Patent Application
20060159809
The present invention generally concerns packaged products comprising vegetables and fruits in a modified gas atmosphere to preserve freshness, methods for the production of the packaged products and apparatus for making the packaged products.
The market for mushrooms has been growing in recent years. Consumers demand fresh mushrooms not only for their taste, but also for their health benefits. According to one report, 86% and 70% of American families regularly purchase button mushrooms and exotic species, respectively.
Many consumers are interested in the nutritional and medicinal aspects of mushrooms. In particular, mushrooms, especially exotic species, are a rich source of proteins, carbohydrates (especially polysaccharides), vitamins (in particular, B and C vitamins), minerals and are low in fat. Stamets (2000). However, the shelf-life of mushrooms, especially exotic species, is relatively short. Therefore, there is a need to investigate new methods to extend the shelf-life of such mushrooms.
The present invention explores the use of modified atmosphere environments along with refrigeration to extend the shelf-life and preserve the microbial quality of exotic mushrooms for a longer period of time, which may provide a substantial savings for mushroom retailers.
An aspect of the present invention relates to packaged products comprising (a) a sealed container, (b) mushrooms in the container, and a gas atmosphere, wherein the gas comprises about 0% to 5% by volume oxygen, about 1% to 20% by volume carbon dioxide, about 0% to 20% by volume hydrogen and at least about 50% by volume nitrogen.
A further aspect of the invention relates to methods of making extended shelf-life packaged mushroom products, comprising packaging mushrooms in a sealed container together with a gas atmosphere wherein the gas atmosphere comprises about 0% to 5% by volume oxygen, about 1% to 20% by volume carbon dioxide, about 0% to 20% by volume hydrogen and at least about 50% by volume nitrogen.
An additional aspect of the invention relates to apparatus for packaging mushrooms comprising a plurality of processing stations for (a) removing existing air from a package comprising mushrooms and (b) adding to the package a gas mixture which comprises about 0% to 5% by volume oxygen, about 1% to 20% by volume carbon dioxide, about 0% to 20% by volume hydrogen and at least about 50% by volume nitrogen.
The present invention is described in greater detail in the drawings herein and the specification set forth below.
The foregoing and other aspects of the present invention will now be described in more detail with respect to other embodiments described herein. It should be appreciated that the invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the embodiments of the invention and the appended claims, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the phrase such as “about X to Y” means “about X to about Y” and also refers to a range of values from about X to about Y.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It will be understood that steps comprising the methods provided herein can be performed independently or at least two steps can be combined when the desired outcome can be obtained.
Further, embodiments of the present invention may be described herein with reference to illustrations that are schematic illustrations of idealized embodiments of the present invention. As such, variations from the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular depictions illustrated herein but are to include deviations in shapes, sizes, processes etc. that result, for example, from employing suitable manufacturing techniques.
All publications, patent applications, patents and other references cited herein are incorporated by reference in their entireties.
“Gas atmosphere” as used herein refers to an environment including at least one gaseous element.
“Oxygen-impermeable” as used herein refers to the limited passage of oxygen through the medium of interest. In some instances, oxygen does not pass through the medium of interest. In the U.S., gas permeability can be measured in cc per 100 square inches per 24 hours at 73° F. and one atmosphere of pressure (see American Society for Testing Materials or “ASTM” D1434-66) and can be further expressed as a function of thickness measured in mils. In shorthand, the value can be expressed in cc's with the other units being understood.
“Shelf-life” as used herein refers to the time frame over which a food product can be relied upon to retain its quality characteristics including, but not limited to, remaining edible, retaining a desirable texture, free from noticeable discoloration, malodor or harmful degradation or contamination by microorganisms.
“Conventional manner of packaging” as used herein refers to packaging produce in a standard packaging container as understood by those of ordinary skill in the art, for example, overwrapping the container with a polymer material, such as polyethylene or polyvinyl chloride, other suitable materials and storing the wrapped container usually at refrigeration temperatures for up to seven days.
“Refrigerated storage” as used herein refers to an environment that maintains an ambient temperature that is low enough to detrimentally affect growth of spoilage microorganisms. An exemplary temperature range is about 2° C. to 8° C.
“Microbial qualities” as used herein refer to the extent of aerobic and anaerobic bacterial growth as well as the growth of other spoilage microorganisms such as yeasts and molds.
“Sensory qualities” as used herein refer to qualities pertaining to sensory perception including, but not limited to, odor, color, texture, etc.
