Patent ID: 8496985

Claim:
A method of producing puffed animal treats from a mixture having protein, starch, and water, comprising: introducing the mixture into an extruder that includes an opening from which the mixture is to be extruded; applying a motive force to the mixture to pass it out of the opening of the extruder to form a shaped extrudate; cutting the extrudate into multiple segments having cross-sectional areas, each of the multiple segments including a moisture-containing interior portion and a skin-like outer surface substantially enclosing the moisture-containing interior portion, the moisture-containing interior portion of each of the multiple segments characterized by an insubstantial void volume, and the outer surface of each segment of the multiple segments being substantially free from holes; air drying the multiple segments to toughen their outer surfaces and reduce their cross-sectional areas; and performing post-extrusion heating in first and second heating phases, the performing of the first heating phase including heating the multiple segments at a first temperature of greater than or equal to about 100 degree C. for a first duration, of greater than about 3 minutes, the first temperature and the first duration coordinated to harden the outer surfaces of the multiple segments and thereby increase the tensile strengths of their outer surfaces, and to transform a portion of the moisture contained in the moisture-containing interior portions of the multiple segments to expanding vapor to produce interior that causes the multiple segments to become multiple puffed segments having cross-sectional areas and hardened outer surfaces, each of the multiple puffed segments including an air-containing interior portion with air pockets and thereby increase produced by the expanding vapor, the multiple puffed segments having larger cross-sectional areas than the cross-sectional areas of the multiple segments, and the air-containing interior portion of each of the multiple puffed segments characterized by a void volume occupied by the air pockets, and the performing of the second heating phase including heating the multiple puffed segments at a second temperature of greater than or equal to about 100 degree C. for a second duration, the second temperature and the second duration coordinated to produce an amount of moisture of less than about 8% by weight in the air-containing interior portions of the multiple puffed segments and thereby provide puffed animal treats with a crunchy structure.