in the shaped dosage unit are well-distributed throughout the aqueous medium in which the cut flowers are stored, it is particularly preferred that the shaped dosage unit sinks when introduced in demineralised water having a temperature of 20 °C. In case the shaped dosage unit is porous, it is preferred that the dosage unit readily absorbs water and sinks after it has absorbed sufficient water. Preferably, the shaped dosage unit sinks within 60 minutes, more preferably within 30 minutes and most preferably within 15 minutes after it has been introduced in demineralised water having a temperature of 20°C.

[0043] In a preferred embodiment, the shaped dosage unit has an average density of at least 0.5 g / mL at 20°C.

[0044] In one embodiment of the present invention, the shaped dosage unit is a porous shaped dosage unit having an average density of 0.5 to 1.1 g / mL, more preferably an average density of 0.6 to 0.9 g / mL.

[0045] In an alternative embodiment, the shaped dosage unit is essentially non-porous having a density of at least 1.01 g / mL at 20°C, more preferably an average density of 1.03-2.0 g / mL at 20°C, and most preferably of 1 .05-1 .5. g / mL at 20°C.

[0046] The average density of the dosage unit can be determined by (i) weighing the dosage unit, (ii) introducing the dosage unit in a measuring cylinder, (iii) fully covering the dosage unit with a resilient powder (e.g. sand) and determining the combined volume, and (iv) determining the volume of the added powder (‘powder volume). The average density is calculated as follows:Weight of dosage unit in grams / (combined volume in mL - powder volume in mL)

[0047] The shaped dosage unit, according to the invention, can have different weights, depending on the anticipated use. For example, when the shaped dosage unit is used to preserve a single bouquet, its weight is preferably in the range of 1-100 grams, more preferably in the range of 2-30 grams. Alternatively, if the shaped dosage unit is used to preserve a large number of cut flowers in a big receptacle, its weight may suitably range from 5-5,000 grams, preferably 10-4,000 grams.

[0048] In a particularly preferred embodiment, the shaped dosage unit and water are introduced in the receptacle in a weight: volume ratio of 1-30 g / L, more preferably in the range of 2-20 g / L, most preferably in the range of 3-15 g / L.

[0049] The dosage unit of the present invention may be shaped in different forms e.g. as a rod, sphere, cube, star or heart.

[0050] Preferably, the shaped dosage unit has the shape of a cylindrical rod. Preferably, such a cylindrical rod has a diameter of 3 - 30 mm and a length of 1 - 120 cm. More preferably, the cylindrical rod has a diameter of 4 - 20 mm and a length of 2 - 70 cm. Most preferably, the cylindrical rod has a diameter of 5 - 10 mm and a length of 10 - 40 cm. Providing the shaped dosage unit in the form of a cylindrical rod offers the advantage that the dosage unit can be immersed into water together with the stems of the cut flowers. This can suitably be achieved, for instance, by bundling together the flower stems and the rod-shaped dosage unit, and by introducing the bundle into water.

[0051] In a preferred embodiment, text or one or more symbols being printed on the surface of the shaped dosage unit. The inclusion of text or symbols on the surface of the shaped dosage unit allows for easy identification and differentiation of the dosage units. In particular,the text may include instructions on how to use the shaped dosage unit. Also a logo or a brand can suitably be printed on the surface of the dosage unit.

[0052] In addition to the previously mentioned components, the shaped dosage unit may suitably comprise further components. Examples include bulking agents (e.g. cellulose), chelating agents, humectants, plant hormones, anti-transpirants, biostimulants, colouring agents, and buffering agents.

[0053] A further aspect of the invention relates to a receptacle comprising cut flowers and water, the stems of the cut flowers being at least partially immersed in the water, wherein the water further comprises a shaped dosage unit as described hereinbefore.

[0054] Examples of suitable receptacles include buckets, vases and floral boxes.

[0055] Another aspect of the invention relates to a shaped dosage unit for treating cut flowers, the shaped dosage unit comprising:• 5 - 30 wt.% of water-insoluble biodegradable thermoplastic polymer;• 40 - 95 wt.% of sugar;• 0.5 - 30 wt.% of acid; and• 0 - 20 wt.% water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit and wherein the shaped dosage unit sinks when introduced in demineralised water having a temperature of 20 °C.

