AU686584B2

AU686584B2 - A package and a method for packaging perishables

Info

Publication number: AU686584B2
Application number: AU56496/94A
Authority: AU
Inventors: Laurence D. Bell
Original assignee: Transfresh Corp
Current assignee: Fresh Express Inc
Priority date: 1987-04-28
Filing date: 1994-03-01
Publication date: 1998-02-12
Anticipated expiration: 2008-04-20
Also published as: EP0289291B1; EP0289291A3; AU1479188A; AU7835791A; ES2043815T3; AU5649694A; AU613909B2; CA1312002C; DE3884851T2; EP0289291A2; DE3884851D1; JPS63281973A

Description

2M

AUSTRALIA

PATENTS ACT 1990 DWISIONAL APPLICATION NAME OF APPLICANT(S)- TRANSFRESH CORPORATION ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street Melbourne, 3000.

INVENTION ITLE: "A PACKAGE AND A METHOD FOR PACKAGING PERISHABLES' The following statement is a full description of this invention, including the best method of performing it known to us: 00..

00 00 0 00 0 .00000 940301,q:\oper~pbh,78357-9.O603 ',2-11-97,,12:47; PATENT OFFICE CBR I 5/ 7 -12tm0

-IA-

This invention relates to packaging for cut or uncut respiring perishables such as cauliflower, lettuce and brc- :oli.

According to the present invention there is provided a sealed package for at least one respiring perishable' comprises said at least one respiring perishable in packaging material that transmits oxygen and carbon dioxide at known or ascertainable rates, said package having an optimum atmosphere quotient value (AQ) for said at least one respiring perishable with a known or ascertainable respiration rate where atmosphere quotient is equal to permeant factor (G) divided by said respiration rate and where permeant factor is equal to the area (A) of said sealed package multiplied by the permeability of said package to oxygen or carbon dioxide and divided by the weight of said at least one perishable in said sealed package, said optimum atmosphere quotient value being at least about 10% greater than the minimum atmosphere quotient value in the range of atmosphere quotient values characteristic of said respiring perishable at said respiration rate sealed in said packaging material, said range of atmosphere quotient values characteristic of said respiring perishable comprising a range of empirically-determined test values representing marketability of said at least one respiring perishable, said range being derived from testing at least one series of sealed test packages for said marketability, each of said sealed test packages in said series being made of said packaging material.

There is further provided a sealed plastic film package for at least one respiring perishable comprises said at least one respiring perishable in plastic film packaging material that transmits oxygen and carbon dioxide at known or ascertainable rates, said sealed plastic film package having an optimum atmosphere quotient value (AQ) for said at least one respiring perishable with a known or ascertainable respiration rate where atmosphere quotient is equal to permeant factor divided by said respiration rate and where permeant factor is equal to the area of said sealed plastic film package multiplied by the permeability of said sealed plastic film package to oxygen or carbon dioxide and divided by the weight of said at least one perishable in said sealed plastic film package, said optimum atmosphere quotient value being at least about 10% greater than the minimum atmosphere s RAk/ ASsN 1~ 9 ISllblP~SSIII g~S- iqlP~ 4n d4

I

2-11-97,12147 PATENT OFFICE CBR 7 lB quotient value in the range of atmosphere quotient values characteristic of said respiring perishable at said respiration rate seaed in said plastic film packaging material, said range of atmosphere quotient values characteristic of said respiring perishable comprising a range of empirically-determined test values representing marketability of said at least one respiring perishable, said range being derived from testing at least one series of sealed test packages for said marketability, each of said sealed test packages in said series being made of said plastic film packaging material.

The methods of this invention comprise the following steps: determining the resFiration rate of a respiring perishable such as cauliflower, broccoli or lettuce; preparing a plurality of packages containing the respiring perishable with each package having a different pi-rmeant factor where the permanent factor is equal tot the area of packaging material, a film, required to enclose a given weight of the respiring perishable in a modified or uinmodified atmosphere, multiplied by the permeability (P) of the packaging material to one of the lases of respiration, such as oxygen or carbon dioxide; and divided ty the weight of the perishable to be enclosed in ,he packaging material; for each of the packages prepared in step above, determining a value called atmosphere quotient (AQI in accordance with the following formula; Atmosphere quotient (AQ) equals permewnt factor from utep 2) above, divided by the respiration rate of the perishable from step above; 1 subjecting each of the packages containing respiring perishable to known temperatures and pressures over a known, preferably predetermined period of time, and correlating the subjective and objective indicia of quality, appearance and marketability of the respiring perishable fr'm each of the packages to the atmosphere quotient values determined in step above; and varying one or more of the values of the components and/or of permeant factor to achieve and maintain the optimum value or range of values for atmosphere quotient determined in step above.