In view of the foregoing, embodiments according to the present invention relate to packaged products comprising (a) a sealed container, (b) mushrooms in the container, and (c) a gas atmosphere, wherein the gas may comprise about 0% to 5% by volume oxygen, about 1% to 20% by volume carbon dioxide, about 0% to 20% by volume hydrogen and at least about 50% by volume nitrogen. In particular, the gas may comprise about 0, 1, 2, 3, 4 or 5% by volume oxygen; about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by volume carbon dioxide; about 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by volume hydrogen; and at least about 50, 60, 70, 80 or 90% by volume nitrogen. In some embodiments, the gas comprises less than about 5% by volume oxygen, about 3% to 12% by volume carbon dioxide, about 0% to 10% by volume hydrogen and at least 70% by volume nitrogen. In other embodiments, the gas comprises less than about 0.5% by volume oxygen, and can comprise less than about 0.1% by volume oxygen. In further embodiments, the gas comprises about 3% by volume oxygen, about 10% by volume carbon dioxide and about 87% nitrogen. In still other embodiments, the gas comprises about 10% carbon dioxide, about 10% hydrogen and about 80% nitrogen.
According to the present invention, the gas may be added to the sealed container concurrently with the addition of the mushrooms. Alternatively, the gas may be added to the container after the mushrooms have been added to the container.
Mushrooms suitable for packaging according to the present invention include any variety of edible mushrooms. Exemplary mushrooms include, but are not limited to, Armillaria mellea, Agaricus bisporus (common button mushrooms), Boletus edulis, Cordyceps sinensis, Coriolus versicolor, Flammulina velutipes (Enokitake), Ganoderma lucidum, Hericium erinaceus, Hypsizygus marmoreus (Bunashimeji), Auricularia auricula-Judae, Phellinus linteus, Pleurotus ostreatus (Hiratake), Grifola frondosa (Bunashimeji), Agaricus campestris, Lentinus edodes (Shiitake), Tremella fuciformis, Volvariella volvacea and Pholiota nameko (Nameko). In some embodiments, the edible mushrooms are common mushrooms or exotic mushrooms. An exemplary common mushroom includes, but is not limited to, button mushrooms. Exemplary exotic mushrooms include, but are not limited to, pom pom, portabella, shiitake and combinations thereof. The present invention further contemplates packaging of other vegetables and fruits. Exemplary vegetables include, but are not limited to, green leaf vegetables such as lettuce, spinach, broccoli, kale, collard green, mustard green, celery, cucumber, carrots and cabbage. Exemplary fruits include, but are not limited to, apples, oranges, grapefruit, lemons, pineapples, strawberries, tomatoes, blueberries, peaches, grapes, raspberries, plums, and cherries.
In some embodiments, packaged products comprising a sealed container, mushrooms in the container, and a gas atmosphere as described above, have a shelf-life of at least 15 days when maintained in a cooled environment, such as refrigerated storage. In other embodiments, the packaged products have a shelf-life of at least 15 days when stored in a cooled environment having a temperature of about 4° C. In still other embodiments, the packaged products have a shelf-life of 21 days when stored in a cooled or refrigerated environment having a temperature, for example, at about 4° C. In other embodiments, the shelf-life of the packaged product can be extended up to about 25 days when stored in cooled or refrigerated temperatures, for example, at about 4° C.
In further embodiments, the packaged products comprising a sealed container, mushrooms in the container, and a gas atmosphere as described above, exhibit decreased growth of bacteria and other spoilage microorganisms compared. to a packaged product packaged in a conventional manner. In particular, addition of a gas atmosphere as described above decreases growth of aerobic bacteria, i.e., bacteria requiring oxygen for growth and survival, and anaerobic bacteria, i.e., bacteria that do not require oxygen for growth and survival, and also decreases growth of other spoilage microorganisms including any type of microorganism that acts to spoil food, such as yeasts and molds, compared to products packaged according to a conventional manner of packaging mushrooms. In some embodiments, the packaged products exhibit improved microbial qualities compared to a packaged product packaged in a conventional manner. More specifically, at least a one log reduction is achieved in the amount of aerobic bacteria contained in the packaged product when stored at about 4° C. for at least 3 days compared to a packaged product packaged in a conventional manner when stored at about 4° C. for at least 3 days.
Methods of packaging fruits and vegetables, in particular mushrooms according to embodiments of the present invention, entail using standard packaging materials which may vary in size and include a wide variety of packaging shapes and materials for high density packaging including trays, pouches, cups, bags and the like so long as the containers provide the features described herein including gas permeability. The produce is packaged in a sealable and readily cold permeable container. The packages can be sealed with films, bags or lids composed of a polymer or other suitable material as known by those of ordinary skill in the art. For example, the sealing material may be a polymer material, such as polyethylene or polyvinyl chloride. In particular embodiments of the invention, the sealed container is oxygen-impermeable.
