FR2751510A1 - Preservation of cut plants and flowers, especially those with white flowers - Google Patents

Abstract

Cut plants and flowers are preserved by a solution based on polyols in which the level of water is at least 10 wt.% w.r.t. mass of plant. Also claimed are (i) preservation involving partial dehydration; and (ii) a floral composition containing flowers preserved as above. Preferably the water level in the preservative is at least equal to 20 wt.%. The plants have 20-70 wt.% tripropylene glycol; and 15-75 wt.% polyethylene glycol as preservatives (in relation to mass of dry material). The plant contains <= 7 wt.% cellulose. The white flowering plant also contains preferably a tiny amount of sodium hypochlorite and/or formic acid and/or one or several cationic colourants.

Description

VEGETAL CUTTING PRESERVE
The present invention relates to cut plants preserved, particularly to flowers or fruits, including roses.

 The technical field of the invention is the field of plant preservation.

 Plant preservation can be achieved by various known methods.

 These processes are intended in particular to replace the water of plant tissues with other products, such as glycerin, and glycols, for example.

 US Patent No. 4,828,890 (TIEDEMANN et al) describes numerous examples of treatment of plants, in particular using solutions containing polyethylene glycol (abbreviated PEG). This document recommends the use of P.E.G., whose molecular mass is in a range of values from 200 to 1000; this document also describes treatment solutions based on tripropylene glycol (abbreviated TPG).

 Patent applications FR2651642 (SARL Compagnie du Nord) and FR2433294 (QUEEN'S University at KINGSTON) describe processes in which cut flower water is replaced by a substance unsuitable for the metabolism of saprophytic agents: according to these documents this substance is a polymer (Such as a polyethylene glycol mixture) or an aqueous solution comprising an exchange agent consisting of one or more monovalent alcohols, preservatives such as lower carboxylic acids, and buffer and mordant reagents.

 A major disadvantage of known methods of plant preservation lies in very long treatment times (dehydration, infiltration), generally from at least 24 hours up to several hundred hours; as a result, the known treatments entail significant energy expenditure (especially for the air conditioning of premises) and entail significant constraints in terms of production.

 In addition, the known methods do not always make it possible to obtain plants whose mechanical characteristics, (strength and flexibility), the physical characteristics including resistance to moisture, color, appearance and longevity are satisfactory and homogeneous. .

 The need to obtain plants with these qualities is particularly important for the production of floral or decorative plant compositions, which comprise several plants assembled together by a mechanical link and / or a common mechanical support.

 Indeed, in this case in particular, quality differences between the plants of the same floral or plant composition have a negative influence on the quality of the composition itself.

 In addition, the mechanical fragility and lack of resistance to moisture of these plants causes significant losses, for example during or before the manufacture of the floral composition.

 The invention aims to overcome the disadvantages of preserved cut plants and their known processing methods.

 The object of the present invention is to provide preserved cut plants whose qualities are, if not improved at least equivalent, requiring a shorter processing time.

 Surprisingly, it has been found that, contrary to the generally prevailing prejudice that fresh plant water must be replaced by a treatment composition, preserved cut plants can be obtained by a solution based on polyols such as polyethylene glycol and / or tripropylene glycol, the qualities of which are generally improved, by not replacing the water with a treatment composition but on the contrary maintaining to a certain extent the content water contained in the tissues of the treated plant, expressed as a percentage of the mass of the treated plant or a part thereof such as the stem or petals.

 The invention thus consists in providing a cut and preserved plant (particularly a flower such as a rose or a fruit) which comprises polyethylene glycol or tripropylene glycol, and whose percentage of water in mass in said plant, particularly in said flower and / or in a part thereof, such as a petal, is greater than 10% of the mass (if any of said portion) of the preserved cut plant, preferably from 20% to 70% by weight. mass percentage of preserved cut plant, particularly ranging from 30 to 60%, for example close to 50%.

 According to the invention, it is possible, for example, to carry out a partial dehydration of the plants and preferably then to stabilize the water content by applying to the plant a coating that is not very permeable to water, such as a polyurethane or silicone film.

 The invention makes it possible to obtain processing times of the order of ten hours and generally less.

According to preferred embodiments of the invention 1 invention
said plant comprises one or more polyvalent alcohol (s) (polyols) whose mass percentage ranges from 10% to 90% of the mass of dry matter of the preserved cut plant, for example at least equal to 20% of the mass of dry matter
said plant comprises tripropylene glycol (TPG) whose percentage by mass in the dry matter mass of the preserved cut plant is greater than 10%, preferably less than or equal to 80% of the mass of dry matter, for example ranging from 20 to 70%
- The plant according to the invention comprises polyethylene glycol (PEG), the percentage by weight relative to the mass of dry matter of the cut plant preserved is greater than 10%, preferably ranging from 15 to 75%
said plant furthermore comprises a small amount of sodium chloride;
said plant further comprises one or more cationic dye (s)
the percentage by mass of cellulose is from 2 to 7% and preferably from 3 to 5% of the mass of dry matter of the preserved cut plant.

