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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #142155
Title: FUNCTIONAL PROPERTIES OF EXTRUDED RICE FLOURS

Author
item Kadan, Ranjit
item BRYANT, ROLFE - 6435-56-00
item PEPPERMAN, ARMAND - 6435-41-00

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2003
Publication Date: 6/1/2003
Citation: Kadan, R.S., Bryant, R.J., Pepperman, A.B. 2003. Functional properties of extruded rice flours. Journal of Food Science. 68(5):1669-1672.

Interpretive Summary: The food industry is exploring the use of rice in new foods. This study reports the effect of two kinds of rice flours processed between 70-120°C for their potential use in foods. These flours were evaluated for their bulk density, water absorption, water solubility, and fat absorption properties. The results showed that bulk densities, which are used to determine process conditions during new food development, stayed in a narrow range of 0.8-0.9. Both water absorption, which is the amount of moisture that a material can hold, and water solubility, which is the amount of solid that can be dissolved in a liquid, accelerated with an increase in processing temperature. This indicates the potential of these flours in soups and beverages. The fat absorption properties determined at 55°C decreased with the increase in processing temperature. The rice flours would absorb less fat than unprocessed rice flour. The substitution of 25% of processed riced flour into a wheat flour based fried snack decreased its fat absorption during deep-frying 35-50%. The study showed that (a) simple tests can be used to screen extruded flours for their potential use in foods and (b) extruded rice flours can be incorporated into fried snack foods and batter which would benefit the food industry in their efforts to produce new, healthier food less fat.

Technical Abstract: The functional properties of a long grain (LG) and a short grain rices extruded at 70-120 C and 22% moisture are reported. The bulk densities essentially stayed unchanged. Both water absorption and water solubility indices increased with the increase in extrusion temperatures. The fat absorption indices decreased only at 55 C, and not at 33 C and 99 C. The cold paste viscosities progressively increased while the peak, breakdown, setback and final viscosities decreased with the increase in extrusion temperatures. Substitution of 25% of unextruded or 70 C extruded LG rice flours into a wheat flour based fried snack decreased its fat absorption by 35-50 % without affecting the overall texture.