Patent Publication Number: US-2010119672-A1

Title: Fruit ripening process using bagging and cooling

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     1. Technical Field of the Invention 
     The present invention relates to a fruit ripening process and, more particularly, a fruit ripening process using bagging and cooling. 
     2. Description of the Related Art 
     Fruit ripening is a process associated with the edibility of fruit. A fruit may become sweeter, less green, and softer as it ripens. The life stages of a fruit are influenced by hormones. An organic compound involved with ripening in fruit is ethylene. Ethylene is a gas created by plants from the amino acid methionine. In fruit and fresh cut produce, ethylene gas increases the intracellular levels of certain enzymes. In small quantities, ethylene gas may be used as an anesthetic agent for expediting the fruit ripening process. Ethylene may act physiologically as a hormone in fruits. Ethylene exists naturally as a gas and may act at trace levels throughout the life of the fruit by stimulating or regulating the ripening of fruit. The ability to inhibit or control the production of ethylene gas by the fruit may be used to increase or decrease the period of time required for the natural ripening process. 
     The climacteric period in fruit corresponds with maximum cell respiration and ethylene production throughout the fruits life cycle. The climacteric period is the final physiological process that marks the end of fruit maturation and the beginning of fruit senescence. The climacteric period is the defining point associated with increased cell respiration of the fruit and normally takes place without any external influences. Subsequently, the fruits cell respiration rate may return to or below previous levels. The respiration rate of the fruit is associated with carbon dioxide production of the fruit. The climacteric period may also lead to other changes in the fruit including pigment changes and sugar release. For those fruits raised as food the climacteric period marks the peak of edible ripeness, with fruits having the best taste and texture for consumption. After this period, fruits are more susceptible to fungal invasion and begin to degrade with cell death. Therefore, both a delay in reaching the climacteric period and the extension of the climacteric period once reached may be desirable qualities during the fruit ripening process. Apples, avocados, bananas, melons, apricots, and tomatoes by way of example are climacteric fruit. 
     Many fruits are picked prior to full ripening because ripened fruits do not ship well. For example, bananas are picked when green and may artificially ripen after shipment by being exposed to ethylene gas. Another method used to artificially ripen fruit may include covering a bed of fruit and a few small open containers of calcium carbide with a plastic covering. The moisture in the air reacting with the calcium carbide releases the gas acetylene. Acetylene may have the same effect on the fruit as exposure to ethylene gas. Calcium carbide once dissolved in water produces acetylene which is an essential gas for the fruit ripening process. However, calcium carbide may contain traces of arsenic and phosphorus. The traces of arsenic and phosphorus, may pose a health risk. Due to possible health concerns, calcium carbide may not be recommended for the fruit ripening process. Acetylene is believed to affect the nervous system by reducing oxygen supply to the brain. 
     Another well known method for synthetically enhancing edibility of fruit is based on 1-methylcycolpropene (1-MCP). 1-MCP&#39;s mode of action is via a preferential attachment to the ethylene receptor, thereby blocking the effects of both endogenous and exogenous ethylene. It is applied in storage facilities and transit containers to slow down the ripening process and the production of the ethylene in fruit. Ethylene gas is not useful for ripe post harvested fruit. This method may be used to inhibit ripening of fruit by even a year. The delay of fruit ripening by approximately one year may result in consumers eating year-old fruit without being aware of it. The use of 1-MCP may be associated with a decline in vitamin C and antioxidant levels. With increased public awareness, the demand for organic fruit is increasing. 
     Using ethylene in the fruit ripening process is known as pre-conditioning the fruit. Pre-conditioning is the process of exposing firm/hard un-ripened fruit to ethylene gas to stimulate ripening. The benefits associated with pre-conditioning and controlled ripening may include increased sales, creation of impulse sales at retail store level, improve inventory control, regulate the period at which the fruit is ready to eat, produce consistent uniformly ripened fruit, and provide better control of quality and ripeness. 
