Stubbs, Clifford A.
| 1. | A method of dehydrating a food product compris¬ ing: a. cutting the food product into individual pieces; b. forming an adhesive surface on the indi¬ vidual pieces; c. coating the individual pieces with a sepa¬ ration particulate in order to separate the individual pieces and form an air pathway therebetween for drying; and d. drying the individual pieces. |
| 2. | The method as recited in claim 1 and further comprising: forming an adhesive surface on the indi¬ vidual pieces by the addition of adhesive elements to the separation particulate which react with moisture on a surface of the individual pieces for adhering the separa¬ tion particulate to the individual pieces. |
| 3. | The method as recited in claim 2 and wherein: the adhesive elements are contained in a dry mixture which also contains the separation particu¬ late. |
| 4. | The method as recited in claim 1 and wherein: forming an adhesive surface on the indi¬ vidual pieces is by the application of adhesive forming elements to the individual pieces. |
| 5. | The method as recited in claim 1 and further comprising: rehydrating the individual pieces by immer¬ sion in water. |
| 6. | The method as recited in claim 3 and wherein the food product is potatoes, and the method further co pris es: forming elongated potato shreds suitable for hash brown potatoes, mixing flavorings, browning and pattybinding ingredients with the dry mixture. |
| 7. | The method as recited in claim 6 and wherein: the adhesive surface is formed by a pre¬ gelatinized starch included with the dry mixture which reacts in the presence of moisture on the potato shreds. |
| 8. | The method as recited in claim 6 and wherein: the adhesive surface is formed by residual native potato starch on the cut potato shreds. |
| 9. | The method as recited in claim 6 and wherein: the adhesive surface is formed from the reaction of an anionic hydrocolloid and cationic polyva¬ lent foodgrade salt combined with the separation particu late, reacting with moisture. |
| 10. | The method as recited in claim 6 and wherein: the adhesive surface is formed from the reaction of alginate and calcium salt included within the dry mixture reacting with moisture on the potato shreds. |
| 11. | The method as recited in claim 10 and wherein: the anionic hydrocolloids include salts of alginic acid, including algin, alginate, sodium alginate, potassium alginate. |
| 12. | The method as recited in claim 10 and wherein: the anionic hydrocolloids include salts of pectinic acids including lowmethoxyl pectin, L.M. pectin, sodium pectinate, potassium pectinate, amidated pectin. |
| 13. | The method as recited in claim 6 and wherein: the separation particulate includes com minuted potato particles applied to the potato shreds prior to drying. |
| 14. | The method as recited in claim 6 and wherein: previously dried whole shredded potatoes are mixed with the potato shreds prior to drying. |
| 15. | A method of producing dehydrated potato pieces comprising: a. cutting potatoes into separate pieces; b. blanching the potato pieces; c. forming an adhesive surface on the potato pieces; d. applying a separation particulate to the individual pieces in order to maintain separation of the individual pieces during drying; and e. drying the individual potato pieces. |
| 16. | The method as recited in claim 15 and wherein: the adhesive surface is formed by residual native potato starch formed from cutting the potatoes. |
| 17. | The method as recited in claim 15 and wherein: the separation particulate is included in a dry mixture applied to the potato shreds. |
| 18. | The method as recited in claim,15 and wherein: the separation particulate includes com¬ minuted potato particles. |
| 19. | The method as recited in claim 15 and compris¬ ing: a. cutting the potato pieces into elongated shreds suitable for hashbrown potatoes; and b. applying a dry mixture containing the sepa ration particulate, flavorings, browning ingredients, and pattybinding ingredients for forming hashbrown potatoes to the potato shreds. |
| 20. | A product formed by the process of claim 19. |
| 21. | The method as recited in claim 15 and wherein: a. the potato pieces are sliced and suitable for use in casserole dishes; and b. the separation particulate includes flavor¬ ings, dehydrated vegetables, and dehydrated cheeses. |
| 22. | A product formed by the process of claim 21. 23. |
| 23. | The method as recited in claim 17 and wherein: the dry mixture includes ingredients which react with moisture on the potato pieces to form the adhe¬ sive surface. |
| 24. | The method as recited in claim 23 and wherein: the dry mixture includes pregelatinized starches which form an adhesive surface on the potato pieces. |
| 25. | The method as recited in claim 23 and wherein: the dry mixture is combined with a muci laginous substance which form an adhesive surface on the potato pieces. |
| 26. | The method as recited in claim 23 and wherein: the dry mixture includes alginate and solu¬ ble calcium salt which react to form an adhesive surface. |
| 27. | The method as recited in claim 19 and wherein: The adhesive surface is formed from the reaction of an anionic hydrocolloid and cationic polyva¬ lent foodgrade salt included in the dry mixture which reacts with moisture on the potato shreds. |
| 28. | The method as recited in claim 25 and wherein: the anionic hydrocolloids include salts of alginic acid, including algin, alginate, sodium alginate, potassium alginate. |
| 29. | The method as recited in claim 25 and wherein: the anionic hydrocolloids include salts of pectinic acids including lowmethoxyl pectin, L.M. pectin, sodium pectinate, potassium pectinate, amidated pectin. |
| 30. | The method as recited in claim 25 and wherein: the polyvalent cationic salt includes any foodgrade salt. |
| 31. | A method of producing a dehydrated hashbrown potato product which, when rehydrated and fried, simulates freshly cut hashbrown potatoes; said method comprising: a. peeling, trimming, and cutting potatoes into thin elongated shreds; b. washing the potato shreds; c. blanching the potato shreds; d. applying a dry mixture containing a sepa¬ ration particulate and adhesive forming ingredients to the potato shreds; e. forming an adhesive surface and adhering the dry mixture to the potato shreds by reaction of ingre¬ dients in the dry mixture in contact with moisture on the potato shreds; f. drying the separated potato shreds to a moisture content of less than about 10%; and g. packaging the dried potato shreds. |
| 32. | The method as recited in claim 31 and wherein: the dry mixture contains flavorings, brown ing ingredients and pattybinding ingredients. |
