Production of A Carotenoid Colorant From Fresh Orange Carrot Slices and Its Use as A Natural Colorant in Yoghurt

Abstract

This research was conducted at the laboratories of (Department of Food Sciences, Faculty of Agriculture, University of Damascus, and chemistry laboratories, Faculty of Science, University of Damascus) with the aim of benefiting from fresh orange carrot slices in the production of a carotenoid dye, and using it as a natural coloring in the coloring of yogurt in different proportions (0.5, 1, 1.5, %2). The results of the study of the extract obtained from fresh orange carrot slices showed its content of total carotenoids (11.94 mg/100g) and antioxidant activity estimated by the DPPH method (49.05%) and the extract represents a rich source of phenolic compounds (18.07 mg Gallic acid /100g) with color indicators L*, a* and b* (62.24,24.92,43.91) respectively. The yield of the powder resulting from freeze drying of the extract of fresh orange slices was (69.24%), and the results of the study of the effect of freeze drying and storage on the chemical indicators of the resulting colorant showed a significant increase in the moisture content of the powder and a decrease in the pH, the content of total carotenoids and the antioxidant activity. The yogurt samples (control) showed a significant increase in the brightness level (L*) and the degree of redness (a*) and a significant decrease in the degree of yellowness (b*) compared to the samples fortified with percentages (0.5, 1, 1.5, 2%) of carotenoids that  Significant differences were evident in all studied color indicators (L*, a*, b*, ΔC, ΔE, and HΔ), while the addition of a carotenoid colorant to 2% led to a decline in all sensory characteristics, and the sample fortified with a carotenoid colorant had 0.5%.  The greater positive effect in improving the sensory properties of the yogurt samples compared to the samples that had higher concentrations of carotenoid colouring.