Optimization of flour mix from three pigmented rice varieties to produce blended instant mixed rice using response surface methodology

Abstract

Importance of the work: Pigmented rice has been proven to have superior nutrition, nutraceutical and hypoallergenic characteristics. The development of specialty food products from pigmented rice is of high interest in response to people’s shifting lifestyles and the increasing trends toward improved health and nutrition. Objectives: To optimize the formulation of three pigmented rice flour types to produce blended instant mixed rice using response surface methodology to evaluate its quality attributes. Materials & Methods: The pigmented rice was processed and prepared into flour using a drum dryer and formulated using a mixture design (d-optimal) with three center points, namely, Hom Hua Bon (18.2–54.5%), Hom Chai Ya (18.2–54.5%) and Riceberry (18.2–36.4%), representing red rice, brown rice and purple rice, respectively. Results: The regression analysis indicated that the mix of the three pigmented rice varieties significantly affected the bulk density, tapped density and peak viscosity. The optimum amounts of Hom Hua Bon, Hom Chai Ya and Riceberry were 54.5%, 18.2% and 27.3%, respectively, with the optimum response values being 0.55 g/cm3 for bulk density, 0.61 g/cm3 for tapped density and 1,886.34 cp for peak viscosity. Main finding: Hom Hua Bon (red rice) provided an acceptable bulk density, tapped density and peak viscosity making it suitable as an ingredient in instant products, such as a cereal beverage that is desirable in the market.