Baked or Extrusion?

Baked or Extrusion?

Pet food can be manufactured in a couple of different ways.  I will explain two of the ways in this blog.

What is food extrusion?  This is the Wikipedia definition. 

In the extrusion process, raw materials are first ground to the correct particle size, usually the consistency of coarse flour. The dry mix is passed through a pre-conditioner, in which other ingredients are added depending on the target product; these may be liquid sugar, fats, dyes, meats or water. Steam is injected to start the cooking process, and the preconditioned mix (extrudate) is then passed through an extruder. The extruder consists of a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die^.  The extruder's rotating screw forces the extrudate toward the die, through which it then passes. The amount of time the extrudate is in the extruder is the residence time.

The extruded product usually puffs and changes texture as it is extruded because of the reduction of forces and release of moisture and heat. The extent to which it does so is known as the expansion ratio. The extrudate is cut to the desired length by blades at the output of the extruder, which rotate about the die openings at a specific speed. The product is then cooled and dried, becoming rigid while maintaining porosity.

Many food extrusion processes involve a high temperature over a short time.  Important factors of the extrusion process are the composition of the extrudate, screw length and rotating speed, barrel temperature and moisture, die shape, and rotating speed of the blades. These are controlled based on the desired product to ensure uniformity of the output.  Most pet food companies prepare their food by steaming it as quickly as possible, usually less than 2-3 minutes, and then extrude it under extreme pressure through a metal die (a steam extrusion process).  This process expands the food with air creating a uniform shape.  This method does not product a highly digestible food that your pet’s system requires.  This extruded food (cooked in a very short time) is usually almost “raw” and requires the addition of what many nutritionists feels is harmful chemical preservative (Ethoxyquin, BHA, BHT) to maintain a reasonable product shelf life.  These chemical products many be associated with dry skin, allergic reactions, dental disease, poor health and degenerative organ dysfunction.  Some of the effects of extrusion are listed below.

Effects

Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. This is achieved by controlling various aspects of the extrusion process. It has also enabled the production of new processed food products and "revolutionized many conventional snack manufacturing processes".

• Inactivation of raw food enzymes
• Destruction of certain naturally occurring toxins
• Reduction of microorganisms in the final product
• Slight increase of iron-bioavailability
• Creation of insulin-desensitizing starches, which are a risk-factor for developing diabetes
• Loss of lysine, an essential amino acid necessary for developmental growth and nitrogen management
• Simplification of complex starches, increasing rates of tooth decay
• Increase of glycemic index of the processed food, as the "extrusion process significantly increased the availability of carbohydrates for digestion
• Destruction of Vitamin A (beta-carotene)
• Denaturation of proteins. 

Example of food that has been extruded.

Oven Baked Pet Food

The oven baking process is quite simple.  A small 2 inch size biscuit is baked, moving slowly through the oven.  After the baking process, the biscuit is broken into smaller, irregular kibble ranging in size from tiny morsels to about ½ inch.  This process makes the food more digestibility and palatability, while most extruded food is less digestible.

The small morsels are very important as they digest very quickly in the pet’s system helping create immediate nutritional value for your pet.  In watching many dogs eat, dogs seem to “wolf” their food down.  The small pieces will digest in the dogs system. 

Digestion is very important to helping your pet thrive, not just survive.