CA1086560A - Refrigerated storage or shipment of fresh produce in a modified gaseous atmosphere - Google Patents
Refrigerated storage or shipment of fresh produce in a modified gaseous atmosphereInfo
- Publication number
- CA1086560A CA1086560A CA254,551A CA254551A CA1086560A CA 1086560 A CA1086560 A CA 1086560A CA 254551 A CA254551 A CA 254551A CA 1086560 A CA1086560 A CA 1086560A
- Authority
- CA
- Canada
- Prior art keywords
- range
- carbon dioxide
- produce
- oxygen
- concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Storage Of Fruits Or Vegetables (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Fresh fruits and vegetables are stored under refrigerated conditions for extended periods of time in a manner which prevents the growth of harmful fungi, and, as well, the environmental atmosphere is a chemical anti-oxidant. All of the above are achieved by maintaining the fresh produce in a storage container including an artificial atmosphere composed of carbon monoxide substantially in excess of 5% and preferably above about 10%, carbon dioxide, a significant amount of oxygen, and the remainder nitrogen.
Fresh fruits and vegetables are stored under refrigerated conditions for extended periods of time in a manner which prevents the growth of harmful fungi, and, as well, the environmental atmosphere is a chemical anti-oxidant. All of the above are achieved by maintaining the fresh produce in a storage container including an artificial atmosphere composed of carbon monoxide substantially in excess of 5% and preferably above about 10%, carbon dioxide, a significant amount of oxygen, and the remainder nitrogen.
Description
:~L0~656~
BACKGROUND OF THE INVENTION
1. The Field of the Invention This invention relates generally to the storage, both fixed and movable, of fresh produce, and, more particularly, to such storage-and shipment in refrigerated containers containing a preservative modified gaseous environment.
BACKGROUND OF THE INVENTION
1. The Field of the Invention This invention relates generally to the storage, both fixed and movable, of fresh produce, and, more particularly, to such storage-and shipment in refrigerated containers containing a preservative modified gaseous environment.
2. Deseription of the Prior Art In U. S. patent 2,490,951, FOOD TREATMENT PROCESS, by M. E. Dunkley, undesirable enzymic action which produces spoilage of food products is sought to be eliminated or sharply deterred by enclosing the food produets in a special gaseous atmosphere of carbon monoxide and aeetylene, which gaseous atmosphere is otherwise noted for its substantial lack of atmospherie oxygen (less than 0.50%). In order to maintain the speeified eomposition of gases, and in particular the low oxygen content, the food produet and speeial gaseous atmosphere must, according to this patent, be maintained in a sealed eontainer.
3,y~,1~q U. S. patent-~74~4~, STORAGE OF FRESH LEAFY :~
VEGETABLES by John W. MeGill, discloses a method of treating fresh leafy vegetables in whieh they are maintained in an atmosphere of 1~o~5% earbon monoxide, 1%-10~ oxygen, not more ;
than 5~ carbon dioxide, and the remainder nitrogen.
.~ .
- 2 - ~
~.~86~60 - SUMM~RY ~ND DESCRIPTION OF THE INVENTION
, In the pxactice of the present discovery, fresh fruits and vegetables are stored under refrigerated conditions fox extended periods of time iIl a manner which prevents the growth of harmful fungi, and, as well, thé environmental atmosphere is a chemical anti-oxidant. All of the above are achieved by maintaining the fresh produce in a storage container including an artificial atmosphere composed of carbon monoxide substantially in excess of 5% and preferably above about 10%, carbon dioxide, a significant amount of oxygen, and the remainder nitrogen.
As used herein, refrigeration relates to establishing the ambient temperature in the range of 29-60 F., depending on the requirements of the particular product. Also, when the ! :
term "produce" is used herein, it is to be understood to apply to any of the fresh fruits and vegetables, examples of which are bell peppers, cauliflower, mushrooms, grapes and blueberries.
DESCRIPTION OF THE WORKING EXAMPLES
Example 1: Cauliflo~er Storage A pallet was stacked with ten (10) corrugated fibreboard boxes of cauliflower with 16 heads per box, and then stored in a sealed container having its internal temperature - maintained at approximately 40 F. The container was cha~ged with an artificial atmosphere consisting of approximately 2O2%
carbon dioxide, 1.8~ oxygen, 6.0% carbon monoxide and the ':.~', ' ~ 3 --'' ~3651~(~
remainder gaseous nitrogen. The cauliflower was kept in this special atmosphere and at the stated temperature for a period of six (6) days, at the end of which time the boxes were opened and the cauliflower removed.
On examination, the cauliflower at the end of the test period was found to contain some yellow patches indicating discoloration to curd and/or jacket leaves, wh~ch averaged one cauliflower head per carton. Some riciness was evident, averaging about one head every other carton. No heads were found to be undersized and the overall appearance was satisfactory.
Thirty other boxes of cauliflower were stacked, as a control, in a similar manner on a pallet and maintained at 40~ F.
in atmospheric oxygen for the same period of time as the ahove test cartons of cauliflower. At the conclusion of the storage, the control cauliflower was found to exhibit yellow discoloration ranging from patches to entire heads, w'nich averaged three to four heads per box. Riciness averaged two heads per box and substantial bacterial soft rot was found on an average of one head every other box. Overall appearance was at best borderline for commercial accep~ability.
, ~xample 2: Cauliflower Storage Thirty six (36) corrugated cardboard boxes having twel~e (12) cauiiflower heads per box were sealed in four and five mil plastic bags, each bag containing 10 pounds of lime.
VEGETABLES by John W. MeGill, discloses a method of treating fresh leafy vegetables in whieh they are maintained in an atmosphere of 1~o~5% earbon monoxide, 1%-10~ oxygen, not more ;
than 5~ carbon dioxide, and the remainder nitrogen.
.~ .
- 2 - ~
~.~86~60 - SUMM~RY ~ND DESCRIPTION OF THE INVENTION
, In the pxactice of the present discovery, fresh fruits and vegetables are stored under refrigerated conditions fox extended periods of time iIl a manner which prevents the growth of harmful fungi, and, as well, thé environmental atmosphere is a chemical anti-oxidant. All of the above are achieved by maintaining the fresh produce in a storage container including an artificial atmosphere composed of carbon monoxide substantially in excess of 5% and preferably above about 10%, carbon dioxide, a significant amount of oxygen, and the remainder nitrogen.
As used herein, refrigeration relates to establishing the ambient temperature in the range of 29-60 F., depending on the requirements of the particular product. Also, when the ! :
term "produce" is used herein, it is to be understood to apply to any of the fresh fruits and vegetables, examples of which are bell peppers, cauliflower, mushrooms, grapes and blueberries.
DESCRIPTION OF THE WORKING EXAMPLES
Example 1: Cauliflo~er Storage A pallet was stacked with ten (10) corrugated fibreboard boxes of cauliflower with 16 heads per box, and then stored in a sealed container having its internal temperature - maintained at approximately 40 F. The container was cha~ged with an artificial atmosphere consisting of approximately 2O2%
carbon dioxide, 1.8~ oxygen, 6.0% carbon monoxide and the ':.~', ' ~ 3 --'' ~3651~(~
remainder gaseous nitrogen. The cauliflower was kept in this special atmosphere and at the stated temperature for a period of six (6) days, at the end of which time the boxes were opened and the cauliflower removed.
On examination, the cauliflower at the end of the test period was found to contain some yellow patches indicating discoloration to curd and/or jacket leaves, wh~ch averaged one cauliflower head per carton. Some riciness was evident, averaging about one head every other carton. No heads were found to be undersized and the overall appearance was satisfactory.
Thirty other boxes of cauliflower were stacked, as a control, in a similar manner on a pallet and maintained at 40~ F.
in atmospheric oxygen for the same period of time as the ahove test cartons of cauliflower. At the conclusion of the storage, the control cauliflower was found to exhibit yellow discoloration ranging from patches to entire heads, w'nich averaged three to four heads per box. Riciness averaged two heads per box and substantial bacterial soft rot was found on an average of one head every other box. Overall appearance was at best borderline for commercial accep~ability.
, ~xample 2: Cauliflower Storage Thirty six (36) corrugated cardboard boxes having twel~e (12) cauiiflower heads per box were sealed in four and five mil plastic bags, each bag containing 10 pounds of lime.
- 4 -', : ' i5~ ~
;~:
Aftex sealing, the bags were flushed with carbon monoxide gas until there was a residual of about 15% remaining. Carbon dioxide was then added until it formed approximately 10~ of the . composition which left 12~-13% oxygen and the rest nitrogen.
On conclusion of the test, the four mil bags had maintained the carbon dioxide at about 5~, oxygen at 5~ and no carbon monoxide was detectable after six days. In the five mil bags, the levels of oxygen soon bec~me very low, and a further 10 pound quantity of lime was added after four days to reduce the carbon dioxide level.
After a total of seven days holding period, only slight differences could be detected in the bagged cauliflower having the indicated artificial atmosphere over eiyht similarly packed boxes of cauliflower in a control atmosphere of normal atmospheric air. The curd was more compact in modified atmospheres and the green leaf tissue had a slightly better color. No significant floret mold developed in any of the bags.
All of the bag samples were then broken open and allowed to remain in the air for an additional four days with the temperature held at approximately 60 F. Dramatic ~ -differences were then detected between those samples of cauliflower which had been maintained in the artificial at sphere and those in the air control. Specifically, floret m~ld was significantly more severe in the air control cauliflower and, as well, the leafy tissue was very ye~low as compared to a fresh green color of the artifical atmosphere - r ~tored cauliflower.
' ' d . ' ' . -- S -- . ' ' :
8~560 Example 3: Cauliflower St~
Cauliflower was stored in plastic bags and in sealed barrels at approximately 38 F. for a total of 17 days.
Artificial atmospheres were provided in the various bags and barrels of the following compositions:
Bag 1 & Barrel 1 10%-20% 0% 5~ Remainder Bag 2 ~ Barrel 2 10%-20% 5~ 5% Remainder Barrel 3 0% ~ 5% 5% Remainder , At ~he end of 17 days storage, all of the leafy cauliflower parts held in 5% carbon dioxide atmospheres had a fresh green color. Significant yellowing of the green leafy . .
parts was evident in an air control sample and in those stored in artificial atmospheres without carbon dioxide. All of the cauliflower samples treated with carbon monoxide were free of mold growth on the flower parts. Where carbon monoxide was not used, but with 5% carbon dioxide, mold growth was significant and differed little from air control.
, . . .
At the conclusion of storage, all of the cauliflower samples were cooked and tasted. No off color or off flavor was detected. It was concluded from this example that floret molding was particularly inhibited by carbon monoxide in the presence of either/or both elevated carbon dioxide and/or reduced oxygen.
'~ ~
. - 6 - .
, .
~86560 Example 4: Bell Pe~per Stora~e Six boxes of washed and waxed bell peppers were obtained, four boxes of which were placed in barrels, sealed to include an artificial atmosphere. The two remaining boxes were ~ -located in unsealed barrels exposed to ambient atmosphere. All of the barrels were maintained at 45% F.
Barrel 1 contained an atmosphere of 10~-20% carbon dioxide, 3%-4% oxygen, 10~ carbon monoxide and the remainder nitrogen. Barrel 2 had the same composition of artificial atmosphere as barrel 1, except that it had no carbon monoxide -~
component. Barrel 3 was provided with artificial atmosphere .. . .
of 2%-4% carbon dioxide, 5%-7% oxygen, 10~ carbon monoxide, and the remainder nitrogen. Barrel 4 had th~ same artificial -atmosphere as barrel 3 except that there was no-carbon monoxide present.