Once atmosphere quotient has been determined by these methods, the values of the components and/or (W) that correspond to the optimum atmosphere quotient value 15 or values can be further varied as desired.

S* a.

In preferred embodiments, the methods of this a invention may also include the step of determining the oxygen and carbon dioxide quotients independent of one another so that the ratio of carbon dioxide-to-oxygen permeabilities for a given package of a perishable can be optimized. The ratio of carbon dioxide-to-oxygen permeabilities for a given package of a given perishable directly influences the equilibrium ratio of carbon dioxide-to-oxygen concentrations inside the package.

At equilibrium, the amount of oxygen permeating into the package is substantially equal to the oxygen consumed by the perishable inside the package, and the amount of 1 carbon dioxide permeating out of the package is substantially equal to the carbon dicxide produced inside the package. Thus, once an optimum carbon dioxide or oxygen quotient is determined as in step above with a packaging material of a given carbon dioxide-co-oxygen permeability ratio, then changing to a material of different carbon dioxid,-to-oxyge.. permeability ratio may require a new atmosphere quotient determination.

An atmosphere quotient value determined in accordance with these methods can differ, for a given respiring perishable in a given packaging material, with the initial void volume per unit weight of perishable within the package, the equilibrium void volume per unit weight of perishable within the package, or both.

Accordingly, the new methods also require redetermining atmosphere quotient values if the initial or the equilibrium void volume within a given package changes.

In preferred embodiments, the permeability of the packaging film is measured in cubic centimeters of gas such as oxygen or carbon dioxide transmitted through 100 square inches of packaging for 24 hours at 72° and less than 50% relative humidity The area of film is preferably measured in 100 square inches, and the weight of packaged perishable in grams, kilograms or pounds.

25 In preferred embodiments, the method for determining the respiration rate of a perishable product such as cauliflower comprises the following steps: r~

A

4 1 placing duplicate, equal-weight samples of the perishable in dessicators that have been cooled to a known temperature above the freezing point of water and below 50 0 say 45 0

F.;

sealing the dessicators, and connecting each dessicator to a continuous, controlled stream of filtered, humidified air, flowing at a nominal rate of about milliliters per minute; maintaining the flow of filtered, saturated air to the dessicators for 24 hours while maintaining the dessicators at 45*F., and then collecting a small sample, say 10 milliliters, of the gases flowing from the dessicators; measuring the percent by volume of carbon dioxide or of oxygen in the gas flowing from the dessicators using gas chromatography precalibrated as necessary, or another analytical method; measuring the actual rate of air flow to the dessicators using, for example, the graduated cylinder/volume displacement method; and repeating these same after another 24 hours of storage 45 0 with gas flow to the dessicators maintained at a known flow rate, for example, 0* o 40 milliliters per minute. The respiration rate of the perishable in milligrams of carbon dioxide per kilogramhours can then be calculated in accordance with the f m following formula: milligrams of carbon dioxide per 1 kilogram-hour is equal to the volume of carbon dioxide in the gas outflow from a dessicator, measured in milliliters per minute, multipled by 60 minutes, divided by the sample weight of the perishable in a dessicator, measured in kilograms, and multipled by the factor 1.964 milligrams, where the factor 1.964 milligrams equals the gram weight of one milliliter of carbon dioxide, or ma CO2/kg-hr (volume CO 2 ml/min)(1.964 mg) (60 min) weight of perishable in kilograms The product respiration rates at the end of 24 hours and at the end of 48 hours are preferably averaged to determine the respiration rate of the perishable.

