|Title of Invention||
A METHOD FOR MAINTAINING FRESHNESS AND EXTENSION OF SHELF LIFE OF CUT-FLOWERS
|Abstract||A method for maintaining freshness and the extension of shelf life of cut-flowers by use of Equilibrium Modified Atmosphere Packaging (MAP). More particularly the method involves a combination of Equilibrium Modified Atmosphere Packaging(MAP) and exposure to gammas radiation and cold temperature of 5C to 15C for mainataining freshness and extension of shelf life of cut-flowers. The invention further relates to storing cut-flowers afresh without the stem being dipped into solvents/preservatives during storage.|
|Full Text||FORM -2
THE PATENTS ACT, 1970
(39 OF 1970)
(See Section 10;rule 13)
(1) TITLE OF INVENTION
A METHOD FOR MAINTAINING FRESHNESS AND EXTENSION OF SHELF LIFE OF CUT-FLOWERS
(2) (a) Secretary, Department of Atomic Energy, Government of India, (b) Anushakti Bhavan, Chatrapati Shivaji Maharaj Marg, Mumbai- 400 001, Maharashtra, India, (c) an Indian company
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.
Field of invention
The present invention relates to a method for maintaining freshness and the extension of shelf life of cut-flowers by use of Equilibrium Modified Atmosphere Packaging (MAP). More particularly it relates to a method which involves a combination of Equilibrium Modified Atmosphere Packaging (MAP) and exposure to gamma radiation and cold temperature for maintaining freshness and extension of shelf life of cut-flowers. The invention further relates to storing cut-flowers afresh without the stem being dipped into solvents/ preservatives during storage.
Background of the invention
It is well known that after harvest cut-flowers can be kept fresh by refrigeration or by keeping the stem in water or preservation solution. The cut-flowers are preserved in various forms of sugar (Glucose, Fructose and Ribose) solutions and other preservation solutions to extend shelf life. Preservation solution containing sucrose is also used to dip the stems of cut-flowers exposed to radiation to overcome any deteriorating effects of irradiation. Various types of irradiation methods have been used to disinfect stems, leaves and cut-flowers.
U.S.6451363 discloses a method of shelf life extension by modifying the atmosphere of the cut-flowers m the packaging poucF^rTsma1t~aTnounts of Nitric oxide gas.
U.S.6440900 discloses a method for extending the life of roses. The solution for dipping the stem is a tablet consisting of chlorine dioxide, one or more sugars and an effervescent agent to be dissolved in water solution to extend shelf life of roses
U.S.6083553 discloses a method for preserving cut-flowers. In this method the tissue cell sap of the stem of the cut-flower is dehydrated with the help of a solvent namely polyethyleneglycol. The specific gravity of the solvent is lower than that of water.
U.S.5,564,225 teaches method and apparatus for packaging and preservation of flowers and other botanicals. The stem of each cut-flower is kept in a sealed vial. The vials contain a flower preservation solution which is composed of an absorbent material, a dehydration material and silverthiosulphate. The cut-flower with the vial is kept in a tray. The tray is passed through an ozone hood to sterilize the cut-flower
against microorganisms. The tray is covered by a sheet of plastic. The air between the tray and plastic sheet is removed by vacuum and replaced by N2, helium and argon gas. Thus creating a modified atmosphere packaging.
U.S.432237 teaches preservation of cut-flower and other parts of plants are kept in water which contains a preservative triflioromethyl-N-(dichloroflouromethyl-Sulphenyl-aminobenzoic acid). The solution also contains a carbohydrate and a salt of magnesium, boron or aluminum.
U.S.5, 044,118 discloses method and apparatus for cut-flower storage and display. The cut^flowerstorage and display assembly is a container in which the flowers are stored and also used as a display assembly. The assembly comprises a liquid circulation and disinfection system through the liquid reservoir of each container in a vertical column, a disinfection system in the form of a UV disinfection unit to control microbes in the circulating liquid. An air cooling apparatus may also be provided to enhance freshness of cut-flowers.
