EXPANDED FOODSTUFF- OR ANIMAL FEED EXTRUDATE

Abstract

Disclosed is an edible, expandable extrudate having a composition that includes a gel-forming component, a crystalline component having a melting point of up to 150° C., water, and additional components that produce an extrudate composition (dough) having no more than 20 dry wt. % starch and no more than 45 dry wt. % protein and a method for producing an edible expanded extrudate product using water incorporated in the extrudate as the puffing or blowing agent to produce a volumetric expansion of at least 200% as a heated and pressurized extrudate is ejected from an extruder such as a twin-screw extruder.

Claims

1. An expanded foodstuff extrudate or animal feed extrudate, wherein the foodstuff extrudate or animal feed extrudate, as structure-forming ingredient, comprises a gel-forming dietary fiber and a crystalline ingredient having a melting point of not more than 150° C., and the other ingredients are present as fillers, the foodstuff extrudate or animal feed extrudate includes, in the sum total of all proportions by weight, a starch content of 0.1%-20 dry wt. % and/or a protein content of 0.1%-45 dry wt. %, the proportion of the crystalline ingredient in the foodstuff extrudate or animal feed extrudate is 15%-70% of the sum total of all proportions by weight and the expansion of the foodstuff extrudate or animal feed extrudate is more than 300%.

2. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 1, wherein the gel-forming ingredient is Psyllium husks and/or a natural or synthetic substance consisting at least to an extent of 10 dry wt. % of the polysaccharide arabinoxylan.

3. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 1, wherein the crystalline ingredient that melts up to 150° C. is a polyol, polysaccharide or a type of sugar having a correspondingly low melting point or a mixture produced therefrom.

4. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 3, wherein the polyol is a sugar alcohol.

5. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 4, wherein the sugar alcohol is erythritol and/or xylitol.

6. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 1, wherein the proportion of gel-forming dietary fiber in the foodstuff extrudate or animal feed extrudate is 8%-40 dry wt. % of the sum total of all proportions by weight.

7. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 1, characterized in that wherein powdered dietary fiber, cereal bran, fiber products of relevance to the foodstuffs or animal feeds sector, cereal products, seed products, nut products, dried fruit, dried vegetables, herbs, spices, yeasts, fungi, minerals, sweeteners including artificial sweeteners, swelling agents of relevance to the foodstuffs or animal feeds sector, mucilages of relevance to the foodstuffs or animal feeds sector, emulsifiers, gelatins, leavening agents, dyes, flavorings, inulin, resistant starch, modified starch, dextrose, polysaccharides, oligosaccharides, pectins, synthetic foodstuff ingredients, ground proteins, protein concentrates, protein isolates, either alone or in combination, are present as further fillers.

8. The expanded foodstuff extrudate or animal feed extrudate as claimed in claim 1, wherein the foodstuff extrudate or animal feed extrudate includes, as constituents, 10 dry wt. % Psyllium husks, 30 dry wt. % erythritol, 30 dry wt. % fiber products and 30 dry wt. % deoiled ground protein of the sum total of all proportions by weight.

Description

DESCRIPTION OF THE INVENTION

[0071] Whereas, in existing processes, the creation of a puffed foodstuff is possible either with a starch content of at least 20 dry wt. % or a content of protein of at least 45 dry wt. %, since only these ingredients are suitable according to the prior art as structure-forming ingredients, the invention proposed discloses a foodstuff extrudate or animal feed extrudate with a starch content between 0-20 dry wt. % (i.e. either starch-free or having only a low starch content) and a protein content of 0-45 dry wt. % (i.e. either protein-free or having a likewise only low protein content or one lower than that disclosed in the prior art to date). This eliminates the significance of starch contents and/or protein contents in the foodstuff extrudate or animal feed extrudate of the invention as essential structure-forming ingredients.

