CA2001955A1 - Preservation of fresh produce - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A vacuum skin package wherein produce in a cleaned and ready to consume condition is vacuum skin packaged between a support member and a conforming skin covering member will preserve such produce without discoloration thereby extend-ing the shelf life and enhancing the consumer appeal of the produce.

Description

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PRESERVATION OF FRE'~H PRODUCE

FIELD OF THE I~rENTION

This invention relates to a method and package for preserving fresh produce and displaying it at the retail grocery or supermarket. In particular, the invention relates to a meth-od and package which prevents the discoloration or browning which occurs in fresh produce.
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B.~.CKGRoUND OF THE INVENTION

Most produce today is sold in bulk a.nd dlsplayed in hi.ns in the ~rocery or supermark~t and is subjcctcd to bruising and other damage and, in general, has a relatively short shelf li~c. Accordingly, one object of the present invention i.~ to provide a method and packagls i.or 1,sngthening the sheli. li~e of i-resh produce.

Q~en, wh~n ~old ln hulk or displa~d in hins at the ~up~rmar-k~t, ~re~h pr~duae ~annot be disp.lay~d -~o its hest advan~
ta~e,~ Thi~ is beaaus~ in som~! types o~ pradllce the autsid~
skin .or pc~l ls the leas~ attractivl3 part o~ th~ produce and the "meat" or edlbl~ portion a~ the produc~ is th~ most ap-. I
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pealing porti~n. Accordingly, it is another object of the pr~sent invention to provide a mcthod and package whereby freshly cut produce may be displayed ~or an extended period.

Today, there is a demand for fre~;h, appealing, and wholesome ready-to-eat produce items be~ause of changing lifestyles and differing diet demands. Accordirlgly, it is yet another ob-ject of the present invention to provide cut and prepared produce in ready-to-cons~ne or in :ready-to-cook p~cka~es.

The foregoing and other objects ~re achieved by the present invention which is sur~narized hcrei.nbelow.

SUMI~RY OF T~TE INVENTION

In one aspect the present inv~ntion is a method for preserv-ing fresh produce comprising the steps of providing a support mernber; placing fresh, cleaned and prepared produce on the support mernber; and, vacuum skin packaging a covering or forming web onto and around the produce. The support member is preferably a tray thermo~ormecl from a plastic material such as polyvinyl chloride and, if desired, the polyvinyl chloride tray may be provided with an oxygen barrier layer such as a layer of a vinylil1ene chloride copolymer or an ethylene vinyl alcohol pol~ncr or copolyrner which can he coex~ruded with thc polyvlnyl chloridc support mcrnber. In other instanc~s, thc support mernber can be simply a ~lat sheek or Lt can be a ~ray ~orrned ~rom polystyrcne foam or paperboard.

The coverlng or ~orming film is one which Ls applied :in a formin~ condi~ion under d:Lfferential air pressure to the producc on ~he suppork mcmber and l:akes on khe shape o~ the pr~duaa. ~hi~ ~l.lm ma~ b~ a M~nol,~ycr film ~r a multLlayer ~llm and dcp~ndln~ on khc n~kure o~ the prod-lce i~ may be a ~as or ~yc3~n barrier ~llm or it: may be a ~as permeable film.

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~ e film is prcfcrably thermo~ormablc and is applied while heated to its forming state. 'rhe Eilm may also be one which has differing permea~llities fc,r different gases, that is, it may be permeable to carbon dioxide to let it pass out of the package while it may bc relatively imperrneable to oxygen to prevent it from entering the package.

In another aspect, the present invention is a package wherein the produce is cleaned and prepared and placed upon a support member and a transparent covering wcb which closely adheres to the shape of the produce in a skin-tight manner covers and seals the produce to the support member. Where the produce is not consumed fresh hut needs t:o be cooked, seasonings, butter, salt, spices, etc., may be added.

It is quite surprising that the browning and discoloration of produce can be reduced and the appearance and shelf life of produce can be extended by the package and process o~ the invention.

The invention may be better urlderstood by reference to the description of the drawings which ~ollows below.

