Blue-colored rice flour innovation: a study of the effect of rice type and butterfly pea flower concentration Erni Sofia Murtini and Margaret Clementine Danielle
Food Technology, Food Science and Biotechnology Department, Agricultural Technology, Universitas Brawijaya
Abstract
commercial rice flour is usually white and odorless. The innovation of making rice flour from natural ingredients such as butterfly pea, which contains a flavonoid component, and pandan leaves, which contain the aromatic compound 2-acetyl-1-pyrroline (ACPY), can be used as an alternative way to produce a more attractive, blue-colored rice flour (BCRF) with pandan fragrance. This study investigates the effects of rice type (white rice and brown rice) and percentage of butterfly pea flowers (1, 3, 5, 7, and 9%) on the physical and chemical characteristics of BCRF, and organoleptic characteristics of kue talam (talam cake). The result showed that these two variables significantly affected the properties of BCRF. The addition of 9% butterfly pea flower to both types of rice was determined as the best treatment using the Multiple Attribute Zeleny method. Compared to the control treatment (rice flour without butterfly pea flower and pandan leaves), BCRF has higher moisture, ash, and protein content. At the same time, the total carbohydrate content (by different) was lower. A general preference for BCRF in the form of talam cake is acceptable in the range (3.73-4.55 out of 6.00). The stability of BCRF to temperature, pH, and light was tested using the interpretation of color change value (Δ-E). The stability test result shows the BCRF is relatively stable when stored at low or room temperature, but the color change is quite visible at 100oC. The color of flour is strongly influenced by pH- the color changes from red (pH 1-4) to blue if pH is increased (7-10)- the color is relatively stable when stored in a dark room but tends to fade with more exposure to light. BCRF has better color stability when stored at low to room temperature, away from direct light, and with a neutral pH.
Keywords: butterfly pea flower, pandan leaf, blue-colored rice flour, stability