WO0060937 teaches a method for the preservation of orchids. Stalks of the orchids are dehydrated of its cell sap with tertiary butyl alcohol leading to brittle condition of flower petals. The cut-flower is rehydrated by a solution consisting of glycerol, citric acid and poly vinyl alcohol. The stalks are then sealed at the bottom tip with powdered rehydrated plaster of paris. The stalk of the orchid is subjected to a heat treatment under pressure and application of transparent wax and lacquer on cooling. These preserved orchids are used as wall hanging.
FR.2643049 discloses a package for displaying the cut-flower vertically in a transparent envelope and preserving the cut-flower by inserting the stalks in the water reserve. A ring attachment at the top of the water reserve leads to formation of a volume of air trapped inside the package which favors the preservation of the flowers and prevents any movement of the said package with respect to the flower.
EP0490744 teaches a process for preserving fresh cut-flowers or plant cuttings which comprises placing fresh cut-flowers or plant cuttings in a pouch made of a barrier material and flushing the pouch with a gas mixture comprising 50% to 80% N20,
having a minimum of 20% 02 with the remainder being N2 at a temperature in the range of 0°C to 8°C. Further a package containing an amount of C02 absorbing product such as, lime is placed for absorbing at least a portion of C02 produced by said cut-flowers or plant cutting.
JP8157303 discloses addition of an anti-microbial agent was added to preservation solution to protect the cut-flowers from infection by saprophytes and also to prolong the life of the cut-flowers.
JP200191402 teaches preservation treatment of a cut-flower performed by laying a suitable amount of molecular sieve on the bottom of a container, fixing a cut-flower in a vessel filled with acetone having a specific gravity smaller than water to dehydrate tissue water in the cut-flower. Then polyethyleneglycol is penetrated to substitute to tissue water to preserve the cut flower.
JP10338601 teaches freshness preservation for cut-flower and preparation of freshness preservation solution for cut-flower. The preservative comprises a mixture of a copper compound (e.g. silver nitrate) and a polymer (e.g. poly vinyl pyrrolidone) containing a (non) substituted structure group of the formula Z is a five membered hetero ring with nitrogen and carbon of carbonyl. A reaction product of the compound and the polymer is formatted optionally with a saccharide, an antimicrobial agent, a surfactant, a stabilizer to give the preservative a pH3-l 1. According to JP 10001401 cut flowers are preserved by dipping the stem in water mixed with a nutritive agent. The freshness preserving material containing fibrous activated carbon as a main component. The freshness preserving material contains an inorganic silver compound. By using this composition, an aging hormone such as ethylene can efficiently be absorbed and removed and also bent neck phenomenon can also be suppressed by addition of silver.
Kikuchi.O.K (2000) Orchid Flowers Tolerance to Gamma Radiation. Radiat Phys. Chem.57, 555-557 teaches that cut-flower is a fresh product that can be infested with many plagues. Radiation is one of the physical methods to disinfect fresh products. For a given specific pest if the generic dose is 300 Gray (Gy). Out of 5 varieties of orchids studied except; cattleya and dendrobium; most of them were intolerant to
doses above 300 Gray (Gy.)
Kikuchi et.al (1998) teaches sucrose delays membrane deterioration of chrysanthemum flowers treated with gamma rays. Radiat. Phys. Chem., 52, 649-654. Teaches sucrose delays membrane deterioration of chrysanthemum treated with gamma rays. Fluidity of the flowers membrane of cut chrysanthemum decreased soon after gamma-irradiation at 750 Gray (Gy.) and continued to decrease during storage following irradiation. Holding chrysanthemum cut flowers in 2% sucrose suppressed the decrease. The results suggest reduced radiation induced physiological deterioration of chrysanthemum flower membranes.