| 33. | The method as recited in claim 31 and wherein: the potato shreds are dried in a multi¬ stage hotair conveyer dryer. |
| 34. | The method as recited in claim 31 and wherein: the dry mixture includes raw starches. |
| 35. | The method as recited in claim 31 and wherein: the dry mixture includes crushed dehydrated potatoes. |
| 36. | A product produced by the process as recited in claim 32. |
| 37. | The method as recited in claim 35 and further comprising: a. rehydrating the potato shreds in water; and b. frying the potato shreds. |
| 38. | The method as recited in claim 31 and wherein: comminuted blanched potato particles are applied to the potato shreds as a separation particulate. |
| 39. | A method of producing a dehydrated potato piece which can be rehydrated and cooked as a casserole dish comprising: a. peeling, trimming, and cutting potatoes into slices; b. washing the potato slices; c. blanching the potato slices; d. applying a dry mixture containing a sepa¬ ration particulate, flavorings, dehydrated cheeses, dehy¬ drated vegetables to the potato slices; e. forming an adhesive surface on the potato slices by reaction of ingredients in the dry mixture in contact with moisture whereby the dry mixture adheres to the potato slices and separation of the potato slices is maintained; f. drying the potato slices to a moisture content of less than about 10%; and g. packaging the potato slices. |
| 40. | A method as recited in claim 38 and wherein: the dry mixture includes a thickening agent which combines with water used to rehydrate the potato slices during a cooking step. |
| 41. | A product formed by the process of claim 39. |
| 42. | A method as recited in claim 39 and further com¬ prising: a rehydrating the potato slices by immer¬ sion in water. |
| 43. | A method as recited in claim 41 and wherein the potatoes are "eliminators". |
| 44. | A method of producing a dehydrated hashbrown potato product which, when rehydrated and fried, simulates freshly cut hashbrown potatoes; said method comprising: a. peeling, trimming, and cutting potatoes into thin elongated shreds; b. washing, blanching, and dewatering the potato shreds; c. blanching the potato shreds; d. applying a dry mixture containing flavor¬ ings and adhesive forming ingredients to the potato shreds; e. adding to the potato shreds previously dried shredded potatoes; f. forming an adhesive surface and adhering the dried, shredded potatoes and the dry mixture to the potato shreds by reaction of ingredients in the dry mix¬ ture in contact with moisture on the potato shreds; g. drying the separated potato shreds to a moisture content of less than about 10%; and h. packaging the dried potato shreds. |
| 45. | The method as recited in claim 44 and wherein: the dry mixture contains a separation par ticulate. |
| 46. | The method as recited in claim 45 and wherein: the previously dried, shredded potatoes are added at a ratio of between 1% and 20% of the blanched, dewatered potato shreds prior to drying. |
| 47. | The method as recited in claim 46 and wherein: the previously dried, shredded potatoes are formed and dried in accordance with the invention. |
| 48. | A product formed by the process of claim 47. |
| 49. | The method as recited in claim 45 and wherein; the previously dried, shredded potatoes are about 5% of the weight of the blanched, dewatered potato shreds. |
| 50. | A method of producing a dehydrated hashbrown potato product which, when rehydrated and fried, simulates freshly cut hashbrown potatoes; said method comprising: a. peeling, trimming, and cutting potatoes into thin elongated shreds; b. washing, blanching, and dewatering the potato shreds; c. adding comminuted blanched potato particles to the shreds; d. applying a dry mixture containing flavor¬ ings and adhesive forming ingredients to the potato shreds; e. forming an adhesive surface and adhering the dry mixture and comminuted blanched potato particles to the potato shreds by reaction of ingredients in the dry mixture in contact with moisture on the potato shreds; f. drying the separated potato shreds to a moisture content of less than about 10%; and g. packaging the dried potato shreds. |
| 51. | A method as recited in claim 50 and wherein: the comminuted blanched potato particles are comminuted to a size sufficient to allow air flow between the shreds during drying. |
| 52. | The method as recited in claim 50 and wherein: the dry mixture contains a separation par¬ ticulate. |
| 53. | A product formed by the process of claim 50. |
Field of the Invention
The present invention relates generally to a dehy¬ dration process for food products particularly suited to dehydrating potatoes for use in the preparation of hash- brown potatoes.
Background of the Invention
Hashbrown potatoes are typically prepared by forming elongated strands or shreds of fresh cut potatoes into a patty which is then fried on both sides. Cutting, shred- ding, or grating potato pieces into elongated strands to form the patties ruptures the potato cells and releases free starch. This free starch acts as a binder which adheres the individual potato strands to one another to form a patty and maintain the patty intact when it is turned to fry both sides.
Another critical feature of hashbrowns is their abil¬ ity to brown during the cooking operation to provide the browned hashbrown coloring on both sides of the patty. Difficulties in producing the desirable browned color are encountered with potatoes for several months after har¬ vesting, as these potatoes have not yet developed suffi¬ cient level of reducing sugars. The browning of the adhe¬ sive mixture of potato shreds provides the flavor and consistency that makes hashbrown potatoes so unique and appealing.
Many attempts have been made in the past to formulate dry or dehydrated hashbrown potato products which dupli¬ cate the appearance and flavor of fresh-made hashbrowns. U.S. Patent No. 4,828,856 to Willard, for instance, dis- closes a method for forming a dehydrated fabricated potato product for use in the preparation of hashbrown potatoes. Other methods of making similar dry hashbrown products are disclosed in U.S. Patent Nos. 3,634,105 and 3,991,222 to
Beck; 3,725,087 to Miller; 3,410,702 to Frank; 3,635,729 to Englar; and 3,650,776 to Tschirgi.
Another form of dehydrated potatoes which can be fried to produce "home fried" potatoes are thin slices. These slices are traditionally used for making casserole dishes such as scalloped potatoes. Because of the longer rehydration time required for the thicker potato slices, they are not as well favored by institutional users for the preparation of home fries. For those who do prefer this shape, the problems of adhesion and optimum sugar content for browning are the same as described for shred¬ ded hashbrown products.
