Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B31/00—Packaging articles or materials under special atmospheric or gaseous conditions; Adding propellants to aerosol containers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B25/00—Packaging other articles presenting special problems
  • B65B25/02—Packaging agricultural or horticultural products
  • B65B25/04—Packaging fruit or vegetables
  • B65B25/041—Packaging fruit or vegetables combined with their conservation

Definitions

• This invention relates to a method for deter­mining proper modified or unmodified atmosphere packaging for cut or uncut respiring perishables such as cauliflower, lettuce and broccoli.
• the methods of this invention comprise the following steps:
• the methods of this 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 carbon dioxide permeating out of the package is substan­tially equal to the carbon dioxide produced inside the package.
• 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.
• 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° F., and less than 50% relative humidity (RH).
• the area of film is preferably measured in 100 square inches, and the weight of packaged perishable in grams, kilograms or pounds.
• the method for deter­mining the respiration rate of a perishable product such as cauliflower comprises the following steps:
• the method for determining film permeability comprises the following steps:
• the permeant factor can be adjusted or varied by changing film permeability, i.e., 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.
• 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 package should be made of the same packaging material, have the same package area, the same internal void volume per unit weight of perishable in the package, and the same packaging material permeability.
• such packages can have differing, known weights of perishable enclosed in them.
• the effect of such variations in atmosphere quotient upon marketability of the perishable are determined.
• flexible packaging material is preferably used, with the permeability and surface area of the 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 evaluations 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 marketability indices of the perishable can be developed. For nearly all respiring perishables, the correlation between atmosphere quotient and marketability is curvi­linear. 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.
• the range of atmosphere quotient values so developed can be used to determine the corresponding range of permeant factor values in accordance with the formula Q equals G divided by R, where Q is atmosphere quotient, G is permeant factor, and R is the respiration rate of the perishable.
• G equals AP divided by W, where G equals permeant factor; A is the area of the packaging film, preferably measured in 100 square inches; P is the permeability of the packaging film 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 batches 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 respiring perishable to another batch, the respiration rate should be measured for each new batch of perishable of the same kind. Batches can vary from one another in 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.
• 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 taking 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 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 perishable can be held constant by adjusting the area of material in the package.
• the benefits of atmosphere modification can be more easily determined.
• the initial void volume in a package is small, it may be necessary to add oxygen to the package before sealing to attain the desired initial oxygen concentration.
• 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 from 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 package by permeability or otherwise.
• the permeability of the packaging film was measured 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°F., and a relative humidity of less than 50%.
• W weight to pack
• G permeant factor
• Example 2 Using the data obtained in Example 1, we computed the optimum packaging for cauliflower packages required to contain three pounds of cauliflower using the oxygen atmosphere quotient range of 29 to 31 determined in Example 1 above. We adjusted the size of the package to maintain the oxygen atmosphere quotient within the range of 29 to 31.
• the permeant factor (G) is 1423 (4268/3).
• the respiration rate range had to be in the range 47 to 50 as computed by the formula R equals G divided by AQ, where R is 50 or 47, G is 1423, and AQ is 29 or 31.
• the heat seal was made across the width of the package to produce a package length of about 30.2 inches.
• the heat seal would have to be placed to produce a package length of 25.2 inches.
• the heat seal would have to be placed to produce a package length of 37.8 inches.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Agronomy & Crop Science (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Packages (AREA)
• Storage Of Fruits Or Vegetables (AREA)
• Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
• Storage Of Harvested Produce (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=21927114

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (1)

Family Cites Families (3)

• 1988
  • 1988-04-20 AU AU14791/88A patent/AU613909B2/en not_active Ceased
  • 1988-04-22 CA CA000564895A patent/CA1312002C/en not_active Expired - Lifetime
  • 1988-04-27 ES ES88303808T patent/ES2043815T3/es not_active Expired - Lifetime
  • 1988-04-27 EP EP19880303808 patent/EP0289291B1/de not_active Expired - Lifetime
  • 1988-04-27 DE DE19883884851 patent/DE3884851T2/de not_active Expired - Fee Related
  • 1988-04-28 JP JP63104436A patent/JPS63281973A/ja active Pending
• 1991
  • 1991-06-12 AU AU78357/91A patent/AU7835791A/en not_active Abandoned
• 1994
  • 1994-03-01 AU AU56496/94A patent/AU686584B2/en not_active Ceased

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