Use of expanded constituents and manufacture of products therefrom

Abstract

The present invention provides methods and products made thereby, wherein a pre-expanded constituent, including an edible constituent, is thermally treated to melt it, preferably in a dynamic process environment, to produce products ranging from high to quite low densities and from very strong to soft to apparently dry textures. The wide range of textures enables the provision of food products such as low calorie, digestible and safe, long duration pet food chews. Non-food products suitable for use in manufacture may also be produced. Cooking is preferably carried in an extruder, preferably at low moisture or in the total absence of added water. The methods of dynamic cooking reduce cost in a number of ways including but not limited to decreased process steps, increased throughput, decreased capital expenses and decreased raw product cost.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to bio-plastics products having high structural integrity. The products may include materials of manufacture as well as foods. More specifically, the present invention relates to methods for providing biodegradable polymeric materials of controllable texture and product materials so produced. BACKGROUND TO THE INVENTION [0002] Numerous methods are available for producing food products and biodegradable polymers. In the case of foods, these methods may be categorized generally as static (still) or dynamic methods. Static methods may be defined as those in which a batch of constituents is disposed in a cooking vessel and allowed to remain still or free of movement while being cooked, such as in an oven baking process or pressure moulding or baking process. These include processes in which the batch of material is caused to move on a conveyor through a cooking apparatus, such as a baking tunnel. Here the constituents...

AI Technical Summary

Benefits of technology

[0050] It is therefore an advantage of the present invention to provide an improved method of operating a food factory to reduce drying requirements and consequently the emission of the by products of drying processes.

[0051] It is also an advantage of the present invention to provide an improved polymeric material that can be a food product or a material of manufacture or construction.

[0052] Another advantage of the present invention is to provide an improved chewable pet food product.

[0053] A further advantage of the present invention is to provide a safe long duration chewable pet food product.

[0054] Moreover, an advantage of the present invention is to provide a dietary pet food snack that does not add significantly to the metabolic energy provided by the pet's primary pet food.

[0055] Still another advantage of the present invention is to provide an improved pet product that can be used for promoting and maintaining dental hygiene.

Problems solved by technology

In contrast, the diet of domesticated pets frequently-lacks naturally chewy foods, depriving them of the above benefits.

Conventional food processing methods often do not produce products that have textures comparable to naturally chewy foods.

But, most of these products have disadvantages.

Some are simply not edible.

When the pets chew or break up and swallow these products, they suffer digestive problems.

Some pass undigested through the pet and can contribute to diarrhea and increased fecal volume.

Even some products that claim to be made from edible constituents are not edible in final form, because of processing that fails to ensure digestibility.

Corncobs and cellulosic materials are not readily digestible and can also contribute to diarrhea and increased fecal volume.

However, some of these prior art chewy products are high in calories.

A further problem with some prior art chewy products is production cost.

The pliable materials tend to be expensive.

Attempts to mix pliable materials and less expensive materials have created a complex balancing system in which it is often difficult to ensure that the less expensive materials do not compromise the strength and integrity of the more expensive pliable materials.

Still another problem with certain prior art highly resistant chewable products is safety.

High protein products, including those fabricated from refined high protein constituents, are not only expensive but may bring potential danger as well.

Some experts believe that high protein levels can contribute to renal failure and to blockage of the urinary tract in pets consuming same.

Certain of these products are virtually rock hard.

These products can chip or break a pet's teeth.

Many of the harder products of the prior art are glassy in nature and have a tendency to shatter into sharp, hard fragments when bitten.

These fragments can lodge in the animal's throat or injure its mouth.

This is especially a problem with products produced by high pressure injection molding techniques.

For example, some non-glassy products of the prior art may not shatter, but may be poorly designed, causing extensive bleeding of the gums when chewed.

In part, one of the problems of prior art chewy food products is that they have a limited range of textures to choose from, culminating in products having a texture that causes bleeding of the gums.

Furthermore, the textures of many chewy products are often unappealing and unpalatable.

For example, extruded dry pet foods are typically provided in hard lumps and have a dry, dusty appearance.

They can be inconvenient for the consumer to handle.

Still further, some prior art products are unstable, so that their texture changes with time and they lose desirable characteristics.

However, the injection molding equipment that is typically used to convert such starch-based materials is expensive and complex to operate and known methods of solidifying starch-based materials provide a limited range of textures.

Extruding food constituents at low water activities, although known, has until now been fraught with difficulty.

The constituents required for such extrusion were often expensive and produce a limited range of textures.

If this unraveling and recombination is restricted or interrupted, the resulting products have little binding and are relatively weak.

At low water activities there is little water available.

These systems hence have limited hydration potential.

The large amount of water necessitates energy-intensive and environmentally unfriendly post-extrusion drying or the adding of acid and other preservatives.

This often has undesirable consequences for the products; for example, the water restricts the range of textures that can result.

However, these parameters are too high to-produce the textures needed for products of extended chewing duration.

At these water activities, however, if the methods of the prior art are used, there is insufficient water for hydration, and it is necessary to cook at very high temperatures and pressures or for extended periods, which frequently results in high levels of starch damage and / or burning of the products.

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