Hayashi etal (1998) Electron beam disinfestations of cut-flowers and their radiation tolerance Radiat. Phys. Chem. Vol.5, 175-179 discloses the effect of electron beams on spider mite and flour bettle were slightly smaller than those of gamma-rays at equal doses. Chrysanthemum, rose, Lilly, calla, antherium, sweet pea and iris were intolerant to a dose of 400 Gray (Gy). The detrimental effects of irradiation were delay inhibition of flowering, withering and browning of flowers and leaves and bending of petioles. Commercial floral preservation solutions consisting of 2% of sucrose, glucose, fructose and maltose delayed bloom wilting and foliage yellowing of cut chrysanthemum [dose 750 Gray (Gy)]. Sugar solutions prevented foliage yellowing of roses brought about by irradiation but not flower wilting.
Thus the above methods teach that the cut-flowers can be preserved fresh and their shelf life extended by dipping the stem of the cut-flowers in preservation solution. Preservation solutions are composed of various organic and inorganic solvents, surfactants, acidifiers, desiccators, effervescent agents, antimicrobial agents, UV disinfectants, polyethyleneglycol (rehydrating agent), absorbents and substances that maintain definite pH. But the main components of such solutions which preserve cut-flowers are different kinds of sugars (sucrose, fructose, ribose, glucose, mannose, sorbets). The preservation solution can preserve irradiated and non-irradiated cut-flowers. In irradiated cut-flowers only leaves are prevented from yellowing by preservation solution. Non-irradiated cut-flowers have to be placed in containers or apparatus containing preservation solution.
The draw back in using preservation solutions is disinfection of the sugar rich solution is a must, otherwise stem of the cut-flower will be infested by microbes and fungi. The preservation solution in containers has to be replenished during transportation. This will drastically enhance the cost of the cut-flowers. Also this method does not report disinfection of cut-flowers stem and other plant parts against insects. Transportation of cut flowers in preservation solution is very cumbersome. Moreover customers will have to buy preservation fluid to maintain vase life of cut-flowers.
Mostly cut-flowers are kept dipping stem in water or some form of preservation solution. These methods of preservation of cut-flowers are expensive, cumbersome and not at all easy to transport. The shelf life extension of refrigerated cut-flowers is less than one week. Even under refrigerated condition the stems have to be kept dipped in water.
In some methods Modified Atmosphere Packaging (MAP) has to be included along with preservation solution to extend shelf life of cut-flowers. In such cases either a single gas or combination of gases is used. (N2O, O2, N2, Helium, Argon). The use of such gases makes such methods expensive,
Moreover, the Modified Atmosphere Packaging (MAP) described in the prior art are externally created and maintained around 0°C.
Studies on the extension of shelf life of cut-flowers after gamma or other types of irradiation for disinfection of various mites and insects show severe deterioration of cut-flowers and foliage. Some of these deterioration are delayed inhibition of flowering, withering and browning of flowers, yellowing of leaves, bending of petiole and dropping of petals. The tolerant dose for roses was below 400 Gray (Gy). This detrimental effect of radiation on cut-flower was overcome only in some variety of cut-flowers. In cases where radiation is used in combination with use of preservative solution the methods become cumbersome.
Thus there exists a need to preserve flowers by a simple method which do not use preservative solutions or expensive gases and at the same time is free from the detrimental effects of irradiation.
Objects of Invention
Thus the main object of the present invention is to provide a method for maintaining freshness and increasing the shelf life of cut-flowers.
Another object of the present invention is to provide a method for storing cut-flowers afresh without the stems being dipped into solvents/preservatives during storage.
A further object of the present invention is to provide a method for the increasing of shelf-life of cut-flowers by exposure gamma radiation without any detrimental effects to the freshness and shelf life.
Another object of the present invention is to provide a method for increasing vase life of the flowers whose freshness and shelf life has been thus increased.
Summary of Invention
Thus according to the main aspect of the present invention there is provided a method for maintaining freshness and extension of shelf life of cut-flowers comprising : Providing equilibrium Modified Atmosphere Packaging (MAP) for cut-flowers; at a temperature of 5 to 15°C.