In general, each of the above-noted patents involve dehydrating the potato by hot air drying. Typically, this involves a processing step in which a bed of potatoes (either fresh or reconstituted) are placed in a multi¬ stage, conveyer belt dryer and subjected to heated air for a period of several hours. As is known to those skilled in the art, processing and heating the potatoes diminishes the potato flavor of the final product.
This processing problem is compounded by the use of binder materials which may be added during processing of the potatoes to enable formation of stable patties during final cooking. The Englar '729 and Tschirgi , 776 patents, for instance, teach the use of free starches which may be applied in an aqueous solution to the processed potatoes before completion of the drying process. This binder may cause the processed potatoes to also bind together during the dehydration process. This requires additional heating to heat the bound strands of processed potato pieces and causes further loss of flavor and additional costs for the final product. Additionally, with the use of a binder, processing problems such as clumping and the formation of "blow holes" within a potato bed and adherence of the
potatoes to parts of the processing equipment may also occur.
The Frank '702 patent approached this prior art prob¬ lem by adding a potato binder (made by drying cooked pota- toes that had been riced into small strands) to conven¬ tionally diced or shredded potatoes after they had been dried. This process produced a product having a non-ho¬ mogenous mealy texture. In addition, the previously men¬ tioned processing problems associated with prolonged heat- ing for drying the potatoes were still present.
As is apparent, there is a need in the art for a dehydration process in which food products can be economi¬ cally and efficiently dehydrated in a minimum time to reduce flavor loss to a minimum. Additionally, there is a need in the art for an economical processed dehydrated potato product which functions in the same manner as a fresh-made hashbrown potato patty and in which the potato flavor of the final product has not been lost in process¬ ing. The novel and unique dehydration process of the present invention satisfies these prior art needs. More¬ over, dehydrated hashbrown potatoes processed in accor¬ dance with the process of the present invention closely resemble the appearance and texture of fresh-made hash¬ brown potatoes and can be easily rehydrated and prepared by an end user.
Summary of the Invention
In accordance with the present invention, a process for dehydrating food products especially suited for pro¬ cessing dehydrated hashbrown potatoes is disclosed. The process, simply stated, includes the steps of: preparing separate pieces of a food product for dehydration; forming an adhesive surface on the separate pieces of the food product; coating the adhesive surface of the food product with a separation particulate in order to maintain separa- tion of the food product pieces to form an air pathway for
heated air flow between the separated pieces; drying the separated food product pieces to reduce the moisture con¬ tent thereof to below about 10%. The dehydrated food product pieces can then be packaged as a shelf-stable item and reconstituted by immersion in water for use by an end user in final cooking preparation of potato dishes.
The process of the invention is particularly suited to the formation of elongated potato strands or shreds which may be rehydrated and cooked as hashbrown potatoes. It is contemplated, however, that potatoes may be cut into sizes and shapes and processed for uses other than for the formation of hashbrown, such as slices used for making casserole dishes such as scalloped potatoes.
In accordance with an illustrative embodiment of the invention for forming hashbrown potatoes, as an initial step, fresh potatoes are first prepared for dehydration. This typically includes the steps of cutting, shredding, or slicing whole fresh potatoes into elongated shreds suitable for the formation of hashbrown potatoes. As a next step, the potato shreds are washed to re¬ move free starches, blanched to inactivate enzymes, and then washed again. These steps can be accomplished by techniques which are known in the art.
An adhesive coating is then formed on the surface of potato shreds. The adhesive coating may be formed by techniques which are known in the art and may be in the form of pregelatinized starches formed as a film, a film of polymerized alginate, or simply residual native potato starches. In a preferred form of the invention, the adhe- sive coating is formed by dry ingredients included in a dry mixture containing the separation particulates and which react in the presence of moisture on the potato shreds to form an adhesive surface.
The dry mixture also contains the separation particu- late. The separation particulate is preferably in the
form of particulate foodstuff which adheres to the adhe¬ sive surface of the potato shreds. The separation partic¬ ulate may be formed of various foodstuff particles such as crushed potatoes or corn or dehydrated potato particles. The separation particulate functions to maintain separa¬ tion of the individual potato shreds so that the potato shreds may be more efficiently and uniformly air dried for dehydration.
The particulate-separated potato shreds can be dehy- drated by conventional drying, such as with a heated-air conveyer dryer, to a moisture content of about 10%. Sepa¬ ration of the individual potato shreds by the separation particulate JΠBS spaces or an air pathway for air flow around each potato strand. This facilitates moisture loss from the potato shreds to the heated air and, in general, increases the efficiency and uniformity of the drying process. This in turn decreases the processing time and lessens loss of potato flavor from the processed potato pieces. Additionally, the separated potato shreds are not subjected to clumping and isolated "blow holes" are great¬ ly minimized within a bed of potato shreds being air dried. Moreover, the particulate-laden potato shreds are heavier and easier to handle than unprocessed shreds.
In addition to containing particulate foodstuffs which function to maintain separation of the individual potato shreds and adhesive forming ingredients, the dry mixture may also include patty-binding ingredients, brown¬ ing ingredients, flavorings, preservatives, and antioxi- dants. These additional ingredients may be formulated to be activated during the high heat of final cooking by an end user. Since these additional ingredients are adhered to the surface of the potato pieces during processing, separate mixing of spices by an end user is not required.
Many other objects, advantages, and capabilities of the present invention will become apparent as the descrip¬ tion proceeds.
