Semi-moist food compositions that maintain soft texture

Abstract

A soft semi-moist composition, for example semi-moist extruded kibbles, is formulated to substantially maintain softness through storage in a blend with dry food compositions. Softness is maintained by hindering formation of protein-starch complexes during storage. In an embodiment, the soft semi-moist food composition comprises at least 0.5% of a free amino acid, such as glutamate, and the soft semi-moist composition has a pH at which the free amino acid is charged. In some embodiments, hydrolyzed animal or vegetable substrates are included to provide one or more free amino acids that are charged at the pH of the semi-moist food composition and maintain softness of the semi-moist food composition.

The invention is claimed as follows: 
     
         1 . A method of producing a soft semi-moist food composition comprising:
 forming a mixture having a pH from about 4.0 to about 8.0 and comprising water, a starch source, a humectant, and a free form amino acid selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, and combinations thereof; and   extruding the mixture to form an expanded extrudate.   
     
     
         2 . The method of  claim 1 , wherein the free form amino acid comprises glutamic acid. 
     
     
         3 . The method of  claim 1 , wherein the free form amino acid is present in the mixture in an amount of at least about 0.5 wt %. 
     
     
         4 . The method of  claim 1 , comprising adding at least a portion of the free form amino acid to the mixture in a form separate from any other material. 
     
     
         5 . The method of  claim 1 , comprising adding at least a portion of the free form amino acid to the mixture by adding a digest to the mixture. 
     
     
         6 . The method of  claim 5 , wherein the free form amino acid in the digest is at least 10% of the digest. 
     
     
         7 . The method of  claim 1 , wherein the pH is from about 5.0 to about 6.0. 
     
     
         8 . The method of  claim 1 , comprising adding an edible acid to the mixture to obtain the pH of about 4.0 to about 8.0. 
     
     
         9 . The method of  claim 1 , wherein the humectant comprises a polyol selected from the group consisting of glycerol, propylene glycol, and a combination thereof. 
     
     
         10 . The method of  claim 1 , comprising adding the starch source to the mixture by adding starch and gluten to the mixture separately. 
     
     
         11 . A method of producing a blended food composition comprising:
 forming a mixture having a pH from about 4.0 to about 8.0 and comprising water, a starch source, a humectant, and a free form amino acid selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, and combinations thereof;   extruding the mixture to form a soft semi-moist food composition; and   mixing the soft semi-moist food composition with a dry food composition to form the blended food composition.   
     
     
         12 . The method of  claim 11 , wherein the blended food composition comprises the dry food composition and the soft semi-moist food composition in a ratio from about 75:25 to about 90:10. 
     
     
         13 . A soft semi-moist extruded food composition comprising:
 a starch source,   a humectant, and   a free form amino acid selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, and combinations thereof, the soft semi-moist extruded food composition having a pH at which the free form amino acid is charged.   
     
     
         14 . The soft semi-moist extruded food composition of  claim 13 , wherein the pH is from about 4.0 to about 8.0. 
     
     
         15 . The soft semi-moist extruded food composition of  claim 13 , comprising a digest that provides the free form amino acid. 
     
     
         16 . The soft semi-moist extruded food composition of  claim 13 , wherein the free form amino acid comprises glutamic acid. 
     
     
         17 . The soft semi-moist extruded food composition of  claim 16 , wherein free form lysine is substantially absent from the soft semi-moist extruded food composition. 
     
     
         18 . The soft semi-moist extruded food composition of  claim 13 , wherein the free form amino acid is present in the soft semi-moist extruded food composition in an amount of at least about 0.5 wt %. 
     
     
         19 . A blended food composition comprising:
 a dry food composition; and   a soft semi-moist extruded food composition comprising a starch source, a humectant, and a free form amino acid selected from the group consisting of arginine, histidine, lysine, aspartic acid, glutamic acid, and combinations thereof, the soft semi-moist extruded food composition having a pH at which the free form amino acid is charged.   
     
     
         20 . A method of providing nutrition to a companion animal, the method comprising administering to the companion animal a blended food composition comprising a dry food composition and a soft semi-moist extruded food composition comprising a starch source, a humectant, and a free form amino acid and having a pH from about 4.0 to about 8.0.