According to a further aspect of the present invention there is provided a method for maintaining freshness and extension of shelf life of cut-flowers comprising:
i). exposing said MAP cut-flowers to gamma radiation of predetermined dose;
ii). Storing said irradiated cut-flowers at a temperature of between 5 to 15°C
Detailed Description of Invention
The method of present invention provides for maintaining freshness of cut-flowers and extends their shelf life without the use of preservatives.
The flowers are cut to a size such that the stem length is of 23 to 33 cm, preferably 26 to 30 cm. Such flowers are packed in Low Density Poly Ethylene (L.D.P.E) bags of particular size with length varying from 40 to 50 cm, preferably 43 to 47 cm and width of 33 to 44 cm, preferably 36 to 40 cm. The thickness of such bags varied from 22u to 38u preferably 25u to 35u. Numbers of flowers packed in such packages vary from 2 to 8 preferably 3 to 7.
The equilibrium Modified Atmosphere Packaging (MAP) for cut -flowers is provided by packing the cut-flowers in said low Density Poly Ethylene (L.D.P.E) bags which are sealed and maintained at temperature of 7 to 13°C preferably at 10°C for 1 to 4 hrs preferably 2 to 3 hrs. Such equilibrium Modified Atmosphere Packaging (MAP) provides for the maintenance of natural freshness in cut-flowers. The present method of equilibrium Modified Atmosphere Packaging (MAP) is an endogenous one where gases produced from the cut-flower I foliage respiration along with the air present in the package which when equilibrated is used as the passive MAP. This alone provides for freshness of cut-flowers for 5 to 7 days.
A combination of equilibrium MAP with any ionizing radiation like gamma rays, X-rays or electron beam further helps in extending the shelf life upto about 14 days. In the absence of this MAP the ionizing radiation has shown deleterious effects on cut-flowers.
The preset invention indicates gamma irradiation as a tool to preserve the cut-flowers in a state of natural freshness. Gamma irradiation also delayed the blooming of the cut-flowers in bud stage or half open bud stage. This deliberate delay in blooming of the rose buds increases the shelf life of the cut-flowers. There is a shelf life extension more than 14 days.
In addition gamma irradiation acts as a disinfectant for stem, leaves and cut-flowers it also prevents formation of mold in cut-flowers i.e., Botrytis blight infections in roses are controlled.
Gamma irradiation was carried out on cut-flowers under equilibrium MAP to help extend the shelf life of roses. To slow down the blooming of the rose buds into half
open or fully open flowers. Gamma radiation using cobalt 60 source and a dose range of 100 to 1000 Gy, preferably 400 to 800 Gy are applied to the flower buds. The dose range for chrysanthemum is 200 to 400Gy, that for gerbera is from 200 to 400Gy while that for carnation is from 200 to 800Gy. The dose rate for the gamma radiation to which the flowers are exposed varies from 5.5 to 26Gy : preferably 5 to 25 Gy per minute. The ratio of maximum to minimum dose received varies from 1.25 to 3.5 preferably 1 to 3. Any other source of radiation like Caesium 137 (Csl37), X-ray or Electron beam can be used provided it"s energy is close to 0.31 to 1.33 MeV. Also it is important to maintain an equilibrium MAP before exposure to radiation.
The MAP treated and irradiated cut-flowers are stored in cold temperature in the range of 7 to 13°C preferably at 10°C to maintain the freshness as well as extend the shelf life of cut-flowers.
The flowers which may be preserved by the present process includes rose, gerbera, carnation, chrysanthemum and the like.
The method of the present invention is now described by way of non-limiting illustrative examples with accompanying figures and tables. Cut-flowers namely rose buds of red, pink, orange colour are used for present examples:
5 cut rose buds with stem and leaves are packed in each pouch.
The rose buds are divided into two groups. One group is exposed to equilibrium MAP
according to present invention as provided below.