DESCRIPTION OF THE DRAWINGS

In the drawings which are descrlbed below and appended hereto and made a part of this disclosure;

Figure 1 is a perspective view o~ a picce of produce which has been vacuum skin packaged to a support member or tray;

Figurc 2 is a cross section o~ the pa,-kage shown in Figure l;

~l~ur~ 3 1~ a b~ttom vlew oE ~h~ paak,l~e ~hown in Fi~ure 1 1~89082~.}B/SPECFLDR
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igure 4 is an alternatc cmbodiment of the present invention showing sliced pieces of produce vacuum skin packaged to -a support member;

Figure 5 is a cross section view of the package of Figure 4;

and, Figure 6 is a bo-ttom view of the package shown in Fic3ure 4.

I:~ETAILED DE',C 'TION

As used herein, the term "vacuum skin packaging" or "vacuum skin packaged" or "VSP" mcans a process which produces a package in which a product is place~l on a flat sheet or tray-like support member and a covering web or film is formed around the produce and assumes the shape of the produce and is `sealed to the support membe:r tightly around the periphery of the product. In this type o~ packaging process, the prod-uct acts as the mold as the heated ~ilm is driven against the product by differential air pressure ancl forms around the product. The space which the product occupies between the covering web or ~orming ~ilm and the support member is evacu-ated. Such a process and product is described in USP
RE.30,009, the d~sclosure of which is incorporateci herein by reference. In USP 4,833,862 a procc!ss o~ vacuum ~kin packag lng products in-lin~ on trays i~ dcscribeci.

As used herein, the term "produca" encompa~ses those products normally sold in the produce ~;~ction o~ a grocery store or supermarke~ which generally are sold ~resh in essentially the same state in which ~hey are picked or gathered. Thesc prod-ua~ inalud~ varic~us ~rul~s, v~etables, herbs, ber~ , root pro~uats, an~ large ~raln prociu~ts. Examples are a~ples, ~ar~, corn-an-th~-coh, toma~Q~, potatoes, celery, radlsh~s, mushroom~, ca~ro~s, ctc.

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r Other than the product, th~ components of the package are the covering or formins web and the support or bottom web. The covering web is pref~rably a th~rmoplastic material which is heat formable and may be selectccl from the group comprlsing polyethylene, ethylene vinyl acctate copolymers, linear low density polyethylenes, very low density polyethylenes, ionomers, ethylene acrylate acid copolymerO, methacrylic acid copolymers, polyamides, and, in general, any thermoplastic self supporting ~ilm which is heat formable and transparent.
The film may be sin~le layer or it may comprise several lay-ers such as an abuse layer, an oxygen or gas barrier layer, and a sealing layer.

The support member may be a ilat sheet of plastic or paperboard or it may bc a tray of plastic or plastic ~oam or paperboard. A preferred matexial i5 polyvinyl chloride which can~ be formed into a semi-rigid tray and a gas barrier layer or coating may be added. The gas barriers of preEerence are vinylidene chloride copolymers, et:hylene vinyl alco~ol poly-mers and copolymers, or, in some instances, polyamides.
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Turning now to Figure 1, package 1 comprising tray 2 with product 3 resting thereupon is shown. The covering web or film 4 closely conforms to thc shape of th~ product and seals around the periphery therco~. Figure 2 is a side view o~
this package and Fi~lre 3 is .1 bot:tom view. In this embodi-ment the tray is a clear, tr;lnspa,rent, barrier tray and the product is a potato cut in h~llf and when turned upstde-down and viewed from th~ bottom, th~ cle~n white surfac~ of the cut potato can be s~en. This cl~an white surfclcc le~s the purchas~r see the condition o~ th~ potato and that i~ is ~ree ~rom blcmishcs or "c~as" or undcsirabla lumps. Thc face oE
~ha, po~ato is a~alnst tha barricr~ sa no ox~gen qntcrs. It has been ~urprisinyl~ Eound ~hat -this packa~ p~e~erve~ ~h~
pO~iltO and the clcan whl~e appeclrancc o~ its sur~aa~ Eor ~, sev~ral days bc~or~ any discolc~ration se-ts in. Thus, a premi-1/890822~1B/SPE~FL~R08/28/~9 .

um price can be obtained for thc po-tato as its condition is readily observed. Fur-thermore, clS the potato has been cleaned and cut it makes a more appealing package for the consumer to buy. The potato in this condition can be easily cooked by peeling back the forming weh to the edge of the potato to allow steam -to escape, in,erting a patty of butter or other seasoning which can be provided with the package, and then cooking in a microwave. Thus, no utensil is needed nor is it necessary to wrap the potato in a ~oil or other material as it is already prewrapped.