     The pre-conditioning process may be used to stimulate ripening of avocados. The avocados are received and handled at a warehouse at ambient temperature having a corresponding avocado pulp temperature which may also be referred to as an internal fruit seed temperature. The avocado may then be placed in a controlled temperature environment for achieving a desired pulp temperature. The controlled temperature environment may use equipment capable of increasing and decreasing the pulp temperature of the avocado within a particular temperature range within a specified period of time. Avocados may produce 2-3 times more heat than bananas and thus stand to benefit from improved air circulation. Forced air cooling systems may result in the optimal heating and cooling of the avocado to the desired pulp temperatures. The air flow rate may be approximately 0.5 cubic feet per minute for every 16 avocados in the controlled temperature environment. 
     Proper pre-conditioning/ripening procedures may begin with placing the avocado within the controlled temperature environment and increasing the pulp temperature of the avocado to a range between 15° C. and 20° C. Using an ethylene generator or bottled ethylene to maintain ethylene at 10-100 parts per million (PPM) throughout the entire conditioning cycle. Optimum relative humidity level may be between 90 and 95 percent. The pulp temperature of the avocado may be cooled to 4° C.-6° C. to slow the ripening process. Warehouse storage of the pre-conditioned fruit at 4° C.-6° C. is recommended between 10 to 14 days. Older or stressed fruit may hold for less time resulting in irregular ripening and greater decay. After pre-conditioning, the ripened avocado is ready to be consumed. At 10° C. pulp temperature, the avocado may require between 7 and 10 days to ripen. At 15° C. pulp temperature, the avocado may require between 3 and 6 days to ripen. At 20° C. pulp temperature, the avocado may take between 2 and 4 days to ripen. The pre-conditioning/ripening process may be adjusted for non-forced air storage areas. Warehouse stacking may be implemented to improve the ripening process when forced air is not used. For example, the fruit may be stacked in an alternating four-block or five-block pattern resulting in adequate refrigeration and improved air circulation for controlling an increase in heat associated with the avocado. 
     Common causes of uneven ripening include improper amount of ethylene gas exposure, incorrect exposure time, ill-advised storage temperatures, and humidity levels below 85%. An increase in storage temperature resulting in pulp temperatures above 21° C. adversely affects the ripening process. In fact, a pulp temperature above 25° C. may block the ripening process. Improper air flow and circulation may cause hot spots within the fruit to develop. Additionally, excessive carbon dioxide buildup above 1% inhibits ripening of fruit. Excessive holding periods prior to beginning the ripening cycle, wide variation of pulp temperatures during arrival at the fruit packing warehouse and fruit stored below 6° C. before pre-conditioning may adversely impact the ripening process. 
     Accordingly, there exists a need in the art for an improved fruit ripening process using bagging and cooling which addresses one or more of the above or related deficiencies. 
     BRIEF SUMMARY 
     A method of handling fruit at ambient temperature is provided using bagging and cooling for prolonged storage and ripening of fruit. The type of fruit that is contemplated with respect to the method is a fruit having an internal fruit seed. The method begins with enclosing the fruit within a perforated plastic packaging material to produce an enclosed fruit. The method continues with the enclosed fruit being exposed to an air flow. The enclosed fruit is exposed to the air flow until the internal fruit seed has a pulp temperature corresponding to a first cool temperature. In this regard, the fruit is transferred from a surrounding environment at an ambient temperature to a surrounding environment which allows the internal fruit seed to cool to the first cool temperature or remain at the first cool temperature. The first cool temperature may be substantially below the ambient temperature. The internal fruit seed cools from the ambient temperature to the first cool temperature within a cool-down period. The method may conclude with the fruit being maintained at the first cool temperature of the internal fruit seed for a storage period. 