Embodiments of the present invention further relate to methods of making an extended shelf-life packaged mushroom product, comprising packaging mushrooms in a sealed container together with a gas atmosphere wherein the gas atmosphere comprises 0% to 5% by volume oxygen, 1% to 20% by volume carbon dioxide, 0% to 20% by volume hydrogen and at least 50% by volume nitrogen. In particular, the gas may comprise compositions by volume as described above.
In the process of making an extended shelf-life packaged mushroom product, the gas may be added to a sealed container concurrently with the addition of the mushrooms. Alternatively, the gas may be added to a sealed container after the mushrooms have been added to the container.
The methods according to the present invention can provide packaged products that are oxygen-impermeable. The methods can further entail storing the packaged products in a refrigerated environment. Moreover, methods of making an extended shelf-life packaged mushroom product, as described herein, further provide packaged products that have a shelf-life of at least 15 days when stored at about 4° C. In some embodiments, the methods provide packaged products having a shelf-life of 21 days when stored in refrigerated temperatures, for example, at about 4° C. In still other embodiments, the methods provide packaged products wherein the shelf-life of the packaged products can be extended up to about 25 days when stored in refrigerated temperatures, for example, at about 4° C.
The methods according to the present invention further produce packaged products that exhibit decreased growth of bacteria and other spoilage microorganisms compared to a packaged product packaged in a conventional manner. In particular, addition of a gas atmosphere as provided in the methods of the present invention contribute to decreased growth of aerobic and anaerobic bacteria and also decreased growth of other spoilage microorganisms, as noted above, compared to products packaged according to a conventional manner of packaging mushrooms. In some embodiments, methods of preparing the packaged products enable the packaged products to exhibit improved microbial qualities compared to a packaged product packaged in a conventional manner. For example, these methods can result in at least a one log reduction in the amount of aerobic bacteria contained in the packaged product when stored at about 4° C. for at least 3 days compared to a packaged product packaged in a conventional manner when stored at about 4° C. for at least 3 days.
Embodiments of the present invention further relate to apparatus for packaging mushrooms comprising a plurality of processing stations for (a) removing existing air from a package comprising mushrooms and (b) adding to the package a gas mixture comprising about 0% to 5% by volume oxygen, about 1% to 20% by volume carbon dioxide, about 0% to 20% by volume hydrogen and at least about 50% by volume nitrogen. In particular, the gas may comprise compositions by volume as described above.
In some embodiments, the processing stations are sequentially arranged. In other embodiments, processing stations further comprise a processing station for sealing the package to provide an air-tight seal. The processing stations can be facilitated and/or modulated by a control device.
In particular embodiments, the apparatus enable the gas mixture to be added to the package concurrently with the mushrooms. In still other embodiments, the apparatus enable the gas mixture to be added to the package after addition of the mushrooms.
Embodiments of the present invention will be further explained with reference to certain examples, which are included herein for illustration purposes only, and which are not intended to be limiting of the invention.
Portabella, pom pom and shiitake mushrooms were provided by Phillips Mushroom Farms, Pennsylvania. All mushrooms were packaged in three different atmospheric environments including air (CO), a modified atmosphere containing no oxygen (MA1) and a modified atmosphere containing 3% oxygen (MA2). Samples stored under air served as controls. All samples were stored at 4° C. for 15 days.
Total aerobic bacterial counts were determined on Tryptic Soy Agar (TSA) following 48 incubation at 37° C. Anaerobic bacteria were enumerated on reinforced clostridial medium (RCM) and plates were incubated at 37° C. in an anaerobic environment for 48 hours. Bacterial counts were expressed as log10CFU/mL as shown in
Sensory evaluation of samples was performed by an eight-member panel. Panelists were asked to evaluate off-odor, surface discoloration, texture (softness) and overall difference of each sample versus the appropriate control using a 7-point scale (−3=less than control, 0=same as control and 3=more than control). Data were analyzed by ANOVA using SAS. Dunnett's test was used to compare treatment means to control. Results are presented in the table shown in the document found at Appendix A.
Panelists found samples packaged under modified atmosphere to be highly acceptable compared to their respective controls. The control samples were judged unacceptable in that the control samples exhibited strong off-odor, an indication of spoilage, and loss of fresh mushroom color.
Sensory acceptability correlated well with microbial analyses. Samples stored under air had higher microbial loads (as judged by TSA and RCM) than those stored under a modified gas atmosphere.
Shelf-life extension of mushrooms by at least one week was achieved using modified atmosphere packaging, in particular, in combination with cold storage.
The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/645,381 filed Jan. 19, 2005, the disclosure of which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60645381 | Jan 2005 | US |