Brief Description of the Drawings Figure 1 is a flow diagram of a process for dehydrat¬ ing a food product in accordance with the invention;
Figure 2 is an enlarged side-elevation view of por¬ tions of adjacent food product pieces in which separation of the food product pieces is maintained in accordance with the invention during drying of the food product piec¬ es;
Figure 3 is a flow diagram of a process for dehydrat¬ ing potatoes in accordance with the invention for use as hashbrown potatoes; Figure 4 is a perspective view of a potato strand shaped to provide an increased surface area for rehydra- tion;
Figure 5 is a graph of a consumer preference test comparing untreated potato shreds, a commercially avail- able Redi-Shred™ product, and treated potato shreds pro¬ cessed in accordance with the invention; and
Figure 6 is a graph showing the drying rate of potato shreds processed in accordance with invention compared to the drying rate of untreated shreds. Detailed Description of the Preferred Embodiment
Referring now to Figure 1, a process for dehydrating a food product in accordance with the present invention is shown. The process broadly stated includes the steps: preparing a food product for dehydration, in- eluding the formation of separate pieces of the food product, step 10; forming an adhesive surface on the separate pieces of food product, step 11; applying a separation particulate to the adhe- sive surface of the separate pieces of food product
in order to maintain separation and form air pathways between adjacent pieces, step 12; and drying the separated pieces to remove moisture therefrom, step 14. The dried food product pieces are then packaged, step 16, and can be rehydrated by immersion in water, step 18, prior to final cooking by an end user.
A critical step of the process is step 12 in which a separation particulate is applied to the surface of the food product in order to maintain separation of the sepa¬ rate pieces of food product and provide an air pathway to allow air flow therebetween during the drying step, step 14. Maintaining separation of the separate food product pieces increases the efficiency and uniformity of the drying process and allows the end product to be more ef¬ fectively and economically produced.
Prior to application of the separation particulate, step 12, an adhesive surface must first be formed on the surface of the food product, step 11, in order to adhere the separation particulate to the separate pieces of food product. This may be done by techniques which are known in the art. For instance (and as taught in U.S. Patent No. 3,527,646 to Scheick) , a dry powder containing one or more pregelatinized starches may be added to the separa- tion particulate or to a dry mixture containing the sepa¬ ration particulate and reacted with a moist surface of the food product pieces to form an adhesive film. Alterna¬ tely, an adhesive surface may be formed from the polymer¬ ization of alginate and calcium salt which may be included within the dry mixture and reacted in the presence of moisture on the food product surface to form an adhesive surface. Additionally, gums or other mucilaginous sub¬ stances may also be used to form an adhesive surface. For potato food products, an adhesive surface may simply be
formed by native potato starches formed on the potato surface by cutting the potato into separate pieces.
Water or moisture may be present on the surface of the food product pieces because during preparation the food product pieces are typically washed. The water or moisture must be present in sufficient quantities to allow the necessary chemical reaction for forming or polymeriz¬ ing the adhesive surface to occur. Conversely, there must not be so much water on the food product pieces that the dry separation particulate mixture is washed away prior to formation of an adhesive surface.
With reference to Figure 2, an enlarged cross-section of separate food product pieces 22 having an adhesive surface 28 and a separation particulate 24 formed thereon are shown. For the purpose of illustration, the food product pieces 22 and the separation particulate 24 are shown with a greatly enlarged size in Figure 2. In prac¬ tice, the separation particulate may be sized in the range of a fine powder passing through a U.S. 40 mesh sieve (0.42 mm diameter) to particles having a diameter of about 1/32 inch (0.794 mm) or passing through a U.S. 20 mesh sieve (0.841 mm). Use of larger particles facilitates the separation of the particulate materials from the surfaces of the dried piece during drying and handling. As shown in Figure 2, the separation particulate 24 is comprised of a plurality of irregularly shaped individual particles.
The separation particulate 24 functions to maintain separation of the individual food product pieces 22 to provide an air pathway therebetween such that air flow (denoted by arrow 26 in Figure 2) for drying the food product pieces, step 14, can be more easily directed through and around the individual pieces 22. This in¬ creases the rate of heat transfer by convection and in¬ creases the efficiency of drying the food product pieces 22.
The separation particulate 24 may be formed of any food product compatible particulate foodstuff which re¬ mains as a particle solid and does not totally dissolve in water from the moist surface of the food product (e.g., salt particles would be ineffective). By way of example and not be limitation, some suitable foodstuff particles may be raw granular starches (potato, corn, or other) , crushed or milled potato particles, or dehydrated potato particles. Other granular or powdered edible particles may also be suitable for this application, provided the material functions to adhere to the surface of the potato pieces 22 and maintain separation of the individual potato pieces 22 to provide an air pathway therebetween.
Once the individual food product pieces 22 have been coated with the separation particulate 24, the food prod¬ uct pieces 22 can be air dried, step 14, to a moisture content of less than about 10% and preferably about 7% for potato products. The food product pieces may be dehydrat¬ ed by equipment and procedures which are known in the art. As an example, potato pieces may be hot-air dried in a belt conveyer dryer such as a Proctor and Schwartz convey¬ er dryer or the like, which subjects a moving bed of pota¬ to pieces to a hot air stream of from about 150° to 225°F (65.5° to 107.2°C) for a period of from about 1 to 4 hours.
The drying or dehydration time of food product pieces processed in accordance with the invention may be de¬ creased significantly, over similar unprocessed food prod¬ uct pieces. Additionally, the separated food product pieces tend not to bind together in moist clumps as with conventional uncoated food product pieces, and a rate of throughput through a conveyer dryer or the like can be proportionately increased. Moreover, the overall drying process is more uniformly accomplished and the formation of "blow holes" through a bed of food product pieces is
minimized. ("Blow holes" being air conduits through a bed of food product pieces which provide a short circuit for air flow and detract from air distribution and the overall efficiency of the drying process. ) After the food product pieces 22 have been dried to a moisture content of less than about 10%, they can be packaged for storage. In this dehydrated form, the food product pieces are a shelf stable food product and can be simply packaged in plastic bags or the like. Prior to final cooking, the food product pieces 22 must be rehydrated by an end user, step 18. For rehydra- tion, the food product pieces 22 may be placed in cold tap water and allowed to remain overnight for use the follow¬ ing morning, or by placing in hot water for a shorter period. The food product pieces, when rehydrated to a ratio of 4 parts rehydrated weight for 1 part dry weight, are returned to approximately the same original dimension of the food product pieces with a texture that is not tough or leathery, or soft and mushy. The food product pieces can then be prepared in conventional dishes.