After twelve days of storage under the prescribed conditions and with the prescribed atmospheres, the peppers in barrel 3 had a field fresh appearance witn no indication of '~r surface mold, and only two individual peppers showed any indication of soft rot. The peppers in barrel 4 did show surface mold and seventeen (17) indicated soft~rot, with their general appearance all being diminished somewhat by the presence of black stem ends. Similarly, the air control samples had a relatively high numher with soft rot, surface mold was - ~-substantially in evidence and most had black stem ends.
':' ' ' , ` ' ,, :
, ' ' , ~ , .. . . . .
,: , .
;56~
Aftex a total of sixteen days of storage, the pcppers in barrel 1 were asain examined and found to have a ield fresh appearance with no surface mold present at all, although two peppers did show evidence of soft rot. Barrel 2 had three peppers with soft rot, substantial surface mold was present, and an off flavor condition. The air control samples included 13 and 17 peppers, respectively, with soft rot, surface mold was clearly in evidence and many had black stem ends.
It is concluded from this example that carbon monoxide enhanced the appearance of the peppers and inhibited fungus growth.
:
-Example 5: ushroom Storage ,: . .
Four open boxes of mushrooms were placed in three different barrels and sealed with the following artificial atmospheres:
. CO C2 N2 Barrel 1 20% , 5% 3% Remainder Barrel 2 15~ 15% 10% Remainder Barrel 3 10~ 15~ 20~ Remainder In addition, four boxes were maintained in atmospheric air as a .
control.
None of the mushrooms experienced any marked weight loss during the test, either those in the control air storage or in the artificial atmospheres, with overall weight loss being only about 1% more in air storage than in the artificial atmospheres.
' ''' . ~' .
.
.
,. . .
~6S6~ -At the end of 14 days of storage, with the temperature maintained throughout at approximately 33-34 F. for all samples, the mushrooms in barrel 1 were only slightly better in appearance than the air control mushrooms. It is concluded from S this that a significant oxygen level should be maintained for successful mushroom storage.
The mushrooms in barrel 2 at the conclusion of the 14 day test had a good external appearance with some slight . .
internal discoloration of the cap and stem tissue, which was concluded to-be a result of growing conditions rather than .
produced during stoFage.
Barrel 3 had the best overall external and internal appearance at the conclusion of the test. The mushrooms had a fresh smell, only very slight external discoloration and no `~
internal discoloration of the cap tissue. The stem tissue did have some discoloration resulting from growing conditions.
Example 6: Mushroom Storage ~ ushrooms from a different source than those used in Example 5 were stored at 33-34 F. i~ two separate sealed containers. The first contained an artificial gaseous environment of 20% carbon monoxide, 20% oxygen, less than 1 carbon dioxide and the remaihder nitrogen. The atmosphere in the second barrel consisted of 15% carbon monoxide, 20~ oxygen, 12% carbon dioxide and the remainder nitrogen. A separate environmental air control barrel was also provided.
' ~ .
, . _ 9 _ .
, : :
~ 656~
After 14 days of storage~ the mushrooms in the first barrel had a good external appearance, with some internal discoloration equal to that experienced in the air control.
Those mushrooms stored in barrel 2 were in nearly perfect condition after the storage of 14 days. Almost no internal discoloration could be found in either the caps or the ~ `
stems. - `
Example 7: Grape Storage A quantity o~ Emperor grapes in open boxes and previously treated with sulphur dioxide gas were stored in the following respective modified atmospheres with the temperature maint~ined at 33-34 F.: ~
Container 1 5~ 0%-l~ 5% Remainder Container 2 0~-1% 5~ Remainder Container 3 10% 5% 5~ Remainder Container 4 5% 5~ Remainder Container 5 10% 5% Remainder In addition, two boxes of grapes were maintained in air storage as a control. All of the grapes, whether in the air storage or the modified atmosphere were stored for ninety-seven (97) days.
At the conclusion of the storage, those grapes held in artificial atmospheres including carbon monoxide (containers 1 and 3) were completely free of any mold grow~h. In addition, ~ ;
' ' , S6~
these grapes were firm, the taste was normal and the bloom was good. Stem and pedical tissue was gxeener in those atmospheres having a lower percentage of carbon dioxide (containers l and 2).
Grapes stored in container 2 had the freshest appearing stem and pedicel tissue, although there was some accompanying mold growth. Berry firmness, bloom and taste were good.
The condition of container 4 grapes was comparable to that of container 3, except that the stem and pedicel tissue was browner and more shriveled. ~ ~
lQ Grapes from container 5 had an off-flavor and stem ~ -tissue was very brown and shriveled. No mold growth was evident.
The air controi grapes experienced severe mold growth and, also, the stems and pedicels were mar]cedly shriveled and brown.
Example 8: Blueberry_Storage Individual pint containers of blueberries of the "Wolcott" variety were placed in separate desiccators having ten (lO) different modified atmospheres at 38-40 F. for - 20 sixteen (16) days, after which they were removed and examined.
The atmospheres used and the results obtained are shown in the following table:
. . . ' .
- 11 ' ,.:. ' '' ', ~ . ' -~656(~
TREATMENT % GOOD % RUNNY SOFT % MOLDY ~ BAD
.
Air Control Sample 1 89. a 6.7 4.3 11.0 ~ir Control Sample 2 81.6 13.3 5.1 18.4 1. 5% C2t 10% 291.2 7.1 1.7 8.8 2. 5% CO2, 10~ 2~
15%-25% CO 96.8 2.9 0.3 3.2 3O 5% CO2, 3~ 291.6 7.1 1~3 ~.4 4. 5% CO2, 3% O , 8%-25~ CO 97.1 2.6 0.3 2.9
;~:
Aftex sealing, the bags were flushed with carbon monoxide gas until there was a residual of about 15% remaining. Carbon dioxide was then added until it formed approximately 10~ of the . composition which left 12~-13% oxygen and the rest nitrogen.
On conclusion of the test, the four mil bags had maintained the carbon dioxide at about 5~, oxygen at 5~ and no carbon monoxide was detectable after six days. In the five mil bags, the levels of oxygen soon bec~me very low, and a further 10 pound quantity of lime was added after four days to reduce the carbon dioxide level.
After a total of seven days holding period, only slight differences could be detected in the bagged cauliflower having the indicated artificial atmosphere over eiyht similarly packed boxes of cauliflower in a control atmosphere of normal atmospheric air. The curd was more compact in modified atmospheres and the green leaf tissue had a slightly better color. No significant floret mold developed in any of the bags.
All of the bag samples were then broken open and allowed to remain in the air for an additional four days with the temperature held at approximately 60 F. Dramatic ~ -differences were then detected between those samples of cauliflower which had been maintained in the artificial at sphere and those in the air control. Specifically, floret m~ld was significantly more severe in the air control cauliflower and, as well, the leafy tissue was very ye~low as compared to a fresh green color of the artifical atmosphere - r ~tored cauliflower.
' ' d . ' ' . -- S -- . ' ' :
8~560 Example 3: Cauliflower St~
Cauliflower was stored in plastic bags and in sealed barrels at approximately 38 F. for a total of 17 days.
Artificial atmospheres were provided in the various bags and barrels of the following compositions:
Bag 1 & Barrel 1 10%-20% 0% 5~ Remainder Bag 2 ~ Barrel 2 10%-20% 5~ 5% Remainder Barrel 3 0% ~ 5% 5% Remainder , At ~he end of 17 days storage, all of the leafy cauliflower parts held in 5% carbon dioxide atmospheres had a fresh green color. Significant yellowing of the green leafy . .
parts was evident in an air control sample and in those stored in artificial atmospheres without carbon dioxide. All of the cauliflower samples treated with carbon monoxide were free of mold growth on the flower parts. Where carbon monoxide was not used, but with 5% carbon dioxide, mold growth was significant and differed little from air control.
, . . .
At the conclusion of storage, all of the cauliflower samples were cooked and tasted. No off color or off flavor was detected. It was concluded from this example that floret molding was particularly inhibited by carbon monoxide in the presence of either/or both elevated carbon dioxide and/or reduced oxygen.
'~ ~
. - 6 - .
, .
~86560 Example 4: Bell Pe~per Stora~e Six boxes of washed and waxed bell peppers were obtained, four boxes of which were placed in barrels, sealed to include an artificial atmosphere. The two remaining boxes were ~ -located in unsealed barrels exposed to ambient atmosphere. All of the barrels were maintained at 45% F.
Barrel 1 contained an atmosphere of 10~-20% carbon dioxide, 3%-4% oxygen, 10~ carbon monoxide and the remainder nitrogen. Barrel 2 had the same composition of artificial atmosphere as barrel 1, except that it had no carbon monoxide -~
component. Barrel 3 was provided with artificial atmosphere .. . .
of 2%-4% carbon dioxide, 5%-7% oxygen, 10~ carbon monoxide, and the remainder nitrogen. Barrel 4 had th~ same artificial -atmosphere as barrel 3 except that there was no-carbon monoxide present.
After twelve days of storage under the prescribed conditions and with the prescribed atmospheres, the peppers in barrel 3 had a field fresh appearance witn no indication of '~r surface mold, and only two individual peppers showed any indication of soft rot. The peppers in barrel 4 did show surface mold and seventeen (17) indicated soft~rot, with their general appearance all being diminished somewhat by the presence of black stem ends. Similarly, the air control samples had a relatively high numher with soft rot, surface mold was - ~-substantially in evidence and most had black stem ends.
':' ' ' , ` ' ,, :
, ' ' , ~ , .. . . . .
,: , .
;56~
Aftex a total of sixteen days of storage, the pcppers in barrel 1 were asain examined and found to have a ield fresh appearance with no surface mold present at all, although two peppers did show evidence of soft rot. Barrel 2 had three peppers with soft rot, substantial surface mold was present, and an off flavor condition. The air control samples included 13 and 17 peppers, respectively, with soft rot, surface mold was clearly in evidence and many had black stem ends.
It is concluded from this example that carbon monoxide enhanced the appearance of the peppers and inhibited fungus growth.
:
-Example 5: ushroom Storage ,: . .
Four open boxes of mushrooms were placed in three different barrels and sealed with the following artificial atmospheres:
. CO C2 N2 Barrel 1 20% , 5% 3% Remainder Barrel 2 15~ 15% 10% Remainder Barrel 3 10~ 15~ 20~ Remainder In addition, four boxes were maintained in atmospheric air as a .
control.
None of the mushrooms experienced any marked weight loss during the test, either those in the control air storage or in the artificial atmospheres, with overall weight loss being only about 1% more in air storage than in the artificial atmospheres.
' ''' . ~' .
.
.
,. . .
~6S6~ -At the end of 14 days of storage, with the temperature maintained throughout at approximately 33-34 F. for all samples, the mushrooms in barrel 1 were only slightly better in appearance than the air control mushrooms. It is concluded from S this that a significant oxygen level should be maintained for successful mushroom storage.
The mushrooms in barrel 2 at the conclusion of the 14 day test had a good external appearance with some slight . .
internal discoloration of the cap and stem tissue, which was concluded to-be a result of growing conditions rather than .
produced during stoFage.
Barrel 3 had the best overall external and internal appearance at the conclusion of the test. The mushrooms had a fresh smell, only very slight external discoloration and no `~
internal discoloration of the cap tissue. The stem tissue did have some discoloration resulting from growing conditions.