[0056] Preferred embodiments of the shaped dosage unit have already been described hereinbefore.

[0057] A final aspect of the invention relates to a process of preparing the shaped dosage unit of the present invention, the process comprising the following steps:• introducing water-insoluble biodegradable thermoplastic polymer and sugar into an extruder;• kneading and heating the combination of water-insoluble biodegradable thermoplastic polymer and sugar in the extruder to produce a hot blend; and• expelling the hot blend from the extruder, the hot blend having an exit temperature of at least 40°C.

[0058] The water-insoluble biodegradable thermoplastic polymer and sugar may be introduced into the extruder together, or they may be introduced separately.

[0059] According to a preferred embodiment, the process additionally comprises introduction of an effervescent carbonate and an acid into the extruder.

[0060] The extruder employed in the present process preferably is a twin screw extruder.

[0061] Preferably, the combination of water-insoluble biodegradable thermoplastic polymer and sugar is heated in the extruder to a temperature of 45-200 °C, more preferably of 50-150 °C, most preferably of 55-100 °C.

[0062] The hot blend preferably has an exit temperature of 45-200 °C, more preferably of 50- 150 °C, most preferably of 55-100 °C.

[0063] The hot blend may be expelled in the form of a strand. The shape of this strand is determined by the die that is used. The strand may be cut up into pieces to obtain the shaped dosage unit.

[0064] Alternatively, the hot blend may be expelled into a mould, and the shaped dosage unit is obtained after demoulding.

[0065] The following non-limiting examples further illustrate the invention.EXAMPLESExample 1A solid treatment product according to the present invention was produced by extrusion on the basis of the recipe that is shown in Table 1.Table 11Capa® 6500, ex Ingevity (melting point 60 °C, mean MW: 50 kDa)The extrudate was prepared by feeding the sugar and polymer from separate hoppers into a twin screw extruder in which these two ingredients were intimately mixed and heated to a temperature of 80°C before being extruded through a die to form a cylindrical extrudate having a diameter of approximately 0.6 cm. The extrudate was transported by a belt conveyor while being cooled by a flow of cold air. The cooled extrudate was manually cut into rods having a length of approximately 30 cm and a weight of approximately 12.5 grams. The cutting of the cooled extrudate can also be done by a rotating chopper.Example 2Example 1 was repeated. This time the product was prepared on the basis of the recipe that is shown in Table 2.Table 21Capa® 6500, ex Ingevity (melting point 60 °C, mean MW: 50 kDa)This time the extrudate was cut into rods having a length of approximately 15 cm. The rods so obtained are shown in Figure 1a.Figure 1b shows a vase into which water and the rod-shaped dosage unit have been introduced.Figure 1c shows the same vase into which water, the rod-shaped dosage unit and cut roses have been introduced.Example 3Example 1 was repeated. This time the product was prepared on the basis of the recipe that is shown in Table 3.Table 31Capa® 6500, ex Ingevity (melting point 60 °C, mean MW: 50 kDa)The rod-shaped treatment product so obtained was sufficiently robust to be handled without breaking apart.Example 4Example 2 was repeated, except that this sucrose was used instead of glucose. The treatment product so obtained differed from the treatment product of Example 2 in that it was more hygroscopic.Example 5Example 2 was repeated, except that polycaprolactone was replaced by polybutylene succinate (BioPBS FD92PM, ex PTT MCC Biochem). Because the melting of polybutylene succinate is approximately 84 °C, the mixture of sugar and polymer had to be heated to a temperate of 110 °C in the extruder before being expelled through the die.The properties of the treatment product so obtained were comparable to those of the treatment product of Example 2.Example 6Example 2 is repeated, except that this time the recipe produce was prepared on the basis of the recipe that is shown in Table 4.Table 41Capa® 6500, ex Ingevity (melting point 60 °C, mean MW: 50 kDa)Example 7Using the procedure as described in Example 1 , rod-shaped dosage units were prepared on the basis of the recipes shown in Table 5.Table 51Capa® 6500, ex Ingevity (melting point 60 °C, mean MW: 50 kDa)The rods that were prepared using potassium bicarbonate showed porosity. Porosity was most pronounced in rod no. 3.A test was carried out in which mixed flower bouquets (Aster, Campanula, Phlox, Phoenix and Rosa) were put into vases with water and one of the rod 1 , 2 or 3 (each weighing about 10.5 g), or only water (Reference). Water was replenished on a daily basis. Rod no. 1 sank immediately after it was introduced the vase water. After introduction into the vase water, rods 2 and 3 briefly floated before sinking.It was found that the vase life of the flowers was extended by the presence of the rods in the vase water compared to the Reference. Best result in terms of vase life was achieved by rods2 and 3.