It is common knowledge that the cut surface of an apple will brown and become unsightly with:in a few minutes after having been cut. The present invent:ion surprisingly provides a retail package where cut sur~aces of fresh apples may be displayed and retain their c:Lean, fresh cut appearance.
Viewing Figure 4 in package 6 s:Lices 7 of an apple are shown vacuum skin packaged undt~r covering web 9 and displayed on tray 8. Figure 5 is a side view of this package and Figure 6 is the bottom view. This packagc c~nfiguration provides the retail consumer a view o:E thc contents and the vi~w of the - whole slice of apple so that the c~nsumer purchases a piece of fruit without blemish or bruise. When the coverinc~ web is peeled back the slices can be removed and are ready to con-sume. In this particular package confit~uration, in order to preserve the fresh cut look o~ t:he s,lices, both the covering`
web and the bottom web should c:omprise an oxygen barricr as oxygcn is th~ compont~nt in ambiont ai:r which casos the discol oration of the cuk apple slic~s. Othtr fruits which will benefit from ~his package ar~ pears, bananas, etc. Even slices o~ melons sUch as cantaloup and wat~rmelon can be preserved in packages in th.is manner.
" ; ' Ano~h~r ik~m Which is rqaclily packatJ~d ls corn-Qn-thq~aob which can be ~hucked, de-silk~:l, wash~c1 ~Incl plac~d on l:he ~ra~ and v~cuum skin p~ckcl~q ~c~ prc~;en~ a ~ui~e a~ra~ive 1/890822 . IB/SP~CFLDR
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, ,C~5 retail package. 'With the addit;ion of seasonings and peeling back a portion of th,e covering web to allow steam to escape, the corn can be cooked in a microwave oven in the xetail package thus obviating the n~eces,sity to employ an additional utensil in the cooking proces,s.

In general,any item of produre which suffers from discolora-tion by exposure to air wi:ll benefit from tnis invention~
even items such as cut melons and bananas, for example.

Many other emkodiments and uses of the present invention are possible within the scope of thi,s disc]osure and this inven~
tion is limited only by the claims which are appended hereto:
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Claims (10)

1. A method for preserving fresh produce comprising the steps of:
a) Providing a support member;

b) Placing fresh, cleaned and prepared produce on said member and, c) Vacuum skin packaging a covering film onto and around the produce.

2. The process of claim 1 wherein the material com-prising the support member is selected from the group consisting of monolayer rigid and semi-rig-id films and multilayer rigid and semirigid thermoplastic films.

3. The process of claim 2 wherein the support member is a transparent plastic material and has been formed into the shape of a tray.

4. The process of claim 1 wherein the produce is prepared in a ready to heat and eat condition and is selected from the group consisting of pota-toes, carrots, and corn-on-the-cob.

5. The procrss of claim 1 wherein the covering web is a barrier film selected from the group consist-ing of monolayer films and multilayer films.

6. The process of claim 5 wherein the multilayer film comprises an oxygen barrier layer and a sealing layer, said oxygen barrier layer being 1/890822.1B/SPECFLDR

selected from the group consisting of vinylidene chloride copolymer and ethylene vinyl alcohol polymers and copolymers.

7. The process of claim 6 wherein the produce com-prises a product selected from the group consist-ing of freshly cut apples, pears, bananas, or melons.

8. A package for preserving produce comprising:

a) A support member;

b) Freshly cleaned and prepared produce upon said support member;

c) A covering web of the thermoplastic film which closely conforms to the shape of the produce in a skin-like manner; and, d) The space which the produce occupies between the covering web and the support member being initially evacuated.

9. The package of claim 8 wherein the support member is thermoformed into the shape of a tray and is transparent and is an oxygen barrier.

10. The package of claim 9 wherein the produce is freshly cut and arranged so that the freshly cut surfaces are visible.

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