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The objective of this research was to develop low fat salad dressing supplemented with purple rice flour. The central composite design (CCD) was used to study the effect of three independent variables including rice bran oil (10-30 %), purple rice flour (1.0-7.0 %), and xanthan gum (0.1-0.6 %) on rheological properties and color (L*, a*, b*) of salad dressing. The three formulas of salad showing the similar rheological properties to the commercial low-fat salad dressing were selected for sensory evaluation using 9-point hedonic scale. It was found that the ratio of rice bran oil: purple rice flour: xanthan gum equaled to 25.95 : 5.78 : 0.50 by weight gave the highest score of color and flavor but the sensory acceptance in consistency, taste and overall liking was not significant different (p ≥ 0.05). The flow behavior of salad dressing changed from shear thinning to Herschel-Bulkley after pasteurizing. The consistency coefficient and the yellowness value (b*) of salad dressing increased but the redness value (a*) decreased with storage time at 25 ºC for 28 days. The antioxidant activity (EC50) was not significantly changed along the storage time.
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