In preferred embodiments, the method for determining film permeability comprises the following steps: placing an 8 inch diameter sample of the 4.

packaging film, free of manufacturing defects and S* mechanical abrasions, between two 7-inch, 550 milliliter containers that are sealed to prevent inflow or outflow of gas, as by use of an 0-ring and clamp; directing a flow of gas whose film S. permeability is to be tested, such as oxygen or carbon dioxide, into one of the two containers, through inlet and outlet valves, at a predetermined rate, say one liter per minute, while flushing the other container with nitrogen; 3asl~ i g -plsl 1 maintaining gas flow to each container as in step until one container contains 99% or more of the gas whose film permeability is to be tested, namely oxygen or carbon dioxide, and the other container contains 0.02% or less of the test gas; shutting off the valves and recording the time and temperature; waiting until sufficient test gas has diffused through the film into the second chamber to raise the concentration of the test gas in the second chamber to a value in the range of 1.5% to 2.5% by volume; extracting a small, say 10 milliliter gas sample from the second chamber and measuring the percentage of test gas in the sample as, for example, by gas chromatography, and recording the time and temperature of sample collection; and calculating the gas transmission rate in *terms of volume of gas diffusing through the film per unit Sarea of the film within a specific time interval in accordance with the following formula: permeability equals volume of the second container multiplied by the area of the film and by the percentage of test gas found in the second container minus the amount of test gas in the second container before diffusion began and divided by the diffusion time and by the factor 100. The permeability so determined is expressed in units of cubic centimeters of gas per 100 square inches of film diffusing -lqq 1 IIISS~P~ S~ 5 DBB"ranrrraau~ nnsl~p~- 1 through it over a 24-hour period at 72°F. In mathematical terms, the formula is as follows: Permeability (volume of second chamber)(net percent of permeant gas diffused)(area of film)(24 hours) (100)(diffusion time) In preferred embodiments, the permeant factor can be adjusted or varied by changing film permeability, film thickness or film composition. The package dimensions can be varied by increasing or decreasing the surface area of packaging. The package weight can be varied by simply increasing or decreasing the weight of perishable enclosed within a given package.

In preferred embodiments, atmosphere quotient as a measure of marketability of a perishable is determined by assigning arbitrary atmosphere quotient values to a plurality of packaged samples of the perishable. Each S package should be made of the same packaging material, have the same package area, the same internal void volume 20 per unit weight of perishable in the package, and the same packaging material permeability. To achieve the assigned quotient values, such packages can have differing, known weights of perishable enclosed in them. Finally, the effect of such variations in atmosphere quotient upon 25 marketability of the perishable are determined. In such determinations, flexible packaging material is preferably used, with the permeability and surface area of the 0** ***ft L ~C qqp~q~ 8 1 package held constant, to facilitate maintaining the internal void volume per unit weight packaged substantially the same for all samples.

Marketability can be evaluated by storing each of the packaged perishable samples at a given temperature, say, 45°F., for a period of time, say 20 days or more, but preferably not more than about 10 or 15 days, followed by subjective evaiuations of each sample for freshness of appearance, taste and/or other sensory attributes indicative of marketability. Objective indices of marketability are derived from analyses of such variables as microbiological content, pigmentation, carbohydrate content, and fermentation products such as ethanol and acetaldehyde. In this way, a first series of atmosphere quotient values that correlate with subjective and objective S. marketability indices of the perishable can be developed.

For nearly all respiring perishables, the correlation between atmsphere quotient and marketability is curvi- S. linear. Below and above the optimum values on this curve, marketability of the perishable declines. For each of the subjective and objective indicia, linear correlations, either positive or negative, with the atmosphere quotient values can be observed and plotted.

Thereafter, further series of such correlations 25 can be obtained by varying the permeability of the packaging film while holding all other variables the same, or by varying the area of the package while holding all ~~B~pJ~ ~1IYI~ 1 other variables the same. From these series of tests, a range of atmosphere quotients that correlate most closely with marketability of the perishable can be developed.

Thereafter, the range of atmosphere quotient values so developed can be used to determine the corresponding range of permeant factor values in accordance with the forrula Q equals G divided by R, where Q is atmosphere quotient, G is permeant factor, and R is the respiration rate of the perishable. Utilizing the range of permeant factors so determined, the area of the package, the psrmeability of the packaging film, and the weight of perishable packaged can be optimized by appropriate adjustments of one or more of these variables in accordance with the following formula: G equals AP divided by W, where G equals permeant factor; A is the O area of the packaging film, preferably measured in 100 0000 square inches; P is the permeability of the packaging film 9:00 per 100 square inches of film; and W is the weight, measured in pounds, of perishable enclosed in the package.