Embodiment II: Hashbro n Eiη pflimQnt Referring now to Figure 3, a process for producing potato strands or shreds in accordance with the invention and suitable for use as hashbrown potatoes is illustrated. In general, for producing a hashbrown potato product, the process is the same as previously described for a food product piece but with the addition of a dry mixture con¬ taining the separation particulate as well as browning ingredients for the hashbrowns, and patty-binding ingredi¬ ents for forming the hashbrowns into patty form. Flavor¬ ing in the form of spices or the like may also be added. These additional ingredients are mixed with the separation particulate in a dry mixture and adhere to the adhesive surface of the potato pieces or shreds as does the separa-
tion particulate. Those additional ingredients with non- dissolving character which maintain their particulate character in a moist environment may also function as a separation particulate for maintaining separation of the potato shreds during drying. The patty-binding ingredi¬ ents and browning ingredients, as will hereinafter be more fully explained, are activated by the high temperature used for cooking the hashbrowns by an end user. Since the flavorings or spices are adhered to the surface of the potato shreds during processing, a final end user need not further season or add spices to the mixture, which adds to the convenience of the final product.
With reference to Figure 3, as a first step of the process, fresh whole potatoes are peeled, trimmed, and cut into elongated thin strands, shreds, or strips, step 30. A typical strip size may be 1/16 inch (1.59 mm) in diame¬ ter by 2 inches (50.8 mm) long. By way of example, a suitable slice may be a model CC Urschel slicer manufac¬ tured by URSCHEL Manufacturing Company, Valparaiso, Indi- ana.
Following the preparation step, step 30, the elon¬ gated shreds are washed in cold water to remove surface starch, step 32. Following washing, the shreds are blanched by conventional blanching equipment 32. As is known in the art, blanching heats the potato tissue throughout at time and temperature conditions high enough to inactivate the enzymes which would otherwise cause oxidative darkening of the potato tissue, but not suffi¬ cient to soften the tissue enough for normal consumption. Normal blanching conditions range from about 2 to 6 min¬ utes at about 170°F or 190°F (77 β C to 88 β C). After blanching, the potato shreds may optionally be washed again, step 36.
The blanched shreds are then partially de-watered of surface moisture by suitable means such as draining or
drum spinning, step 38. Preferably, excess water is re¬ moved from the shreds, but the potato shreds still contain enough moisture to enable formation of an adhesive surface from the dry mixture including the separation particulate to be added in the following steps.
Following de-watering, a dry mixture containing the separation particulate adhesive-forming ingredients, browning and binding ingredients, and spices is mixed with the potato shreds, step 40, so that the moist exposed surfaces of the shreds are uniformly covered by the dry mixture. This can be accomplished by metering the dry mixture onto the shreds as they pass through a rotating coating drum or alternately by other suitable means. The dry particulate is preferably distributed uniformly on all of the exposed surfaces of the potato shreds and coats the potato shreds. As previously stated, the dry mixture may include the separation particulate, dry spices, and patty- forming and browning ingredients for the hashbrowns. The dry mixture may be on the order of 2 to 8 percent of the total weight of the blanched shreds-dry mix blend. This corresponds to a dry mix content on the order of 8 to 26 percent of the total weight of finished, dried product.
In addition to forming a separated product, the dry mixture adds weight to the potato shreds. This improves the handling of the potato shreds during processing, helps prevent the formation of "Blow holes" in a bed of potato shreds during the drying step, step 48, and provides a more formable bulk density for packaging. Further, the dry mixture absorbs and retains extra water during rehy- dration by the end user which is necessary for activation of patty forming ingredients, and also produces a less leathery, more moist, natural tasting end product.
For adhering the dry mixture to the surface of the potato shreds, an adhesive coating or film is formed on the surface of the separate potato shreds, step 42. As
previously explained, this may be accomplished by reaction of the adhesive particles which may be included in the dry mixture with moisture on the surface of the potato shreds. An adhesive material for adhering the separation particulate flavorings, spices, browning, and patty-bind¬ ing ingredients is a gelatinized starch. The most avail¬ able source is the residual potato starch on the surfaces of the cut potato pieces following blanching and washing. The amount and consistency of this starch may vary, howev- er, due to the conditions of the potatoes, the extent of blanching, and the extent of washing following blanching. While satisfactory adhesion of the particulates has been accomplished using a potato's own residual starch, it is deemed best to add a dry powdered pregelatinized starch to the dry mixture. Such starches that have been tested successfully include pregelatinized potato and corn starch, and modified starches such as Bakasnak Starch (National Starch & Chemical), Ultra-Sperse Starch (Nation¬ al Starch & Chemical), Ultra-Tex Starch (National Starch & Chemical), and Mira-Thik 469 Starch (A. E. Staley Manu¬ facturing).
The preferred means of forming an adhesive surface is including in the dry mixture a gel forming reactive mix¬ ture of a food-grade polyvalent salt (cationic), such as calcium or aluminum salt, and anionic hydrocolloid, such as algin or low-methoxyl pectin. It is well known in the art that polyvalent salts react with hydrocolloids con¬ taining anionic sites, cross-linking closely aligned hydrocolloids, thus forming insoluble gels. Calcium salts are preferred cross-linking agents.
Effective levels of polyvalent salt-gelling hydro¬ colloid are between 0.5% to 5%, by weight, of dry mix (all components except food being dried); 1.5% hydrocolloid being a preferred level. Polyvalent salt levels in dry mix, sufficient to cause desired gelling, must be adjusted
to compliment the polyvalent salt-gelling hydrocolloid level.
Polyvalent salt levels may be in the range of 20% to 80% of the level of polyvalent salt-gelling hydrocolloid. When using a preferred polyvalent salt-gelling hydrocol¬ loid level of 1.5% by weight of dry mix, a polyvalent salt level of 0.54% of dry mix weight has been found effective. With the formation of an adhesive surface, the sepa¬ ration particulate contained within the dry mixture ad- heres to the separate potato shreds and maintains separa¬ tion of the separate potato shreds, step 46.
