US2336291A - Method of packing perishables and package - Google Patents

Description

1943- l. L. PHILLIPS 2,336,291

METHOD OF PACKING PERISHABLES AND PACKAGE Filed May 25, 1940 INVENTOR. 18 w/vs L PHILLIPS ATTORNEY Patented Dec. 7, 1943 UNITED STATES PATENT OFFICE mzs'rnon or PACKING rsmsnanms AND PACKAGE Irvine L. Phillips, Long Beach; Calii'., assignor to Seal-Pack Corporation, San Francisco, Calif., a corporationof California Y Application May 25, 1940, Serial Nag-337,288 (01. 99-193) Claims.

This invention relates to a new and useful process and package for refrigerating perishable commodities, and is particularly'applicable to the prevention of discoloration of lettuce during storage and shipment. The instant application is a continuation-in-part of my prior application, Serial No. 222,444, filed August 1, 1938.

The stem end of the vegetables such as lettuce, after being trimmed with a conventional iron knife, exudes from the many severed vascular openings a milky-white substance called latex. The contactof the latex with air causes it to oxidize and discolor. The stem end when drypacked becomes brown-red in color and when ice packed become vivid red-purple.

The bulk of such products is sold in markets hundreds of miles away and is shipped there in crates which contain ice. These crates in turn are placed in an ice-filled refrigerated car. When they reach the market the crate lid is opened and the appearance of the lettuce at that time affects materially the price it will bring.

One object of the invention is to provide a process and package for preventing the discoloration of lettuce and the stem ends during storage and shipment, or to at least substantially delay said discoloration.

Another object of the invention is to provide a simple package which will allow quick packing at low cost.

Other and further objects will appear from the following specification, in which some examples of my invention are disclosed for illustrative purposes only.

In the drawing, the figure is a view of the package in perspective and partially in section.

The crate or box I0 is usually deep enough to take three rows or layers of lettuce II. The top I2 is secured in place when the packing is completed.

- ber of heads with the top ends of the lettuce down (stalk ends up). The layer of lettuce is then covered with a layer of crushed ice from one to three inches in thickness. Another layer of lettuce, again with the top ends down. is then placed in the crate, and covered with another inafter.

layer of ice, and so on until the prescribed number of heads and layers have been packed. The ends of the waxed or parchment paper are then placed over the layer of ice and the crate is lidded.

-up. It is usually not necessary first to put in some ice on liner l4. Next a pad l6 substantially the size of the crate is placed over the bottom layer of lettuce and rests on the stem ends l1 and the base It of the leaves. Preferably these pads are absorbent and may or may not be impregnated with an antioxidant as described here- Also, these pads may be dampened before insertion in the crate, thereby making them readily conformable to the irregular surface of the upstanding stalks l1.

Next a layer 20 of ice is distributed over pad it. Its weight causes the pad to conform to the irregular surface just described. As the ice melts moisture is supplied to absorbent pad IS. The ice is kept from injurious direct contact with stems I! and leaves 18.

Next a second layer 2! of heads of lettuce is placed in the crate with the loose end of the leavesburied in the ice layer 20. Then may come a pad 22, another layer 23 of ice, another layer 24 of lettuce, another pad 25, and another layer 26 of ice. Then the liner ends I3 and H are infolded and the lid l2 nailed in place.

The above procedure is followed whether the box is a one, two, three, four or more layer pack.

I have used the antioxidant as a powder dusted directly over the severed lettuce stems, as solutions Qf various concentrations applied directly to the severed stems, and as solutions impregnated in pads. I have used the pads both in the form of individual pads ap lied over the stalk ends of the lettuce and as pads substantially the size of the crate placed in the crate between the, layers of the lettuce and the layers of crushed ice.

Adsorbents such as bentonite and sodium alginate were also incorporated in the absorbent pads, and as gelatinous caps for the individual heads of ,lettuce.

If desired, the antioxidant may be applied to the leaves as well as the stalk. but I have found that excellent results can be obtained by merely treating the stalk of the lettuce.

The following examples illustrate the invention:

(1) Filter paper was immersed for five minutes in a two (2%) per cent. solution of sodium bisulphite and allowed to dry. Sheets of this paper were then used in crating lettuce, being placed over the stalks of the: lettuce and under the crushed ice. After an interval of ten days the crates were opened and the lettuce was observed to be in excellent condition. Some of the sheets were slightly moistened before injsertion, but I prefer to use the dried impregnated filler.

