WO1997048290A1

WO1997048290A1 - Method for making shelf-stable, condensed cream soup products and the products so produced

Info

Publication number: WO1997048290A1
Application number: PCT/US1997/010554
Authority: WO
Inventors: Terry N. Berman; Loren Druz; Diane M. Goihl
Original assignee: Hunt-Wesson, Inc.
Priority date: 1996-06-19
Filing date: 1997-06-18
Publication date: 1997-12-24

Abstract

Disclosed is a method for preparing shelf-stable, condensed cream soup products by mixing a condensed cream soup with from about 0.5 to about 5.0 wt.% of a cook-up starch, from about 3.0 to about 8.0 wt.% of a gelling agent, from about 0.0 to about 5.0 wt.% of a filling starch, and from about 0.0 to about 4.0 wt.% of a wheat flour, where the weight percentages are based on the weight of the product. The mixture is then thermally-processed in an agitator retort with agitation at a temperature and for a time sufficient to sterilize the mixture and form a shelf-stable, condensed cream soup.

Description

METHODFORMAKINGSHELF-STABLE.CONDENSEDCREAMSOUP PRODUCTSANDTHEPRODUCTSSOPRODUCED

BACKGROUNDOFTHEINVENTION

Field of the Invention This invention relates to the chemical arts. In particular, it relates to a method for making condensed cream soup products and the products produced by the method.

Discussion of the Related Art

Currently in the United States, the sale of different kinds of soup products is a

$3.3 billion industry. Of that $3.3 billion, approximately $1.4 billion is for the sale of condensed soups, including condensed cream soups-dairy products having a butterfat content of a least about 0.45 wt.%. A typical condensed cream soup has a uniform, creamy appearance and texture, a very thick viscosity, and a "short" consistency.

A large part of the success of condensed soups, in particular, condensed cream soups, results from their versatility. The condensed soups not only can be reconstituted to form soups having the appearance, texture, and taste of their home-made counterparts, but they also have the tender gel structure and the ability to cling to other ingredients that makes them extremely useful as an ingredient in a wide variety of recipes.

To ensure that condensed soups are free of microbial growth and are stable prior to consumption, they are generally sterilized by heat-treatment. Therefore, the processing of condensed cream soups typically involves mixing the various condensed cream soup ingredients in a batch kettle and heating to at least about 100° F. Individual containers, typically 211 x 315 or 400 cans, are then filled with the mixture, and hermetically sealed. The hermetically sealed containers are then retorted — subjected to a combination of high temperature and high pressure to eliminate microbes and ensure sterility. After retorting, the sterilized, condensed cream soup is cooled.

The traditional method for sterilizing cans of condensed cream soups utilizes little or no agitation throughout retorting and cooling. Such still processing prevents protein agglomeration and fat separation, problems commonly occurring when thermally-processing dairy products. If the soups are processed with little or no movement, then a highly desirable thick viscosity and a semi-gelled structure can be attained. Accordingly, condensed cream soups are heat-treated using a stationary retort, such as a vertical or a horizontal still retort, a crateless retort, a discontinuous agitating retort without agitation or a hydrostatic retort.

A disadvantage of such methods is that with little or no agitation the heat transfer during thermal-processing occurs via conduction. Because conduction is a slow process, the time required for sterilization ranges from 45 to 60 minutes followed by a cooling period of an additional 45 to 60 minutes. These long processing times translate into either slow production throughput or the need to have large, capital intensive retort systems, both of which are costly. Condensed cream soup processing times could be significantly reduced through the use of agitating retorts. With agitation, heat transfer occurs via convection — a much quicker process. It is a drawback of agitation, however, that to create rapid heat transfer and mixing inside the container, the soup to be processed must have a relatively thin viscosity and, during retorting, cannot have a gelled or semi-gelled structure. When traditional condensed cream soup formulations are thinned and processed in agitating retorts, the thinning causes instability. The instability results in protein agglomeration and fat separation giving the resulting condensed cream soups a curdled appearance and an uncreamy texture. Additionally, the unstable condensed cream soups are difficult to reconstitute and function poorly in recipes. The instability, agglomeration, and separation render thinned, condensed cream soups commercially unacceptable.

Accordingly, there has existed a definite need for a faster and more efficient, less capital-intensive method for producing microbially safe, shelf-stable, condensed cream soups while preserving their appearance, texture and functionality. This present invention satisfies these and other needs.