Example 6: Mushroom Storage ~ ushrooms from a different source than those used in Example 5 were stored at 33-34 F. i~ two separate sealed containers. The first contained an artificial gaseous environment of 20% carbon monoxide, 20% oxygen, less than 1 carbon dioxide and the remaihder nitrogen. The atmosphere in the second barrel consisted of 15% carbon monoxide, 20~ oxygen, 12% carbon dioxide and the remainder nitrogen. A separate environmental air control barrel was also provided.
' ~ .
, . _ 9 _ .
, : :
~ 656~
After 14 days of storage~ the mushrooms in the first barrel had a good external appearance, with some internal discoloration equal to that experienced in the air control.
Those mushrooms stored in barrel 2 were in nearly perfect condition after the storage of 14 days. Almost no internal discoloration could be found in either the caps or the ~ `
stems. - `
Example 7: Grape Storage A quantity o~ Emperor grapes in open boxes and previously treated with sulphur dioxide gas were stored in the following respective modified atmospheres with the temperature maint~ined at 33-34 F.: ~
Container 1 5~ 0%-l~ 5% Remainder Container 2 0~-1% 5~ Remainder Container 3 10% 5% 5~ Remainder Container 4 5% 5~ Remainder Container 5 10% 5% Remainder In addition, two boxes of grapes were maintained in air storage as a control. All of the grapes, whether in the air storage or the modified atmosphere were stored for ninety-seven (97) days.
At the conclusion of the storage, those grapes held in artificial atmospheres including carbon monoxide (containers 1 and 3) were completely free of any mold grow~h. In addition, ~ ;
' ' , S6~
these grapes were firm, the taste was normal and the bloom was good. Stem and pedical tissue was gxeener in those atmospheres having a lower percentage of carbon dioxide (containers l and 2).
Grapes stored in container 2 had the freshest appearing stem and pedicel tissue, although there was some accompanying mold growth. Berry firmness, bloom and taste were good.
The condition of container 4 grapes was comparable to that of container 3, except that the stem and pedicel tissue was browner and more shriveled. ~ ~
lQ Grapes from container 5 had an off-flavor and stem ~ -tissue was very brown and shriveled. No mold growth was evident.
The air controi grapes experienced severe mold growth and, also, the stems and pedicels were mar]cedly shriveled and brown.
Example 8: Blueberry_Storage Individual pint containers of blueberries of the "Wolcott" variety were placed in separate desiccators having ten (lO) different modified atmospheres at 38-40 F. for - 20 sixteen (16) days, after which they were removed and examined.
The atmospheres used and the results obtained are shown in the following table:
. . . ' .
- 11 ' ,.:. ' '' ', ~ . ' -~656(~
TREATMENT % GOOD % RUNNY SOFT % MOLDY ~ BAD
.
Air Control Sample 1 89. a 6.7 4.3 11.0 ~ir Control Sample 2 81.6 13.3 5.1 18.4 1. 5% C2t 10% 291.2 7.1 1.7 8.8 2. 5% CO2, 10~ 2~
15%-25% CO 96.8 2.9 0.3 3.2 3O 5% CO2, 3~ 291.6 7.1 1~3 ~.4 4. 5% CO2, 3% O , 8%-25~ CO 97.1 2.6 0.3 2.9
5.' 0% CO2, 5~ 289.5 8.0 2.5 10.5 fi. 0% CO2, 5% O~, 10%-20~ CO 95.7 4.0 0.3 4-3 7. 10% CO2, 10% 293.1 6.3 0.6 6.9 8. 10% CO2, - 10% 2 10%-18% CO 95.7 3.0 1.3 4~3 9. 10% CO2, 3~ 296.3 3.7 -0- 3.7 10. 10~ C2 3~ 2~
18~-25% CO 97.7 2.3 ` -0- 2.3 ~ .
Exc~pt for the No. 5 atmosphere, all the berries were better than the air control samples. The addition of carbon monoxide gave improved results in all cases. Shelf-life remained good through three (3~ days at ambient temperature with no off-flavor, grittiness or other defect detected.
.
,. ~ . . ' , 3LOi~65~a SUPPL~ENTAR~ D~$CLOSURE
It has now been found that the compositlon of thepreservative atmosphere disclosed in the Principal Disclosure for preventing the growth of harmful fungi during storage of fresh fruits and vegetables can be varied somewhat from that already disclosed and still be effective for the purpose.
It has now been found that the proportion of carbon monoxide in a fungistatic amount may be between about 3% and about 25% by volume dependent on the nature o~ the fruit or vegetable, the variety, the length of time between harvesting of the fruit or vegetable and the application of an atmosphere according to this invention, and the kind of fungl involved. Preferably the range is from about 5% to about 25% by volume.
The amount of oxygen may be an amount less than 21%
by volu~e, broadly in the range of about 1% to about 20% by volume.
The remainder will be nitrogen but some carbon dioxide may be present for certain fruits and vegetables but its presence is not always required. The proportion of carbon dioxide may be in amounts from 0% to about 20% by volume.
The amounts of oxygen and carbon dioxide used ~ary with the kind and varlety of fruit or vegetable sub~ected to the preservative modified atmosphere according to the invention. ~--In addition to the Pruits and vegetables to which ~-reference is specifically made in the Principal Disclosure, other fruits and vegetables to whlch the ~nvention is applicable are tomatoes, s~uash, pineapples, peaches, papayas, nectarlnes, ~angoes, melons, egg-plant, cabbage, avocados, lettuce, apples, pears, apricots, cherries, potatoes, sweet potatoes and onions.
_ 13 -~A~
i560 The followln~ table shows broad and more preferred ranges of carbon dioxide, oxygen and carbon monoxide for use with the kind of fruit or vegetable shown.
FRUIT orBroad Ranges More Preferred Ranges VegetablePercent by VolumePercent by Volu~e Bell Pepper1-10 5-20 3-25BALANCE 2-7 5-105-15 BALANCE
Cauliflower1-10 3-20 3-25BALANCE 3-6 5-105-15 B~LANCE
Mushroom 3~20 3-20 3-25BALANCE 5-10 10-1510-20 BALANCE
Grape 0-15 2-15 3-25BALANCE 0-10 5-lO10-20 BALANCE
Blueberry 1-15 2-10 3-25BALANCE 5-10 3-55-15 BAI.ANCE
Tomato 0-7 3-10 3-25BALANCE 0-5 4-85-l5 BALANCE
Squash 3-15 2-10 3-25BALANCE 5-10 3-85-15 BALANCE
Pineapple 1-15 2-15 3-25BALANCE 5-10 5-105-15 BALANCE
Peach 1-lO 2-10 3-25BALANCE 3-6 3-6.5-15 BALANCE
Papaya 2-10 2-10 3-25BALANCE 4-8 3-85-15 BALANCE
Nectarine 1-10 2-10 3-25BALANCE 3-6 3-65-15 BALANCE
Mango 2-10 2-lO 3-25BALANCE 4-8 4-85-15 BALANCE
Melon 2-20 3-15 3-25BALANCE10-15 5-105-15 BALANCE
Eggplant 0-8 2-10 3-25BALANCE 0-3 4-85-15 BALANCE
Green Beans 2-10 2-10 3-25 BALANCE 3-6 3-6 5-15 BALANCE
Apples 1-10 1-10 3-25BALANCE 2-8 1-45-15 BALANCE
Pears 0-8 2-8 3-25BALANCE 1-5 1-35-15 BALANCR
Apricots 1-8 2-8 3-25BALANCE 2~-5 2-55-15 BALANCE
Cherrie~ 3-20 2-15 3-25BALANCE 5-15 3-105-15 BALANCE
Cabbage 1-10 2-10 3-25BALANCE 3-6 3-65-15 BALANCE
Avocado 3-15 2~10 3-25BALANCE 5-10 3 65-15 BALANCE
Lettuce 0-5 2 15. 3-25BALANCE 0-3 5-105-15 BALANCE
Potato 5-20 3-10 3-25BALANCE 5-10 4-85-15 B~LANCE
Onion 4-15 1-7 3-25BALANCE 5-10 2-55-15 BALANCE
Sweet Potato 3-5 5-7 3-25 BALANCE 2-7 4-8 5-15 BALANCE
_ 14 -J,~
~: .', . ' ~., ~ :
.. :,., ~
;560 Not all concentrations oP these gases are effecti~e or equally efective on each and every kind and variety of fruit and vegetable. At certain temperatures and with certain m~xtures of gases, physiological or pathogical damage to certaln Pruits and vegetables may occur, even though fungi growth is inhibited. Such conditions may readily be determined and then avoided.
The Pollowing additional examples illustrate further the scope and content of this invention. In the examples, all per-centages are percentages by volume unless the contrary is expressly stated Example 9: Avocado Storage -~
Two groups of 24 avocados each were placed in separate containers. The atmasphere in the first container was modified to r~
contain initially a preservative atmosphere lncludlng about 10% carbon dioxide, about 8% carbon monoxide, about 3% oxygen, the balance all substantially molecular nitrogen. The atmosphere in the second container was alr. The temperature inside each container was modified to and maintained at 55F. Por 16 days. During tbis time, the atmos-phere in the first contalner was monitored, and ad~ustments were made to maintain the gas concentration close to the starting concentration.
At the end o~ the storage period, avocados held in the second container were soPt, ripe and had slight mold growth on their stem buttons. Avocados held in the first container were hard, green and free of mold growth. After these observations were made, the avocados from the first container were held in air at about 70-75F.
for one day, and then at 45F. in Por another day. Avocados that had been held in the first container were slightly so~t. About half were still green, the other half were purple-brown in color, indicative oP
partial ripen~ng.
.
- : :
; .
S6~
Neither the avocados held in air nor the avocados held in preservative atmosphere developed any chilllng symptoms or decayO
Thls example shows that carbon monoxide is an effectlve fungistat on avocados when used in combinatlon wlth carbon dioxide and oxygen.
Example 10: C age Storage Two groups of cabbage heads, each including twelve heads, were placed in separate containers. The atmosphere in the first container was modifled to contain initially about 5% carbon dioxide, about 5% carbon monoxlde, and about 5% oxygen. The atmosphere in the ~;~
second container was air throughout the test. The temperature within each container was modified to and maintained at 42 F. for three weeks.
During this time, the atmosphere in the ~lrst container was monitored, and adjustments were made to maintain the gas concentrations close to the starting concentrations.
At the end of this period, the cabbages held in air had ~- ~
turned substantially completely yellow, and ~old growth was visible on ~ ~ -the wrapper leaves. Cabbages held in the preservative atmosphere were in good condition. The lea~es had not yellowed and little mold growth was visible.
The improvement that carbon monoxide produced was particularly striking because the quality of the cabbage at the outset of the test was poor; cabbages then had severe leaf spotting on both wrapper and cap lea~es.
~xample ll: ~gplant Storage ;~
Five groups of 18 eggplants each were placed in separate containers. In four of the containers, the atmosphere was modifled to contain initially the following:
Container 1: About 1% - 3% carbon dioxide, about 5% oxygen, about 10%
- carbon monoxide, and the balance substantially all molecular nitrogen.
.~, .
~ ~ .
~0~9~;S6~) Container 2: ~bout 7% carbon dloxide, about 5% oxygen, about 1070 carbon monoxide, and the halance substantially all molecular nitrogen.
Container 3: About 1% - 3% carbon dioxide, about 5% oxygen, and the balance substantlally all molecular nitrogen.
Container 4: About 7% carbon dioxide, about 5% oxygen, and the balance substantially all molecular nitrogen.
The atmosphere in contalner 5 was air throughout the test. The temperatu~e in each o~ the containers was ad~usted to and maintained at 45 ~. for two weeks. During this tlme, the atmospheres in the flrst four containers were monitored and ad~ustments were made to maintain the gas concentrations close to the starting concentrations.