Permeant factor should be adjusted to accommodate varying respiration rates between two or more ba-ches of respiring perishable of the same kind to maintain the atmosphere quotient within the optimum range. Because respiration rate can vary widely from one batch of a given 25 respiring perishable to another batch, the respiration rate should be measured for each new l-atch of perishable of the same kind. Batches can vary from one another in I -~IL~ 1 variety, source, maturity, or some combination of these.

Moreover, the initial and the equilibrium void volume in each package per unit weight of perishable should be substantially the same regardless of package size and regardless of the weight of perishable within the package.

Where the nature of the packaging material precludes maintaining the initial or the equilibrium void volume per unit weight of perishable within each package substantially the same as the values determined without 'aking account of changes in these values, atmosphere quotient may need to be redetermined with each change in these values. These void volume problems arise most often with rigid packaging material. For example, as equilibrium void volume inside a rigid package increases, the 15 quantity of oxygen and/or carbon dioxide enclosed in the package should also increase, and vice-versa. One way of obtaining this result is by varying the permeability of the packaging material. With flexible or rigid packages, the initial void volume in a package per unit weight of S 20 perishable can be held constant by adjusting the area of material in the package.

After determining the atmosphere quotient for a given perishable in a given package, and after redetermining atmosphere quotient, as necessary, to allow for changes in initial and equilibrium void volume, the 11 1 benefits of atmosphere modification can be more easily determined. Where the initial void volume in a package is small, it may be necessary 'o add oxygen to the package before sealing to attain the desired initial oxygen concentration. Further, where the initial void volume in the package contains a gas other than air alone, allowances must be made for changes in internal void space resulting from respiration of the perishable in the package and frc-o permeability of the packaging material.

For example, most flexible packages will become smaller in direct proportion to the initial oxygen concentration in the initial void volume where a perishable inside the package consumes oxygen faster than oxygen enters the 0* package by permeability or otherwise.

S 15 Thus, increases in initial oxygen concentration in flexible packages will cause decreases in equilibrium void space, and vice-versa.

EXAMPLE 1 Following the methods disclosed above, and using S 20 carbon dioxide to measure respiration rate, we determined that the optimum range of oxygen quotients for cauliflower e o* was 19 to 38 where the initial void space in each cauliflower package was filled with 800 milliliters of air per pound of cauliflower.

We measured the respiration rate of cauliflower by the method described above, and determined that the respiration rate of cauliflower was 48 milligrams of carbon dioxide per kilogram per hour.

-R

1 We measured the permeability of the packaging film by the method described above, and determined that the permeability to oxygen of the packaging material, namely 1.5 mil-thick, low-density polyethylene film including 12% by weight of ethylene vinyl acetate, was 550 cubic centimeters of oxygen per 100 square inches for 24 hours at 72 0 and a relative humidity of less than We measured the area of each package for the cauliflower and determined the area to be 776 square inches or 7.76 times 100 square inches.

We then computed the weight of cauliflower to be enclosed in each package from this formula: W (weight to pack) equals AP (package area times package permeability) divided by G (permeant factor) with A equal to 7.76 (100 15 square inches), P equal to 550 (cc's of CO 2 per 100 square inches per 24 hours at 72 0 and less than 50% relative humidity, and AP equal to 1,268. For the four atmosphere quotient values of 21, 27, 33 and 38, we computed the permeant factor and the weight of cauliflower per package 20 as shown in this table: Weight to Pack Quotient Permeant Factor (AQxR) (AP/G) 21 1008 4.2 lbs. (a) 27 1296 3.3 lbs. (b) 33 1584 2.7 lbs. (c) 38 1824 2.3 lbs. (d) -I r II 13 I After' storing each of these sample packages (a) and at 45*F. for 10 da2ys, evaluated each package for the ptrcentagc of marketable caulif lower in each package, and obtained the data shown in this table: Quotient Averaqe Marketat.biiy Score 21 18% 27 33 3 38 24% Based on the results shown in this table, we concluded that the oxygen atmosphere quotient range of 1~7 to 33 appeared most likely to optimize marketability of cauliflower. By continuing our testing as set forth *in this example, we determined that the optimum atmosphere quotient range for 02 is 29 to 31 for cauliflower florets initially packaged with 800 milliliters of air in the void space per pound.