Equilibrium Modified Atmosphere Packaging (MAP) of the cut-flowers (roses) is done in Low Density Poly Ethylene (L.D.P.E) pouches and sealed cut-flowers. The stem length of cut-flower is 28cm. The sizes of the pouch used have a length of 45cm and width of 38cm and the thickness of the pouch is 25 u. The sealed pouch is kept at a temperature of 10°C to generate and maintain an equilibrium MAP within 2 to 3 hours, to keep the cut-flowers in a state of natural freshness.
The other group is exposed to MAP which is externally created. The flowers are maintained at 0 to 4°C under such MAP. 5 stems of cut-flowers are placed in L.D.P.E pouches from which air was completely flushed out and N2 gas filled into the pouch and sealed. The sealed pouches were stored at 0 to 4°C. There was an extension of shelf life of 5 to 7 days in red and orange roses and 4 to 6 days in pink roses (Tablel).
Tablel:Extension of shelf-life of cut-flowers with different MAP and temperature
COLOUR OF ROSES ROSES WITH MAP + 0 TO 4°C IN DAYS ROSES WITH MAP +10°C IN DAYS
5 TO 7 DAYS 6.66±0.58 RANGE 6.08-7.29
4 TO 6 DAYS 4.33±0.58 RANGE
5 TO 7 DAYS 5.33 ±0.58 RANGE 4.75-5.91
Footnote: Roses with MAP + 0 to 4°C represent roses present in a N2 gas atmosphere stored at 0 to 4°C. Roses with MAP + 10°C represent roses stored in an endogenous equilibrium MAP at 10°C.
The result indicates that the present process of exposure to equilibrium MAP provides similarity in extension of shelf life as compared to those exposed to externally created MAP at 0 to 4 °C. In other words exposure to equilibriated MAP without any external gases or other manipulations alone provided preservation of cut-flowers for a period
comparable to ideal condition for preservation. Thus even in absence of the ideal condition of freezing temperature which is expensive as well as difficult to maintain specially during transport and display the cut flowers exposed to equilibrium MAP at 10 °C according to the process of the present invention have a comparable shelf life. Further more the freshness of the cut-flowers in MAP + 0 to 4°C tend to get reduced during this period. The red rose petals suffers chill injury causing browning of petals. Also the calyx of pink and orange rose buds were fully opened. On the other hand in the cut flowers exposed to MAP + 10°C according to the present invention the calyx is attached to the rose buds. There is also no browning of petals due to chill injury. Thus the cut flowers exposed to the process of present invention were more fresh during the shelf life compared to those of ideal/ prior art methods. Thus the process of present invention provides for better freshness of flowers even at adverse condition with comparable shelf life to that of ideal/known conditions.
5 cut rose buds with stem and leaves are packed in each pouch. They are exposed to equilibrium MAP according to the present invention as in Example 1 and further to the following process steps:
Gamma radiation of roses: Gamma irradiation was provided to help extend the shelf life of rose buds to slow down the blooming of the buds into half open buds or fully open flowers. Different doses of gamma radiation are given to the rose buds. The doses are 100 Gy, 400 Gy, 800 Gy, lOOOGy. Gamma radiation is provided using a cobalt 60 Food Package Irradiator (A.E.C.L, Canada) at a dose rate of 5.78 Gy per min. The ratio of maximum to minimum dose received is 1.3.
Cold temperature storage at 10°C. Storage of MAP cut-flowers roses at 10°C and cut-flowers roses given a combination treatment of MAP at 10°C and gamma irradiation and stored at final 10°C to maintain the freshness as well as extend the shelf life of cut-flowers.
Description of the figures
Figure 1: Graph showing percentage of pink rose buds preserved in MAP (passive)
given different doses of gamma radiation.
Figure 2: Graph showing percentage of orange rose buds preserved in MAP (passive) given different doses of gamma radiation.