I have found that the concentration of the sodium bisulphite solution may be varied between a one-half of one per cent. solution and a ten per cent. solution.

(2) A three (3%) per cent. solution of sodium bisulphite was applied directly to the stalks of the lettuce. Some of the stalks of lettuce were treated immediately after being inserted in the crate and other stalks immediately after being severed. The resultswere equally satisfactory in that practically no discoloration was apparent even after an interval of fifteen days.

The concentration of the solution may again be varied within wide limits. I have found that excellent results can be obtained with a onehalf of one per cent. solution of sodium bisulphite, and also with a five per cent. solution.

(3) A mixture was made of:

VVater cubic centimeters 200 Sodium bisu1phite e grams Bentonite do 10 The mass was mixed thoroughly. and after that a sheet of filter paper weighing gm. was allowed to soak in the mixture for five minutes. The sheet was then allowed to dry and another sheet was inserted in, the mass. Four sheets weighing 25 gm. each were treated in this man- Water cubic centimeters..- 200 Trlethannlamine rrrams 6 Bentoni-te do 10 The mixture was mixed thoroughly and a sheet of filter paper weighing 25 gm. was then allowed to soak in the mixture for about 5 minutes. The sheet was allowed to dry and a total of four sheets were treated in the mixture in this manner. The treated sheets gave excellent results in use.

Lhave found that the amount of triethanolamine used could be varied within wide limits and obtained excellent results with both one per cent. (1%) and five per cent. tions. A

Although I have described my invention with respect to certain particular embodiments thereof, nevertheless, I do not desire to be limited to the particular details shown and described except as clearly specified in the appended claims, since many changes, modifications and substitutions may be made without departing from my invention in its broader aspects, which may be found useful irrmauy other applications thereof.

I claim;

1. The method of packing lettuce heads said heads within a container with the cut stalkends of the heads disposed upwardly, placing an container with the .cut stalk-ends of the heads (5%) soludisposed upwardly, taking an absorbent sheet of material treated with an antioxidant and placing same over the-exposed cut surfaces of the lettuce stalk-ends, and finally placing crushed ice upon the upper surface of said sheet, whereby when the ice melts the sheet will be caused to seal and treat said stalk-ends with the antioxidant to inhibit discoloration and deterioration of said lettuce heads.

3. The method of packing lettuce heads for shipment or storage in containers which comprises placing said heads of lettuce within a container with the cut stalk-ends of the heads disposed upwardly, impregnating an absorbent sheet of material with a solution of an antioxidant, drying said sheet, placing said dry impregnated sheet over the exposed cut surfaces of the lettuce stalk-ends, and finally placing crushed ice upon the upper surface of said sheet, whereby when the ice melts the sheet will be softened to seal and treat said stalk-ends with the antioxidant to inhibit discoloration and deterioration of said lettuce heads.

4. A refrigerated package for storing and shipping lettuce heads comprising a receptacle containing a layer of lettuce heads with their out stalk-ends disposed upwardly, a pad embracing the butt ends of each head and enclosing the cut stalks thereof, a layer of crushed ice supported on said pad over each head, a second layer of lettuce heads supported on said ice layer with the loose ends of the leaves thereof buried in the crushed ice, and a crushed ice supporting pad extending over and embracing the butt ends and enclosing the cut stalks of each head of said second layer. 5. A refrigerated. package for shipping or storing lettuce heads comprising a crate, a plurality of superimposed layers of lettuce heads arranged in said crate with the stalk-ends 0 each head disposed uppermost, an absorbent sheet of material extending over each layer of heads and in intimate contact with the stalkends of each head, and a layer of crushed ice extending entirely across said sheets and supporting the heads of the superimposed layers of heads with the loose ends of their leaves buried in the ice layer, whereby the crushed ice will exert pressure on the sheets over each head to seal the stalk-ends to inhibit discoloration and deterioration of said lettuce heads.

6. A refrigerated package for shipping or storing lettuce heads. comprising a crate having a lining of waterproof material, a plurality of superimposed layers of lettuce heads arranged in for shipment or storage which comprises placing l said crate with the stalk-ends of each head disposed upwardly, an absorbent sheet of antioxidant carrying material extending over each layer of heads and in intimate contact with the stalkends of each head, and a layer of crushed ice extending entirely across said sheets and supporting the heads of the superimposed layers of heads with the loose ends of their leaves buried in the ice layer, whereby as the ice melts the sheets will be caused to seal and treat the stalk-ends under the pressure of the crushed ice layer to inhibit discoloration and deterioration of said lettuce heads.