     In another embodiment, the enclosed fruit may be placed within a vented storage container. After placing the enclosed fruit within the vented storage container, the enclosed fruit may be characterized as a packed bag fruit. The enclosed fruit is placed within the vented storage container prior to being exposed to the air flow. Placing the enclosed fruit within the vented storage container may increase the quantity of fruit to be transported while still allowing for adequate air flow to reach the packed bag fruit. In one embodiment, the fruit enclosed in the plastic packaging material are avocado. Because the fruit that may be enclosed within the plastic packaging material may be avocado, the plastic packaging material may be perforated. The perforation may allow for the optimal CO 2  atmosphere for preserving the fruit. The plastic packaging material may enclose a plurality of the fruit in accordance with the method described. 
     In another embodiment, the vented storage container may be arranged in a stacked configuration. The advantage associated is the ability to store a greater quantity of the packed bag fruit in the environment that may enable the internal fruit seed to reach the first cool temperature. The vented storage container may also include a plurality of layers to enable the storage of a greater quantity of packed bag fruit. One embodiment describes the air flow being produced by a forced air cooling system. If the forced air cooling system is used, then it may be configured to deliver between 2 and 3 cubic feet of air per minute per pound of fruit. A plurality of packed bag containers may be stored in bulk boxes. Forced air cooling may include exposing the bulk boxes of the packed bag fruit to a higher air pressure on side of the box. The unequal air pressure forces the cool air past the enclosed fruit, thereby increasing the cooling rate. The optimal humidity level associated with the forced air cooling may range between 90 and 95 percent. 
     In another embodiment, the first cool temperature is between 4 degrees Celsius and 6 degrees Celsius. In this regard, the environment in which the enclosed fruit is placed should be configured to enable the internal fruit seed temperature to cool from ambient temperature to the first cool temperature ranging between 4 and 6 degrees Celsius. The cool-down period associated with the time it takes the internal fruit seed temperature to cool from ambient temperature until the first cool temperature may be up to 48 hours. However, this assumes that forced air cooling is not used. Preferably, the cool down period may range between 6 and 12 hours when using forced air cooling. In further detail, the first cool temperature of the internal fruit seed may be maintained for a storage period of up to 45 days. However, it may be preferable for the storage period to last between 10 and 15 days. In the scenario where the fruit is an avocado, the subcutaneous compaction of the avocado is greater than 27 PSI during the storage period. The subcutaneous compaction may be measured using pentrometer. 
     The method may continue by exposing the enclosed fruit to an air flow until the internal fruit seed reaches a second cool temperature. The second cool temperature is between the ambient temperature and the first cool temperature. The environments in which the enclosed fruit are placed enable the internal fruit seed to increase in temperature from the first cool temperature to the second cool temperature. The second cool temperature may be maintained for a triggering period. The triggering period is induced subsequent to the storage period. In one embodiment, the second cool temperature is between 12 degrees Celsius and 14 degrees Celsius. The triggering period may last up to 48 hours. Maintaining the internal fruit seed at the second cool temperature for the triggering period of 48 hours may enable the fruit to uniformly turn to an expected color. For example, an avocado will turn black. A triggering period substantially less than 48 hours may risk the uniform color change involved during the triggering period. During the triggering period, the subcutaneous compaction of the enclosed fruit may be between 10 and 20 PSI. 
     In another embodiment, the method may continue with a ripening period following the triggering period. During the ripening period, the enclosed fruit is exposed to ambient temperature. The ambient temperature may vary between 15 degrees Celsius and 20 degrees Celsius. The ripening period may range between 48 hours and 96 hours. During the ripening period the subcutaneous compaction of the enclosed fruit is between 5 and 8 PSI. Following the ripening period, the enclosed fruit may be removed from the plastic packaging material and placed on a shelf for display for an extended shelf life. In the alternative, if the enclosed fruit must be shipped subsequent to the ripening period, the enclosed fruit may be shipped at a temperature ranging between 4 degrees Celsius and 6 degrees Celsius prior to being removed from the plastic packaging material and stored on a display shelf. It is preferable to avoid removing the enclosed fruit from the plastic packaging material prior to displaying the fruit on a shelf. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a flow chart of a method of post-harvest handling of fruit in accordance with the present invention; 
         FIG. 2  is a step by step example for storing and packing a plurality of fruit; 
         FIG. 3  is an aerial view of the packed fruit within a vented storage container; and 
         FIG. 4  is a perspective view of the packed fruit being exposed to an air flow for cooling the packed fruit. 