After the two week period, the eggplant held in air had poor color, severely molded calyxes, and some pitted surfaces, indicating that ~lternaria rot had begun to develop.
By contrast, eggplant held in containers 1 and 2 retained good green color in the calyxes, had little or no decay, and retained a fresh appearance. Eggplant held in container 1 appeared slightly better than the eggplant held in container 2 ~ggplant held in containers 3 and 4 were in poor condition. Calyxes on these eggplant had as much mold as eggplant held in air ? and some scaldlng of eggplant surfaces had also occurred.
Example 12: Lettuce Storage Three groups o~ lceberg lettuce, each containlng 24 heads, were placed ln separate containers. The atmosphere in the first container was modified to contain initially about 10% oxygen, about 9%
carbon monoxide, and the balance substantlally all molecular nitrogen.
The atmosphere in the second was modi~ied to contain initially ~bout ~-10% oxygen, about 15% carbon monoxide, and the balance substantially all molecular nltrogen. The atmosphere in the third contained air throughout the test. The temperature ln each container was maintained "' ~ "
~li36S~;lD
at about 34F. ~or 19 da~s. Dur~ng the test, the atmosphere in con-tainers 1 and 2 was monitored, and adJustments were made to maintain the gas concentrations close to the starting concentrations.
At the end of the l9-day perlod, half of the heads were moved and inspected lmmediately, and the other half were held at about 70 - 75 F. in air ~or two days and then inspected. The results were as follows: ;~
After 19 days, three of the 12 heads held in air exhibited Botrytis rot; none of the 24 lettuce heads held in the carbon monoxide-containing atmospheres showed any. Forty-eight hours later, ;
nine of the 12 lettuce heads held in air exhibited Botrytis rot; none of the remaining lettuce heads held in the carbon monoxide containing- ~
atmospheres exhibited any such rot. These results show that carbon ~ ~ -monoxide effectively controls fungi growth that otherwise causes severe damage to lettuce.
Example 13: Lettuce Storage Two groups o~ lceberg lettuce, each containing 60 heads, ~
were placed in separate containers. The atmosphere in the first ~ ;
container was modified to produce an atmosphere initially containing about 8% oxygen, about 20% carbon monoxide, and the balance substantially `
all molecular nitrogen. The second container held air throughout the test. The temperature ln each contalner was lowered to and maintained at about 33 - 34F. for two weeks. During that time, the atmosphere in the first container varied from about 20% carbon monoxide to about 7%, and the oxygen, from about 8% to about 10%.
'` ~t the end of the two week period, none of the lettuce held in the first container exhiblted Botrytis, but two of the lettuce heads held in air did. Moreover9 only 12 of theheads held in the first container exhlbited developing soft rot; 22 from the air control did.
Severity of decay was considerably lower for lettuce hsads treated with :
S6~;3 carbon monoxide than ~or lettuce heads held in air without carbon monoxide. Again, carbon monoxide appeared to inhibit substantially the growth of Botrytis fungi and bacterial soft rot on lettuce.
Example 14: Honeydew Melon Storage Five groups of ~ive honeydew melons each were placed in separate containers. The atmosphere ln four of the containers was modified; the atmosphere in the ~i~th was air throughout the test.
The modified atmospheres were as follows:
Container 1: Zero to about 2% carbon dioxide, about 5% oxygen, about 10% - 15% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 2: About 5% carbon dioxide, about 5% ox~gen, about 10% - 15%
carbon monoxlde, and the balance substantlally all molecular nitrogen.
Container 3: About 10% carbon dioxide, about 5% oxygen, about lO% - 15%
carbon monoxide, and the balance substantially all molecular nitrogen.
Container 4: ~bout 15% carbon dioxide, about 5% oxygen, about 10% -15% rarbon monoxide, and the balance substantially all molecular nitrogen.
The atmosphere in each container was maintained at about 50 F. for three weeks. During this time, the atmosphere in each of the first four containers was monitored, and ad~ustments were made to maintain the gas concentration close to the starting concentrations.
The containers were opened after the three week period, and the melons inspected. Those in the modified atmosphere treatment were free from rot and mold growth. Three of the five melons from the air control exhibited decay, mold growth or both.
After holding the melons ~rom each of the containers at about 70 - 75F. in air ~or ~our days, four of the ~ive melons held exhibited decay, but none of the melons held in modified atmosphere did.
No rind blemishes developed in melons held in modified atmospheres, ~7 - 19 .:
.. . . ., . . .
. ~ .
~ . .
, .
.
656~9 .
and the taste and aroma of all melons, including those held ln air, was normal.
Example 15: Cantaloupe Storage Six groups o~ 16 cantaloupes each were placed in separate containers. The atmospheres in ~ive o the containers were modified to contain the following:
Container 1: Zero - about 2% carbon dioxlde, about 5% oxygen, 10% - 15~ carbon monoxide, and the balance substantially all molecular nitrogen.
Container 2: About 5% carbon dioxide, about 5% oxygen, about 10% - 15%
carbon monoxide, and the balance substantially all molecular nitrogen.-Container 3: ~bout 10% carbon dioxide, about 5% oxygen, about 10% -15% carbon monoxide, and the balance substantially all molecular nitrogen. ~;
Container 4: About 15% carbon dioxide, about 5% oxygen, about 10%
15% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 5: About 0 - 5% carbon dioxide, about 21% ~ 4% oxygen, about 10% - 15% carbon monoxide~ and the balance substantially all molecular nitrogen.
The sixth container held air throughout the test. The temperature in each container was lowered to and maintained at about 50 F. for three weeks. During the three weeks, the gas concentrations in containers 1 through 5 were monitored, and adjustments were made to maintain the gas concentrations close to the starting concentratlons.
Ho~ever, in container 5, the oxygen concentration was permitted to decrease from 21% at the outset to 4% at the end o~ the three week period.
At the end o~ the three weeks, the containers were opened and the cantaloupes exalQined. All melons exhibited some mold and - 20 ~
F~
.. .
. ~ . . .. . .
, ~
10~i56~9 decay, but the carbon monoxide treated melons exhibited substantially less decay than cantaloupes held in air. Higher concentrations of carbon dioxlde in comblnatlon wlth carbon monoxide enhanced inhibition of the fungi.
Example 16: Nectarine Storage ~our groups of nectarlnes, each containing from 25 to 30 fruit, were placed ln sepa~ate contalners. The atmosphere in three of the containers was modified to contaln initially the following con-centratlons of gases:
Container 1: ~bout 12% carbon dioxlde, about 3% oxygen, and the balance substantially all molecular nitrogen.
Container 2: About 12% carbon monoxide, about 10% oxygen, and the ~ ;
balance substantially all molecular nitrogen.
Container 3: About 7% carbon dioxide, about 7% oxygen, about 10%
carbon monoxide, and the balance substantlally all molecular nitrogen.
The fourth container held air throughout the test.
The temperature oR each container was lowered to 32~. initially, but rose to 50~. for at least part of the test period. Dur-Lng the three week period, the gas concentrations in each of the first three containers were monitored and ad~ustments were made to maintain the concentrations at or near the starting concentration.
~fter three weeks, the containers were opened and the fruit inspected. Of the 28 fruit in container 1, 8 exhibited some brown rot and some off-flavor. Of the 25 ruit container 2, none exhibited brown rot, but some were off-flavor. Of the 25 fruit in container 3, none exhlbited brown rot, and flavor was acceptable. Of the 31 ~ruit held in air, 12 exhibited brown rot, and again flavor was acceptable.
Carbon monoxide inhibited development of brown rot fungi without any detrimental impact on flavor. ~oreover, where carbon monoxide was present, carbon dioxide could be maintained at lower levels, .
, . ' ' .
~(1 8~S6~
insuring preservatlon o~ good flavor.
Example 17: Papaya Storage Two groups of papaya, one containlng 14 fruit, the other 16 fruit, were placed ln separate contalners. The atmosphere in the first container was modified to contain initially an atmosphere of about 10~ carbon dioxide, about 3% oxygen, about 10% carbon monoxide, and the balance substantial all molecular nltrogen. The atmosphere in the second container was air throughout the test. The temperature in each container was modl~led to, and held at 55~. ~or 10 days. During the 10 days, the atmosphere in the first container was monitored, and ad~ustments made to maintain gas concentrations at or near the initial concentrations.
~t the end of 10 days, papayas held in air were riper than those held in the modlfled atmosphere. All ~ruit was~held another four days at about 70-75~. in air to observe ripening and shelf life. ~ `
At the end of four days, fruit held in modified atmosphere was still not nearly as ripe as the fruit held ln air throughout.
None o~ the fruit developed any ~nthracnose rot, but 4 of the 16 fruit held in alr developed stem end rot. Only 1 o~ the fruit held in the modif~ed atmosphere exhibited any stem end rot.
Taste and aroma of all fruit was normal, indicating that carbon monoxide had no deleterious effect on flavor.
Example 18: Peach Storage Three groups of peaches of the Summerset variety, 100 fruit ln each group, were placed in separate containers. The atmosphere ;~
in the fruit container was modlfied to contain initially about 3% carbon dioxide, about 4% oxygen, about 10% carbon monoxide, and the balance substantially all molecular nitrogen. The atmosphere in the second `
container was modi~ied to contain about 5% carbon dioxide, about 5 oxygen, about 10% carbon monoxlde, and the balance substantially all :
~ - 22 - ~ ~
., . ~ .: . . ..
.
:
iS6C~
molecular nitrogen. The third container held air throughout the test.
The temperature in each container was reduced to and held at about 32F. for five weeks. During this time, the gas concentrations in the first two containers were monitored, and ad~ustments were made to maintain the gas concentrations at or near the startlng concentrations.
At the end of three weeks, the containers were opened, and 50 peaches were removed from each of the containers. O~ the 50 peaches removed from the air container, 8 were decayed at mechanically damaged areas. ~d~ancement of decay was moderate, and mycelial growth was abundant. Of the 50 peaches ~rom container 2, 5 were decayed at mechanically damaged areas, but decay was much less advanced than with peaches held in air, and both mycelial growth and sporulation were inhibited. Of the 50 peaches held ln container 1, 3 were decayed at mechanically damaged areas, but again, mycelial growth and sporulation were inhibited.
The rest of the peaches were held two more weéks in the containers under the same condi~ions. O~ the lO0 peaches from the two modified atmosphere containers, only 13 in all (6 ~rom container 1 and 7 from container 2) were decayed at mechanically damaged areas. Of the 50 peaches from the air control atmosphere, 22 were decayed in mechanically damaged areas. No mycellal growth or sporulation was evident on peaches held in modified atmospheres, but such growth and sporulation was pro~use on peaches held in air. Moreover, peaches held in modified atmosphere containing the higher concentration of carbon dioxide had the best texture and taste of the three groups. Peaches held in the lower concentration of carbon dioxide and the peaches held in air were drier and much less tasty.
Example 19: _ 1 pepper Storage ~our groups o~ about 100 bell peppers each were placed in se~arate contalners. In the first container, the atmosphere was ~7 , . .
., .
S6~3 modi~ied to produce an atmosphere containlng initially about 3% carbon dloxide, about 5% oxygen, about 25% carbon monoxide, and the balance substantlally all molecular nitrogen. In the second container, the atmosphere was alr throughout the test. The temperature in each container was reduced to and held at about 48 to about 50~. for 23 days. During thls tlme, the oxygen concentr~tion varled ~rom about 5% to about 10%, and the carbon ~onoxlde concentratlon Prom about 25%
to about 10% ln the first container.