[0072] Claim 1 therefore claims a foodstuff extrudate or animal feed extrudate which is characterized in that the foodstuff extrudate or animal feed extrudate, as structure-forming ingredient, comprises a gel-forming dietary fiber and a crystalline ingredient having a melting point of not more than 150° C., and the other ingredients are present as fillers, the extrudate of the invention includes, in the sum total of all proportions by weight, a starch content of 0.1%-20% and/or a protein content of 0.1%-45%, the proportion of the crystalline ingredient in the foodstuff extrudate or animal feed extrudate is 15%-70 dry wt. % of the sum total of all proportions by weight and the expansion of the foodstuff extrudate or animal feed extrudate is more than 300%.

[0073] In the case of a proportion of the crystalline ingredient that melts at up to 150° C. in the extrusion dough of more than 70 dry wt. %, the dough becomes so fluid after this ingredient has melted in the extruder that there is no longer any occurrence of expansion.

[0074] According to claim 2, the gel-forming ingredient is Psyllium husks and/or another natural or synthetic substance consisting at least to an extent of 10 dry wt. % of the polysaccharide arabinoxylan.

[0075] The invention is based on the finding that Psyllium husks, given suitable configuration of the extruder, are capable of gelatinization, i.e. of forming a gel-like structure that elasticizes the extrusion dough. Such extrusion doughs may then expand by 300% or more.

[0076] “Gelatinization” here is an operation that alters the elasticity of an extrusion dough (=extrudate of high viscosity after addition of water) by mechanical and/or thermal treatment to give a gel-like structure. While the relevant literature uses the term “gelatinization” predominantly for starch-based processes, the term is also applied here mutatis mutandis to comparable protein- and dietary fiber-based reactions.

[0077] However, the disadvantage of Psyllium is that, in a water-containing dough, the result of the extrusion becomes rubbery and, by contrast with starch and proteins, Psyllium seeds are incapable of sufficiently stabilizing the structures formed by the expansion.

[0078] There is therefore the risk that, once the water vapor condenses after cooling, the expanded foodstuff extrudate or animal feed extrudate will collapse again.

[0079] Therefore, according to the invention, as per claim 3, a crystalline ingredient that melts at up to 150° C. is added to the foodstuff extrudate or animal feed extrudate in a proportion of 15%-70 dry wt. % of the sum total of all proportions by weight, and the crystalline ingredient that melts at up to 150° C. is advantageously a polyol, polysaccharide or a type of sugar with a correspondingly low melting point or a mixture created therefrom.

[0080] Claim 4 defines the polyol as a sugar alcohol.

[0081] In a particular embodiment of the invention, according to claim 5, the crystalline ingredient that melts at up to 150° C. is erythritol and/or xylitol.

[0082] The crystalline ingredient that melts at up to 150° C. is heated in the extruder to a temperature above the melting point, is liquefied and is then distributed very homogeneously in the extrusion dough by the extruder action. After expansion through the die, and induced by the evaporative cooling of the water, the crystalline ingredient that melts at up to 150° C. crystallizes and hence stabilizes the expanded dough.

[0083] According to claim 6, the proportion of the gel-forming dietary fiber in the foodstuff extrudate or animal feed extrudate is 8%-40 dry wt. % of the sum total of all proportions by weight, since expansion will not take place otherwise. In the case of a proportion of Psyllium husks, for example, exceeding 40 dry wt. %, the extrusion dough becomes so labile that the extrudate collapses again immediately after exiting from the die.

[0084] After drying of the foodstuff extrudate or animal feed extrudate, the Psyllium husks also lose their rubbery consistency, and the foodstuff extrudate or animal feed extrudate produced takes on a crispy consistency.

[0085] What is essential for the foodstuff extrudate or animal feed extrudate of the invention in this respect, aside from the gel-forming ingredient as one constituent, is at least one crystalline ingredient having a melting point of not more than 150° C., preferably a sugar alcohol, especially erythritol and/or xylitol, the crystals of which are melted in the extruder and, on recrystallization, stabilize the expansion of the foodstuff extrudate or animal feed extrudate.