Claims

CLAIMS1. Use of a solid treatment product for preserving cut flowers by introducing the treatment product together with water and the stems of cut flowers into a receptacle, wherein the solid treatment product is a shaped dosage unit comprising:• 5 - 50 wt.% of water-insoluble biodegradable thermoplastic polymer;• 40 - 95 wt.% of sugar;• 0 - 20 wt.% water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit.

2. Use according to claim 1, wherein the thermoplastic polymer is a polyester.

3. Use according to claim 2, wherein the polyester is selected from polycaprolactone, poly lactic acid polybutylene succinate, polyhydroxy alkenoates, poly(butylene adipate-co- terephthalate), polypropylene carbonate, poly(lactic-co-glycolic acid), poly(butylene succinate-co-adipate), poly(ethylene adipate), poly(salicylic glycolide) and poly(salicylic methyl glycolide) and combinations thereof.

4. Use according to any one of the preceding claims, wherein the thermoplastic polymer has a melting point of 30-200 °C.

5. Use according to any one of the preceding claims, wherein the sugar is selected from glucose, fructose, sucrose, dextrose, maltose, lactose, mannose and combinations thereof.

6. Use according to any one of the preceding claims, wherein introduction of the shaped dosage unit reduces pH of the water in the receptacle to within the range of 3 - 6.5.

7. Use according to claim 4, wherein the acid is selected from citric acid, acetic acid, lactic acid, gluconic acid, glucono-deltalactone, tartaric acid, propionic acid, glycolic acid, fumaric acid, sorbic acid, malic acid, oxalic acid, ascorbic acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, boric acid and combinations thereof.

8. Use according to any one of the preceding claims, wherein the combination of biodegradable thermoplastic polymer and sugar constitutes at least 80 wt.%.

9. Use according to any one of the preceding claims, wherein the solid treatment product contains 0.01-5 wt.% of preservative.

10. Use according to any one of the preceding claims, wherein the shaped dosage unit comprises 0.5-25 wt.% of an effervescent carbonate.

11. Use according to any one of the preceding claims wherein the shaped dosage unit has a weight of 1 to 100 grams.

12. Use according to any one of the preceding claims, wherein the dosage unit sinks when introduced in demineralised water having a temperature of 20 °C.

13. A receptacle comprising cut flowers and water, the stems of said cut flowers being at least partially immersed in the water, wherein the water further comprises a shaped dosage unit as defined in any one of the preceding claims.

14. A shaped dosage unit for treating cut flowers, the shaped dosage unit comprising:• 5 - 50 wt.% of water-insoluble biodegradable thermoplastic polymer;• 40 - 95 wt.% of sugar;• 0.5 - 30 wt.% of acid; and• 0 - 20 wt.% water; wherein the water-insoluble biodegradable thermoplastic polymer and the sugar are homogeneously distributed throughout the shaped dosage unit and wherein the shaped dosage unit sinks when introduced in demineralised water having a temperature of 20 °C.

15. Shaped dosage unit according to claim 14, wherein the thermoplastic polymer has a melting point of not more than 120°C.

16. A process of preparing a shaped dosage unit according to claim 13 or 14, the process comprising the following steps:• introducing water-insoluble biodegradable thermoplastic polymer and sugar into an extruder;• kneading and heating the combination of water-insoluble biodegradable thermoplastic polymer and sugar in the extruder to produce a hot blend; andexpelling the hot blend from the extruder, the hot blend having an exit temperature of at least 40°C.16

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