The separation particulates can be any insoluble food stuff. Dry particulates, however, which are slow to ab¬ sorb water, thus maintaining their basic physical partic- ulate character in a moist environment are most suitable for this application. Additionally, the separation par¬ ticulate must be compatible to the finished food product. By way of illustration, and not limitation, examples of suitable separation particulates are as follows: Raw crystalline starches including potato starch, corn starch, tapioca starch, etc. These ingredients serve the dual purpose of separating the potato shreds during drying and also furnishing adhesive quality to the recon¬ stituted shreds during preparation. For example, at the moment of frying the potato shreds of this invention, water is available at the surface such that, when the surface temperature of the rehydrated shreds exceeds the gelatinization temperature of the starches 150° to 170°F ■65.5° to 76.7°C) . a starch gel forms, providing an adhe- sive film for bonding the shreds. This results in patty formation to a degree not possible in normally prepared dried potato shreds, which lack sufficient native surface starch for developing well-defined patties. Crispness is also significantly improved.
Other suitable starches include specialty starches, such as Amylomaize VII Starch (American Maize Co.) and Textaid Starch (National Starch & Chemical). Specialty starches can serve the dual purpose of separating the potato shreds during drying and also impart their own respective qualities of increased σrispness, patty forming film, or enhanced internal texture (mealiness) to the final grilled/cooked product.
It has been found that dehydrated potato products can also be used to coat the surfaces of the potato shreds. These can include dehydrated mashed potatoes in any conve¬ nient form such as potato granules, potato flakes, potato buds, or crushed dehydrated potato pieces, preferably ground to a size less than about 1/32 of an inch (0.794 m) in diameter or to pass a 20 mesh (0.0328 inch or 833 mm) sieve. Particles larger than this function well as air pathway forming particulates, but tend to separate during drying and handling of the finished product. For a more uniform-appearing finished product, a crushed dehy- drated potato passing through a 40 mesh (0.0165 inch or 0.425 mm) screen is preferred.
It has also been found that it is possible to add back previously dried whole shredded potatoes (add-back shreds) to the treated shreds, including previously dried shreds made by the process of this invention. This can be done after partial de-watering, step 38, of the process whereat the shreds are still moist. When added at a ratio of between 1% and 20% (basis: dry weight of add-back/wet weight of treated shreds) to the moist, washed, dewatered treated shreds, before drying, the add-back shreds rapidly absorb water from the treated wet shreds and partially hydrate. This creates a textural change to the shreds mixture resulting in significantly more, and larger, air pathways between shreds, resulting in more rapid drying and less shred-to-shred adhesion. Absorption of water by
the dry shreds during the first stages of drying is such that undesirable browning of the add-back shreds is avoid¬ ed. Products made in this matter have shown drying rates significantly faster than the rates achieved with smaller separation particulates. As an example, it has been found that add-back of 5% dehydrated potato shreds to wet potato shreds by weight will result in reduction of first stage drying time in a multi-stage drier of about 38% compared to potato shreds treated with small particulates, and about 60% faster than plain, wet, untreated, conventional potato shreds.
Comminuted, blanched and dewatered potato particles may also be added to the shreds as a separation particu¬ late. Starting with raw, whole potatoes, these comminuted potato particles will typically have a moist surface (i.e., native moisture of whole potatoes). The moist potato particles can be added to the potato shreds after dewatering, step 38, and prior to covering the shreds with the dry mixture, step 40. This optional step is shown as step 39 in the flow diagram of Figure 3.
After treatment with the dry mixture, the potato shreds can then be air dried to a moisture content of less than 10% and preferably about 7%, step 48. A suit¬ able drying arrangement involves depositing the potato shreds in layers of several inches thick on a two-stage conventional Proctor And Schwartz conveyer dryer. The particulate separated potato shreds tend not to matt down or stick together, minimizing resistance to drying air, resulting in improved efficiency of the drying process. The dried potato shreds can then be packaged in plas¬ tic bags, sealed cartons, boxes, or other suitable means, step 50. Potatoes processed in this matter are shelf- stable under normal distribution conditions and do not require refrigeration.
For use by an end user, the potato shreds must be rehydrated by an end user, step 52. This can be simply accomplished by immersion of the potato shreds in cold tap water and allowing the shreds to remain overnight for use the following morning, or by placing in hot water for a shorter period. The potato shreds, when rehydrated to a ratio of 4 parts rehydrated weight for 1 part dry weight, are returned to approximately the same original dimension of blanched raw cut potatoes with a texture that is typi- cal of natural, fresh potato shreds, not tough or leath¬ ery, or soft and mushy.
It has been determined that potato shreds formed with relatively larger surface areas can be more efficiently rehydrated during step 52. One such suitable cross-sec- tional shape for the potato shreds 58 is shown in Figure 4. As is apparent, a generally cup-shaped (either concave or convex) cross-sectional configuration provides a rela¬ tively larger surface area for water absorption than a generally square, rectangular, or triangular cross-section and thus improves the efficiency of the rehydration step, step 52.
The rehydrated potato shreds can then be prepared in conventional dishes. As previously stated, further sea¬ soning or mixing of spice packets is not necessary as the dry mixture containing flavorings or spices adheres to the surface of the potato shreds, even though the rehydration step, step 52.
The rehydrated hashbrown potatoes can, for instance, be cooked by an end user by frying on a heated, oiled surface, step 54, or by other conventional means. During cooking, browning and patty-binding ingredients present in the separation particulate are activated by the relatively high cooking temperatures to produce a browned hashbrown patty, step 56.
Embodiment III: Slices and Other Dehydrated Potato Pieces The invention may also be practiced with sliced dehy¬ drated potatoes, normally cut .125 inch (3.175 mm) to .0625 inch (1.59 mm) thick from small potatoes typically called "eliminators". The invention may also be practiced with other sizes and shapes of dehydrated potatoes such as, for example, a generally square piece measuring .750" x .750" x .125" .19.05 mm x 19.05 mm x 3.175 mm) or .25" x 1.0" x .375" (6.35 mm x 25.4 mm x 9.52 mm) , etc. Be¬ cause of the popularity of casseroles prepared from dehy¬ drated sliced potatoes for both retail and institutional feeding, the discussion will be directed toward the appli¬ cation of the invention to sliced dehydrated potatoes of about .125" (3.175 mm) thickness.