7. The method of packing lettuce heads for shipment or storage in containers which comprises placing said heads of lettuce within a container with the cut stalk-ends of the heads disposed upwardly, taking an absorbent sheet of material treated with an antioxidant and placing same over the exposed cut surfaces of the lettuce stalk-ends with crushed ice, whereby the sheet will be caused to seal and treat said stalkends with the antioxidant to inhibit discoloration and deterioration of said lettuce heads.

8. A refrigerated package for shipping or storingiettuce heads comprising a crate, a plurality of superimposed layers of lettuce heads arranged in said crate with the stalk-ends of each head disposed upwardly, an absorbent sheet of antioxidant carrying material extending over each layer of heads and in intimate contact with the stalk-ends of each head, and a layer of crushed ice extending entirely across said sheets and supporting the heads of the superimposed layers of heads with the loose ends of their leaves buried in the ice layer, whereby as the ice melts the sheets will be caused to seal and treat the stalk-ends under the pressure of the crushed ice layer to inhibit discoloration and deterioration of said lettuce heads.

9. A refrigerated package for shipping or storing lettuce headscomprising a crate, a plurality of superimposed layers of lettuce heads arranged in said crate with the stalk-ends of each head disposed upwardly, an absorbent sheet of antioxidant carrying material extending over one or more layer of heads and in intimate contact with the stalk-ends of each head, and a layer of crushed ice extending entirely across said sheets and supporting the heads of the superimposed layers of heads with the loose ends of their leaves buried in the ice layer, whereby as the ice melts the sheets will be caused to seal and treat the stalk-ends under the pressure of the crushed ice layer to inhibit discoloration and deterioration of said lettuce heads.

10. A refrigerated package for shipping or storing lettuce heads comprising a crate, a plurality of superimposed layers of lettuce heads arranged in said crate with the stalk-ends of each head discoloration and deterioration'of said lettuce heads.

11. A refrigerated package for shipping or storing lettuce heads comprising a crate having a plurality of superimposed layers of lettuce. heads arranged in said crate with the stalk-ends of each head disposed upwardly, an absorbent sheet of antioxidant carrying material extending over the top layer of heads and in intimate contact with the stalk-ends of each head, and a layer of crushed ice extending entirely across said sheet, whereby as the ice melts the sheet will be caused to seal and treat the stalk-ends under the pressure of the crushed ice layer to inhibit discoloration and deterioration of said lettuce heads.

12. The method of packing lettuce, which comprises placing a layer or lettuce with the butt ends up in a crate, covering said butt ends with a sheet of absorbent material carrying an agent normally foreign to said lettuce to prevent deterioration thereof, and placing fragmentary ice in said crate above said sheet and out of direct contact with said layer of lettuce.

13. The method of packing lettuce, which comprises dampening a sheet of absorbent paper with a solution of an agent normally foreign to the lettuce to prevent discoloration by discharge of milk" from a head of lettuce, said dampening being suflicient to make said sheet conformable, and placing the resulting damp, conformable sheet on the cut stem end of a' head of lettuce. I

14. A package of lettuce, comprising a layer of heads of lettuce with the. butts up, a layer of fragmentary ice above and adjacent said butts, and an absorbent sheet between said layer of ice and said butts and in contact with said butts,

\said sheet carrying and supplying an agent normally foreign to said lettuce," said sheet and agent eo-operating to inhibit deterioration at said butts.

15. A package of lettuce comprising superposed layers of heads of lettuce with the butts up, a layer of fragmentary ice above and adjacent said butts, and an absorbent sheet between each layer of ice and said butts and in contact with said as butts, said sheets carrying and supplying an agent normally foreign to said lettuce, said sheets and agent co operat ing to inhibit deterioration at said butts.

IRVINE L. PEEL- 1P8.

DISCLAIMER 2,336,291.-Irvin L. Phillips, Long Beach, Calif. Mm'non or PACKING Pnmsn- Anus AND PACKAGE. Patent dated Dec. 7, 1943. Disclaimer filed Nov. 15, 1946, by the 'assignee,'Seal-Paclc Corpmation. Y Hereby enters this disclaimer toclaims 1, 4, and 5 of thel patent. [Oficial Gazette December 17, 1946.] L

Images