Summary of the Invention

Now in accordance with the invention, there has been found a quick and inexpensive method for preparing shelf-stable, condensed cream soup products. The method involves mixing a condensed cream soup with from about 0.5 to about 5.0 wt.% of a cook-up starch, from about 3.0 to about 8.0 wt.% of a gelling agent, from about 0.0 to about 5.0 wt.% of a filling starch, and from about 0.0 to about 4.0 wt.% of a wheat flour, where the weight percentages are based on the weight of the product. The mixture is then thermally-processed in an agitator retort with agitation at a temperature and for a time sufficient to sterilize the mixture and form a shelf-stable, condensed cream soup.

In some preferred embodiments, the condensed cream soup is mixed with from about 1.0 to about 3.0 wt.% of a modified waxy maize cook-up starch and from about 3.5 to about 7.5 wt.% of an unmodified com starch gelling agent, more preferably an acid-thinned, dent com starch gelling agent, from about 0.0 to about 1.5 wt.% of a modified waxy maize filling starch, and from about 0.0 to about 3.0 wt.% of a wheat flour. In those embodiments where the gelling agent is an unmodified com starch, the mixture can additionally contain up to about 1.5 wt.% of a gum, preferably from about 0.1 to about 1.5 wt.% of a hydrocolloid gum, such as xanthan gum. The resulting mixture is then sterilized by retorting in an agitator retort while agitating at a speed of from about 6 to about 30 rpms at a temperature of from about 240° to about 270° F. for a time less than about 25 minutes. Processing is completed by cooling the sterilized mixture from about 15 to about 25 minutes. The resulting shelf-stable, condensed cream soup product has an appearance, texture, functionality and taste as good as, or better than, condensed cream soups prepared by other methods.

Detailed Description of the Preferred Embodiments

The method in accordance with the invention is useful with any condensed cream soup. Such soups contain a minimum of 0.45% butterfat provided by cream, whole milk, or combinations of various butterfat content creams and milks and equivalent compositions formed by suitable admixtures of milk solids and water having comparable butterfat contents. The soups also can contain particulate ingredients, such as potatoes, broccoli, spinach, chicken or clams. Additionally, the soups can contain flavorants such as seasonings and spices, and colorants.

The condensed soup is mixed with from about 0.5 to about 5.0 wt.%, preferably from about 1.0 to about 3.0 wt.%, based on the weight of the product, of a cook-up starch. The cook-up starch remains thin during mixing and filling. It only begins to thicken at temperatures of from about 160° to about 180° F. and does not achieve its peak viscosity until thermal- treatment. The cook-up starch then maintains its viscosity throughout the shelf-life of the product. When measured at 203 ° F. on a Brabender Viscograph (in a 6.5 pH buffer containing salt), the cook-up starch typically has an initial viscosity of from about 300 to about 500 B.U. and when held at 203 ° F. for 30 minutes, it has a viscosity of from about 400 to about 600 B.U. The cook-up starch stabilizes the soup's fats and proteins during retorting and cooling, without substantially increasing the soup's viscosity during thermal-treatment. The cook-up starch also contributes a large portion of the final viscosity, texture and mouthfeel of the finished product. Representative cook-up starches include modified or unmodified wheat, rice, com, or potato starches. Modified waxy maize starches are the preferred cook-up starches, because they provide outstanding shelf-life stability and they cook-out during retorting to give the final soup a "short" consistency and cream-like texture. Commercially available cook-up starches include Perma-Flo, Perma-Flo HV, and Resista, from A. E. Staley, Decatur, Illinois, Pure-Flo, Thermo-Flo, and 465, from National Starch and Chemical Co., Bridgewater, New Jersey, and Polar Gel 5, 10, and 15, from American Maize Products Co., Hammond, Indiana.

The condensed soup is also mixed with from about 3.0 to about 8.0, preferably from about 3.5 to about 7.5 wt.%, based on the weight of the product, of a gelling agent. The preferred gelling agent is an unmodified com starch. The unmodified com starch remains thin through filling and retorting, then begins to thicken during cooling. After cooling, the unmodified com starch continues to thicken, until finally forming a tender gel. When measured at 203 ° F. on a Brabender Viscograph (in a 6.5 pH buffer containing salt), the unmodified com starch achieves a maximum viscosity of about 1500 B.U. after about 30 minutes. When held at 203 ° F. for an additional 10 and 20 minutes, the viscosity is reduced to about 600 and 100 B.U., respectively. After cooling to about 122° F., the viscosity increases to about 2400 B.U. and 10 minutes after the cooling has been completed, the viscosity of the unmodified corn starch increases to about 5000 B.U.