At the end of 23 days, the peppers were removed and observed. Peppers held ln alr had mold growth on all stems, and many exhlbited severe rottlng. Peppers held ln the modified atmosphere were Pree of surface mold growth and rots.
In a separate test, a third group of peppers was placed in a third container, and ~he atmosphere therein modified to contain ;~
initially about 2% carbon dioxide, about 5% oxygen, about 15% carbon monoxide, and the balance substantlally all molecular nitrogen. The atmosphere ln the fourth container, into whlch was placed the fourth group of bell peppers, was air throughout this second test. The temperature in the thlrd and Pourth contalners was reduced to and ~ ;~
malntained at about 48 to about 50~. throughout a 14 day test perlod. ;~ ; ' ThereaPter, the peppers were removed and observed, and results were ;
comparable to those obtained with the peppers held in containers 1 and 2 for 23 days. ~ ~
~.: -' : :
Example 20: Zucchini Squash Sto~age ~ .
Six groups of Zucchini squash, each group containing :~ :
about 110 to about 120 squash, were placed in separate containers. ~`
The atmospheres in 5 of the containers were modiPied to produce the Pollowing compositions:
Container 1: About 10% carbon dioxide, about 3% to about 5% oxygen7 and the balance sub~tantlally all molecular nltrogen.
..
~7 24 - -~;' .
' . . :, .~ :, .'. .
; :: , ~ : . , 1~6~6~
Container 2: About 10~ carbon dloxide, about 3% to about 5% oxygen!
about 10% carbon monoxlde, and the balance substantially all molecular nitrogen.
Container 3: About 5% carbon dioxide, about 3% to about 5% oxygen, and the balance substantially all molecular nltrogen.
Container 4: About 5% carbon dioxide, about 3% to about 5~ o~ygen, about 10% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 5: ~bout 20% oxygen, about 10% carbon monoxide, and the balance substantially all molecular nitrogen.
The sixth container held air throughout the test. The temperature in each of the containers was reduced to and maintained at about 45F.
to 47F. for two weeks. During this time, the atmospheres in containers 1 through 4 were monitored, and ad~ustments made to hold the concentra-tions at or near the starting concentrations. However, in the fifth container, the oxygen concentration was permitted to decrease naturally by respiration to about 3% at the end of the test period.
At the end of two weeks, the squash were removed and inspected. The squash held in air had surEace mold growth on virtually the entire surface of all the squash. Ten squash held in air exhibited some decay. Squash held in container 1 had a small quantity of surEace mold growth; 7 squash were slightly decayed. Squash held in container 2 had no decay and only traces of surface mold growth. Squash held in container 3 had the most surPace mold growth and the highest number of decayed squash. The squash from container 4 were not decayed and exhibited only traces of surface mold growth. Squash held in container 5 had little decay but exhibited substantial mold growth, indicating that car~on dioxide also has a valua~le role in preserving the life of this vegetable.
- 25 ~
.. .
.
18~-25% CO 97.7 2.3 ` -0- 2.3 ~ .
Exc~pt for the No. 5 atmosphere, all the berries were better than the air control samples. The addition of carbon monoxide gave improved results in all cases. Shelf-life remained good through three (3~ days at ambient temperature with no off-flavor, grittiness or other defect detected.
.
,. ~ . . ' , 3LOi~65~a SUPPL~ENTAR~ D~$CLOSURE
It has now been found that the compositlon of thepreservative atmosphere disclosed in the Principal Disclosure for preventing the growth of harmful fungi during storage of fresh fruits and vegetables can be varied somewhat from that already disclosed and still be effective for the purpose.
It has now been found that the proportion of carbon monoxide in a fungistatic amount may be between about 3% and about 25% by volume dependent on the nature o~ the fruit or vegetable, the variety, the length of time between harvesting of the fruit or vegetable and the application of an atmosphere according to this invention, and the kind of fungl involved. Preferably the range is from about 5% to about 25% by volume.
The amount of oxygen may be an amount less than 21%
by volu~e, broadly in the range of about 1% to about 20% by volume.
The remainder will be nitrogen but some carbon dioxide may be present for certain fruits and vegetables but its presence is not always required. The proportion of carbon dioxide may be in amounts from 0% to about 20% by volume.
The amounts of oxygen and carbon dioxide used ~ary with the kind and varlety of fruit or vegetable sub~ected to the preservative modified atmosphere according to the invention. ~--In addition to the Pruits and vegetables to which ~-reference is specifically made in the Principal Disclosure, other fruits and vegetables to whlch the ~nvention is applicable are tomatoes, s~uash, pineapples, peaches, papayas, nectarlnes, ~angoes, melons, egg-plant, cabbage, avocados, lettuce, apples, pears, apricots, cherries, potatoes, sweet potatoes and onions.
_ 13 -~A~
i560 The followln~ table shows broad and more preferred ranges of carbon dioxide, oxygen and carbon monoxide for use with the kind of fruit or vegetable shown.
FRUIT orBroad Ranges More Preferred Ranges VegetablePercent by VolumePercent by Volu~e Bell Pepper1-10 5-20 3-25BALANCE 2-7 5-105-15 BALANCE
Cauliflower1-10 3-20 3-25BALANCE 3-6 5-105-15 B~LANCE
Mushroom 3~20 3-20 3-25BALANCE 5-10 10-1510-20 BALANCE
Grape 0-15 2-15 3-25BALANCE 0-10 5-lO10-20 BALANCE
Blueberry 1-15 2-10 3-25BALANCE 5-10 3-55-15 BAI.ANCE
Tomato 0-7 3-10 3-25BALANCE 0-5 4-85-l5 BALANCE
Squash 3-15 2-10 3-25BALANCE 5-10 3-85-15 BALANCE
Pineapple 1-15 2-15 3-25BALANCE 5-10 5-105-15 BALANCE
Peach 1-lO 2-10 3-25BALANCE 3-6 3-6.5-15 BALANCE
Papaya 2-10 2-10 3-25BALANCE 4-8 3-85-15 BALANCE
Nectarine 1-10 2-10 3-25BALANCE 3-6 3-65-15 BALANCE
Mango 2-10 2-lO 3-25BALANCE 4-8 4-85-15 BALANCE
Melon 2-20 3-15 3-25BALANCE10-15 5-105-15 BALANCE
Eggplant 0-8 2-10 3-25BALANCE 0-3 4-85-15 BALANCE
Green Beans 2-10 2-10 3-25 BALANCE 3-6 3-6 5-15 BALANCE
Apples 1-10 1-10 3-25BALANCE 2-8 1-45-15 BALANCE
Pears 0-8 2-8 3-25BALANCE 1-5 1-35-15 BALANCR
Apricots 1-8 2-8 3-25BALANCE 2~-5 2-55-15 BALANCE
Cherrie~ 3-20 2-15 3-25BALANCE 5-15 3-105-15 BALANCE
Cabbage 1-10 2-10 3-25BALANCE 3-6 3-65-15 BALANCE
Avocado 3-15 2~10 3-25BALANCE 5-10 3 65-15 BALANCE
Lettuce 0-5 2 15. 3-25BALANCE 0-3 5-105-15 BALANCE
Potato 5-20 3-10 3-25BALANCE 5-10 4-85-15 B~LANCE
Onion 4-15 1-7 3-25BALANCE 5-10 2-55-15 BALANCE
Sweet Potato 3-5 5-7 3-25 BALANCE 2-7 4-8 5-15 BALANCE
_ 14 -J,~
~: .', . ' ~., ~ :
.. :,., ~
;560 Not all concentrations oP these gases are effecti~e or equally efective on each and every kind and variety of fruit and vegetable. At certain temperatures and with certain m~xtures of gases, physiological or pathogical damage to certaln Pruits and vegetables may occur, even though fungi growth is inhibited. Such conditions may readily be determined and then avoided.
The Pollowing additional examples illustrate further the scope and content of this invention. In the examples, all per-centages are percentages by volume unless the contrary is expressly stated Example 9: Avocado Storage -~
Two groups of 24 avocados each were placed in separate containers. The atmasphere in the first container was modified to r~
contain initially a preservative atmosphere lncludlng about 10% carbon dioxide, about 8% carbon monoxide, about 3% oxygen, the balance all substantially molecular nitrogen. The atmosphere in the second container was alr. The temperature inside each container was modified to and maintained at 55F. Por 16 days. During tbis time, the atmos-phere in the first contalner was monitored, and ad~ustments were made to maintain the gas concentration close to the starting concentration.
At the end o~ the storage period, avocados held in the second container were soPt, ripe and had slight mold growth on their stem buttons. Avocados held in the first container were hard, green and free of mold growth. After these observations were made, the avocados from the first container were held in air at about 70-75F.
for one day, and then at 45F. in Por another day. Avocados that had been held in the first container were slightly so~t. About half were still green, the other half were purple-brown in color, indicative oP
partial ripen~ng.
.
- : :
; .
S6~
Neither the avocados held in air nor the avocados held in preservative atmosphere developed any chilllng symptoms or decayO
Thls example shows that carbon monoxide is an effectlve fungistat on avocados when used in combinatlon wlth carbon dioxide and oxygen.
Example 10: C age Storage Two groups of cabbage heads, each including twelve heads, were placed in separate containers. The atmosphere in the first container was modifled to contain initially about 5% carbon dioxide, about 5% carbon monoxlde, and about 5% oxygen. The atmosphere in the ~;~
second container was air throughout the test. The temperature within each container was modified to and maintained at 42 F. for three weeks.
During this time, the atmosphere in the ~lrst container was monitored, and adjustments were made to maintain the gas concentrations close to the starting concentrations.
At the end of this period, the cabbages held in air had ~- ~
turned substantially completely yellow, and ~old growth was visible on ~ ~ -the wrapper leaves. Cabbages held in the preservative atmosphere were in good condition. The lea~es had not yellowed and little mold growth was visible.
The improvement that carbon monoxide produced was particularly striking because the quality of the cabbage at the outset of the test was poor; cabbages then had severe leaf spotting on both wrapper and cap lea~es.
~xample ll: ~gplant Storage ;~
Five groups of 18 eggplants each were placed in separate containers. In four of the containers, the atmosphere was modifled to contain initially the following:
Container 1: About 1% - 3% carbon dioxide, about 5% oxygen, about 10%
- carbon monoxide, and the balance substantially all molecular nitrogen.
.~, .
~ ~ .
~0~9~;S6~) Container 2: ~bout 7% carbon dloxide, about 5% oxygen, about 1070 carbon monoxide, and the halance substantially all molecular nitrogen.
Container 3: About 1% - 3% carbon dioxide, about 5% oxygen, and the balance substantlally all molecular nitrogen.
Container 4: About 7% carbon dioxide, about 5% oxygen, and the balance substantially all molecular nitrogen.
The atmosphere in contalner 5 was air throughout the test. The temperatu~e in each o~ the containers was ad~usted to and maintained at 45 ~. for two weeks. During this tlme, the atmospheres in the flrst four containers were monitored and ad~ustments were made to maintain the gas concentrations close to the starting concentrations.
After the two week period, the eggplant held in air had poor color, severely molded calyxes, and some pitted surfaces, indicating that ~lternaria rot had begun to develop.
By contrast, eggplant held in containers 1 and 2 retained good green color in the calyxes, had little or no decay, and retained a fresh appearance. Eggplant held in container 1 appeared slightly better than the eggplant held in container 2 ~ggplant held in containers 3 and 4 were in poor condition. Calyxes on these eggplant had as much mold as eggplant held in air ? and some scaldlng of eggplant surfaces had also occurred.
