Abstract:The effects of different ratios of raw materials on the quality characteristics of twin-screw extruded potato rice cakes were determined by adding different proportions of potato granules to japonica rice flour, glutinous rice flour, and indica rice flour under specific twin-screw extruding conditions. The results showed that with increasing ratio of potato granules, the L* value of potato rice cakes decreased and the b* value increased. After the addition of potato granules, the highest cooking loss from potato rice cakes was found in the glutinous rice group, followed by the indica rice group, and the lowest cooking loss was found in the japonica rice group. Increasing the proportion of potato granules increased the cooking loss in all groups. With the addition of potato granules, the hardness and the chewiness of the potato rice cakes increased; for the japonica rice group, the stickiness first increased and then decreased, and the stickiness reached a maximum when the proportion of added potato granules was 40%. The stickiness of the glutinous rice group increased with the addition of potato granules, but the elasticity did not change significantly. Scanning electron microscopy results indicated that the structure of glutinous rice cakes was relatively loose, that of indica rice cakes was relatively firm, and the addition of potato granules made the structure of the rice cakes more compact. Considering all of the above results, the quality of potato rice cakes made by twin-screw extrusion was better when japonica flour was used as the raw material and the amount of added potato granules was 40%.
