18A-13

M. A. RODRÍGUEZ-PÉREZ¹, V. Santana², B. J. Rodriguez-Terrazas³, A. Quintero-Ramos¹, F. R. Del Valle⁴, and J. A. Jimenez⁵. (1) Facultad de Ciencias Químicas, Univ. Autónoma de Chihuahua, Ciudad Universitaria, Chihuahua, Mexico, (2) Facultad de Ciencias Quimicas, Univ. Autonoma de Chihuahua, Ciudad Universitaria, Chihuahua, 31240, Mexico, (3) Food Science and Technology Graduate Program, Univ. Autónoma de Chihuahua, P.O. Box 1542-C, Chihuahua, 31160, Mexico, (4) Dept. of Chemical Engineering, New Mexico State Univ., PO Box 30001, MSC 3805, Las Cruces, NM 88003-8001, (5) Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Chihuahua, 31000, Mexico

Oats are a favorite cereal in Mexico. Although oats are consumed mostly in the form of hot or cold (commercial) breakfast cereals, it was believed that oat-based expanded products might represent novel snack foods and breakfast cereals of good quality. The objectives of this research, therefore, were to study the effect of addition of different amounts of tapioca starch, as well as of different extrusion conditions, on the physical properties of the resulting expanded oat-based products. A composite second-order experimental design was employed, utilizing three factors, each at 5 levels, and the results were plotted as a response surface. Variables studied were: raw material moisture content, 17, 20, 25, 30, and 33%; extruder screw speed, 96, 110, 130, 150, and 163 rpm; tapioca starch content, 0, 8, 20, 33, and 41%. A single-screw extuder was utilized, operating at a constant temperature of 130^o C. Dependent variables were expansion index, water absorption index and crush force. The first factor was considered to be important for snack food products, while the other 2 were considered to be important for breakfast cereals. Results obtained showed that processing conditions for maximum expansion index as well as for minimum crush force were tapioca starch content, 33%; moisture content, 25%; and screw speed, 130 rpm. Processing conditions for maximum water absorption index were tapioca starch content, 33%, screw speed, 130 rpm and moisture content, 30%. These results show that, by combining tapioca starch with oat flour, it would be possible to obtain expanded extruded products that would be of suitable quality for snack foods as well as for breakfast cereals.

Session 18A, Carbohydrate: General
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

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