Example 12: Lettuce Storage Three groups o~ lceberg lettuce, each containlng 24 heads, were placed ln separate containers. The atmosphere in the first container was modified to contain initially about 10% oxygen, about 9%
carbon monoxide, and the balance substantlally all molecular nitrogen.
The atmosphere in the second was modi~ied to contain initially ~bout ~-10% oxygen, about 15% carbon monoxide, and the balance substantially all molecular nltrogen. The atmosphere in the third contained air throughout the test. The temperature ln each container was maintained "' ~ "
~li36S~;lD
at about 34F. ~or 19 da~s. Dur~ng the test, the atmosphere in con-tainers 1 and 2 was monitored, and adJustments were made to maintain the gas concentrations close to the starting concentrations.
At the end of the l9-day perlod, half of the heads were moved and inspected lmmediately, and the other half were held at about 70 - 75 F. in air ~or two days and then inspected. The results were as follows: ;~
After 19 days, three of the 12 heads held in air exhibited Botrytis rot; none of the 24 lettuce heads held in the carbon monoxide-containing atmospheres showed any. Forty-eight hours later, ;
nine of the 12 lettuce heads held in air exhibited Botrytis rot; none of the remaining lettuce heads held in the carbon monoxide containing- ~
atmospheres exhibited any such rot. These results show that carbon ~ ~ -monoxide effectively controls fungi growth that otherwise causes severe damage to lettuce.
Example 13: Lettuce Storage Two groups o~ lceberg lettuce, each containing 60 heads, ~
were placed in separate containers. The atmosphere in the first ~ ;
container was modified to produce an atmosphere initially containing about 8% oxygen, about 20% carbon monoxide, and the balance substantially `
all molecular nitrogen. The second container held air throughout the test. The temperature ln each contalner was lowered to and maintained at about 33 - 34F. for two weeks. During that time, the atmosphere in the first container varied from about 20% carbon monoxide to about 7%, and the oxygen, from about 8% to about 10%.
'` ~t the end of the two week period, none of the lettuce held in the first container exhiblted Botrytis, but two of the lettuce heads held in air did. Moreover9 only 12 of theheads held in the first container exhlbited developing soft rot; 22 from the air control did.
Severity of decay was considerably lower for lettuce hsads treated with :
S6~;3 carbon monoxide than ~or lettuce heads held in air without carbon monoxide. Again, carbon monoxide appeared to inhibit substantially the growth of Botrytis fungi and bacterial soft rot on lettuce.
Example 14: Honeydew Melon Storage Five groups of ~ive honeydew melons each were placed in separate containers. The atmosphere ln four of the containers was modified; the atmosphere in the ~i~th was air throughout the test.
The modified atmospheres were as follows:
Container 1: Zero to about 2% carbon dioxide, about 5% oxygen, about 10% - 15% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 2: About 5% carbon dioxide, about 5% ox~gen, about 10% - 15%
carbon monoxlde, and the balance substantlally all molecular nitrogen.
Container 3: About 10% carbon dioxide, about 5% oxygen, about lO% - 15%
carbon monoxide, and the balance substantially all molecular nitrogen.
Container 4: ~bout 15% carbon dioxide, about 5% oxygen, about 10% -15% rarbon monoxide, and the balance substantially all molecular nitrogen.
The atmosphere in each container was maintained at about 50 F. for three weeks. During this time, the atmosphere in each of the first four containers was monitored, and ad~ustments were made to maintain the gas concentration close to the starting concentrations.
The containers were opened after the three week period, and the melons inspected. Those in the modified atmosphere treatment were free from rot and mold growth. Three of the five melons from the air control exhibited decay, mold growth or both.
After holding the melons ~rom each of the containers at about 70 - 75F. in air ~or ~our days, four of the ~ive melons held exhibited decay, but none of the melons held in modified atmosphere did.
No rind blemishes developed in melons held in modified atmospheres, ~7 - 19 .:
.. . . ., . . .
. ~ .
~ . .
, .
.
656~9 .
and the taste and aroma of all melons, including those held ln air, was normal.
Example 15: Cantaloupe Storage Six groups o~ 16 cantaloupes each were placed in separate containers. The atmospheres in ~ive o the containers were modified to contain the following:
Container 1: Zero - about 2% carbon dioxlde, about 5% oxygen, 10% - 15~ carbon monoxide, and the balance substantially all molecular nitrogen.
Container 2: About 5% carbon dioxide, about 5% oxygen, about 10% - 15%
carbon monoxide, and the balance substantially all molecular nitrogen.-Container 3: ~bout 10% carbon dioxide, about 5% oxygen, about 10% -15% carbon monoxide, and the balance substantially all molecular nitrogen. ~;
Container 4: About 15% carbon dioxide, about 5% oxygen, about 10%
15% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 5: About 0 - 5% carbon dioxide, about 21% ~ 4% oxygen, about 10% - 15% carbon monoxide~ and the balance substantially all molecular nitrogen.
The sixth container held air throughout the test. The temperature in each container was lowered to and maintained at about 50 F. for three weeks. During the three weeks, the gas concentrations in containers 1 through 5 were monitored, and adjustments were made to maintain the gas concentrations close to the starting concentratlons.
Ho~ever, in container 5, the oxygen concentration was permitted to decrease from 21% at the outset to 4% at the end o~ the three week period.
At the end o~ the three weeks, the containers were opened and the cantaloupes exalQined. All melons exhibited some mold and - 20 ~
F~
.. .
. ~ . . .. . .
, ~
10~i56~9 decay, but the carbon monoxide treated melons exhibited substantially less decay than cantaloupes held in air. Higher concentrations of carbon dioxlde in comblnatlon wlth carbon monoxide enhanced inhibition of the fungi.
Example 16: Nectarine Storage ~our groups of nectarlnes, each containing from 25 to 30 fruit, were placed ln sepa~ate contalners. The atmosphere in three of the containers was modified to contaln initially the following con-centratlons of gases:
Container 1: ~bout 12% carbon dioxlde, about 3% oxygen, and the balance substantially all molecular nitrogen.
Container 2: About 12% carbon monoxide, about 10% oxygen, and the ~ ;
balance substantially all molecular nitrogen.
Container 3: About 7% carbon dioxide, about 7% oxygen, about 10%
carbon monoxide, and the balance substantlally all molecular nitrogen.
The fourth container held air throughout the test.
The temperature oR each container was lowered to 32~. initially, but rose to 50~. for at least part of the test period. Dur-Lng the three week period, the gas concentrations in each of the first three containers were monitored and ad~ustments were made to maintain the concentrations at or near the starting concentration.
~fter three weeks, the containers were opened and the fruit inspected. Of the 28 fruit in container 1, 8 exhibited some brown rot and some off-flavor. Of the 25 ruit container 2, none exhibited brown rot, but some were off-flavor. Of the 25 fruit in container 3, none exhlbited brown rot, and flavor was acceptable. Of the 31 ~ruit held in air, 12 exhibited brown rot, and again flavor was acceptable.
Carbon monoxide inhibited development of brown rot fungi without any detrimental impact on flavor. ~oreover, where carbon monoxide was present, carbon dioxide could be maintained at lower levels, .
, . ' ' .
~(1 8~S6~
insuring preservatlon o~ good flavor.
Example 17: Papaya Storage Two groups of papaya, one containlng 14 fruit, the other 16 fruit, were placed ln separate contalners. The atmosphere in the first container was modified to contain initially an atmosphere of about 10~ carbon dioxide, about 3% oxygen, about 10% carbon monoxide, and the balance substantial all molecular nltrogen. The atmosphere in the second container was air throughout the test. The temperature in each container was modl~led to, and held at 55~. ~or 10 days. During the 10 days, the atmosphere in the first container was monitored, and ad~ustments made to maintain gas concentrations at or near the initial concentrations.
~t the end of 10 days, papayas held in air were riper than those held in the modlfled atmosphere. All ~ruit was~held another four days at about 70-75~. in air to observe ripening and shelf life. ~ `
At the end of four days, fruit held in modified atmosphere was still not nearly as ripe as the fruit held ln air throughout.
None o~ the fruit developed any ~nthracnose rot, but 4 of the 16 fruit held in alr developed stem end rot. Only 1 o~ the fruit held in the modif~ed atmosphere exhibited any stem end rot.
Taste and aroma of all fruit was normal, indicating that carbon monoxide had no deleterious effect on flavor.
Example 18: Peach Storage Three groups of peaches of the Summerset variety, 100 fruit ln each group, were placed in separate containers. The atmosphere ;~
in the fruit container was modlfied to contain initially about 3% carbon dioxide, about 4% oxygen, about 10% carbon monoxide, and the balance substantially all molecular nitrogen. The atmosphere in the second `
container was modi~ied to contain about 5% carbon dioxide, about 5 oxygen, about 10% carbon monoxlde, and the balance substantially all :
~ - 22 - ~ ~
., . ~ .: . . ..
.
:
iS6C~
molecular nitrogen. The third container held air throughout the test.
The temperature in each container was reduced to and held at about 32F. for five weeks. During this time, the gas concentrations in the first two containers were monitored, and ad~ustments were made to maintain the gas concentrations at or near the startlng concentrations.
At the end of three weeks, the containers were opened, and 50 peaches were removed from each of the containers. O~ the 50 peaches removed from the air container, 8 were decayed at mechanically damaged areas. ~d~ancement of decay was moderate, and mycelial growth was abundant. Of the 50 peaches ~rom container 2, 5 were decayed at mechanically damaged areas, but decay was much less advanced than with peaches held in air, and both mycelial growth and sporulation were inhibited. Of the 50 peaches held ln container 1, 3 were decayed at mechanically damaged areas, but again, mycelial growth and sporulation were inhibited.
The rest of the peaches were held two more weéks in the containers under the same condi~ions. O~ the lO0 peaches from the two modified atmosphere containers, only 13 in all (6 ~rom container 1 and 7 from container 2) were decayed at mechanically damaged areas. Of the 50 peaches from the air control atmosphere, 22 were decayed in mechanically damaged areas. No mycellal growth or sporulation was evident on peaches held in modified atmospheres, but such growth and sporulation was pro~use on peaches held in air. Moreover, peaches held in modified atmosphere containing the higher concentration of carbon dioxide had the best texture and taste of the three groups. Peaches held in the lower concentration of carbon dioxide and the peaches held in air were drier and much less tasty.
Example 19: _ 1 pepper Storage ~our groups o~ about 100 bell peppers each were placed in se~arate contalners. In the first container, the atmosphere was ~7 , . .
., .
S6~3 modi~ied to produce an atmosphere containlng initially about 3% carbon dloxide, about 5% oxygen, about 25% carbon monoxide, and the balance substantlally all molecular nitrogen. In the second container, the atmosphere was alr throughout the test. The temperature in each container was reduced to and held at about 48 to about 50~. for 23 days. During thls tlme, the oxygen concentr~tion varled ~rom about 5% to about 10%, and the carbon ~onoxlde concentratlon Prom about 25%
to about 10% ln the first container.
At the end of 23 days, the peppers were removed and observed. Peppers held ln alr had mold growth on all stems, and many exhlbited severe rottlng. Peppers held ln the modified atmosphere were Pree of surface mold growth and rots.