     
    
    
     DETAILED DESCRIPTION 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope of the invention disclosed herein, including various ways of handling post-harvest fruit at an ambient temperature. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments. 
     Referring now to  FIG. 1 , a flow chart illustrating a series of steps and procedures that may be used for post-harvest handling of a fruit  10 . The first step  20  associated with the post-harvest handling of a fruit  10  includes handling fruit at an ambient temperature. With reference now to  FIG. 2 , the method may begin with receiving a fruit  22  at ambient temperature. In one embodiment, a plurality of the fruit  22  may be received at ambient temperature. The fruit  22  or plurality of the fruit  22  may include avocados. Avocados are a commercially valuable crop whose trees and fruit are cultivated in tropical and temperate climates throughout the world. The ambient temperature associated with the fruit  22  ranges depending upon the environment at which the fruit  22  was stored prior to being received. For example, if the fruit  22  is received from a refrigerated container, the ambient temperature may range between 3 degrees Celsius and 6 degrees Celsius. If the fruit  22  is transported directly from the field, the ambient temperature may be greater than 20 degrees Celsius. However, other ambient temperatures outside of this range are compatible with the post-harvest handling of the fruit  10  to extend the lifespan of the fruit  22  and reduce loss in quality associated with the fruit  22 . Thus, the ambient temperature associated with the fruit  22  may vary depending upon the surrounding environment. Temperatures above 21 degrees Celsius may adversely affect the ripening process associated with the fruit  22 . Temperatures above 25 degrees Celsius may prevent the ripening process of the fruit  22  entirely. The fruit  22  such as avocados may be received at ambient temperature from a local farmer, imported from a refrigerated container, or received for repacking by way of example only and not meant to limit the various ways in which the fruit  22  may be received. 
     The fruit  22  includes an internal fruit seed  24  as shown in  FIG. 2 . The internal fruit seed  24  has a temperature associated with it that may vary based upon the ambient temperature to which the fruit  22  was exposed. For example, if the fruit  22  is placed in a refrigerated container the internal fruit seed  24  temperature is cooler than the internal fruit seed  24  temperature of the fruit  22  transported directly from the field. The temperature of the internal fruit seed  24  may also be referred to as the pulp temperature. The pulp temperature of the fruit  22  is an important indicator that may correspond to optimal temperature ranges for preserving the fruit  22  and reducing loss in quality. 
     Referring back to  FIG. 1 , the second step  30  associated with the post-harvest handling of the fruit  10  includes enclosing the fruit in a perforated plastic packaging material. Subsequent to receiving the fruit  22 , the fruit  22  may be placed on a tray  26 . The tray  26  may be provided to facilitate the handling of a plurality of the fruit  22 . However, the tray  26  is not required. The tray  26  with the fruit  22  is then placed in a perforated plastic packaging material  32 . The perforated plastic packaging material  32  is used to bag the fruit  22  as provided in  FIG. 2 . In this regard, the perforated plastic packaging material  32  may include a bag. The bag may be sealed using a fastener or simply tied. Upon placement of the fruit  22  or the tray  26  of fruit  22  within the perforated plastic packaging material  32 , the perforated plastic packaging material  32  may be sealed or tied to produce an enclosed fruit  34 . The use of perforated plastic packaging material  32  for enclosing produce is provided in U.S. Pat. No. 6,190,710 issued to Nir et al. and incorporated by reference herein. The bag used to enclose the fruit  22  may have similar or identical properties in accordance with the plastic packaging material disclosed in the &#39;710 patent. However, other perforated plastic packaging material  32  may also be used to enclose the fruit  22  and produce the enclosed fruit  34  inside the bag comprised of the perforated plastic packaging material  32 . The perforated plastic packaging material  32  may not be limited to the plastic packaging material disclosed in the &#39;710 patent. 