 Said plant is further protected from excessive moisture by a waterproofing coating applied in the form of an invisible polymer film whose nature may be: a polyurethane, a cyclized rubber, a chlorosulfonated rubber, an acrylic resin, vinyl or silicone.

 The invention also consists in using a method of preserving plants by the use of polyvalent alcohol, according to which partial dehydration of the plant is carried out, in particular to produce plants and particularly flowers of a pure and natural white keeping its fresh appearance in the long run.

 The invention also provides floral compositions which comprise a plurality of cut flowers preserved according to the invention, secured to each other and / or to a support.

 The invention gives particularly satisfactory results for roses and flower arrangements based on cut roses preserved.

Example 1: red roses
Two lots of previously dehydrated roses are infiltrated by soaking in a solution comprising, as a percentage by mass - methoxypropanol: 45%,
tripropylene glycol: 40%, polyethylene glycol 1000: 10%,
polyethylene glycol 1500: 5%,
- cationic dye: a few ppm.

 The treatment is carried out at a temperature of 450 to 550C approximately.

 The infiltration operation lasts several hours (generally from 3 to 5 hours) and it is possible, in order to obtain the optimum results, to carry out at regular time intervals a sample of all the treated plants in order to obtain the optimum results. to control the water content and / or the content of at least one of the essential constituents of the treatment solution in the tissues of the sampled plant.

This results after draining and drying roses, roses whose analysis of the petals gives the following results

<tb><SEP> CONSTITUTING <SEP> BATCH <SEP> N <SEP> 1 <SEP> BATCH <SEP> N <SEP> 2
<tb>#<SEP><SEP> PEG <SEP> 700 <SEP> 350
<tb><SEP> TPG <SEP> 195 <SEP> 365
<tb> Ir <SEP> Cellulose <SEP> 4% <SEP> 7% <SEP>
<tb>#<SEP><SEP> Water <SEP><SEP> 46 <SEP>% <SEP> 27 <SEP>% <SEP>
<Tb>
Example 2: white roses
After dehydration, two other batches of flowers undergo a bleaching bath in a solvent medium and in the presence of bubbles of compressed air forming a bubble, which consists of the following elements
- metoxypropanol
- sodium chlorite: 8 gr./litre
- formic acid (to adjust the pH to 4.5)
- wetting deaerating: 1 ml / liter.

After this bleaching, the flowers are infiltrated by soaking in a solution comprising in percentage by weight
- metoxy-popanol: 45%
- tripropylene glycol: 45%
- polyethylene glycol 1000 15%
Thus, after draining and drying roses, products whose analysis gives the following results

<tb><SEP> CONSTITUENTS <SEP> BATCH <SEP> N <SEP> 3 <SEP> BATCH <SEP> N <SEP> 4
<tb>#<SEP><SEP> PEG <SEP> 400 <SEP> 280
<tb><SEP> TPG <SEP> 510 <SEP> 650
<tb>#<SEP><SEP> Cellulose <SEP> 3 <SEP>% <SEP> 5 <SEP>% <SEP>
<tb>#<SEP><SEP> Water <SEP> 66 <SEP><SEP>%<SEP> 53 <SEP>% <SEP>
<Tb>
Measurement of the moisture content of the samples can be carried out by passing to the oven, after which the dry matter is analyzed; in the tables above, the mass content of PEG and
TPG is expressed in milligrams per gram of dry matter; the cellulose content is in percentage of the mass of dry matter; the water content is as a percentage of the total mass of the preserved rose.

Claims (11)

 1. Vegetable cut and preserved by a solution based on polyols, characterized in that its water content is at least equal to 10% of the mass of said plant.  2. Plant according to claim 1, the water content of which is at least 20% of the mass of said plant.  3. Plant according to any one of claims 1 or 2, which comprises one or more polyvalent alcohol (s) whose proportion by mass as a percentage of the mass of dry matter contained in said plant is at least 10. %, preferably from 20% to 95%.  4. Plant according to any one of claims 1 to 3 comprising tripropylene glycol, the percentage by mass in the mass of dry matter of the cut plant preserved is greater than 10%.  The plant according to claim 4, wherein said percentage of TPG is between 20% and 70% of the mass of dry matter.  6. Plant according to any one of claims 1 to 5, which comprises polyethylene glycol whose percentage by weight relative to the mass of dry matter preserved is greater than 10%.  The plant of claim 6, wherein said percentage of PEG is between 15% and 75%.  8. Plant according to any one of claims 1 to 7, wherein the percentage by weight of cellulose is less than or equal to 7% of the mass of dry matter of the cut plant preserved.  A plant according to any one of claims 1 to 8 which is white in color and which preferably comprises a small amount of sodium chlorite and / or formic acid and / or one or more cationic dyes ( s).  10. A process for preserving plants by the use of polyvalent alcohol, characterized in that partial dehydration of the plant is carried out, in particular to produce plants and particularly flowers of a pure and natural white keeping its fresh appearance long-term.  11. Floral composition which comprises a plurality of cut flowers preserved according to any one of claims 1 to 9, which flowers are secured together and / or a support.