Thinly sliced potatoes have been used traditionally to prepare baked casseroles known as scalloped potatoes or au gratin potatoes by combining milk, cheese, or other vegetables such as onions and green peppers. A wide vari- ety of such dishes are commonly prepared in households and restaurants. Dried sliced potatoes are also widely used for household preparation, mainly for casseroles. For these, a packet of dried ingredients is furnished together with the dried potatoes for preparing the casserole. The dry ingredients include the thickening agents which com¬ bine with the water or milk added to the mixture to rehy- drate the dried potatoes during baking. The dry mixture also contains optional ingredients such as seasonings, spices, dehydrated cheeses, and dehydrated vegetables, particularly dried onions.
It has been determined that the process of this in¬ vention can be applied to dried slices and utilized for casserole dishes without the use of the separately added packet of seasonings, thickeners, and other ingredients. In general, the separation particulate must be formed with
particles with a size which corresponds to the size of the product being dried. For slices, which are typically larger than potato shreds utilized for hashbrowns, the size of the separation particles must also be proportion- ately larger.
Example
SHREDDED HASHBROWN POTATOES Uncoated, plain potato shreds and dry mixture coated, treated shreds (hereinafter abbreviated "Control" and "Treated" products, respectively) were made and dried in a pilot plant as follows:
A bulk quantity of dry mixture (abbreviated herein¬ after as "Dry Mix") containing desired air pathway forming separation particulates and hydrocolloid film-forming adhesive components (alginate and calcium salt), plus flavorings and browning agents, was made as follows: Ingredient function codes: F - Flavor
B - Browning during grilling P - Particulates
A - Dry mix adhesive D - Dust control H - Hashbrown patty adhesive T - Hashbrown texture enhancer
Ingredients 11a through lie are potato flavor profile ingredient as disclosed in U.S. Patent No. 4,698,230. Dry mixture ingredients were homogeneously blended in three parts. Part "A" consisted of blending sodium chloride, sucrose, citric acid, malic acid, and calcium chloride for 1 minute in a Leland Model 1000A food mixer, then adding warm, liquefied glycerol monooleate (abbreviated hereafter as "GMO") over 1 minute, followed by approximately 8 min¬ utes additional mixing to thoroughly disperse the GMO. Any liquid high-stability fat (oil) will substitute for
GMO for the purpose of dust control at the same level of application. Part "A" mixture was then transferred to a Marion Model FPS-2436 Mixer, set at 65-70 revolutions per minute. Part "B" consisting of potato starch and corn starch was added to the Marion Mixer and mixing continued until dust subsided, approximately 5 minutes. Finally, Part "C", consisting of all remaining ingredients, was added to the Marion Mixer and mixing continued until salt analysis indicated a homogeneous mixture (approximately 17% salt), which required about 10 minutes. Blended Dry Mix was stored in poly-lined paper bags until used.
Idaho Russet potatoes were peeled, trimmed, cut to a maximum length of 2.50 inches (63.5 mm) and cut into shreds with an Urschel Model CC cutter equipped with num- ber 22065 Crinkle blades, offset to produce shreds (in¬ stead of crinkle slices). Freshly cut potato shreds were thoroughly rinsed in copious amounts of cool tap water to remove native surface starch. After rinsing, shreds were dipped in a 200 ppm sulfite solution (sodium metabisulfite in cool tap water) for approximately 1 minute, then drained.
Rinsed, sulfite-treated shreds were then blanched in a steam cabinet under atmospheric steam, twenty pounds ( KG) at a time, evenly distributed over four trays with screen bottoms, for 3% minutes. Blanched shreds were then quickly transferred to a wire basket immersed in a barrel of cool tap water. Immersed shreds were agitated in the cool water until cooled below 75 β F (23.9°C) then removed from water and drained in the wire basket, tilted at ap- proximately a 45° angle to facilitate draining. Proper dewatering was achieved when nearly all drip ceased from the basket, approximately 10 minutes.
Blanched, dewatered potato shreds were divided into two portions: one portion for Control product (plain, uncoated shreds), and the other portion for Treated prod-
uct (to be coated with the Dry Mix). Control and Treated products were stored in plastic pails and covered with plastic film to retain moisture until dried.
Control product was prepared by carefully weighing 21 pounds .9.45 KG) of blanched, drained shreds and distrib¬ uting over a tared shallow dryer tray to a bed depth of approximately 2.25 inches f57.15 mm) .
Treated product was prepared as follows: 93.5% blanched, drained shreds; 6.5% bulk blend Dry Mix. Coat- ing of shreds with Dry Mix was done in a lab seasoning tumbler which consisted of a motorized 55 gallon (208.2 ___) plastic drum tilted approximately 15° from horizontal, flights removed, rotating at 24 revolutions per minute. Dry Mix was added by shaking onto tumbling shreds over 15 seconds and tumbling continued for an additional 60 sec¬ onds. Initially, the mass of Treated shreds was quite sticky and cohesive. By the end of the mixing the coated shreds had a waxy, slightly cohesive texture with a mealy, fluffed, or "open" appearance. Twenty-one pounds (9.45 £G) of shreds dough was carefully weighed and spread over a tared dryer tray in the same manner as the Control prod¬ uct above. Bed depth was approximate 2.5 inches (63.5 mm) . The difference in bed depths indicates the open, fluffed state of the Treated product which creates the air pathways which improve drying and reduce sticking.
Bulk densities for Control and Treated products be¬ fore drying was 31.6 and 32.3 pounds per cubic foot (506.2 and 517.4 KG per m 3 ι . respectively. The tray of Control shreds and tray of Treated shreds were placed in a Proctor And Schwartz Model 8078A test dryer for drying (hereinaf¬ ter abbreviated "P&S dryer") .