     The perforated plastic packaging material  32  may have a relatively high permeability to water vapor. The perforated plastic packaging material  32  may reduce condensation on the surface of the perforated plastic packaging material  32  when used to enclose or seal the fruit  22  or fruits therein. The composition of the perforated plastic packaging material  32  may include homopolymers, copolymers containing amides, esters, anhydrides, or urethanes, or their derivatives, or containing acyle groups, carboxyl groups, or alcohol groups, or their derivatives. The perforated plastic packaging material  32  may be micro-perforated to include very fine perforations. The amount of perforations may be increased or decreased to achieve a desired water vapor permeability level. In the example mentioned above for avocados, it may be preferable to use a perforated plastic packaging material  32  including micro-perforations having a diameter of less than 1 millimeter. The perforated plastic packaging material  32  allows for an increased percentage of carbon dioxide to exist within the perforated plastic packaging material  32  while minimizing condensation within. The environment within the perforated plastic packaging material enables reduced water loss associated with the fruit  22 . Reduced water loss may preserve the quality of the fruit  22  for a longer time period. The perforated plastic packaging material  32  may absorb ethylene gas produced naturally by the internal fruit seed  24 . Alternatively, the perforated plastic packaging material  32  may be configured to degrade ethylene gas produced naturally by the internal fruit seed  24 . The characteristics or properties associated with a preferred plastic packaging material  32  may be determined by observing the sensitivity of the fruit  22  to carbon dioxide and the presence of water condensation. Additionally, by controlling the thickness of the perforated plastic packaging material  32  an optimal level of humidity within the perforated packaging material  32  may be achieved. 
     Placing the fruit  22  within the perforated plastic packaging material  32  before exposing the fruit  22  to a temperature controlled environment having a cooler ambient temperature than the pulp temperature of the internal fruit seed  24  reduces the likelihood of excess condensation. If the fruit  22  and consequently the internal fruit seed  24  are exposed to a temperature that is lower than the pulp temperature prior to being placed in the perforated plastic packaging material  32 , a possible result may include extensive condensation that is not desired and may possibly harm or damage the fruit  22 . Enclosing the fruit  22  within the perforated plastic packaging material  32  enables the control of moisture and gas composition of the environment in which the fruit  22  is maintained. The control of moisture and gas may facilitate a delay in the ripening process, preservation of the fruit  22 , quality, and increased shelf-life. Additionally, the post-harvest handling of the fruit  10  does not require the pre-cooling of the fruit  22  prior to placement within the perforated plastic packaging material  32 . This may result in substantial energy savings. Although pre-cooling the fruit  22  is not required, pre-cooling may be used. For example, when the fruit  22  is transported in a refrigerated container this may be a form of pre-cooling. The fruit  22  may experience a loss in quality between the period when the fruit  22  is harvested and the fruits  22  final destination such as a store shelf. The loss in quality of the fruit  22  may be unavoidable. However, loss in quality may be reduced according to the method provided. The fruit  22  is placed within the perforated plastic packaging material  32  and then placed in a controlled temperature environment. The controlled temperature environment is used to set the pulp temperature of the internal fruit seed  24 . This method of post-harvest handling of fruit  10  delays the decay of the fruit  22  while attempting to preserve the quality. The avocado may contain up to 80% water when it is harvested. Furthermore, because the avocado has high respiration rates, and releases carbon dioxide and ethylene, the avocado degrades at a high rate with internal and irreversible changes. Thus, reducing dehydration of the avocado preserves the quality of the avocado. 
     Following the step  30  of enclosing the fruit within the perforated plastic packaging material  32 , the next step  40  provides that the enclosed fruit  34  is placed in a vented storage container  42  to produce a packed fruit  46  as provided in the third step  40  of the flow chart in  FIG. 1  and shown in  FIGS. 2 and 3 . The vented storage container  42  may be configured from a variety of materials including but not limited to wood, plastic, and/or cardboard. However, other types of material may be used in accordance with the post-harvest handling of the fruit  10 . The vented storage container  42  may facilitate ventilation to the enclosed fruit  34  stored therein. The vented storage container  42  may enable the transportation of a plurality of the fruit  22  from a first location to a second location. The vented storage containers  42  may also receive a plurality of the enclosed fruit  34  in one vented storage container  42 . The vented storage container  42  may include a plurality of vent  44  openings that facilitate the exposure of the packed fruit  46  to an air flow. 
     Referring now to  FIGS. 1 and 4 , the fourth step  50  provided in the flow chart requires the packed fruit  46  to be exposed to an air flow  52 . The placing of the enclosed fruit  34  within the vented storage container  42  enables the packed fruit  46  to be exposed to the air flow  52 . The air flow  52  may pass through the vented storage containers  42  that contain the enclosed fruit  34 . The vented storage container  42  enable the fruit  22  to cool down from ambient temperature to a first cool temperature associated with the internal fruit seed  24 . Exposing the packed fruit  46  to the air flow  52  may increase the life span of the fruit  22  by reducing dehydration with respect to the fruit  22 . 
     The fruit  22  may need energy from the food reserves it stores. This process is called cell respiration. Heat energy is released during cell respiration. For the fruit  22  such as avocado, the internal avocado seed releases a substantial amount of heat energy during respiration. Exposing the fruit  22  to the air flow  52  and cooling the internal avocado seed to the first cool temperature reduces the heat energy released during cell respiration and thus prolongs the lifespan of the avocado. Further, cooling the internal avocado seed reduces the rate of ethylene production, moisture loss, spread of microorganisms, and deterioration from bruising. In addition, because the avocado was placed in the perforated plastic packaging material  32  prior to being exposed to the air flow  52 , the conditions within the perforated plastic packaging material  32  while cooling to the first cool temperature enable the reduction of the cell respiration rate. 
     The air flow  52  may be generated by a forced air cooling system that includes a fan  56 . The forced air cooling system creates an environment where the temperature of the internal fruit seed  24  of the packed fruit  46  is cooled from ambient temperature to the first cool temperature within a cool down period according to step five  60  as shown in  FIG. 1 . The cool down period may last between 6 and 12 hours when using forced air cooling. However, other known cooling techniques may be used to facilitate the method described herein. The cool down period for the packed fruit  46  may last up to 48 hours when other cooling techniques are used. Any cooling technique that requires a cool down period greater than 48 hours to reach the first cool temperature for the internal fruit seed  24  is not recommended. If the cool down period lasts longer than 48 hours, the quality of the fruit  22  or the shelf life may be adversely affected. The first cool temperature may range between 4 and 6 degrees Celsius. This temperature range applies to the pulp temperature or the internal fruit seed  24  temperature and not to the outer layer of the fruit  22  or the surrounding environment. 
     The following step  70  provides for the internal fruit seed  24  temperature to be maintained for a storage period. Following step  60  of cooling the internal fruit seed to the first cool temperature, the packed fruit  46  is stored for a period of time while maintaining the first cool temperature associated with the internal fruit seed  24 . In this regard, the controlled temperature environment must be sufficiently cool to maintain the first cool temperature associated with the internal fruit seed  24 . In one embodiment, the recommended storage period for the packed fruit  46  ranges between 10 and 15 days. As a result, the internal fruit seed  24  temperature remains at the first cool temperature for a period of 10 to 15 days. However, the packed fruit  46  may be stored for a period of up to 45 days with the internal fruit seed  24  temperature in the range of the first cool temperature without significantly affecting the quality of the fruit  22 . 