An acid-thinned, common dent corn starch, such as a "confectioners starch," is most preferred. Confectioners starch is used predominantly in the manufacture of gum candies. Commercially available confectioners starch includes Confectioners F and G, from A. E. Staley, Decatur, Illinois, Flojel 60, 65, and 75, from National Starch and Chemical Co., Bridgewater, New Jersey, and Amazio QMZ2 and 90TB, from American Maize Products Co., Hammond, Indiana. Also useful are other dent corn starches and starches derived from other edible food grade precursors.

In some embodiments, particularly where the gelling agent is an unmodified com starch, it is useful to include up to about 1.5 wt.%, preferably from about 0.1 to about 1.0%, based on the weight of the product, of a gum. The gum provides additional viscosity to the cooled condensed cream soup and provides cling to ingredients used by consumers when preparing recipes with the soup. The gum also assists in providing filling homogeneity, stability to the fats and proteins during the beginning of thermal-processing and resistance to starch retrogradation during storage. Significantly, as the condensed soup approaches retort temperatures the gum's viscosity is temporarily reduced to enhance heat penetration.

Hydrocolloidal gums are preferred, with xanthan gum being most preferred.

Suitable xanthan gums are commercially available from Kelco, San Diego, California, Ashland Chemical Co., Columbus, Ohio, Meer, North Bergen, New Jersey, and Zumbro, Inc., Hayfield,

Minnesota. Other commercial gums from marine plants, terrestrial plants, microbial polysaccharides and polysaccharide derivatives with similar functionality are of use.

In some embodiments, especially when the soup contains paniculate ingredients, it is desirable to increase the viscosity of the condensed cream soup during the filling of the soup into containers. In these embodiments, up to about 5.0 wt.% preferably from about 0.25 to about 1.5 wt.% , based on the weight of the product, of a filling starch is included. The filling starch thickens at a temperature of from about 160° to about 180° F. to suspend particulates during filling and then thins to form a water thin or semi-viscous fluid as the temperature of the soup is increased to sterilize the product. When measured at 203° F. on a Brabender Viscograph (in a 6.5 pH buffer containing salt), the filling starch typically has an initial viscosity of about 600 to about 700 B.U. and when held at 203 ° F. for 30 minutes it has a viscosity of from about 350 to about 500 B.U. In addition to helping maintain the particulate suspension throughout the filling of the container, the filling starch provides thickness and initial protein and fat stabilization of the soup when retorting. Representative filling starches include modified or unmodified wheat, rice, com, or potato starches. Modified waxy maize filling starches are preferred. Commercially available modified waxy maize filling starches include Waxy and Shur-Fil 427, from A. E. Staley, Decatur, Illinois, 150, 1545, and Can-Fil, from National Starch and Chemical Co., Bridgewater, New Jersey and Amioca and E-Z Fill , from American Maize Products Co., Hammond, Indiana. Some embodiments also include up to about 4.0 wt.%, preferably from about 0.5 to about 3.0 wt.%, based on the weight of the product, of a wheat flour to provide opacity, body, and a thick, short texture to the final condensed cream soup. The wheat flour begins to thicken at 140° F., prior to filling the containers with the product, and continues to thicken during retorting and through cooling. The wheat flour retains viscosity and opacity during storage, until the soup is consumed. Preferred wheat flours include bleached, white wheat cake flour and all purpose flour, with bleached white cake flour being most preferred. The cook-up starch, the gelling agent and, if used, the filling starch, the wheat flour, and the gum are combined with the condensed cream soup ingredients in a batch kettle at a temperature of less than about 140° F. The amount of each ingredient to be used in any particular formulation will depend on a number of factors, including the composition of the condensed cream soup, and the size of the individual containers. The amount will be readily determinable by one skilled in the art. The amounts are chosen to ensure that the proper range of viscosities is maintained throughout the filling, retorting and cooling of the condensed cream soup. In particular, the viscosity during retort must be great enough to ensure that the fat and protein are stabilized, while being thin enough so that convection heating is possible. The cook-up starch, the gelling agent, the filling starch, the wheat flour, and the gum can be added directly to the batch kettle or first added to water to form a slurry and the slurry added to the batch kettle separately. All the ingredients are then heated with agitation.