Figure 3: Graph showing percentage of red rose buds preserved in MAP (passive) given different doses of gamma radiation.
Gamma radiation using cobalt 60 source and a dose range of 100 to lOOOGy are applied to the rose buds. During storage at 10°C there was no drooping or wilting of the rose buds or the yellowing of the leaves due to gamma irradiation. No fluid support was given to the cut-flowers. It was found that roses are not adversely affected by doses ranging from lOOGy to lOOOGy (Figure 1, 2 and 3). This is because equilibrium MAP maintained before radiation. There is significantly less Botrytis blight in red and orange roses. In pink roses Botrytis blight is completely eliminated at higher doses but it is observed at and below 400 Gy.
Pink rose buds give best results on exposure to Gamma radiation of 800 Gy while orange raised buds and red rode buds gives best results between 100 to 1000 Gy.
Thus MAP, using LDPE packaging, gamma irradiation and cold temperature give a hygienized floriculture product which can be transported easily from farm to consumer by the cold chain process (10°C). The packaging also facilitates branding of cut-flowers.
Hence the method provides to extend the shelf life of cut-flowers (roses) in its natural freshness by first generating an equilibrium atmosphere for the roses to be preserved as if in a state of hibernation.
The rose buds are divided into two groups. One group is maintained as in example 1 with exposure to MAP and Cold temperature (10°C) for 2 hours, second group with exposure to MAP and Cold temperature (10°C) for 2 hours and Gamma radiation. Third group with exposure to Gamma radiation and final cold (10°C) storage and fourth group with exposure to MAP and cold temperature (10°C) for 2 hours. Gamma
radiation and final cold (10°C) storage. The results indicating the shelf life are summarized in Table 2.
Table 2: Extension of shelf life of cut-flowers (roses) in days
COLOUR OF ROSES ROSES WITH
MAP + 10°CIN DAYS ROSES WITH MAP +
800 Gy IN DAYS *
800 Gy AND FINAL 10°CIN DAYS ROSES
MAP + 800
RED 6.66 ±0.58 RANGE
6.08-7.29 3.5 ±0.58 RANGE
2.92-4.08 1.25 ±0.5 RANGE
0.75-1.75 14 ± 1.73 RANGE
PINK 4.33 ±0.58
RANGE 3.75-4.91 2.25 ± 0.5 RANGE
1.75-2.75 1.25 ±0.5
0.75-1.75 7.33 ±0.58
ORANGE 5.33 ±0.58 RANGE
4.75-5.91 3 ± 0.82
2.18-3.82 1.25 ±0.5
0.75-1.75 8.66±1.15 RANGE
Footnote: Roses with MAP+10°C represent roses preserved in its natural freshness without fluid support in an equilibrium MAP. Roses with MAP + 10°C and 800 Gy represent roses preserved in its natural freshness without fluid support in an equilibrium MAP combined with gamma radiation and ambient temperature (27°C). Roses with 800 Gy and final 10°C represent roses without MAP and without 10°C and with gamma radiation and final 10°C storage temperature. Roses with MAP +10°C + 800 Gy+10°C represent roses preserved in its natural freshness without fluid support in an equilibrium MAP at 10°C and gamma radiation (800 Gy) and Final storage at cold temperature (10°C). Mean values are followed by ± SD. p 13
It is found that Gamma radiation of 800 Gy and the final storage of flowers at 10°C along with the equilibrium MAP at 10°C help extend shelf life of roses and maintain their freshness for the longest period of time. Thus presence of all three steps of the present method extends the shelf life to the maximum as well maintain the freshness of flowers.
Rose buds are taken and divided into three groups. They are exposed to conditions as in example 2 except that the dose of Gamma irradiation is varied. Thus one group was exposed to dose of 400Gy, second group to a dose of 800Gy and third group to a dose of 2000Gy. The results are given in Table 3.