In a separate test, a third group of peppers was placed in a third container, and ~he atmosphere therein modified to contain ;~
initially about 2% carbon dioxide, about 5% oxygen, about 15% carbon monoxide, and the balance substantlally all molecular nitrogen. The atmosphere ln the fourth container, into whlch was placed the fourth group of bell peppers, was air throughout this second test. The temperature in the thlrd and Pourth contalners was reduced to and ~ ;~
malntained at about 48 to about 50~. throughout a 14 day test perlod. ;~ ; ' ThereaPter, the peppers were removed and observed, and results were ;
comparable to those obtained with the peppers held in containers 1 and 2 for 23 days. ~ ~
~.: -' : :
Example 20: Zucchini Squash Sto~age ~ .
Six groups of Zucchini squash, each group containing :~ :
about 110 to about 120 squash, were placed in separate containers. ~`
The atmospheres in 5 of the containers were modiPied to produce the Pollowing compositions:
Container 1: About 10% carbon dioxide, about 3% to about 5% oxygen7 and the balance sub~tantlally all molecular nltrogen.
..
~7 24 - -~;' .
' . . :, .~ :, .'. .
; :: , ~ : . , 1~6~6~
Container 2: About 10~ carbon dloxide, about 3% to about 5% oxygen!
about 10% carbon monoxlde, and the balance substantially all molecular nitrogen.
Container 3: About 5% carbon dioxide, about 3% to about 5% oxygen, and the balance substantially all molecular nltrogen.
Container 4: About 5% carbon dioxide, about 3% to about 5~ o~ygen, about 10% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 5: ~bout 20% oxygen, about 10% carbon monoxide, and the balance substantially all molecular nitrogen.
The sixth container held air throughout the test. The temperature in each of the containers was reduced to and maintained at about 45F.
to 47F. for two weeks. During this time, the atmospheres in containers 1 through 4 were monitored, and ad~ustments made to hold the concentra-tions at or near the starting concentrations. However, in the fifth container, the oxygen concentration was permitted to decrease naturally by respiration to about 3% at the end of the test period.
At the end of two weeks, the squash were removed and inspected. The squash held in air had surEace mold growth on virtually the entire surface of all the squash. Ten squash held in air exhibited some decay. Squash held in container 1 had a small quantity of surEace mold growth; 7 squash were slightly decayed. Squash held in container 2 had no decay and only traces of surface mold growth. Squash held in container 3 had the most surPace mold growth and the highest number of decayed squash. The squash from container 4 were not decayed and exhibited only traces of surface mold growth. Squash held in container 5 had little decay but exhibited substantial mold growth, indicating that car~on dioxide also has a valua~le role in preserving the life of this vegetable.
- 25 ~
.. .
.
6~;i61D -Example 21: Tom~to Stor~ge .
Three groups o~ 48 tomatoes each were placed in separate containers. The atmospheres in the first two containers were modified to produce the followlng:
Container 1: About 3% to about 5% oxygen, about 5% to about 10%
carbon monoxide, and the balance substantlally all molecular nitrogen.
Container 2: About 3% to about 5% oxygen, and the balance substantially all molecular nitrogen.
The third container held air throughout the test. The temperature in each container was seduced to and held at about 50 F. Por 23 days.
During this time, the concentrations of gases in containers 1 and 2 were monltored, and adJustments made to maintain the concentrations at or near the startlng concentratlons.
~t the end oP 23 days, the tomatoes held in container 1 were free from rot. Tomatoes Prom containers 2 and 3 were severely rotted. This test proves that carbon monoxide effectlvely inhibits : - . , the growth of fungi on tomatoes.
Example 22: Tomato Storage ;~
Two groups oP 72 tomatoes each were placed in sepa~ate containers. Half of each group had a color index of 2-3; the other -~half, 4-5. Atmosphere in container 1 was modiPied to contain initially about 5% oxygen, about 14% carbon monoxide, and the balance substantially all ~olecular nitrogen. The atmosphere in container 2 was alr through~
out the test. The temperature ln each container was modified to and held at about 50F. for two weeks. During that time, the gas con- ~;
centrations in container 1 were monitored and ad~ustments made to ;~ `
maintain the concentrations at or near the starting concentrations. ;
At the end oP two weeks, the tomatoes held in air had ~ ~
all advanced to a color index oP 5. Those lnltlally of lndex 4-5 were ~ -40% decayed and surface mold growth was present on all stem scars.
_ 26 -':'' ''~ ' ;S6~
Those inltlally of color index 2-3 we~e ~bout 20% decayed, and surface mold growth was present on about 50% o~ the stem scars.
Those tomatoes held in modi~ied atmosphere that initially had the color lndex 4 5 advanced to color index 5 almost entirely, and were free of surface mold growth and decay. Those tomatoes held in modi~ied atmosphere that had an initial color index of 2-3 were still substantially all at index 2~3, and were also free of surface mold growth and decay.
Example 23:- Thompson Seedless Grape Storage ~ ;
Four boxes o~ Thompson seedless grapes, each box containing about 20 pounds o~ grapes, were placed in separate containers.
These grapes had been pseviously treated with sulfur dioxide in order to control decay. The atmospheres in the flrst three containers were modified to produce atmospheres initially having the following compositions:
Container 1: About 10% carbon dioxide, about 5% to about 10% oxygen, about 10% to about 20% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 2: About 5% carbon dioxide, about 5% to about 10% oxygen, about 10% to about 20% carbon monoxide, and the balance substantially all molecular nltrogen.
Container 3: About 5% to about 10% oxygen, about 10% to about 20% ~ ~ -carbon monoxide, and the balance substantially all molecular nitrogen.
The atmosphere in the ~ourth container was air throughout the test.
The temperature in each of the containers was modified to, and held at about 33 to about 34 ~. for 11 weeks. During this time, the gas concentrations in the first three containers were monitored, and adjustments made to maintain the concentratlons of each of the gases at or near the initial concentrations. After four weeks, mold was evident in alr control grapes. After seven weeks of storage, the air control -' ~
;S~O
grapes were a solid mass o~ ne~tlng mold. ~ll g~apes held ln ~odlfled atmospheres were free of rots and mycelial growth at the end of the 11-week period. These results were particul~rly striking because the ideal storage temperature for grapes is about 30 to about 31 F.
Example 24: Grape Storage Grapes of two varieties, namely Cabernet Sauvignon and ~
Johannesberg Reisllng, each variety lncluding some grapes of grade one -Irot free) and grade two (Alternaria fleld rot infected) were divided ~ -as follows for testing. ~pproximately one pound of grade one grapes rom each variety was placed in a first container, and approximately ;
one pound of grade two grapes of each variety was placed in a second container. Approximately the same quantities and comblnations were placed in third and ourth containers to serve as controls. -The atmosphere in the first container was modified to produce a composition including about 5% to about 12% oxygen about 15% to about 20% carbon monoxide, and the balance substantially all ~ ~ -molecular nitrogen. Thé atmosphere in the second container modified to produce a composition including about 2% to about 5%-oxygen, about ;~
20% to about 25% carbon monoxide, and the balance substantially all molecular nitrogen. The second container also included amounts of carbon dioxide that did not exceed about 1% at any time during the ~est.
The atmosphere in the third and fourth containers was air throughout ~
the test. The temperature in each of the containers was modified to ;
and maintained at about 34 to about 35F. for a 45-day period.
During that time~ the carbon monoxide and oxygen concentrations in the first two containers fluctuated between the values set forth above, and adjustments were made to maintain these values within these ranges throughout the test period.
' ' , ' ,~
~: , , .
;56(~
At the end of 45 days, the grade 1 grapes from container 1 were free of mold growth. The Alternaria field rot infectlons on the grade 2 grapes from container 2 had not advanced, indicating that the rot infections were inhibited. By contrast, the grade 2 grapes from the air control container 4 were grossly rotted and mycelial growth was abundant. Mold growth on grade 1 grapes from container 3 was also ob~ectionable though not as severe as that on grade 2 grapes from container 4.
. :
.
~ : ' ~
.. . .
, . -. ! : . ;
Three groups o~ 48 tomatoes each were placed in separate containers. The atmospheres in the first two containers were modified to produce the followlng:
Container 1: About 3% to about 5% oxygen, about 5% to about 10%
carbon monoxide, and the balance substantlally all molecular nitrogen.
Container 2: About 3% to about 5% oxygen, and the balance substantially all molecular nitrogen.
The third container held air throughout the test. The temperature in each container was seduced to and held at about 50 F. Por 23 days.
During this time, the concentrations of gases in containers 1 and 2 were monltored, and adJustments made to maintain the concentrations at or near the startlng concentratlons.
~t the end oP 23 days, the tomatoes held in container 1 were free from rot. Tomatoes Prom containers 2 and 3 were severely rotted. This test proves that carbon monoxide effectlvely inhibits : - . , the growth of fungi on tomatoes.
Example 22: Tomato Storage ;~
Two groups oP 72 tomatoes each were placed in sepa~ate containers. Half of each group had a color index of 2-3; the other -~half, 4-5. Atmosphere in container 1 was modiPied to contain initially about 5% oxygen, about 14% carbon monoxide, and the balance substantially all ~olecular nitrogen. The atmosphere in container 2 was alr through~
out the test. The temperature ln each container was modified to and held at about 50F. for two weeks. During that time, the gas con- ~;
centrations in container 1 were monitored and ad~ustments made to ;~ `
maintain the concentrations at or near the starting concentrations. ;
At the end oP two weeks, the tomatoes held in air had ~ ~
all advanced to a color index oP 5. Those lnltlally of lndex 4-5 were ~ -40% decayed and surface mold growth was present on all stem scars.
_ 26 -':'' ''~ ' ;S6~
Those inltlally of color index 2-3 we~e ~bout 20% decayed, and surface mold growth was present on about 50% o~ the stem scars.
Those tomatoes held in modi~ied atmosphere that initially had the color lndex 4 5 advanced to color index 5 almost entirely, and were free of surface mold growth and decay. Those tomatoes held in modi~ied atmosphere that had an initial color index of 2-3 were still substantially all at index 2~3, and were also free of surface mold growth and decay.
Example 23:- Thompson Seedless Grape Storage ~ ;
Four boxes o~ Thompson seedless grapes, each box containing about 20 pounds o~ grapes, were placed in separate containers.
These grapes had been pseviously treated with sulfur dioxide in order to control decay. The atmospheres in the flrst three containers were modified to produce atmospheres initially having the following compositions:
Container 1: About 10% carbon dioxide, about 5% to about 10% oxygen, about 10% to about 20% carbon monoxide, and the balance substantially all molecular nitrogen.
Container 2: About 5% carbon dioxide, about 5% to about 10% oxygen, about 10% to about 20% carbon monoxide, and the balance substantially all molecular nltrogen.
Container 3: About 5% to about 10% oxygen, about 10% to about 20% ~ ~ -carbon monoxide, and the balance substantially all molecular nitrogen.
The atmosphere in the ~ourth container was air throughout the test.
The temperature in each of the containers was modified to, and held at about 33 to about 34 ~. for 11 weeks. During this time, the gas concentrations in the first three containers were monitored, and adjustments made to maintain the concentratlons of each of the gases at or near the initial concentrations. After four weeks, mold was evident in alr control grapes. After seven weeks of storage, the air control -' ~
;S~O
grapes were a solid mass o~ ne~tlng mold. ~ll g~apes held ln ~odlfled atmospheres were free of rots and mycelial growth at the end of the 11-week period. These results were particul~rly striking because the ideal storage temperature for grapes is about 30 to about 31 F.
Example 24: Grape Storage Grapes of two varieties, namely Cabernet Sauvignon and ~
Johannesberg Reisllng, each variety lncluding some grapes of grade one -Irot free) and grade two (Alternaria fleld rot infected) were divided ~ -as follows for testing. ~pproximately one pound of grade one grapes rom each variety was placed in a first container, and approximately ;
one pound of grade two grapes of each variety was placed in a second container. Approximately the same quantities and comblnations were placed in third and ourth containers to serve as controls. -The atmosphere in the first container was modified to produce a composition including about 5% to about 12% oxygen about 15% to about 20% carbon monoxide, and the balance substantially all ~ ~ -molecular nitrogen. Thé atmosphere in the second container modified to produce a composition including about 2% to about 5%-oxygen, about ;~
20% to about 25% carbon monoxide, and the balance substantially all molecular nitrogen. The second container also included amounts of carbon dioxide that did not exceed about 1% at any time during the ~est.
The atmosphere in the third and fourth containers was air throughout ~
the test. The temperature in each of the containers was modified to ;
and maintained at about 34 to about 35F. for a 45-day period.
During that time~ the carbon monoxide and oxygen concentrations in the first two containers fluctuated between the values set forth above, and adjustments were made to maintain these values within these ranges throughout the test period.
' ' , ' ,~
~: , , .
;56(~
At the end of 45 days, the grade 1 grapes from container 1 were free of mold growth. The Alternaria field rot infectlons on the grade 2 grapes from container 2 had not advanced, indicating that the rot infections were inhibited. By contrast, the grade 2 grapes from the air control container 4 were grossly rotted and mycelial growth was abundant. Mold growth on grade 1 grapes from container 3 was also ob~ectionable though not as severe as that on grade 2 grapes from container 4.
. :
.
~ : ' ~
.. . .
, . -. ! : . ;
Claims (32)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In the process of storage or shipment of fresh produce refrigerated to a temperature in the range of 29-60°F, the improvement which consists essen-tially of maintaining said produce in a modified gaseous atmosphere of carbon dioxide, about 1-20% by volume; molecular oxygen, about 1.8-20% by volume;
carbon monoxide, about 5-20% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said fresh produce.
carbon monoxide, about 5-20% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said fresh produce.
2. In the process of storage or shipment of fresh cauliflower refrigerated to a temperature in the range of 29-60°F, the improvement which consists essentially of maintaining said cauliflower in a modified gaseous atmos-phere of carbon dioxide, about 2.2-10% by volume; molecular oxygen, about 1.8-12%
by volume; carbon monoxide, about 5-20% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said cauliflower.
by volume; carbon monoxide, about 5-20% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said cauliflower.
3. In the process of storage or shipment of fresh mushrooms refrigerated to a temperature in the range of 29-60°F, the improvement which consists essentially of maintaining said mushrooms in a modified gaseous atmos-phere of carbon dioxide, about 5-20% by volume; molecular oxygen, about 3-20%
by volume; carbon monoxide, about 10-20% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said mushrooms.
by volume; carbon monoxide, about 10-20% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said mushrooms.
4. In the process of storage or shipment of fresh bell peppers refrigerated to a temperature in the range of 29-60°F, the improvement which consists essentially of maintaining said bell peppers in a modified gaseous atmosphere of carbon dioxide, about 10-20% by volume; molecular oxygen, about 3-7% by volume; carbon monoxide, about 10% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said bell peppers.
5. In the process of storage or shipment of fresh grapes refrigerated to a temperature in the range of 29-60°F, the improvement which consists essen-tially of maintaining said grapes in a modified gaseous atmosphere of carbon dioxide, about 5-10% by volume; molecular oxygen, about 5% by volume, carbon monoxide, about 5-10% by volume; and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said grapes.
6. In the process of storage or shipment of refrigerated fresh blue-berries, the improvement which consists essentially of maintaining said blue-berries in a modified gaseous atmosphere of carbon dioxide, about 5-10% by volume;
molecular oxygen, about 3-10% by volume; carbon monoxide, about 8-25% by volume;
and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said blueberries.
CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE
molecular oxygen, about 3-10% by volume; carbon monoxide, about 8-25% by volume;
and the remainder essentially molecular nitrogen during the period of storage or shipment, to inhibit the growth of fungi on said blueberries.
CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE
7. A process for inhibiting the growth of fungi on fresh produce during storage or shipment, comprising maintaining said fresh produce at a temperature in the range of about 29°F to about 60°F, and in a modified gaseous atmosphere including carbon dioxide in an amount from zero to about 20% by volume, molecular oxygen in an amount of about 1% to about 20% by volume, carbon monoxide in an amount of about 3% to about 25% by volume, and the remainder substantially all molecular nitrogen, the fresh produce being maintained in said modified gaseous atmosphere during the period of storage or shipment, thereby inhibiting the growth of fungi on said fresh produce.
8. The process of claim 7, wherein the produce is bell peppers, the carbon dioxide concentration is in the range of about 1% to about 10%, and the oxygen concentration is in the range of about 5% to about 20%.
9. The process of claim 7, wherein the produce is cauliflower, the concentration of carbon dioxide is in the range of about 1% to about 10%, and the oxygen concentration is in the range of about 3% to about 20%.
10. The process of claim 7, wherein the produce is mushrooms, the carbon dioxide concentration is in the range of about 3% to about 20%, and the oxygen concentration is in the range of about 3% to about 20%.
11. The process of claim 7, wherein the produce is grapes, the carbon dioxide concentration is in the range of zero to about 15%, and the oxygen concentration is in the range of about 2% to about 15%.
12. The process of claim 7, wherein the produce is blueberries, the carbon dioxide concentration is in the range of about 1% to about 15%, and the oxygen concentration is in the range of about 2% to about 10%.
13. The process of claim 7, wherein the produce is tomatoes, the carbon dioxide concentration is in the range of about zero to about 7%, and the oxygen concentration is in the range of about 3% to about 10%.
14. The process of claim 7, wherein the produce is squash, the carbon dioxide concentration is in the range of about 3% to about 15%, and the oxygen concentration is in the range of about 2% to about 10%.
15. The process of claim 7, wherein the produce is pineapples, the carbon dioxide concentration is in the range of about 1% to about 15%, and the oxygen concentration is in the range of about 2% to about 15%.
16. The process of claim 7, wherein the produce is peaches, the carbon dioxide concentration is in the range of about 1% to about 10%, and the oxygen concentration is in the range of about 2% to about 10%.
17. The process of claim 7, wherein the produce is papaya, the carbon dioxide concentration is in the range of about 2% to about 10%, and the oxygen concentration is in the range of about 2% to about 10%.
18. The process of claim 7, wherein the produce is nectarines, the carbon dioxide concentration is in the range of about 1% to about 10%, and the oxygen concentration is in the range of about 2% to about 10%.
19. The process of claim 7, wherein the produce is mangoes, the carbon dioxide concentration is in the range of about 2% to about 10%, and the oxygen concentration is in the range of about 2% to about 10%.
20. The process of claim 7, wherein the produce is melons, the carbon dioxide concentration is in the range of about 2% to about 20%, and the oxygen concentration is in the range of about 3% to about 15%.
21. The process of claim 7, wherein the produce is eggplant, the carbon dioxide concentration is in the range of zero to about 8%, and the oxygen concentration is in the range of about 2% to about 15%.
22. The process of claim 7, wherein the produce is green beans, the carbon dioxide concentration is in the range of about 2% to about 10%, and the oxygen concentration is in the range of about 2 % to about 10%.
23. The process of claim 7, wherein the produce is apples, the carbon dioxide concentration is in the range of about 1% to about 10%, and the oxygen concentration is in the range of about 1% to about 10%.
24. The process of claim 7, wherein the produce is pears, the carbon dioxide concentration is in the range of zero to about 8%, and the oxygen concen-tration is in the range of about 2% to about 8%.
25. The process of claim 7, wherein the produce is apricots, the carbon dioxide concentration is in the range of about 1% to about 8%, and the oxygen concentration is in the range of about 2% to about 8%.
26. The process of claim 7, wherein the produce is cherries, the carbon dioxide concentration is in the range of about 3% to about 20%, and the oxygen concentration is in the range of about 2% to about 15%.
27. The process of claim 7, wherein the produce is cabbage, the carbon dioxide concentration is in the range of about 1% to about 10%, and the oxygen concentration is in the range of about 2% to about 10%.
28. The process of claim 7, wherein the produce is avocado, the carbon dioxide concentration is in the range of about 3% to about 15%, and the oxygen concentration is in the range of about 2% to about 10%.
29. The process of claim 7, wherein the produce is lettuce, the carbon dioxide concentration is in the range of zero to about 5%, and the oxygen concentration is in the range of about 2% to about 15%.
30. The process of claim 7, wherein the produce is potatoes, the carbon dioxide concentration is in the range of about 5% to about 20%, and the oxygen concentration is in the range of about 3% to about 10%.
31. The process of claim 7, wherein the produce is onions, the carbon dioxide concentration is in the range of about 4% to about 15%, and the oxygen concentration is in the range of about 1% to about 7%.
32. The process of claim 7, wherein the produce is sweet potatoes, the carbon dioxide concentration is in the range of about 3% to about 5%, and the oxygen concentration is in the range of about 5% to about 7%.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US63861975A | 1975-12-08 | 1975-12-08 | |
| US638,619 | 1975-12-08 | ||
| US78452877A | 1977-04-04 | 1977-04-04 | |
| US784,528 | 1977-04-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1086560A true CA1086560A (en) | 1980-09-30 |
Family
ID=27093131
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA254,551A Expired CA1086560A (en) | 1975-12-08 | 1976-06-10 | Refrigerated storage or shipment of fresh produce in a modified gaseous atmosphere |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1086560A (en) |
-
1976
- 1976-06-10 CA CA254,551A patent/CA1086560A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4411921A (en) | Method for inhibiting fungal growth on fresh fruits and vegetables | |
| AU607200B2 (en) | Preservation of cut and segmented fresh fruit pieces | |
| US4224347A (en) | Process and package for extending the life of cut vegetables | |
| Kader | Prevention of ripening in fruits by use of controlled atmospheres | |
| US4883674A (en) | Controlled atmosphere cut fruit package and method | |
| US4943440A (en) | Controlled atmosphere cut vegetable produce package and method | |
| US4209538A (en) | Method for inhibiting fungi in citrus fruit | |
| IL26462A (en) | Storage of perishable vegetable produce | |
| CN105994593B (en) | Method for packaging and preserving harvested broccoli in modified atmosphere | |
| Barkai-Golan | Postharvest disease suppression by atmospheric modifications | |
| US5110609A (en) | Intermediate moisture vegetables | |
| Geeson | Modified atmosphere packaging of fruits and vegetables | |
| Sharma et al. | Storage life and fruit quality of individually shrink-wrapped apples (Malus domestica) in zero energy cool chamber | |
| Manolopoulou et al. | Storage and processing of apricots | |
| Leshuk et al. | Controlled atmosphere storage requirements and recommendations for vegetables | |
| US6451363B1 (en) | Method and package for the preservation of whole fruits and fresh-cut salads and flowers | |
| US8025912B2 (en) | Method for packaging bananas for ripening | |
| CN102293244B (en) | Fresh keeping method of fresh litchi fruit | |
| CA1086560A (en) | Refrigerated storage or shipment of fresh produce in a modified gaseous atmosphere | |
| CN102550646B (en) | Method for preserving waxberries by way of pressure reduction treatment | |
| WO1986001686A1 (en) | Intermediate moisture vegetables | |
| Terry et al. | Small fruit and berries | |
| JP2571165B2 (en) | Gas refrigeration of fruits and vegetables requiring ripening | |
| CA1105317A (en) | Process for extending the life of cut vegetables | |
| Chunyang et al. | Effect of high oxygen modified atmosphere packaging on fresh-cut onion quality |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |