18F-29

M. XIE, H. E. Huff, F.-H. Hsieh, and A. Mustapha. Dept. of Food Science, Univ. of Missouri, 256 William C. Stringer Wing, Eckles Hall, Columbia, MO 65211-5160

The insoluble byproduct of soymilk and tofu manufacture, called okara, is a nutritious, cheap, and rich source of protein (22%) and dietary fiber (15%). The objective of this study was to develop a novel puffed soy rice cake product with blends of okara pellets and parboiled rice. Okara pellets were prepared by extruding a mixture of dried okara and rice flour at a ratio of 3:2 (w/w) with a twin-screw extruder. The experiment was a 3 x 2 x 3 x 3 x 2 factorial design with two replications. Okara pellets and rice were blended in three ratios: 90/10, 70/30, and 40/60 (w/w) and tempered to two moisture contents: 14 and 17%. The blends were puffed at three heating temperatures (221, 232, 243^o C) and times (4, 5, 6 sec). The soy-rice cakes were evaluated for specific volume (SPV), texture, color, and percent weight loss after tumbling. All the processing factors had significant effects (P < 0.05) on the quality of the soy-rice cakes, with the exception of two to four interactions. Increases in heating temperature, time, and moisture led to greater SPV, higher hardness, lighter color, and decreased redness and yellowness values. Higher okara content led to lower SPV, higher hardness, darker color, and increased redness and yellowness values. The SPV for the okara pellet percentages of 0, 40, 70, and 90% were 9.80, 5.35, 4.26, and 3.81 mL/g, respectively, while the corresponding hardness values were 1.38, 1.50, 1.47, and 1.56 g, respectively. Respectively, lightness (L) values were 81.5, 70.6, 69.9, and 68.4, redness (a) values were 1.39, 4.65, 5.61, and 6.93, and yellowness (b) values were 14.9, 19.0, 21.6, and 25.5. This study has demonstrated that soy-rice cakes could successfully be manufactured, using a rice cake machine, making it a novel approach to using okara as human food.

Session 18F, Product Development: General
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana