Studying the Madder extract application as a natural colorant on qualitative properties of flavoured milk-based dessert

In the past decades, Food colorants which are used in food industries are suspected due to the increased world sensitivity against the health of human diet; hence, many of researchers tried to extract the edible colorants from natural resources. One of the natural resources is the root of madder (Rubia tinctorum) which has the most stable natural red pigment, Alizarin. In this research the madder extract as natural colorant at 2, 3 and 4% and pectin as a replacer for gelatin at 3:0, 1.5:1.5 and 0:3% were used in flavoured milk- based dessert and their various qualitative parameters were evaluated during 15 days of storage. The results showed that increasing of madder extract with various ratios of gelatin: pectin, changed the dry matter and pH of the specimens significantly (p<0.05) and after 15 days, the pH raised up clearly. The texture evaluation showed that in the samples containing 3:0 gelatin: pectin, were more rigid than the others and demonstrated the least textural changes during 15 days according to the lower syneresis (p<0.05). The results of sensory evaluation showed that the addition of madder extract at its maximum level (4%), had the best results about the color, in the viewpoint of panelists and had no side effects on other parameters like odor, taste, apparent shape, texture and overall acceptance. Totally and according to the results, it can be concluded that by addition of 3% of gelatin along with 4% of madder extract in flavoured milk- based dessert, the qualitative parameters can be improve along with more shelf life and marketability, too.