     The packed fruit  46  may be exposed to an air flow  52  for increasing the internal fruit seed  24  temperature according to next step  80 . The internal fruit seed temperature  24  is increased from the first cool temperature to a second cool temperature. The second cool temperature may be between the first cool temperature and the ambient temperature at which the fruit  22  was received. The initiation of the increase in temperature from the first cool temperature to the second cool temperature marks the start of a triggering period  90  provided in the following step  90 . During the triggering period  90  it may be critical to have optimal air circulation around the packed fruit  46 . The triggering period  90  may last up to 48 hours. In other words, the internal fruit seed  24  temperature of the packed fruit  46  is maintained at the second cool temperature. The second cool temperature may range between 12 degrees Celsius and 14 degrees Celsius. The result of requiring the triggering period  90  to last approximately 48 hours enables the outer portion or peel of the fruit  22  to change color in a uniform manner. If the packed fruit  46  is in the triggering period  90  for a time substantially less than 48 hours it may result in non-uniform change of color and possibly other internal deficiencies associated with the quality of the fruit  22 . Conversely, if the triggering period  90  is maintained past the 48 hours, the shelf life of the packed fruit  46  upon removal from the perforated plastic packaging material  32  may be reduced. The triggering period  90  may prepare the fruit  22  for the ripening process. 
     Following the triggering period  90 , is a ripening period  100 . During the ripening process the packed fruit  46  may be exposed to an ambient temperature. Typically the ambient temperature that the packed fruit  46  is exposed to for the ripening period  100  may range between 15 degrees Celsius and 20 degrees Celsius for proper storage of the packed fruit  46 . The ripening period  100  for the fruit  22  may range between 48 hours and 96 hours. During this time the internal fruit seed  24  temperature may increase. After the ripening period  100  is completed the packed fruit  46  may be removed from the vented storage containers  42 . The enclosed fruit  34  may also be removed from the perforated plastic packaging material  32  and displayed for sale. In some cases, after the ripening period  100  is completed, the packed fruit  46  may require shipping to reach the desired destination for the sale or consumption of the fruit  22 . In this regard and in accordance with industry standards, the packed fruit  46  may be shipped while cooling the internal fruit seed  24  temperature from ambient level to the first cool temperature range between 4 and 6 degrees Celsius. The shipping period may last between 48 and 96 hours. Upon the fruit&#39;s  22  arrival to the final destination, the enclosed fruit  34  may remain in the perforated plastic packaging material  32  until the fruit  22  is ready to be displayed. 
     If the fruit  22  that is handled post-harvest is an avocado, there are important parameters associated with each stage of the post-harvest handling of the fruit  10 . When the avocado is picked from its tree it is in an un-ripened stage wherein the exterior may be very hard. Typically, the pressure is greater than 27 pounds per square inch (PSI). As a result, the subcutaneous compaction of the avocado prior to being enclosed within the perforated plastic packaging material  32  and subsequently the vented storage container  42  may be greater than 27 PSI. During the storage period when the enclosed avocado&#39;s internal fruit seed  24  temperature is cooled from ambient temperature to the first cool temperature, the subcutaneous compaction of the avocado should remain greater than 27 PSI. After the storage period, the enclosed avocado begins a triggering period  90  in accordance with the method provided. During the triggering period, the subcutaneous compaction of the avocado decreases. In other words, the exterior of the avocado softens. At this stage the subcutaneous compaction may range between 10 and 20 PSI. Although the subcutaneous compaction has decreased, at this stage the avocado may still be considered to have a hard exterior that is not ready for consumption. Following the triggering period  90  the avocado begins to ripen during the process known as the ripening period  100 . The exterior of the avocado begins to soften. The subcutaneous compaction may range between 5 and 8 PSI throughout the ripening period  100 . If the avocados are to be shipped to the desired location, the avocados may be shipped in refrigerated containers that allow for the subcutaneous compaction of the avocado to remain generally constant during shipping, namely, between 5 and 8 PSI. Upon removal of the avocados from the perforated plastic packaging material  32  after either the ripening process or the shipping process, the subcutaneous compaction of the avocados should be less than 5 PSI. The avocados are ready for consumption when the subcutaneous compaction is below 5 PSI. 