Table3: Roses in equilibrium MAP (10°C) was given different doses of Gamma
Colour of roses Dose in Gy
Number Of Days
400 800 2000
RED 13.5±1.29 14=1=1.73 8.25±0.96
PINK 7.5±0.58 7.33±0.58 5.75±0.96
ORANGE 8.33±0.58 8.66=1=1.15 6.5±0.58
Footnote: Roses of different colours were sealed in L.D.P.E pouches and kept at 10°C for 1 to 2 hours to generate equilibrium MAP after 2 hours the cut-flowers were exposed to 400Gy, 800Gy and 2000Gy of gamma radiation and stored at 10°C to study shelf life extension.
Thus it is seen that roses exposed to a dose of 400Gy and 800Gy give better result than those exposed to 2000Gy. Thus a dose of Gamma irradiation beyond that of the present invention does not give the desired results.
Rose buds are taken and exposed to MAP and cold temperature (10°C) as in Example2. They are maintained as such for 6 days. After 6 days they are divided into two groups. Each group is removed from the equilibrium MAP pouches and the stem dipped in tap water. One such group is maintained at 27°C and the other at cold temperature of 10°C. The results indicating their vase life are summarized in Table 4.
Table 4: Vase life of non-irradiated roses after 6 days in equilibrium MAP
Colour of roses Vase life of non-irradiated roses in days
Red 3.00±1 9.00±1
Pink 2.66±0.58 8.33±0.58
Orange 2.66±0.58 7.67±0.58
Footnote: Roses were kept for 6 days; in equilibrium MAP at 10°C; were removed from the pouches and the stems were dipped in tap water to study the vase life at two different temperatures i.e., 27 °C and 10°C.
It was observed that the vase life of cut-flowers exposed to cold temperature after the removal from the equilibrium pouches is higher than those exposed to higher temperature. This indicates that the method of invention with equilibrium MAP provides better vase life at 10°C.
Rose buds are taken and are exposed to MAP and cold temperature 10°C and gamma radiation (400Gy, 800Gy, lOOOGy) and final temperature 10°C as in Examplel. They are maintained as such for 6 days. At the end of 6 days, they are divided into two subgroups. Each subgroup is removed from the equilibrium MAP pouches and the stem dipped in tap water. One such subgroup of irradiated roses is maintained at 27
°C and the other subgroup of irradiated roses is kept at cold temperature of 10°C. The results indicating their vase life are summarized in Table 5.
Table 5: Vase life of irradiated roses after 6 days in equilibrium MAP
Dose (Gy) Vase life of irradiated roses (red) in days
400 8.33±1.53 12.33±1.58
800 8±1.0 11.33±0.58
1000 7.33±0.58 10.67±1.5
Footnote: Roses were kept for 6 days in equilibrium MAP and 10°C and gamma irradiation and final 10°C were removed from the pouches and the stems dipped in tap water to study the vase life of the irradiated roses at two different temperatures 27°C and 10°C.
The vase life of irradiated cut-flowers exposed to cold temperature (10°C) after removal from equilibrium pouches is higher than those exposed to higher temperature (27°C). This indicates that with fluid supplement the vase life of those equilibrium MAP and gamma radiation and final 10 °C exposed flowers which are later exposed to cold temperature is better. This indicates that the method of invention with equilibrium MAP, gamma irradiation and final exposure to 10°C provides better vase lifeatlOX.
Thus from the results obtained irradiated cut-flowers show a better vase life than non-irradiated at 27°C. The rose buds bloom into half open or fully open flowers (Table 4 and 5).Thus confirming the turgidity of the stem at 27°C. Comparing the data in tables 4 and 5 it is seen that at 27 °C the vase life of the flowers are improved using irradiation .
The study of vase life of cut-flowers both MAP + 10°C and MAP + Irrad. + 10°C is to monitor the turgidity of the stem at 10°C i.e. the temperature of cut-flower storage. The stem could imbibe water after 6 days in MAP showing natural freshness of the cut-flowers at 10°C also both irradiated and non-irradiated cut flowers showed better extension vase life at 10°C (Table 4 and 5).