EXAMPLE 2 Using the data obtained in Example 1, we computed the optimum packaging for cauliflower packages requir- to contain three pounds of cauliflower using the oxygen aLmosphere quotient range of 29 to 31 determined in Example I above. We adjusted the size of the package to mnaintain the oxygen atmosphere quotient within the range of 2?9 ta 31.

For cauliflower-containing packages having an oxygen permeability of 550, as determined in accordance 14 1 with Example 1; an area of 7.76 times 100 square inches, as determined in Example 1; and a package weight of three pounds, the permeant factor is 1423 (4268/3).

To maintain the atmosphere quotient in the range of 29 to 31, arid to maintain permeant factor at 1423, the respiration rate range had to be in the range 47 to 50 as computed by the formula R equals G divided by AO, where R is 50 or 47, G is 1423, and AQ is 29 or 31.

Where the initial respiration rate fell outside the 47-50 range, we had to ad3ust the length of the packaging by adjusting the placement of the heat seal on the package to maintain the desired permeant factor.

For example, to attain an oxygen atmosphere quotient of 0* for cauliflower having a respiration rate of about 48 miligrams per kiligram-hour, with a packaged cauliflower weight of 3 pounds, packagc film oxygen permeability of 550, and a package width of 13 inches, the heat seal was made across the width of the package to produce a package length of about 30.2 inches. For a respiration rate of 40, the heat seal would have to be placed to produce a package length of 25.2 inches. For a respiration rate of the heat seal would have to be placed to produce a package length of 37.8 inches.

For the package of cauliflower weighing 3 pounds, with cauliflower respiration rate of 48, where the package film oxygen permeability was 550, and the package width was 13 inches, we multiplied respiration rate by r I atmosphere quotient to determine perm.eant factor# then multiplied permeant factor by the weight of the perishable, and di' ided the product by the permeabihtty (550) to determine the package area. We then determined package length from the formula: package film area equals the number two (because this package was two-sided) multiplied by the length and by the width Mw of the package, and divided by the number 100, or A (2)M(1M(MO10). In this case, the area was 7.85 X 100 or 785 square inches, and the width was 13 inches. Therefore, the length, determined arithmetically, was 30.2 inches.

Claims

1. A sealed package for at least one respiring perishable comprises said at least one respiring perishable in packaging material that transmits oxygen and carbon dioxide at known or ascertainable rates, said package having an optimum atmosphere quotient value (AQ) for said at least one respiring perishable with a known or ascertainable respiration rate where atmosphere quotient is equal to permeant factor divided by said respiration rate and where permeant factor (G) is equal to the area of said sealed package multiplied by the permeability of said package to oxygen or carbon dioxide and divided by the weight of said at least one perishable in said sealed package, said optimum atmosphere quotient value being at least aEW)6c-4fg percent greater than the minimum atmosphere quotient value in the range of atmosphere quotient values characteristic of said respiring perishable at said respiration rate sealed in said packaging material, said range of atmosphere quotient values 20 characteristic of said respiring perishable comprising a range of empirically-determined test values representing marketability of said at least one respiring perishable, said range being derived from testing at least one series of sealed test packages for said marketability, each of said sealed test packages in said series being made of said packaging material. The package of claim 1 further comprising a desired initial internal void volume per unit weight of said perishable.

3. The package of claim 2 wherein said permeability of said package is to oxygen.

4. The package of claim 2 wherein said permeability of said package is to carbon dioxide. The package of claim 1 wherein said permeability of 94030,qopekph.78357-9l.div l16 I' -17- said package is to oxygen.

6. The package of claim 1 wherein said permeability of said package is to carbon dioxide.

7. The package of claim 1 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

8. The package of claim 1 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

9. The package of claim 2 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

10. The package of claim 2 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

11. The package of claim 3 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

12. The package of claim 3 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

13. The package of claim 4 wherein said atmosphere quotient value is at least about thirty-three percent greater than 940301,qope\phh,783579LdiY 17 a I 3 1 ~~gpp I -18- minimum atmosphere quotient value in said range of atmosphere quotient values.