Immediately upon hydration, the gum will thicken to its maximum viscosity. As the temperature of the mixture reaches above about 140° F., the filling starch also begins to thicken. The filling starch will fully thicken at temperatures between about 170° to about 180° F. and will suspend particulates to ensure homogeneity during the subsequent filling step. At temperatures from about 170° to about 180°F., the wheat flour and the cook-up starch will begin to hydrate, but will only partially thicken.

Conventional canning equipment is then used to fill and hermetically seal the mixture into individual containers for subsequent thermal sterilization. Suitable materials for the individual containers include glass, metal, plastic, and composite materials.

The sealed containers are then transferred to a continuous or a discontinuous agitating retort and thermally-treated with agitation for a time sufficient to sterilize the mixture. The temperatures for retort sterilization typically range from about 250° to about 265° F. It is an advantage of the process in accordance with this invention that the time required for sterilization is significantly less than the time required with a stationary retort. When the condensed cream soup is agitated at a speed of about 6 to about 30 rpms, the time for retort sterilization is less than about 25 minutes. In contrast, when using conventional stationary retorts, the time is from about 45 to about 60 minutes. During thermal treatment most of the viscosity contributed by the filling starch is lost and the gum will thin. However, as the filling starch is destroyed and the gum thins, the cook-up starch will continue to thicken until it reaches its peak viscosity. Meanwhile, the wheat flour will continue to thicken slowly and the unmodified com starch will begin to hydrate. The overall effect is that the fat and protein are stabilized, even though the condensed cream soup is thin enough to heat by a convection process.

Once sterilized, the condensed cream soup is cooled while being agitated in the retort, typically for a period of from about 15 to about 25 minutes. Again, the use of the agitating retort significantly decreases the time when compared to conventional stationary processes. With stationary retorts, the time for cooling is generally from about 45 to about 60 minutes. As the condensed soup begins to cool, the gum will regain the thickness it had prior to retorting. The cook-up starch will maintain its peak viscosity, while the wheat flour and the gelling agent will continue to thicken and build viscosity. Upon completion of cooling, the condensed soup is thick and creamy with a short texture, but has not gelled.

When held over the next seven days, the gelling agent continues to thicken until a tender gel has formed. The gum provides stability to the gel structure once formed.

Not only is the time for retorting and cooling lessened, but the resulting, shelf- stable condensed cream soup product is uniformly creamy with a tender gel structure. The final product has exceptional texture, appearance, and functionality upon reconstitution and in recipes. Furthermore, the ingredients used for thickening and stabilization have bland, neutral flavors allowing for the manufacture of excellent tasting cream soups.

While the invention has been described in detail with reference to certain preferred embodiments thereof, it will be understood that modifications and variations are within the spirit and scope of that which is described and claimed.

Claims

1. A process for preparing a shelf-stable, condensed cream soup product comprising the steps of: mixing a condensed cream soup with from about 0.5 to about 5.0 wt.% of a cook-up starch, from about 3.0 to about 8.0 wt.% of a gelling agent, from about 0.0 to about 5.0 wt.% of a filling starch, and from about 0.0 to about 4.0 wt.% of a wheat flour, where the weight percentages are based on the weight of the product, and then retorting the mixture in an agitator retort with agitation at a temperature and for a time sufficient to sterilize the mixture and form a shelf-stable, condensed cream soup.

2. The process in accordance with claim 1 wherein the cook-up starch is present in an amount of from about 1.0 to about 3.0 wt.%.

3. The process in accordance with claim 2 wherein the cook-up starch is a modified, waxy maize starch.

4. The process in accordance with claim 2 wherein the gelling agent is present in an amount of from about 3.5 to about 7.5 wt.%.

5. The process in accordance with claim 4 wherein the gelling agent is an unmodified com starch.

6. The process in accordance with claim 5 wherein the gelling agent is an acid- thinned, dent com starch.

7. The process in accordance with claim 4 wherein the mixture is agitated at a speed of from about 6 to about 30 rpms.

8. The process in accordance with claim 4 wherein the mixture is retorted at a temperature of from about 250° to about 265° F.

9. The process in accordance with claim 4 wherein the mixture is retorted for less than about 25 minutes.

10. The process in accordance with claim 1 further comprising cooling the sterilized mixture.

1 1. The process in accordance with claim 4 further comprising cooling the sterilized mixture for from about 15 to about 25 minutes.

