The effects of powdered suji leaves (Dracaena angustifolia (medik.) roxb.) on the pasting properties of wheat flour and characteristics of steamed bun

Abstract

Water-extract of fresh suji leaves has been traditionally used as a green food colorant in Indonesia. Innovations of whole suji leaves into powder form are expected to fulfill the zero-waste concept and be a more applicable natural food colorant than using fresh leaves. This study aims to evaluate the changes in pasting properties of wheat flour and characteristics of steamed buns as affected by adding powdered suji leaves (PSL). The study is done following Randomized Block Design with PSL concentration (0-5%) as the factor. The results show that the increase of PSL concentrations significantly (α = 0.05) reduces pasting properties of wheat flour except pasting temperature, increases the green color, and reduces the moisture content of the dough, as well as reduces specific volume and texture profile of steamed buns. Considering the role of PSL as a natural coloring food additive, it is expected to add the least concentration to create green color without creating negative effects for the other steamed bun qualities. This study shows that the PSL at a concentration of 1% is sufficient to produce a green color (L*, a*, b* crust 70.45, 2.16, 25.8) steamed buns with volume (91.00 cm3), specific volume (3.15 g/cm3), moisture content (crust 33.01%, crumb 35.27%) and texture profile (cohesiveness 0.67, springiness 0.92, chewiness 246.46 g and resilience 0.32), and these qualities are comparable to the steamed buns without PSL.