     The method of post-harvest handling of fruit  10  that is provided is advantageous because of the flexibility associated with the various processes. The method is flexible with respect to where and who may facilitate the handling of the fruit  22  in accordance with the method described. In one example, the entire method may be undertaken by a fruit packinghouse. In this scenario, the packinghouse receives the fruit  22  at an ambient temperature. Upon receiving the fruit  22 , the fruit  22  is enclosed in the perforated plastic packaging material  32  and then stored in a controlled temperature environment so that the internal fruit seed  24  temperature is either cooled to or maintained at the first cool temperature. In one embodiment, the fruit  22  may be enclosed immediately in the perforated plastic packaging material  32 . However, in another embodiment, the fruit  22  received by the packinghouse may go through a quality inspection process or other well know processes associated with industry standards prior to being enclosed within the perforated plastic packaging material  32 . The storage period of the enclosed fruit  34  at the first cool temperature may be completed at the packinghouse. Additionally, the triggering period  90  and the ripening period  100  may be completed at the packinghouse. After the ripening period  100  is completed at the packinghouse, the fruit  22  may be removed and displayed for sale or shipped to a particular location prior to removal from the perforated plastic packaging material  32 . 
     In another example, the post-harvest handling of fruit  10  provided may be accomplished by a shipping company or a separate entity from the packinghouse. In this example, upon picking of the fruit  22  from the field, the fruit  22  may be enclosed in the perforated packaging material  32  prior to cooling the internal fruit seed  24  to the first cool temperature. The enclosed fruit  34  may be stored in a vented storage container  42  for the storage period at the first cool temperature. The triggering period  90  may then be initiated during shipping assuming that there is adequate airflow. The ripening period  100  may then be initiated and completed after shipping of the enclosed fruit  22 . There are a variety of combinations in which the handling of the fruit  10  may be accomplished by a single entity or multiple entities. 
     The method of handling fruit that is provided may reduce the cost significantly of handling fruit in comparison to industry standards. Enclosing the fruit  22  in the perforated plastic packaging material  32  allows for the control of temperature and atmosphere within the perforated plastic packaging material  32 . The perforated plastic packaging material  32  enables the fruit  22  to produce its own ethylene gas naturally at optimal conditions. There is no need for the use of ethylene gassing rooms. The savings associated with not requiring ethylene gassing may be substantial. Using the method provided also enables added flexibility and control with respect to when the fruit  22  may be displayed. Upon receiving the fruit  22 , the customer may have the option to hold the enclosed fruit  22  in a controlled temperature environment for up to three days. The method facilitates uniform ripening of the fruit  22  partly because the perforated plastic packaging material  32  produces the optimal balance between dioxide and carbon dioxide, creating the conditions for uniform fruit ripening during the storage period, the triggering period, and the ripening period. Uniform fruit ripening may prevent or reduce checker boarding and discoloration. Another added benefit is the ability to consolidate shipments of fruit and adjusting to the variations associated with retail demand. 
     The post-harvest handling of fruit  10  through the storage of fruit  22  in perforated plastic packaging material  32 , then cooling during a storage period, triggering period, and finally a ripening period preserves the fresh flavor of the fruit  22  and the nutritional value. The modified atmosphere and humidity also reduces dehydration and weight loss, which in turn preserves firmness and prevents shrinkage of the fruit  22 . The condensation associated with the fruit  22  is reduced which may inhibit the growth of pathogens. Condensation is reduced by achieving proper humidity levels within the perforated plastic packaging material  32 , allowing excess moisture to escape. This process allows the shelf life to be extended while maintaining the internal and external quality of the fruit  22 . Subsequently, ripening may be induced by triggering the fruit  22  with a change in temperature. The method allows the enclosed fruit  22  to naturally create the optimal atmosphere for ripening that is triggered by temperature changes at the appropriate time. The storage life of the enclosed fruit  22  may be extended between 45 and 60 days, without significant chilling injury, internal fruit disorder, or external fruit disorder. Normal fruit ripening may occur after removal from the bag at ambient temperature of approximately 20 degrees Celsius. Ripening of the fruit  22  without using the method provided may result in non-uniform ripening and considerable weight loss in the fruit  22 . In the event where fruit is not handled according to the method, a high incidence of pulp discoloration and Anthracnose decay may exist after 30 days of storage.