Drying was conducted in several stages, which is common practice in the art. In Stage #1, air was main¬ tained at 200"F (93.3°C) at a velocity of about 400 feet per minute (121.9 m per minuted through the trays. Drying
was monitored by weighing each tray of product at approxi¬ mately 5-minute intervals to determine drying rates. After weighing, each tray was turned end-for-end and dryer shelves exchanged to ensure each product received the same average drying environment. Airflow was changed from up low to downflow after 15 minutes. The conditions of Stage #1 drying were maintained for a period sufficient to dry the shred surfaces so that they could be removed from Stage #1 and dried in a deeper bed in Stage #2 without sticking together. This state is normally achieved at a moisture content between 45% to 55% and is characterized by a "leatheriness" of individual shreds. More extended drying in Stage #1 can result in product scorching, re¬ duced production, and excessive fuel cost. Transfer from Stage #1 of insufficiently dried shreds can result in matting and sticking during Stage #2 with resultant forma¬ tion of blow holes and non-uniformly dried product.
The Treated product dried quickly and uniformly in Stage #1 as a result of the increased passage of a air between shreds provided by the occluded particulates. There were no wet, matted-down zones with this product and only a minor amount of slightly over-dried shreds at the periphery, the latter being unavoidable in stationary batch-type driers. There was no sticking to the tray. The Control product did not produce an evenly dried bed in Stage #1. Large internal zones of wet, matted shreds were noted, as well as excessively dry peripheral areas, especially certain areas near holes which had been blown through the bed of product as a result of air block- age by the zones of wet shreds. Establishing the end of Zone #1 for Control shreds was made by drying the trays to approximately the same degree of weight loss. By mixing the under-and over-dried shreds manually prior to begin¬ ning Stage 2, the Control Product could be dried further without scorching the over-dried shreds in the same trays.
In every case, at the end of Stage #1, the Control Product strongly adhered to the tray and was difficult to remove.
At the end of Stage #1 drying, each product was re¬ moved from its tray and dumped into a plastic barrel. The shreds were pulled apart, then gently but thoroughly mixed. Samples for moisture analysis were taken. Control shreds were more difficult to pull apart and breakage occurred due to overly dry shreds. Treated shreds, being more uniformly dried and leathery did not break and parted more easily.
The drying rates for the Control and Treated product are shown below in Table 1, and are based on an initial moisture content of 83% for the blanched, washed shreds.
Table 1
(a) Water/solids ratio
(b) Adjusted for 5% solids added to shreds before drying
The Treated product contained 5% additional dried ingredients, resulting in a starting moisture content of
78% in contrast to the 83% for the Control product. Fig-
ure 6 shows conventional drying rate curves for the above data. Plot 4.1 of water/solids ratio (W/S) versus drying time illustrates the longer drying time required for the Control product compared to Plot 4.2 for the Treated prod- uct. The adjusted drying rate calculated for the shreds only in the Treated sample is shown as Plot 4.3. At about W/S — 1.9 to 2.0, the reduction in rate of water removal has reached the point where movement of water to the sur¬ face by capillary action stops (FOOD DEHYDRATION, Van Arsdale and Copley, AVI, 1963, p. 95).
Upon completion of mixing after Stage #1, both prod¬ ucts were placed in a single deep tray separated by a divider. Bed depths were adjusted to 6 inches (152.4 mm) for each product. Products were finish dried together at 180°F (82.2 * 0) at an air velocity of about 400 feet per minute (121.9 ~ per minute) through the product beds. Air flow was reversed between upflow and downflow at 20-minute intervals. Stage #2 drying time was 40 minutes for both products. Final moistures were 7.4% for Control product and 10.0% for Treated product. Dried products were equil¬ ibrated in plastic food bags until further analyzed and sensory evaluated.
Several days later, each product was rehydrated by covering dried shreds with 150°F (65.6°C) tap water in a glass beaker (6:1 water to shreds ratio). Temperatures of each beaker of product equilibrated to about 140°F (60°C) immediately. Beakers were placed in a temperature con¬ trolled water bath at 140°F (60°C) and rehydration ratios (wet/dry weights) were monitored by draining and weighing shreds, until a target rehydration value of 4.0 (wet/dry) was achieved. Once optimum rehydration times were estab¬ lished, new batches of Control and Treated products were optimally rehydrated for grilling and sensory evaluations. A fabricated, dehydrated commercial hashbrown product, Redi-Shreds™ (Basic American Foods, Blackfoot, Idaho) was
also optimally rehydrated per package instructions for product preference sensory evaluations.
Each of the three products were simultaneously grilled on a commercial gas grill at 375°F (190.7°C) "to color". Effort was made to achieve the same degree of browning for each product. Each product had a distinct hue of brown which could not directly relate one to anoth¬ er.
Data from repetitive grillings by three lab techni- cians showed Redi-Shreds™ formed significantly stronger patties and were most easy to manipulate on the grill. Treated product was deemed acceptable in handling, but the patties were less cohesive that Redi-Shreds™. Untreated shreds were difficult to handle because they were lacking any cohesive property, resulting in an "all-over-the- grill" effect; patty forming was nil. Thus, Control prod¬ uct was difficult to turn with a spatula.
Grilled products were coded and presented to seven uninformed consumer panelists for preference evaluation of key characteristics and overall preference. T r e a te d shreds were preferred over Redi-Shreds™ in all categories except mouthfeel. Treated shreds outscored Control shreds in all categories, except matched scores in crispness. Treated shreds was preferred overall. The graphic results of the consumer preference test are illustrated in Figure 5. The following key applies to the chart of Figure 5: KEY: A = Visual Appeal B = Color C = Crispness D = Bite of Single Shred
E = Mouthfeel F = Moistness G = Oiliness H = Flavor I = Overall Preference
In general, panelists responses were based on perception of ideal hashbrowns, not judging one product against an¬ other.
It has been observed in repetitive lab grillings that Treated shreds retain crispness significantly longer than Redi-Shreds™ or Control shreds. Treated, grilled shreds retain nearly full crispness up to 30 minutes, while Redi- Shreds™ and Control shreds significantly decline in crisp¬ ness. It has also been noted that if rehydration of Redi- Shreds™ is continued beyond the stated conditions, the product becomes soft and mushy.
While the process of the invention has been described with reference to preferred embodiments thereof, as will be apparent to those skilled in the art, certain changes and modifications can be made without departing from the scope of the invention as defined by the following claims.