14. The package of claim 4 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values. The package of claim 5 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

16. The package of claim 5 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

17. The package of claim 6 wherein said atmosphere quotient 20 value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

18. The package of claim 6 wherein said atmosphere quotient 25 value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

19. The package of claim 1 wherein said sealed package 30 comprises more than one kind of respiring perishable. A sealed plastic film package for at least one respiring perishable comprises &aid at least one respiring perishable in plastic film packaging material that transmits oxygen and carbon dioxide at known or ascertainable rates, said sealed plastic film package having an optimum atmosphere quotient value (AQ) for said at least one respiring perishable with a 940301,q:koper~phh,78357-91divl8 ,1III -19- known or ascertainable respiration rate where atmosphere quotient is equal to permeant factor divided by said respiration rate and where permeant factor is equal to the area of said sealed plastic film package multiplied by the permeability of said sealed plastic film package to oxygen or carbon dioxide and divided by the weight of said at least one perishable in said sealed plastic film package, said atmosphere quotient value (AQ) being at least -'aX fr l percent greater than the minimum atmosphere quotient (AQ) in the range of atmosphere quotient (AQ) values characteristic of said at least one respiring perishable at said respiration rate sealed in said plastic film packaging material, said range of AQ values characteristic of said respiring perishable comprising a range of empirically- determined test values representing marketability of said at least one respiting perishable, said range being derived from "testing at least one series of sealed test packages for said marketability, each of said sealed test packages in said series being made of said plastic film packaging material. :21. The package of claim 20 further comprising a desired initial internal void voluime per unit weight of said at least one perishable. 25 22. The package of claim 21 wherein said permeability of said package is to oxygen.

23. The package of claim 21 wherein said permeability of said package is to carbon dioxide.

24. The package of claim 20 wherein said permeability of said package is to oxygen. The package of claim 20 wherein said permeability of said package is to carbon dioxide.

26. The package of claim 20 wherein said atmosphere quotient N^ 940301,q:\oper\phh78357-91.div,19 1, value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

27. The package of claim 20 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

28. The package of claim 21 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

29. The package of claim 21 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values. 20 30. The package of claim 22 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value ii said range of atmosphere quotient values. 25 31. The package of claim 22 wherein said atmosphere quotient value is at least about fifty percent greater than said «O minimum atmosphere quotient value in said range of atmosphere quotient values. 30 32. The package of claim 23 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values.

33. The package of claim 23 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere 94030i,q:\operphb.7835791div,20 L -6 ~p~I -21- quotient values.

34. The package of claim 24 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values. The package of claim 24 wherein said atmosphere quotient value is at least about fifty percent greater than said minimum atmosphere quotient value in said range of atmosphere quotient values.

36. The package of claim 25 wherein said atmosphere quotient value is at least about thirty-three percent greater than minimum atmosphere quotient value in said range of atmosphere quotient values. 0

37. The package of claim 25 wherein said atmosphere quotient value is at least about fifty percent greater than said 20 minimum atmosphere quotient value in said range of atmosphere quotient values.

38. The package of claim 20, wherein said sealed package comprises more than one kind of respiring perishable. DATED this 1st day of March, 1994. I TRANSFRESH CORPORATION 30 By its Patent Attorneys DAVIES COLLISON CAVE 940301,q:\Aoper\phb78357-91.div21 s I~ 22 ABSTRACT A method for determining and controlling the proper modified or unmodified atmosphere packaging for cut or uncut respiring perishables such as cauliflower, lettuce and broccoli includes the steps of determining the respiration rate of the respiring perishable, preparing a plurality of packages containing the respiring perishable with each package having a different permeant factor, determining a value called atmosphere quotient for each of the packages according to this formula: atmosphere quotient equals permeant factor divided by respiration rate; subjecting each of the packages to known conditions of temperature and pressure over a known period of time and correlating the subjective and objective indicia of quality, appearance and marketability of the respiring perishable from each package to the atmosphere quotient values determined according to the foregoing formula, and then varying one or more of the values of te components that affect.permeant factor to achieve and maintain the o 0 optimum value or range of val es for atmosphere'quotient. In addition a sealed package including at least one o respiring perishable sealed in packaging material that 0 transmits oxygen and carbon dioxide has an atmosphere quotient value that is at least 15% greater than the Sminimum atmosphere quotient value in the range of attainable atmosphere'quotient values for said respiring perishable at said respiration rate sealed in said packaging material. 91061ZPHHSPEO16,ft332&SPe29