[0086] With the aid of the expanded, extruded, puffed foodstuff or animal feed of the invention, based on Psyllium seeds and with erythritol, for example, as structure-forming ingredient combination, it is possible to produce almost sugar-, fat- and starch-free, highly puffed foodstuff extrudates or animal feed extrudates of very low calorific value.

[0087] Since it is possible through the invention in principle to produce carbohydrate-free foodstuffs, it is possible to produce highly puffed snack and breakfast products for increasingly popular low-carb nutrition.

[0088] Furthermore, the invention enables highly puffed foodstuff extrudate or animal feed extrudate having a dietary fiber content of up to 70 dry wt. %, where not all dietary fiber constituents also act as structure-forming ingredients.

[0089] In summary, it can be stated that, in the puffing of foodstuffs or animal feeds, starch at concentrations exceeding 25 dry wt. % in the foodstuff extrudate or animal feed extrudate is the structure-forming ingredient usually used for expansion. Starch in high concentrations (>50 dry wt. %) enables very high expansions. The present invention, however, by contrast with the prior art, concerns foodstuff extrudate or animal feed extrudates without starch contents or extrudates having starch contents of less than 20 dry wt. %, such that these starch contents have only a minor effect, if any, on expansion.

[0090] Proteins are of different suitability as a structure-forming ingredient according to the type and concentration of the protein in the foodstuff extrudate or animal feed extrudate (typically >45 dry wt. %). Vegetable proteins may lead to expansion in high concentrations; animal proteins may likewise contribute to expansion in particular methods. The present invention, however, by contrast with the prior art, concerns foodstuff extrudates or animal feed extrudates without protein contents or extrudate with protein contents of less than 45 dry wt. %, such that these protein contents have only a minor effect, if any, on expansion.

[0091] Further foodstuff extrudate or animal feed extrudates of the invention, according to claim 7, include powdered dietary fiber, cereal bran, fiber products of relevance to the foodstuffs or animal feeds sector (e.g. potato fibers, apple fibers, wheat fibers, pea fibers, cacao fibers from the shells of the cacao bean, or else licorice), cereal products, seed products, nut products, dried fruit, dried vegetables, herbs, spices, yeasts, fungi, minerals, sweeteners including artificial sweeteners, swelling agents of relevance to the foodstuffs or animal feeds sector, mucilages of relevance to the foodstuffs or animal feeds sector, bones, emulsifiers, gelatins, leavening agents, dyes, flavorings, inulin, resistant starch, modified starch, dextrose, polysaccharides, oligosaccharides, pectins, synthetic foodstuff ingredients, ground proteins, protein concentrates, protein isolates (all protein sources each of animal or vegetable origin), either alone or in combination, as further ingredients of no relevance to expansion, although maintaining the fulfillment of the condition from claim 1 that, in the sum total of all proportions by weight, the total starch content of the foodstuff extrudate or animal feed extrudate is between 0.1%-20 dry wt. % and/or the total protein content is between 0.1%-45 dry wt. %.

[0092] As a specific embodiment of the invention, claim 8 claims that the extrusion dough consists of a mixture of 10% Psyllium husks, 30% erythritol, 30% fiber products and 30% ground protein, and a proportion by weight of 10% of water.

[0093] Described hereinafter is an advantageous combination of ingredients in the foodstuff extrudate or animal feed extrudate of the invention, as is the production of extrusion dough by a known production method:

Example

[0094] A mixture of 10 dry wt. % Psyllium seeds, 30 dry wt. % erythritol, 30 dry wt. % cacao fibers and 30 dry wt. % deoiled pumpkinseed flour was extruded in a twin-screw extruder. 10% percent by weight of water was added within the extruder, and a temperature of 140° C. was established. The pressure was 60-80 bar. The passage time through the extruder was about 30 seconds.

[0095] Discharge was effected through a 2.5 mm die. The foodstuff extrudate or animal feed extrudate expanded to 6 mm, which constituted a radial expansion by almost 600%. Directly after the expansion, the foodstuff extrudate or animal feed extrudate had a soft but stable structure. After drying to a water content below 5%, a crispy consistency was established.