LOW DENSITY EDIBLE ANIMAL CHEWS AND METHODS OF MAKING SAME
Edible chews for pets have a low density (e.g. about 1.0 Kg/L or less) and a smooth exterior surface. One method by which the low density and the smooth exterior surface can be achieved uses a modified extrusion die to increase shear and restrict surface bubbles. Another method by which the low density and the smooth exterior surface can be achieved uses an extruder screw with a modified profile that holds a dough longer therein to create a whipping effect resulting in more bubble nucleation sites and hence a more uniform cellular matrix. The puffed (expanded) product was experimentally tested and provided better dental cleaning scores than a current unexpanded similarly formulated commercial dental product.
1 . A method of making an edible pet chew, the method comprising:
preparing a dry mix comprising a pre-gelatinized cereal flour;
metering the dry mix into an extruder comprising an extrusion die;
adding a hydrogen bond-forming component to the dry mix to form a dough;
promoting nucleation of the dough by subjecting the dough to a combination of shear and temperature in the extruder; and
directing the nucleated dough through an opening of the extrusion die comprising grooves, each of the grooves has an open end and a bottom surface opposite to the open end, and the width of the bottom surface is greater than the width of the open end.
2 . The method of claim 1 , wherein the grooves have a substantially triangular cross-section.
3 . The method of claim 1 , wherein the grooves have a width that continuously decreases as the grooves extend toward the center of the opening.
4 . The method of claim 1 , wherein the grooves are evenly spaced along an inner periphery of the opening of the extrusion die.
5 . The method of claim 1 , wherein the temperature applied to the dough is at least 120° C.
6 . The method of claim 1 , wherein the hydrogen bond-forming component comprises a polyhydric solvent.
7 . The method claim 1 , wherein the dry mix further comprises a bicarbonate.
8 . The method of claim 7 , wherein the bicarbonate is sodium bicarbonate.
9 . The method of claim 8 , wherein the sodium bicarbonate is 0.2 to 1.5 wt. % of the dry mix.
10 . The method of claim 1 , wherein the extruder further comprises a barrel comprising a vent and a vent-stuffer.
11 . The method of claim 10 , comprising using a reverse element of the extruder to extend a time spent by the dough in the barrel comprising the vent and the vent-stuffer.
12 . The method of claim 10 , comprising using mixing elements in the barrel comprising the vent and the vent-stuffer to whip the dough and promote the nucleation of the dough.
13 . The method of claim 10 , comprising aerating the dough in the barrel comprising the vent and the vent-stuffer.
14 . The method of claim 10 , comprising using the vent to provide ambient pressure.
15 . The method of claim 1 , wherein the combination of shear and temperature is applied to the dough in a section of the extruder adjacent to the extrusion die, wherein the temperature in the section adjacent to the extrusion die is higher than a temperature of at least one previous section of the extruder.
16 . The method of claim 1 , wherein the edible pet chew has a substantially smooth exterior surface and a density not greater than about 1.0 Kg/L.
17 . The method of claim 16 , wherein the edible pet chew has a caloric density of 1.5-2.7 Kcal/cm 3 .
18 . The method of claim 16 , wherein the density of the edible pet chew is at most about 0.9 Kg/L.
19 . An edible pet chew made by a process of claim 1 .
20 . A method of cleaning teeth of a pet, the method comprising administering to the pet an edible pet chew made by the process of claim 1 , wherein the edible pet chew comprises an expanded pre-gelatinized cereal flour matrix and has a substantially smooth exterior surface and a density not greater than about 1.0 Kg/L.