12. The process in accordance with claim 4 wherein the amount of filling starch is present in an amount from about 0.25 to about 1.5 wt.%.

13. The process in accordance with claim 12 wherein the filling starch is a modified waxy maize starch.

14. The process in accordance with claim 4 wherein the amount of wheat flour is from about 0.5 to about 3.0 wt.%.

15. The process in accordance with claim 3 further comprising adding up to about 1.5 wt.% of a hydrocolloid gum to the mixture before retorting.

16. The process in accordance with claim 4 further comprising adding up to about 1.5 wt.% of a hydrocolloid gum to the mixture before retorting.

17. The process in accordance with claim 16 wherein the amount of hydrocolloid gum is from about 0.1 to about 1.0 wt.%.

18. The process in accordance with claim 17 wherein the hydrocolloid gum is xanthan gum.

19. A process for preparing a shelf-stable, condensed cream soup product comprising the steps of: mixing condensed cream soup with from about 1.0 to about 3.0 wt.% of a modified waxy maize cook-up starch, from about 3.5 to about 7.5 wt.% of an unmodified com starch gelling agent, from about 0.0 to about 1.5 wt.% of a modified waxy maize filling starch, from about 0.0 to about 3.0 wt.% of a wheat flour, and from about 0.1 to about 1.0 wt.% of a hydrocolloid gum, where the weight percentages are based on the weight of the product; retorting the resulting mixture in an agitator retort while agitating at a speed of from about 6 to about 30 rpms at a temperature of from about 250° to about 265° F. for a time less than about 25 minutes to sterilize the mixture; and then cooling the sterilized mixture for from about 15 to about 25 minutes to form a shelf- stable, condensed cream soup.

20. The process in accordance with claim 19 wherein the gelling agent is an acid- thinned, dent com starch.

21. The process in accordance with claim 20 wherein the hydrocolloid gum is xanthan gum.

22. A shelf-stable, condensed cream soup product comprising a sterilized mixture of condensed cream soup with from about 0.5 to about 5.0 wt.% of a cook-up starch, from about 3.0 to about 8.0 wt.% of a gelling agent, from about 0.0 to about 5.0 wt.% of a filling starch, and from about 0.0 to about 4.0 wt.% of a wheat flour, where the weight percentages are based on the weight of the product.

23. The shelf-stable, condensed cream soup product in accordance with claim 22 wherein the cook-up starch is present in an amount of from about 1.0 to about 3.0 wt.%.

24. The shelf-stable, condensed cream soup product in accordance with claim 23 wherein the cook-up starch is a modified, waxy maize starch.

25. The shelf-stable, condensed cream soup product in accordance with claim 23 wherein the gelling agent is present in an amount of from about 3.5 to about 7.5 wt.%.

26. The shelf-stable, condensed cream soup product in accordance with claim 25 wherein the gelling agent is an unmodified com starch.

27. The shelf-stable, condensed cream soup product in accordance with claim 26 wherein the gelling agent is an acid-thinned, dent com starch.

28. The shelf-stable, condensed cream soup product in accordance with claim 25 wherein the filling starch is present in an amount of from about 0.0 to about 1.5 wt.%.

29. The shelf-stable, condensed cream soup product in accordance with claim 25 wherein the wheat flour is present in an amount of from about 0.0 to about 3.0 wt.%.

30. The shelf-stable, condensed cream soup product in accordance with claim 24 further comprising a hydrocolloid gum.

31. The shelf-stable, condensed cream soup product in accordance with claim 25 further comprising up to about 1.5 wt.% of a hydrocolloid gum.

32. The shelf-stable, condensed cream soup product in accordance with claim 31 wherein the amount of hydrocolloid gum is from about 0.1 to about 1.0 wt.%.

33. A shelf-stable, condensed cream soup product comprising a sterilized mixture of condensed cream soup with from about 1.0 to about 3.0 wt.% of a cook-up starch, from about 3.5 to about 7.5 wt.% of a unmodified corn starch gelling agent, from about 0.0 to about 1.5 wt.% of a modified waxy maize filling starch, from about 0.0 to about 3.0 wt.% of a wheat flour, and from about 0.1 to about 1.0 wt.% of a hydrocolloid.

34. The shelf-stable, condensed cream soup product in accordance with claim 33 wherein the cook-up starch is an acid-thinned, dent com starch.

35. The shelf-stable, condensed cream soup product in accordance with claim 34 wherein the hydrocolloid gum is xanthan gum.