Thus the significance of vase life at 27°C and 10°C is to show that the stem of the cut-flower could imbibe water after a period of time 5 to 12 days during which time the stem is deprived of water as required by the said process. Thus there is a significant extension in vase life and freshness of irradiated cut-flowers at two different temperatures.
1. A method for maintaining freshness and extension of shelf life of cut-flowers
i) providing equilibrium Modified Atmosphere Packaging (MAP) for cut-flowers
at a temperature of 5°C to 15°C;
ii) exposing said MAP flowers to gamma radiation of 100 Gray (Gy). to 1000
Gray dose., iii) storing said irradiated under cold temperature of 5°C to 15°C
2. A method as claimed in claim 1 wherein the cut-flowers are provided with equilibrium Modified Atmosphere Packaging (MAP) by packing them in selective Low Density Poly Ethylene (L.D.P.E) bags of particular size, sealing the bags and exposing them to low temperature.
3. A method as claimed in any preceding claim wherein the temperature at which the cut-flowers in said Low Density Poly Ethylene (L.D.P.E) bags are maintained for equilibrium Modified Atmosphere Packaging (MAP) is from 7 to 13°C; preferably at 10°C.
4. A method as claimed in any preceding claim wherein the time for which the cut-flowers in said Low Density Poly Ethylene (L.D.P.E) bags are maintained for equilibrium Modified Atmosphere Packaging (MAP) is for 1 to 4 hrs, preferably 2 to 3 hrs.
5. A method as claimed in any preceding claim wherein the dose of Gamma radiation to which the cut-flowers are exposed to 200 Gray (Gy). to 800 Gray (Gy.).
6. A method as claimed in any preceding claim wherein the rate for the gamma radiation to which the cut-flowers are exposed varies from 5.5 Gray (Gy). to,Gray (Gy.) preferably. Gray (Gy.) to 25 Gray (Gy.) per minute.
7. A method as claimed in any preceding claim wherein the ratio of maximum to minimum dose of gamma radiation to which the cut-flowers are exposed varies from 1.25 to 3.35 preferably 1 to 3.
8. A method as claimed in any preceding claim wherein storing of the cut-flowers after MAP treatment and gamma irradiation is in the cold temperature in the range of 7 to 13 °C; preferably at 10°C.
9. A method as claimed in claim 2 wherein the length of said selective Low Density Poly Ethylene (L.D.P.E) bag is from 40cm to 50 cm, preferably 43cm to 47 cm.
10. A method as claimed in claim 2 wherein the width of said selective Low Density Poly Ethylene (L.D.P.E) bag is from 35cm to 44cm, preferably 36cm to 40cm.
11. A method as claimed in claim 2 wherein the thickness of said selective Low Density Poly Ethylene (L.D.P.E) bag is from 22^ to 38u, preferably 25u. to 35u.
12. A method as claimed in any preceding claim wherein the flowers used are cut at particular size that the stem length is of 23 to 33cm, preferably 26 to 30cm.
13. A method as claimed in any preceding claim wherein the numbers of flowers to be packed in such package vary from 3 to 8; preferably 3 to 7.
14. A method as claimed in any preceding claim wherein the cut-flowers used are buds selected from roses, carnationy chrysanthemumuaad the like.
15. A method as claimed in claim lA wherein the cut-flowers used are rose buds.
Dated this 9th day of March 2004
|Indian Patent Application Number||311/MUM/2004|
|PG Journal Number||45/2007|
|Date of Filing||12-Mar-2004|
|Name of Patentee||SECRETARY, DEPARTMENT OF ATOMIC ENERGY, GOVERNMENT OF INDIA|
|Applicant Address||Anushakti Bhavan, Chatrapati Shivaji Maharaj Marg Mumbai 400 001|
|PCT International Classification Number||B65B025/02|
|PCT International Application Number||N/A|
|PCT International Filing date|